| 220 |
18 Mar 2011 |
Loopy Loops: Print the numbers from 1 to |
1000 without using loops or conditionals |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel Shanks’ Square Form Factorization Algorithm: A simple and very fast factorization algorithm for integers between 105 and |
1020 |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel Shanks’ Square Form Factorization Algorithm: A simple and very fast factorization algorithm for integers between |
105 and 1020 |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition |
{1,…,16} into two sets of equal size so each subset has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 261 |
09 Aug 2011 |
Hett’s Problem |
1.28: Sorting a list of lists according to length of sublists |
exercise solution codepad |
| 129 |
20 Apr 2010 |
|
145 Puzzle: Build and evaluate expressions using the digits one through nine and the simple arithmetic operators |
exercise solution codepad |
| 284 |
01 Nov 2011 |
RIP John McCarthy: Implementation of the “Maxwell’s equations of software” from the LISP |
1.5 Programmer’s Manual |
exercise solution codepad |
| 271 |
13 Sep 2011 |
Tetrahedral Numbers: Find the base of the tetrahedron that contains |
169179692512835000 balls |
exercise solution codepad |
| 215 |
01 Mar 2011 |
An Early LISP Program: A program to flatten a list, from the March |
1960 LISP I manual |
exercise solution codepad |
| 51 |
17 Jul 2009 |
International Mathematical Olympiad: Three exercises from |
1960s math competitions |
exercise solution codepad |
| 68 |
15 Sep 2009 |
Regular Expressions, Part |
1: A parser for regular expressions |
exercise solution codepad |
| 163 |
31 Aug 2010 |
Data Encryption Standard: Part |
1: Basic block enciphering and deciphering using DES |
exercise solution codepad |
| 206 |
28 Jan 2011 |
Population Count: Count the number of set bits |
(1-bits) in the binary representation of an integer |
exercise solution codepad |
| 130 |
23 Apr 2010 |
Modern Elliptic Curve Factorization, Part |
1: Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 177 |
19 Oct 2010 |
Text File Databases: Part |
1: Functions to read records with fields in various formats |
exercise solution codepad |
| 197 |
28 Dec 2010 |
Carmichael Numbers: Composite numbers such that an-1 ≡ |
1 (mod n) if a is prime to n |
exercise solution codepad |
| 197 |
28 Dec 2010 |
Carmichael Numbers: Composite numbers such that an-1 |
≡ 1 (mod n) if a is prime to n |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The Factorization Of F7: Part |
1: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 86 |
17 Nov 2009 |
Master Mind, Part |
1: Referee a two-player game of deductive logic |
exercise solution codepad |
| 220 |
18 Mar 2011 |
Loopy Loops: Print the numbers from |
1 to 1000 without using loops or conditionals |
exercise solution codepad |
| 24 |
14 Apr 2009 |
Google Treasure Hunt |
2008 Puzzle 4: A prime-number puzzle |
exercise solution codepad |
| 211 |
15 Feb 2011 |
Google Code Jam Qualification Round Africa |
2010: Three simple exercises |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data Encryption Standard: Part |
2: ECB, CBC, CFB and OFB block modes for DES and other block ciphers |
exercise solution codepad |
| 131 |
27 Apr 2010 |
Modern Elliptic Curve Factorization, Part |
2: Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 242 |
03 Jun 2011 |
Mersenne Primes: The Lucas-Lehmer test for identifying primes of the form |
2n−1 |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The Factorization Of F7: Part |
2: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 87 |
20 Nov 2009 |
Master Mind, Part |
2: Solve a Master Mind puzzle in five probes or less |
exercise solution codepad |
| 69 |
18 Sep 2009 |
Regular Expressions, Part |
2: The corresponding matcher |
exercise solution codepad |
| 259 |
02 Aug 2011 |
The Nth Prime: The n prime, counting from p1 |
= 2 |
exercise solution codepad |
| 259 |
02 Aug 2011 |
The Nth Prime: The n prime, counting from p1 = |
2 |
exercise solution codepad |
| 178 |
22 Oct 2010 |
Text File Databases: Part |
2: Various functions to process records with fields |
exercise solution codepad |
| 232 |
29 Apr 2011 |
Rule 30 RNG: The random number generator from Mathematica, based on Stephen Wolfram’s Rule |
30 cellular automata |
exercise solution codepad |
| 232 |
29 Apr 2011 |
Rule |
30 RNG: The random number generator from Mathematica, based on Stephen Wolfram’s Rule 30 cellular automata |
exercise solution codepad |
| 70 |
22 Sep 2009 |
Regular Expressions, Part |
3: A regular expression test suite |
exercise solution codepad |
| 273 |
20 Sep 2011 |
Project Euler Problem |
3: Thorough explanation of integer factorization by trial division |
exercise solution codepad |
| 165 |
07 Sep 2010 |
Data Encryption Standard: Part |
3: Triple DES and cryptographic hashing |
exercise solution codepad |
| 24 |
14 Apr 2009 |
Google Treasure Hunt 2008 Puzzle |
4: A prime-number puzzle |
exercise solution codepad |
| 166 |
10 Sep 2010 |
Data Encryption Standard: Part |
4: DES driver program |
exercise solution codepad |
| 65 |
04 Sep 2009 |
Ron’s Cipher |
#4: Stream cipher by Ron Rivest that underlies the SSL and WEP protocols |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for big integers: display factorials to |
50, determine if a number is prime, and compute its prime factors |
exercise solution codepad |
| 267 |
30 Aug 2011 |
Hamming Numbers: List the numbers with no factors greater than |
5, a classic problem popularized by Dijkstra |
exercise solution codepad |
| 89 |
27 Nov 2009 |
|
$7.11: A math puzzle: a+b+c+d = a×b×c×d = 7.11 |
exercise solution codepad |
| 89 |
27 Nov 2009 |
$7.11: A math puzzle: a+b+c+d = a×b×c×d |
= 7.11 |
exercise solution codepad |
| 89 |
27 Nov 2009 |
$7.11: A math puzzle: a+b+c+d = a×b×c×d = |
7.11 |
exercise solution codepad |
| 208 |
04 Feb 2011 |
Excel Columns: Numbers as in Excel column names, |
A=1, Z=26, IV=256 |
exercise solution codepad |
| 89 |
27 Nov 2009 |
$7.11: A math puzzle: |
a+b+c+d = a×b×c×d = 7.11 |
exercise solution codepad |
| 45 |
26 Jun 2009 |
Treaps: A randomized dictionary data structure, provides in-order |
access to key |
exercise solution codepad |
| 261 |
09 Aug 2011 |
Hett’s Problem 1.28: Sorting a list of lists |
according to length of sublists |
exercise solution codepad |
| 213 |
22 Feb 2011 |
Sliding Window Minimum: List of minimums sliding |
across an input list |
exercise solution codepad |
| 209 |
08 Feb 2011 |
The First Computer Program: |
Ada Lovelace’s program to compute Bernoulli numbers for Charles Babbage’s Analytical Engine |
exercise solution codepad |
| 109 |
09 Feb 2010 |
Numerical Integration: Quadrature by the rectangular, trapezoidal and Simpson’s method, including |
adaptive quadrature |
exercise solution codepad |
| 292 |
29 Nov 2011 |
AVL Trees, Extended: |
Add additional functionality to AVL trees |
exercise solution codepad |
| 120 |
19 Mar 2010 |
Extending Pollard’s P−1 Factorization Algorithm: |
Add a second stage to allow larger factorizations |
exercise solution codepad |
| 292 |
29 Nov 2011 |
AVL Trees, Extended: Add |
additional functionality to AVL trees |
exercise solution codepad |
| 143 |
22 Jun 2010 |
Matrix Operations: Matrix |
addition, scalar multiplication, multiplication and transposition |
exercise solution codepad |
| 241 |
31 May 2011 |
Big Numbers: |
Addition, Subtraction And Multiplication: A library for big integers: grade-school algorithms for addition, subtraction, and multiplication |
exercise solution codepad |
| 241 |
31 May 2011 |
Big Numbers: Addition, Subtraction And Multiplication: A library for big integers: grade-school algorithms for |
addition, subtraction, and multiplication |
exercise solution codepad |
| 48 |
07 Jul 2009 |
Modular Arithmetic: A function library for performing modular |
addition, subtraction, multiplication, division, and square root |
exercise solution codepad |
| 169 |
21 Sep 2010 |
Kaprekar Numbers: Square the number and |
add the digits in halves |
exercise solution codepad |
| 57 |
07 Aug 2009 |
|
ADFGX: A classic German military field cipher from the First World War |
exercise solution codepad |
| 246 |
17 Jun 2011 |
|
Adi Shamir’s Threshold Scheme: Use cryptography to share a secret, by Graham Enos |
exercise solution codepad |
| 268 |
02 Sep 2011 |
Two String Exercises: Remove duplicate characters, and squish |
adjacent blanks |
exercise solution codepad |
| 94 |
15 Dec 2009 |
|
Affine-Shift Cipher: A cryptographically weak but mathematically interesting cipher |
exercise solution codepad |
| 211 |
15 Feb 2011 |
Google Code Jam Qualification Round |
Africa 2010: Three simple exercises |
exercise solution codepad |
| 133 |
04 May 2010 |
Spectacular Seven: Compute the odds at jai |
alai |
exercise solution codepad |
| 120 |
19 Mar 2010 |
Extending Pollard’s P−1 Factorization |
Algorithm: Add a second stage to allow larger factorizations |
exercise solution codepad |
| 138 |
04 Jun 2010 |
Williams’ P+1 Factorization |
Algorithm: A factorization algorithm, similar to Pollard’s p−1 algorithm |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel Shanks’ Square Form Factorization |
Algorithm: A simple and very fast factorization algorithm for integers between 105 and 1020 |
exercise solution codepad |
| 52 |
21 Jul 2009 |
Pollard’s P−1 Factorization |
Algorithm: A simple factorization algorithm by John Pollard |
exercise solution codepad |
| 236 |
13 May 2011 |
Dixon’s Factorization |
Algorithm: A slow, but theoretically important, algorithm for integer factorization |
exercise solution codepad |
| 117 |
09 Mar 2010 |
Lexicographic Permutations: Continually generate the next permutation using an |
algorithm by Dijkstra |
exercise solution codepad |
| 52 |
21 Jul 2009 |
Pollard’s P−1 Factorization Algorithm: A simple factorization |
algorithm by John Pollard |
exercise solution codepad |
| 176 |
15 Oct 2010 |
Find The Longest Palindrome In A String: A beautiful linear-time |
algorithm due to Johan Jeuring |
exercise solution codepad |
| 84 |
10 Nov 2009 |
Merge Sort: A fast, stable sorting |
algorithm, especially well-suited to linked lists |
exercise solution codepad |
| 125 |
06 Apr 2010 |
Minimum Spanning Tree: Kruskal’s |
Algorithm: Find the minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 126 |
09 Apr 2010 |
Minimum Spanning Tree: Prim’s |
Algorithm: Find the minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 199 |
04 Jan 2011 |
Dijkstra’s |
Algorithm: Find the shortest path to all vertices of a graph from a single source, guest written by Graham Enos |
exercise solution codepad |
| 56 |
04 Aug 2009 |
Lenstra’s Algorithm: Hendrik Lenstra’s original |
algorithm for elliptic curve factorization |
exercise solution codepad |
| 204 |
21 Jan 0 |
Pollard Rho, Revisited: Richard Brent’s variant of John Pollard’s rho |
algorithm for integer factorization |
exercise solution codepad |
| 236 |
13 May 2011 |
Dixon’s Factorization Algorithm: A slow, but theoretically important, |
algorithm for integer factorization |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel Shanks’ Square Form Factorization Algorithm: A simple and very fast factorization |
algorithm for integers between 105 and 1020 |
exercise solution codepad |
| 243 |
07 Jun 2011 |
Big Numbers: Division: A library for big integers: the grade-school |
algorithm for long division |
exercise solution codepad |
| 59 |
14 Aug 2009 |
Pairing Heaps: A standard |
algorithm for maintaining priority queues |
exercise solution codepad |
| 105 |
26 Jan 2010 |
Primality Checking, Revisited: The Baillie-Wagstaff |
algorithm for primality checking |
exercise solution codepad |
| 66 |
08 Sep 2009 |
Porter Stemming: Martin Porter’s |
algorithm for removing suffices from word stems |
exercise solution codepad |
| 175 |
12 Oct 2010 |
Rotate An Array: A simple but tricky exercise solved by an |
algorithm from the folklore of computing |
exercise solution codepad |
| 56 |
04 Aug 2009 |
Lenstra’s |
Algorithm: Hendrik Lenstra’s original algorithm for elliptic curve factorization |
exercise solution codepad |
| 140 |
11 Jun 2010 |
N-Queens: Our version of a classic |
algorithmic exercise |
exercise solution codepad |
| 134 |
07 May 2010 |
Integer Logarithms: An improved |
algorithm is O(log n) instead of O(n) |
exercise solution codepad |
| 272 |
16 Sep 2011 |
Pollard’s P−1 Factorization |
Algoritihm, Revisited: An improved second stage that is much faster than the original |
exercise solution codepad |
| 241 |
31 May 2011 |
Big Numbers: Addition, Subtraction And Multiplication: A library for big integers: grade-school |
algorithms for addition, subtraction, and multiplication |
exercise solution codepad |
| 138 |
04 Jun 2010 |
Williams’ P+1 Factorization Algorithm: A factorization |
algorithm, similar to Pollard’s p−1 algorithm |
exercise solution codepad |
| 102 |
15 Jan 2010 |
Three Binary |
Algorithms: Multiplication, division and greatest common divisor using binary arithmetic |
exercise solution codepad |
| 154 |
30 Jul 2010 |
Fibonacci Numbers: Three |
algorithms taking exponential time, linear time, and logarithmic time |
exercise solution codepad |
| 111 |
16 Feb 2010 |
Soundex: An |
algorithm to assign people’s last names to equivalence classes based on similar spelling |
exercise solution codepad |
| 8 |
20 Feb 2009 |
The Digits of Pi: A spigot |
algorithm to calculate the digits of pi |
exercise solution codepad |
| 138 |
04 Jun 2010 |
Williams’ P+1 Factorization Algorithm: A factorization algorithm, similar to Pollard’s p−1 |
algorithm |
exercise solution codepad |
| 226 |
08 Apr 2011 |
Credit Card Validation: Validate decimal numbers using the Luhn |
algorithm |
exercise solution codepad |
| 289 |
18 Nov 2011 |
Grade School Multiplication: Display the steps in the grade school multiplication |
algorithm |
exercise solution codepad |
| 291 |
25 Nov 2011 |
AVL Trees: Basic implementation of the original balanced-tree |
algorithm |
exercise solution codepad |
| 2 |
19 Feb 2009 |
Sieve of Eratosthenes: A Scheme implementation of an ancient |
algorithm |
exercise solution codepad |
| 34 |
19 May 2009 |
Fermat’s Method: Integer factorization by Fermat’s |
algorithm |
exercise solution codepad |
| 43 |
19 Jun 2009 |
Monte Carlo Factorization: Integer factorization via Pollard’s rho |
algorithm |
exercise solution codepad |
| 62 |
25 Aug 2009 |
String Search: Knuth-Morris-Pratt: Search for a pattern in a text using an O(n) |
algorithm |
exercise solution codepad |
| 63 |
28 Aug 2009 |
String Search: Boyer-Moore: Search for a pattern in a text using a fast and simple |
algorithm |
exercise solution codepad |
| 64 |
01 Sep 2009 |
String Search: Rabin-Karp: Our final classic string-search |
algorithm |
exercise solution codepad |
| 82 |
03 Nov 2009 |
Quick Sort: Tony Hoare’s divide-and-conquer sorting |
algorithm |
exercise solution codepad |
| 27 |
24 Apr 2009 |
Word Hy-phen-a-tion By Com-pu-ter: Frank Liang’s hyphenation |
algorithm, used in TeX |
exercise solution codepad |
| 40 |
09 Jun 2009 |
Longest Common Subsequence: A classic programming |
algorithm, with a solution that dates to folklore |
exercise solution codepad |
| 17 |
20 Mar 2009 |
Dodgson's Doublets: A word game invented by the author of |
Alice in Wonderland |
exercise solution codepad |
| 170 |
24 Sep 2010 |
|
Alien Numbers: An exercise from Google Code Jam |
exercise solution codepad |
| 120 |
19 Mar 2010 |
Extending Pollard’s P−1 Factorization Algorithm: Add a second stage to |
allow larger factorizations |
exercise solution codepad |
| 118 |
12 Mar 2010 |
Traveling Salesman: Brute Force: Examine |
all possible permutations to find the least-cost tour |
exercise solution codepad |
| 61 |
21 Aug 2009 |
String Search: Brute Force: Search for a pattern in a text by comparing the pattern to the text at |
all possible positions |
exercise solution codepad |
| 125 |
06 Apr 2010 |
Minimum Spanning Tree: Kruskal’s Algorithm: Find the minimum-cost tree that includes |
all the nodes in a graph |
exercise solution codepad |
| 126 |
09 Apr 2010 |
Minimum Spanning Tree: Prim’s Algorithm: Find the minimum-cost tree that includes |
all the nodes in a graph |
exercise solution codepad |
| 199 |
04 Jan 2011 |
Dijkstra’s Algorithm: Find the shortest path to |
all vertices of a graph from a single source, guest written by Graham Enos |
exercise solution codepad |
| 214 |
25 Feb 2011 |
Sieve Of Euler: An |
alternate, and slow, method of sieving for primes |
exercise solution codepad |
| 106 |
29 Jan 2010 |
Straddling Checkerboard: An |
alternative to the Polybius square for ciphers that must convert letters to digits |
exercise solution codepad |
| 110 |
12 Feb 2010 |
Sieve of Atkin: A modern |
alternative to the Sieve of Eratosthenes for computing prime numbers |
exercise solution codepad |
| 119 |
16 Mar 2010 |
Traveling Salesman: Nearest Neighbor: A greedy heuristic that builds a path by |
always choosing the nearest unvisited point |
exercise solution codepad |
| 7 |
20 Feb 2009 |
Multiple Dwellings: A simple logic puzzle, solved with the |
amb non-deterministic operator |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci Primes: Find primes |
among the fibonacci numbers; includes the Park-Miller random number generator and Miller-Rabin primality checker |
exercise solution codepad |
| 32 |
12 May 2009 |
Loan |
Amortization: Calculate and print a simple loan amortization table |
exercise solution codepad |
| 32 |
12 May 2009 |
Loan Amortization: Calculate and print a simple loan |
amortization table |
exercise solution codepad |
| 207 |
01 Feb 2011 |
Cuckoo Hashing: A hashing system with guaranteed constant-time lookup and |
amortized constant-time insertion |
exercise solution codepad |
| 197 |
28 Dec 2010 |
Carmichael Numbers: Composite numbers such that |
an-1 ≡ 1 (mod n) if a is prime to n |
exercise solution codepad |
| 23 |
10 Apr 2009 |
|
Anagrams: Find anagrams in a dictionary |
exercise solution codepad |
| 23 |
10 Apr 2009 |
Anagrams: Find |
anagrams in a dictionary |
exercise solution codepad |
| 209 |
08 Feb 2011 |
The First Computer Program: Ada Lovelace’s program to compute Bernoulli numbers for Charles Babbage’s |
Analytical Engine |
exercise solution codepad |
| 22 |
07 Apr 2009 |
Flipping Pancakes: A sorting method |
analyzed by Bill Gates |
exercise solution codepad |
| 90 |
01 Dec 2009 |
Wolves And Rabbits: |
Analyze population dynamics using the Lotka-Volterra equations |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest Common |
Ancestor: Find the lowest node in a binary search tree that is a common ancestor to two given nodes |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest Common Ancestor: Find the lowest node in a binary search tree that is a common |
ancestor to two given nodes |
exercise solution codepad |
| 2 |
19 Feb 2009 |
Sieve of Eratosthenes: A Scheme implementation of an |
ancient algorithm |
exercise solution codepad |
| 162 |
27 Aug 2010 |
Chinese Remainders: An |
ancient application of modular inverses |
exercise solution codepad |
| 153 |
27 Jul 2010 |
HAMURABI.BAS: Manage grain and land in |
ancient Sumeria |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The Factorization Of F7: Part 1: Our fortieth |
anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The Factorization Of F7: Part 2: Our fortieth |
anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 196 |
24 Dec 2010 |
Tracking Santa: How far does Santa travel on his |
annual journey? |
exercise solution codepad |
| 187 |
23 Nov 2010 |
String Subsets: Determine if one string is a subset of |
another |
exercise solution codepad |
| 276 |
30 Sep 2011 |
Logarithm Tables: Print old-fashioned tables of logarithms and |
anti-logarithms |
exercise solution codepad |
| 88 |
24 Nov 2009 |
Sunrise, Sunset: Calculate the times of sunrise and sunset on |
any day anywhere in the world |
exercise solution codepad |
| 88 |
24 Nov 2009 |
Sunrise, Sunset: Calculate the times of sunrise and sunset on any day |
anywhere in the world |
exercise solution codepad |
| 225 |
05 Apr 2011 |
Fortune: Print a random |
aphorism from a file |
exercise solution codepad |
| 262 |
12 Aug 2011 |
Word Breaks: Insert spaces between words: |
applepie => apple pie |
exercise solution codepad |
| 262 |
12 Aug 2011 |
Word Breaks: Insert spaces between words: applepie |
=> apple pie |
exercise solution codepad |
| 262 |
12 Aug 2011 |
Word Breaks: Insert spaces between words: applepie => |
apple pie |
exercise solution codepad |
| 162 |
27 Aug 2010 |
Chinese Remainders: An ancient |
application of modular inverses |
exercise solution codepad |
| 227 |
12 Apr 2011 |
House Of Representatives: |
Apportion representatives by the Huntington-Hill method |
exercise solution codepad |
| 73 |
02 Oct 2009 |
Red-Black Trees: A purely functional dictionary data structure based on |
approximately-balanced trees |
exercise solution codepad |
| 258 |
29 Jul 2011 |
|
Approximating Pi: Approximating pi with the logarithmic integral and Riemann’s R function |
exercise solution codepad |
| 258 |
29 Jul 2011 |
Approximating Pi: |
Approximating pi with the logarithmic integral and Riemann’s R function |
exercise solution codepad |
| 201 |
11 Jan 2011 |
Two Integrals: The exponential and logarithmic integral, and an |
approximation for prime-pi |
exercise solution codepad |
| 75 |
09 Oct 2009 |
Calculating Pi: Calculate the value of π by monte-carlo methods and by an |
Archimedean method |
exercise solution codepad |
| 181 |
02 Nov 2010 |
Emirps: Prime numbers that |
are prime when their digits are reversed, but not palindromic |
exercise solution codepad |
| 181 |
02 Nov 2010 |
Emirps: Prime numbers that are prime when their digits |
are reversed, but not palindromic |
exercise solution codepad |
| 237 |
17 May 2011 |
Two Bad Sorts: Stooge sort and bogosort |
are worse than quadratic |
exercise solution codepad |
| 142 |
18 Jun 0 |
Parsing Command-Line |
Arguments: An old-style getopt function |
exercise solution codepad |
| 48 |
07 Jul 2009 |
Modular |
Arithmetic: A function library for performing modular addition, subtraction, multiplication, division, and square root |
exercise solution codepad |
| 205 |
25 Jan 2011 |
Rational Numbers: A library of basic |
arithmetic and comparison of fractions |
exercise solution codepad |
| 195 |
21 Dec 2010 |
Interval |
Arithmetic: An exercise from SICP |
exercise solution codepad |
| 198 |
31 Dec 2010 |
|
Arithmetic Drill: Repetitious drill for children learning basic arithmetic |
exercise solution codepad |
| 128 |
16 Apr 2010 |
Expression Evaluation: Parse and evaluate an |
arithmetic expression with plus, minus, times, divide and parentheses |
exercise solution codepad |
| 129 |
20 Apr 2010 |
145 Puzzle: Build and evaluate expressions using the digits one through nine and the simple |
arithmetic operators |
exercise solution codepad |
| 102 |
15 Jan 2010 |
Three Binary Algorithms: Multiplication, division and greatest common divisor using binary |
arithmetic |
exercise solution codepad |
| 198 |
31 Dec 2010 |
Arithmetic Drill: Repetitious drill for children learning basic |
arithmetic |
exercise solution codepad |
| 130 |
23 Apr 2010 |
Modern Elliptic Curve Factorization, Part 1: Elliptic |
arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 131 |
27 Apr 2010 |
Modern Elliptic Curve Factorization, Part 2: Elliptic |
arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 175 |
12 Oct 2010 |
Rotate An |
Array: A simple but tricky exercise solved by an algorithm from the folklore of computing |
exercise solution codepad |
| 274 |
23 Sep 2011 |
|
Array Duplicates: Find the duplicate integer in a large array |
exercise solution codepad |
| 224 |
01 Apr 2011 |
Maximum Difference In An |
Array: Find maximum Xj &minus Xi, with i ≤ j |
exercise solution codepad |
| 78 |
20 Oct 2009 |
Shuffle: Create random permutations of an |
array or linked list |
exercise solution codepad |
| 77 |
16 Oct 2009 |
Growable |
Arrays: Arrays that grow and shrink at run-time, with O(log n) complexity per operation |
exercise solution codepad |
| 77 |
16 Oct 2009 |
Growable Arrays: |
Arrays that grow and shrink at run-time, with O(log n) complexity per operation |
exercise solution codepad |
| 228 |
15 Apr 2011 |
Partition Numbers: Calculate the partition numbers, using memoization via growing |
arrays |
exercise solution codepad |
| 274 |
23 Sep 2011 |
Array Duplicates: Find the duplicate integer in a large |
array |
exercise solution codepad |
| 279 |
14 Oct 2011 |
The First N Primes: Embedding the Sieve of Eratosthenes in a priority queue instead of an |
array |
exercise solution codepad |
| 111 |
16 Feb 2010 |
Soundex: An algorithm to |
assign people’s last names to equivalence classes based on similar spelling |
exercise solution codepad |
| 110 |
12 Feb 2010 |
Sieve of |
Atkin: A modern alternative to the Sieve of Eratosthenes for computing prime numbers |
exercise solution codepad |
| 112 |
19 Feb 2010 |
Sieve Of |
Atkin, Improved: A faster version of the Sieve of Atkin |
exercise solution codepad |
| 112 |
19 Feb 2010 |
Sieve Of Atkin, Improved: A faster version of the Sieve of |
Atkin |
exercise solution codepad |
| 89 |
27 Nov 2009 |
$7.11: A math puzzle: a+b+c+d |
= a×b×c×d = 7.11 |
exercise solution codepad |
| 89 |
27 Nov 2009 |
$7.11: A math puzzle: a+b+c+d = |
a×b×c×d = 7.11 |
exercise solution codepad |
| 238 |
20 May 0 |
ISBN Validation: Validate ISBN book numbers, and fetch |
author and title from the internet |
exercise solution codepad |
| 229 |
19 Apr 2011 |
Same Five Digits: A math puzzle from New Scientist, solved by guest |
author Bob Miller |
exercise solution codepad |
| 17 |
20 Mar 2009 |
Dodgson's Doublets: A word game invented by the |
author of Alice in Wonderland |
exercise solution codepad |
| 91 |
04 Dec 2009 |
|
Autokey: A cipher in which the input text forms part of the key |
exercise solution codepad |
| 147 |
06 Jul 2010 |
Chaocipher: First look at a ninety-two year old |
autokey-type cipher |
exercise solution codepad |
| 33 |
15 May 2009 |
Cellular Automata: Linear cellular |
automata as described by Stephen Wolfram in his book A New Kind of Science |
exercise solution codepad |
| 33 |
15 May 2009 |
Cellular |
Automata: Linear cellular automata as described by Stephen Wolfram in his book A New Kind of Science |
exercise solution codepad |
| 232 |
29 Apr 2011 |
Rule 30 RNG: The random number generator from Mathematica, based on Stephen Wolfram’s Rule 30 cellular |
automata |
exercise solution codepad |
| 291 |
25 Nov 2011 |
|
AVL Trees: Basic implementation of the original balanced-tree algorithm |
exercise solution codepad |
| 292 |
29 Nov 2011 |
|
AVL Trees, Extended: Add additional functionality to AVL trees |
exercise solution codepad |
| 292 |
29 Nov 2011 |
AVL Trees, Extended: Add additional functionality to |
AVL trees |
exercise solution codepad |
| 209 |
08 Feb 2011 |
The First Computer Program: Ada Lovelace’s program to compute Bernoulli numbers for Charles |
Babbage’s Analytical Engine |
exercise solution codepad |
| 233 |
03 May 2011 |
Squaring The Bishop: Charles |
Babbage’s game of word squares |
exercise solution codepad |
| 4 |
19 Feb 2009 |
Sudoku: A |
backtracking solution to everybody’s favorite puzzle |
exercise solution codepad |
| 237 |
17 May 2011 |
Two |
Bad Sorts: Stooge sort and bogosort are worse than quadratic |
exercise solution codepad |
| 105 |
26 Jan 2010 |
Primality Checking, Revisited: The |
Baillie-Wagstaff algorithm for primality checking |
exercise solution codepad |
| 291 |
25 Nov 2011 |
AVL Trees: Basic implementation of the original |
balanced-tree algorithm |
exercise solution codepad |
| 271 |
13 Sep 2011 |
Tetrahedral Numbers: Find the base of the tetrahedron that contains 169179692512835000 |
balls |
exercise solution codepad |
| 46 |
30 Jun 2009 |
Steve Yegge’s Phone-Screen Coding Exercises: A simple set of programming exercises |
based on a blog entry by Steve Yegge |
exercise solution codepad |
| 26 |
21 Apr 2009 |
Probabilistic Spell Checking: A probabilistic spell-checker |
based on a Bloom filter |
exercise solution codepad |
| 60 |
18 Aug 2009 |
Blum Blum Shub: Stream cipher |
based on a cryptographically secure pseudo-random number generator |
exercise solution codepad |
| 203 |
18 Jan 2011 |
Solitaire Cipher: Bruce Schneier’s strong cryptography |
based on a deck of playing cards |
exercise solution codepad |
| 73 |
02 Oct 2009 |
Red-Black Trees: A purely functional dictionary data structure |
based on approximately-balanced trees |
exercise solution codepad |
| 257 |
26 Jul 2011 |
More Prime-Counting Functions: Prime counting functions by Meissel and Lehmer, |
based on Legendre’s sum |
exercise solution codepad |
| 49 |
10 Jul 2009 |
The Golden Ratio: Evaluate a continued fraction, |
based on my daughter’s math homework |
exercise solution codepad |
| 83 |
06 Nov 2009 |
Heap Sort: A guaranteed O(log n) sorting method |
based on priority queues |
exercise solution codepad |
| 111 |
16 Feb 2010 |
Soundex: An algorithm to assign people’s last names to equivalence classes |
based on similar spelling |
exercise solution codepad |
| 232 |
29 Apr 2011 |
Rule 30 RNG: The random number generator from Mathematica, |
based on Stephen Wolfram’s Rule 30 cellular automata |
exercise solution codepad |
| 271 |
13 Sep 2011 |
Tetrahedral Numbers: Find the |
base of the tetrahedron that contains 169179692512835000 balls |
exercise solution codepad |
| 205 |
25 Jan 2011 |
Rational Numbers: A library of |
basic arithmetic and comparison of fractions |
exercise solution codepad |
| 198 |
31 Dec 2010 |
Arithmetic Drill: Repetitious drill for children learning |
basic arithmetic |
exercise solution codepad |
| 163 |
31 Aug 2010 |
Data Encryption Standard: Part 1: |
Basic block enciphering and deciphering using DES |
exercise solution codepad |
| 54 |
28 Jul 2009 |
Elliptic Curves: Library of |
basic functions on elliptic curves |
exercise solution codepad |
| 291 |
25 Nov 2011 |
AVL Trees: |
Basic implementation of the original balanced-tree algorithm |
exercise solution codepad |
| 67 |
11 Sep 2009 |
|
Beautiful Code: A simple regular-expression matcher by Rob Pike |
exercise solution codepad |
| 176 |
15 Oct 2010 |
Find The Longest Palindrome In A String: A |
beautiful linear-time algorithm due to Johan Jeuring |
exercise solution codepad |
| 260 |
05 Aug 2011 |
Ninety-Nine Bottles Of |
Beer: The popular song |
exercise solution codepad |
| 179 |
26 Oct 2010 |
|
Benford’s Law: A useful mathematical oddity, and an example of text file databases |
exercise solution codepad |
| 113 |
23 Feb 2010 |
Engineering A Sort Function: A high-performance quicksort by Jon |
Bentley and Doug McIlroy |
exercise solution codepad |
| 190 |
03 Dec 2010 |
Maximum Sum Subsequence: A classic programming exercise due to Jon |
Bentley |
exercise solution codepad |
| 287 |
11 Nov 2011 |
Generators: Write functions that yield a value, but can then |
be re-entered |
exercise solution codepad |
| 281 |
21 Oct 2011 |
Sum, Revisited: SysV and |
Berkeley versions of the Unix V7 sum command |
exercise solution codepad |
| 209 |
08 Feb 2011 |
The First Computer Program: Ada Lovelace’s program to compute |
Bernoulli numbers for Charles Babbage’s Analytical Engine |
exercise solution codepad |
| 210 |
11 Feb 2011 |
Sums Of Powers: Use |
Bernoulli numbers to quickly compute sums of powers |
exercise solution codepad |
| 121 |
23 Mar 2010 |
Texas Hold ‘Em: Find the |
best poker hand |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel Shanks’ Square Form Factorization Algorithm: A simple and very fast factorization algorithm for integers |
between 105 and 1020 |
exercise solution codepad |
| 139 |
08 Jun 2010 |
Diff: Find the differences |
between two text files |
exercise solution codepad |
| 262 |
12 Aug 2011 |
Word Breaks: Insert spaces |
between words: applepie => apple pie |
exercise solution codepad |
| 115 |
02 Mar 2010 |
Goldbach’s Conjecture: Every even number greater than two can |
be written as the sum of two primes |
exercise solution codepad |
| 76 |
13 Oct 2009 |
|
Bifid: A simple but effective fractionating cipher, never used militarily |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for |
big integers: display factorials to 50, determine if a number is prime, and compute its prime factors |
exercise solution codepad |
| 249 |
28 Jun 2011 |
Big Numbers: Functions: A library for |
big integers: gcd, powering, square root, random numbers |
exercise solution codepad |
| 241 |
31 May 2011 |
Big Numbers: Addition, Subtraction And Multiplication: A library for |
big integers: grade-school algorithms for addition, subtraction, and multiplication |
exercise solution codepad |
| 245 |
14 Jun 2011 |
Big Numbers: Input And Output: A library for |
big integers: input and output with radix conversion |
exercise solution codepad |
| 239 |
24 May 2011 |
Big Numbers: Getting Started: A library for |
big integers: representation, comparison, simple functions |
exercise solution codepad |
| 247 |
21 Jun 2011 |
Big Numbers: Testing: A library for |
big integers: testing |
exercise solution codepad |
| 243 |
07 Jun 2011 |
Big Numbers: Division: A library for |
big integers: the grade-school algorithm for long division |
exercise solution codepad |
| 241 |
31 May 2011 |
|
Big Numbers: Addition, Subtraction And Multiplication: A library for big integers: grade-school algorithms for addition, subtraction, and multiplication |
exercise solution codepad |
| 243 |
07 Jun 2011 |
|
Big Numbers: Division: A library for big integers: the grade-school algorithm for long division |
exercise solution codepad |
| 251 |
05 Jul 2011 |
|
Big Numbers: Examples: A library for big integers: display factorials to 50, determine if a number is prime, and compute its prime factors |
exercise solution codepad |
| 249 |
28 Jun 2011 |
|
Big Numbers: Functions: A library for big integers: gcd, powering, square root, random numbers |
exercise solution codepad |
| 239 |
24 May 2011 |
|
Big Numbers: Getting Started: A library for big integers: representation, comparison, simple functions |
exercise solution codepad |
| 245 |
14 Jun 2011 |
|
Big Numbers: Input And Output: A library for big integers: input and output with radix conversion |
exercise solution codepad |
| 247 |
21 Jun 2011 |
|
Big Numbers: Testing: A library for big integers: testing |
exercise solution codepad |
| 101 |
12 Jan 2010 |
Calculating Sines: Calculate sines using Taylor series and the triple-angle formula, by |
Bill Cruise |
exercise solution codepad |
| 22 |
07 Apr 2009 |
Flipping Pancakes: A sorting method analyzed by |
Bill Gates |
exercise solution codepad |
| 102 |
15 Jan 2010 |
Three |
Binary Algorithms: Multiplication, division and greatest common divisor using binary arithmetic |
exercise solution codepad |
| 102 |
15 Jan 2010 |
Three Binary Algorithms: Multiplication, division and greatest common divisor using |
binary arithmetic |
exercise solution codepad |
| 206 |
28 Jan 2011 |
Population Count: Count the number of set bits (1-bits) in the |
binary representation of an integer |
exercise solution codepad |
| 18 |
23 Mar 2009 |
|
Binary Search: A simple task, easy to get wrong |
exercise solution codepad |
| 116 |
05 Mar 2010 |
|
Binary Search Tree: Classic data structure, providing insert, delete and lookup for ordered datatypes |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest Common Ancestor: Find the lowest node in a |
binary search tree that is a common ancestor to two given nodes |
exercise solution codepad |
| 3 |
19 Feb 2009 |
|
Bingo: Calculate the probability of winning at Bingo |
exercise solution codepad |
| 3 |
19 Feb 2009 |
Bingo: Calculate the probability of winning at |
Bingo |
exercise solution codepad |
| 294 |
06 Dec 2011 |
Pascal’s Triangle: Display the |
binomial coefficients |
exercise solution codepad |
| 233 |
03 May 2011 |
Squaring The |
Bishop: Charles Babbage’s game of word squares |
exercise solution codepad |
| 206 |
28 Jan 2011 |
Population Count: Count the number of set |
bits (1-bits) in the binary representation of an integer |
exercise solution codepad |
| 268 |
02 Sep 2011 |
Two String Exercises: Remove duplicate characters, and squish adjacent |
blanks |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data Encryption Standard: Part 2: ECB, CBC, CFB and OFB block modes for DES and other |
block ciphers |
exercise solution codepad |
| 163 |
31 Aug 2010 |
Data Encryption Standard: Part 1: Basic |
block enciphering and deciphering using DES |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data Encryption Standard: Part 2: ECB, CBC, CFB and OFB |
block modes for DES and other block ciphers |
exercise solution codepad |
| 46 |
30 Jun 2009 |
Steve Yegge’s Phone-Screen Coding Exercises: A simple set of programming exercises based on a |
blog entry by Steve Yegge |
exercise solution codepad |
| 146 |
02 Jul 2010 |
Contents: Chronological Listing Of Exercises: |
Blog management |
exercise solution codepad |
| 148 |
09 Jul 2010 |
Contents: Permuted Table Of Contents: |
Blog management |
exercise solution codepad |
| 150 |
16 Jul 2010 |
Contents: Themes: |
Blog Management |
exercise solution codepad |
| 26 |
21 Apr 2009 |
Probabilistic Spell Checking: A probabilistic spell-checker based on a |
Bloom filter |
exercise solution codepad |
| 60 |
18 Aug 2009 |
|
Blum Blum Shub: Stream cipher based on a cryptographically secure pseudo-random number generator |
exercise solution codepad |
| 60 |
18 Aug 2009 |
Blum |
Blum Shub: Stream cipher based on a cryptographically secure pseudo-random number generator |
exercise solution codepad |
| 229 |
19 Apr 2011 |
Same Five Digits: A math puzzle from New Scientist, solved by guest author |
Bob Miller |
exercise solution codepad |
| 58 |
11 Aug 2009 |
Uncle |
Bob’s Bowling Game Kata: Use pattern-matching on lists to solve a classic object-oriented programming exercise |
exercise solution codepad |
| 237 |
17 May 2011 |
Two Bad Sorts: Stooge sort and |
bogosort are worse than quadratic |
exercise solution codepad |
| 33 |
15 May 2009 |
Cellular Automata: Linear cellular automata as described by Stephen Wolfram in his |
book A New Kind of Science |
exercise solution codepad |
| 238 |
20 May 0 |
ISBN Validation: Validate ISBN |
book numbers, and fetch author and title from the internet |
exercise solution codepad |
| 260 |
05 Aug 2011 |
Ninety-Nine |
Bottles Of Beer: The popular song |
exercise solution codepad |
| 58 |
11 Aug 2009 |
Uncle Bob’s |
Bowling Game Kata: Use pattern-matching on lists to solve a classic object-oriented programming exercise |
exercise solution codepad |
| 63 |
28 Aug 2009 |
String Search: |
Boyer-Moore: Search for a pattern in a text using a fast and simple algorithm |
exercise solution codepad |
| 277 |
04 Oct 2011 |
|
Brainfuck: Interpreter for a Turing-line language |
exercise solution codepad |
| 262 |
12 Aug 2011 |
Word |
Breaks: Insert spaces between words: applepie => apple pie |
exercise solution codepad |
| 28 |
28 Apr 2009 |
Morse Code: Translating the dots-and-dashes of Samuel Finley |
Breese Morse’s telegraph code |
exercise solution codepad |
| 204 |
21 Jan 0 |
Pollard Rho, Revisited: Richard |
Brent’s variant of John Pollard’s rho algorithm for integer factorization |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The Factorization Of F7: Part 1: Our fortieth anniversary celebration of Morrison and |
Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The Factorization Of F7: Part 2: Our fortieth anniversary celebration of Morrison and |
Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 203 |
18 Jan 2011 |
Solitaire Cipher: |
Bruce Schneier’s strong cryptography based on a deck of playing cards |
exercise solution codepad |
| 118 |
12 Mar 2010 |
Traveling Salesman: |
Brute Force: Examine all possible permutations to find the least-cost tour |
exercise solution codepad |
| 61 |
21 Aug 2009 |
String Search: |
Brute Force: Search for a pattern in a text by comparing the pattern to the text at all possible positions |
exercise solution codepad |
| 80 |
27 Oct 2009 |
Three Quadratic Sorts: |
Bubble sort, selection sort and insertion sort |
exercise solution codepad |
| 39 |
05 Jun 2009 |
Ternary Search Tries: |
Build a function library for handling ternary search tries |
exercise solution codepad |
| 129 |
20 Apr 2010 |
145 Puzzle: |
Build and evaluate expressions using the digits one through nine and the simple arithmetic operators |
exercise solution codepad |
| 119 |
16 Mar 2010 |
Traveling Salesman: Nearest Neighbor: A greedy heuristic that |
builds a path by always choosing the nearest unvisited point |
exercise solution codepad |
| 6 |
20 Feb 2009 |
ROT13: A simple |
Caesar-shift cipher |
exercise solution codepad |
| 32 |
12 May 2009 |
Loan Amortization: |
Calculate and print a simple loan amortization table |
exercise solution codepad |
| 219 |
15 Mar 2011 |
Look And Say: |
Calculate John Horton Conway’s "Look and Say" sequence |
exercise solution codepad |
| 101 |
12 Jan 2010 |
Calculating Sines: |
Calculate sines using Taylor series and the triple-angle formula, by Bill Cruise |
exercise solution codepad |
| 95 |
18 Dec 2009 |
Calculating Logarithms: Use the methods of Newton and Euler to |
calculate square roots and logarithms |
exercise solution codepad |
| 123 |
30 Mar 2010 |
Passover: |
Calculate the dates of the Jewish holidays Rosh Hashanah and Passover |
exercise solution codepad |
| 174 |
08 Oct 2010 |
Zeller’s Congruence: |
Calculate the day of the week for a given date |
exercise solution codepad |
| 248 |
24 Jun 2011 |
Thank God It’s Friday!: Three methods to |
calculate the day of the week |
exercise solution codepad |
| 8 |
20 Feb 2009 |
The Digits of Pi: A spigot algorithm to |
calculate the digits of pi |
exercise solution codepad |
| 275 |
27 Sep 2011 |
Statistics: |
Calculate the mean, standard deviation, linear regression and correlation |
exercise solution codepad |
| 104 |
22 Jan 2010 |
Phases Of The Moon: |
Calculate the number of days since the last new moon |
exercise solution codepad |
| 228 |
15 Apr 2011 |
Partition Numbers: |
Calculate the partition numbers, using memoization via growing arrays |
exercise solution codepad |
| 3 |
19 Feb 2009 |
Bingo: |
Calculate the probability of winning at Bingo |
exercise solution codepad |
| 88 |
24 Nov 2009 |
Sunrise, Sunset: |
Calculate the times of sunrise and sunset on any day anywhere in the world |
exercise solution codepad |
| 75 |
09 Oct 2009 |
Calculating Pi: |
Calculate the value of π by monte-carlo methods and by an Archimedean method |
exercise solution codepad |
| 95 |
18 Dec 2009 |
|
Calculating Logarithms: Use the methods of Newton and Euler to calculate square roots and logarithms |
exercise solution codepad |
| 75 |
09 Oct 2009 |
|
Calculating Pi: Calculate the value of π by monte-carlo methods and by an Archimedean method |
exercise solution codepad |
| 101 |
12 Jan 2010 |
|
Calculating Sines: Calculate sines using Taylor series and the triple-angle formula, by Bill Cruise |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting Primes Using Legendre’s Formula: Recreate Legendre’s two-century old |
calculation of the number of primes less than a million |
exercise solution codepad |
| 53 |
24 Jul 2009 |
Let’s Make A Deal!: Simulate a tricky probability |
calculation |
exercise solution codepad |
| 1 |
19 Feb 2009 |
RPN |
Calculator: Evaluate numeric expressions at the command line |
exercise solution codepad |
| 15 |
13 Mar 2009 |
Friday, the Thirteenth: A small |
calendar library, and a simple use of it |
exercise solution codepad |
| 98 |
01 Jan 2010 |
Cal: Print a twelve-month |
calendar |
exercise solution codepad |
| 98 |
01 Jan 2010 |
|
Cal: Print a twelve-month calendar |
exercise solution codepad |
| 115 |
02 Mar 2010 |
Goldbach’s Conjecture: Every even number greater than two |
can be written as the sum of two primes |
exercise solution codepad |
| 287 |
11 Nov 2011 |
Generators: Write functions that yield a value, but |
can then be re-entered |
exercise solution codepad |
| 203 |
18 Jan 2011 |
Solitaire Cipher: Bruce Schneier’s strong cryptography based on a deck of playing |
cards |
exercise solution codepad |
| 226 |
08 Apr 2011 |
Credit |
Card Validation: Validate decimal numbers using the Luhn algorithm |
exercise solution codepad |
| 155 |
03 Aug 2010 |
|
Carl Hewitt’s Same-Fringe Problem: Do two trees have the same leaves, solved with streams (lazy lists) |
exercise solution codepad |
| 43 |
19 Jun 2009 |
Monte |
Carlo Factorization: Integer factorization via Pollard’s rho algorithm |
exercise solution codepad |
| 197 |
28 Dec 2010 |
|
Carmichael Numbers: Composite numbers such that an-1 ≡ 1 (mod n) if a is prime to n |
exercise solution codepad |
| 250 |
01 Jul 2011 |
Feet And Inches: Convert decimal inches to |
carpenters’ fractions |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data Encryption Standard: Part 2: ECB, |
CBC, CFB and OFB block modes for DES and other block ciphers |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The Factorization Of F7: Part 1: Our fortieth anniversary |
celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The Factorization Of F7: Part 2: Our fortieth anniversary |
celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 33 |
15 May 2009 |
Cellular Automata: Linear |
cellular automata as described by Stephen Wolfram in his book A New Kind of Science |
exercise solution codepad |
| 33 |
15 May 2009 |
|
Cellular Automata: Linear cellular automata as described by Stephen Wolfram in his book A New Kind of Science |
exercise solution codepad |
| 232 |
29 Apr 2011 |
Rule 30 RNG: The random number generator from Mathematica, based on Stephen Wolfram’s Rule 30 |
cellular automata |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data Encryption Standard: Part 2: ECB, CBC, |
CFB and OFB block modes for DES and other block ciphers |
exercise solution codepad |
| 221 |
22 Mar 2011 |
Two Kaprekar Exercises: Kaprekar |
chains and Kaprekar numbers, from the Indian mathematician Dattaraya Ramchandra Kaprekar |
exercise solution codepad |
| 11 |
27 Feb 2009 |
Mark V. Shaney: Generate parodies of a text using a Markov |
chain |
exercise solution codepad |
| 183 |
09 Nov 2010 |
Subset Sums: Third level of the Greplin Programming |
Challenge, using dynamic programming and memoization |
exercise solution codepad |
| 147 |
06 Jul 2010 |
|
Chaocipher: First look at a ninety-two year old autokey-type cipher |
exercise solution codepad |
| 264 |
19 Aug 2011 |
First Non-Repeating |
Character: Find the first character in a string that doesn’t repeat later in the string |
exercise solution codepad |
| 264 |
19 Aug 2011 |
First Non-Repeating Character: Find the first |
character in a string that doesn’t repeat later in the string |
exercise solution codepad |
| 268 |
02 Sep 2011 |
Two String Exercises: Remove duplicate |
characters, and squish adjacent blanks |
exercise solution codepad |
| 159 |
17 Aug 2010 |
Cut: Select fields or |
characters from input lines |
exercise solution codepad |
| 209 |
08 Feb 2011 |
The First Computer Program: Ada Lovelace’s program to compute Bernoulli numbers for |
Charles Babbage’s Analytical Engine |
exercise solution codepad |
| 233 |
03 May 2011 |
Squaring The Bishop: |
Charles Babbage’s game of word squares |
exercise solution codepad |
| 106 |
29 Jan 2010 |
Straddling |
Checkerboard: An alternative to the Polybius square for ciphers that must convert letters to digits |
exercise solution codepad |
| 29 |
01 May 2009 |
Primality Checking: A probabilistic primality |
checker by Gary Miller and Michael Rabin |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci Primes: Find primes among the fibonacci numbers; includes the Park-Miller random number generator and Miller-Rabin primality |
checker |
exercise solution codepad |
| 29 |
01 May 2009 |
Primality |
Checking: A probabilistic primality checker by Gary Miller and Michael Rabin |
exercise solution codepad |
| 26 |
21 Apr 2009 |
Probabilistic Spell |
Checking: A probabilistic spell-checker based on a Bloom filter |
exercise solution codepad |
| 25 |
17 Apr 2009 |
Spell |
Checking: A spell-checker in a trie-based dictionary |
exercise solution codepad |
| 107 |
02 Feb 2010 |
Proving Primality: A deterministic, not probabilistic, method of |
checking primality |
exercise solution codepad |
| 105 |
26 Jan 2010 |
Primality |
Checking, Revisited: The Baillie-Wagstaff algorithm for primality checking |
exercise solution codepad |
| 105 |
26 Jan 2010 |
Primality Checking, Revisited: The Baillie-Wagstaff algorithm for primality |
checking |
exercise solution codepad |
| 282 |
25 Oct 2011 |
Cksum: Unix |
checksum utility |
exercise solution codepad |
| 198 |
31 Dec 2010 |
Arithmetic Drill: Repetitious drill for |
children learning basic arithmetic |
exercise solution codepad |
| 38 |
02 Jun 2009 |
Pig Latin: A simple exercise to solve a |
children’s game |
exercise solution codepad |
| 216 |
04 Mar 2011 |
Chutes And Ladders: Simulate a |
child’s game, and compute its statistics |
exercise solution codepad |
| 162 |
27 Aug 2010 |
|
Chinese Remainders: An ancient application of modular inverses |
exercise solution codepad |
| 144 |
25 Jun 2010 |
Learn A New Language: Solve the exercise of your |
choice in an unfamiliar language |
exercise solution codepad |
| 119 |
16 Mar 2010 |
Traveling Salesman: Nearest Neighbor: A greedy heuristic that builds a path by always |
choosing the nearest unvisited point |
exercise solution codepad |
| 171 |
28 Sep 2010 |
Maxiphobic Heaps: A priority-queue data structure, similar to leftist heaps, due to |
Chris Okasaki |
exercise solution codepad |
| 146 |
02 Jul 2010 |
Contents: |
Chronological Listing Of Exercises: Blog management |
exercise solution codepad |
| 216 |
04 Mar 2011 |
|
Chutes And Ladders: Simulate a child’s game, and compute its statistics |
exercise solution codepad |
| 65 |
04 Sep 2009 |
Ron’s |
Cipher #4: Stream cipher by Ron Rivest that underlies the SSL and WEP protocols |
exercise solution codepad |
| 47 |
03 Jul 2009 |
The Playfair |
Cipher: A classic military field cipher |
exercise solution codepad |
| 94 |
15 Dec 2009 |
Affine-Shift |
Cipher: A cryptographically weak but mathematically interesting cipher |
exercise solution codepad |
| 37 |
29 May 2009 |
Double Transposition |
Cipher: A simple and effective cipher, easy to perform by hand |
exercise solution codepad |
| 20 |
31 Mar 2009 |
Rail-Fence |
Cipher: A simple transposition cipher |
exercise solution codepad |
| 60 |
18 Aug 2009 |
Blum Blum Shub: Stream |
cipher based on a cryptographically secure pseudo-random number generator |
exercise solution codepad |
| 203 |
18 Jan 2011 |
Solitaire |
Cipher: Bruce Schneier’s strong cryptography based on a deck of playing cards |
exercise solution codepad |
| 65 |
04 Sep 2009 |
Ron’s Cipher #4: Stream |
cipher by Ron Rivest that underlies the SSL and WEP protocols |
exercise solution codepad |
| 37 |
29 May 2009 |
Double Transposition Cipher: A simple and effective |
cipher, easy to perform by hand |
exercise solution codepad |
| 57 |
07 Aug 2009 |
ADFGX: A classic German military field |
cipher from the First World War |
exercise solution codepad |
| 91 |
04 Dec 2009 |
Autokey: A |
cipher in which the input text forms part of the key |
exercise solution codepad |
| 76 |
13 Oct 2009 |
Bifid: A simple but effective fractionating |
cipher, never used militarily |
exercise solution codepad |
| 106 |
29 Jan 2010 |
Straddling Checkerboard: An alternative to the Polybius square for |
ciphers that must convert letters to digits |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data Encryption Standard: Part 2: ECB, CBC, CFB and OFB block modes for DES and other block |
ciphers |
exercise solution codepad |
| 12 |
03 Mar 2009 |
Creation: Cryptanalysis of a Vigenère |
cipher |
exercise solution codepad |
| 147 |
06 Jul 2010 |
Chaocipher: First look at a ninety-two year old autokey-type |
cipher |
exercise solution codepad |
| 20 |
31 Mar 2009 |
Rail-Fence Cipher: A simple transposition |
cipher |
exercise solution codepad |
| 47 |
03 Jul 2009 |
The Playfair Cipher: A classic military field |
cipher |
exercise solution codepad |
| 50 |
14 Jul 2009 |
The Daily Cryptogram: Solve a monoalphabetic substitution |
cipher |
exercise solution codepad |
| 6 |
20 Feb 2009 |
ROT13: A simple Caesar-shift |
cipher |
exercise solution codepad |
| 94 |
15 Dec 2009 |
Affine-Shift Cipher: A cryptographically weak but mathematically interesting |
cipher |
exercise solution codepad |
| 282 |
25 Oct 2011 |
|
Cksum: Unix checksum utility |
exercise solution codepad |
| 111 |
16 Feb 2010 |
Soundex: An algorithm to assign people’s last names to equivalence |
classes based on similar spelling |
exercise solution codepad |
| 140 |
11 Jun 2010 |
N-Queens: Our version of a |
classic algorithmic exercise |
exercise solution codepad |
| 116 |
05 Mar 2010 |
Binary Search Tree: |
Classic data structure, providing insert, delete and lookup for ordered datatypes |
exercise solution codepad |
| 96 |
22 Dec 2009 |
Permuted Index: David Parnas’ |
classic deconstruction of the keyword-in-context index |
exercise solution codepad |
| 279 |
11 Oct 2011 |
Tower Of Hanoi: |
Classic demonstration of recursion |
exercise solution codepad |
| 57 |
07 Aug 2009 |
ADFGX: A |
classic German military field cipher from the First World War |
exercise solution codepad |
| 47 |
03 Jul 2009 |
The Playfair Cipher: A |
classic military field cipher |
exercise solution codepad |
| 58 |
11 Aug 2009 |
Uncle Bob’s Bowling Game Kata: Use pattern-matching on lists to solve a |
classic object-oriented programming exercise |
exercise solution codepad |
| 293 |
02 Dec 2011 |
Knight Rider: |
Classic problem of the knight’s tour |
exercise solution codepad |
| 267 |
30 Aug 2011 |
Hamming Numbers: List the numbers with no factors greater than 5, a |
classic problem popularized by Dijkstra |
exercise solution codepad |
| 40 |
09 Jun 2009 |
Longest Common Subsequence: A |
classic programming algorithm, with a solution that dates to folklore |
exercise solution codepad |
| 190 |
03 Dec 2010 |
Maximum Sum Subsequence: A |
classic programming exercise due to Jon Bentley |
exercise solution codepad |
| 64 |
01 Sep 2009 |
String Search: Rabin-Karp: Our final |
classic string-search algorithm |
exercise solution codepad |
| 14 |
10 Mar 2009 |
Word Frequencies: Our interpretation of a problem solved by a |
classic unix pipeline |
exercise solution codepad |
| 71 |
25 Sep 2009 |
Grep: Simple version of the |
classic unix regular-expression matching utility |
exercise solution codepad |
| 67 |
11 Sep 2009 |
Beautiful |
Code: A simple regular-expression matcher by Rob Pike |
exercise solution codepad |
| 211 |
15 Feb 2011 |
Google |
Code Jam Qualification Round Africa 2010: Three simple exercises |
exercise solution codepad |
| 170 |
24 Sep 2010 |
Alien Numbers: An exercise from Google |
Code Jam |
exercise solution codepad |
| 28 |
28 Apr 2009 |
Morse |
Code: Translating the dots-and-dashes of Samuel Finley Breese Morse’s telegraph code |
exercise solution codepad |
| 173 |
05 Oct 2010 |
George Marsaglia’s Random Number Generators: Nine high-quality RNGs in nineteen lines of |
code |
exercise solution codepad |
| 28 |
28 Apr 2009 |
Morse Code: Translating the dots-and-dashes of Samuel Finley Breese Morse’s telegraph |
code |
exercise solution codepad |
| 46 |
30 Jun 2009 |
Steve Yegge’s Phone-Screen |
Coding Exercises: A simple set of programming exercises based on a blog entry by Steve Yegge |
exercise solution codepad |
| 294 |
06 Dec 2011 |
Pascal’s Triangle: Display the binomial |
coefficients |
exercise solution codepad |
| 208 |
04 Feb 2011 |
Excel Columns: Numbers as in Excel |
column names, A=1, Z=26, IV=256 |
exercise solution codepad |
| 208 |
04 Feb 2011 |
Excel |
Columns: Numbers as in Excel column names, A=1, Z=26, IV=256 |
exercise solution codepad |
| 244 |
10 Jun 2011 |
Steganography: A hand-operable system that |
combines cryptography and steganography |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer Factorization: |
Combine trial division, Pollard’s rho and p−1 methods, and elliptic curves into a single factorization program |
exercise solution codepad |
| 81 |
30 Oct 2009 |
Two Sub-Quadratic Sorts: |
Comb sort and shell sort |
exercise solution codepad |
| 160 |
20 Aug 0 |
Marriage Sort: A sub-quadratic sort similar to shell sort or |
comb sort |
exercise solution codepad |
| 142 |
18 Jun 0 |
Parsing |
Command-Line Arguments: An old-style getopt function |
exercise solution codepad |
| 1 |
19 Feb 2009 |
RPN Calculator: Evaluate numeric expressions at the |
command line |
exercise solution codepad |
| 222 |
25 Mar 2011 |
Sum: The standard Unix V7 file-checksum |
command |
exercise solution codepad |
| 281 |
21 Oct 2011 |
Sum, Revisited: SysV and Berkeley versions of the Unix V7 sum |
command |
exercise solution codepad |
| 16 |
17 Mar 2009 |
Comma-Separated Values: Retrieve records from a |
comma-separated values file using a finite-state machine |
exercise solution codepad |
| 16 |
17 Mar 2009 |
|
Comma-Separated Values: Retrieve records from a comma-separated values file using a finite-state machine |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest |
Common Ancestor: Find the lowest node in a binary search tree that is a common ancestor to two given nodes |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest Common Ancestor: Find the lowest node in a binary search tree that is a |
common ancestor to two given nodes |
exercise solution codepad |
| 102 |
15 Jan 2010 |
Three Binary Algorithms: Multiplication, division and greatest |
common divisor using binary arithmetic |
exercise solution codepad |
| 40 |
09 Jun 2009 |
Longest |
Common Subsequence: A classic programming algorithm, with a solution that dates to folklore |
exercise solution codepad |
| 235 |
10 May 2011 |
Comm: select or reject lines |
common to two sorted files |
exercise solution codepad |
| 235 |
10 May 2011 |
|
Comm: select or reject lines common to two sorted files |
exercise solution codepad |
| 61 |
21 Aug 2009 |
String Search: Brute Force: Search for a pattern in a text by |
comparing the pattern to the text at all possible positions |
exercise solution codepad |
| 205 |
25 Jan 2011 |
Rational Numbers: A library of basic arithmetic and |
comparison of fractions |
exercise solution codepad |
| 239 |
24 May 2011 |
Big Numbers: Getting Started: A library for big integers: representation, |
comparison, simple functions |
exercise solution codepad |
| 51 |
17 Jul 2009 |
International Mathematical Olympiad: Three exercises from 1960s math |
competitions |
exercise solution codepad |
| 77 |
16 Oct 2009 |
Growable Arrays: Arrays that grow and shrink at run-time, with O(log n) |
complexity per operation |
exercise solution codepad |
| 197 |
28 Dec 2010 |
Carmichael Numbers: |
Composite numbers such that an-1 ≡ 1 (mod n) if a is prime to n |
exercise solution codepad |
| 114 |
26 Feb 2010 |
Run Length Encoding: A simple |
compression method for text files |
exercise solution codepad |
| 74 |
06 Oct 2009 |
MapReduce: Google’s famous system for parallelizing |
computations expressed as a programming idiom |
exercise solution codepad |
| 209 |
08 Feb 2011 |
The First Computer Program: Ada Lovelace’s program to |
compute Bernoulli numbers for Charles Babbage’s Analytical Engine |
exercise solution codepad |
| 223 |
28 Mar 2011 |
Look And Say, Revisited: |
Compute Conway’s constant |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for big integers: display factorials to 50, determine if a number is prime, and |
compute its prime factors |
exercise solution codepad |
| 216 |
04 Mar 2011 |
Chutes And Ladders: Simulate a child’s game, and |
compute its statistics |
exercise solution codepad |
| 27 |
24 Apr 2009 |
Word Hy-phen-a-tion By |
Com-pu-ter: Frank Liang’s hyphenation algorithm, used in TeX |
exercise solution codepad |
| 36 |
26 May 2009 |
Word Search Solver: A |
computerized implementation of a popular time-waster |
exercise solution codepad |
| 209 |
08 Feb 2011 |
The First |
Computer Program: Ada Lovelace’s program to compute Bernoulli numbers for Charles Babbage’s Analytical Engine |
exercise solution codepad |
| 210 |
11 Feb 2011 |
Sums Of Powers: Use Bernoulli numbers to quickly |
compute sums of powers |
exercise solution codepad |
| 10 |
24 Feb 2009 |
Mardi Gras: |
Compute the date of Easter |
exercise solution codepad |
| 133 |
04 May 2010 |
Spectacular Seven: |
Compute the odds at jai alai |
exercise solution codepad |
| 110 |
12 Feb 2010 |
Sieve of Atkin: A modern alternative to the Sieve of Eratosthenes for |
computing prime numbers |
exercise solution codepad |
| 103 |
19 Jan 2010 |
Flight Planning: |
Computing the navigation triangle, by Jos Koot |
exercise solution codepad |
| 175 |
12 Oct 2010 |
Rotate An Array: A simple but tricky exercise solved by an algorithm from the folklore of |
computing |
exercise solution codepad |
| 220 |
18 Mar 2011 |
Loopy Loops: Print the numbers from 1 to 1000 without using loops or |
conditionals |
exercise solution codepad |
| 174 |
08 Oct 2010 |
Zeller’s |
Congruence: Calculate the day of the week for a given date |
exercise solution codepad |
| 115 |
02 Mar 2010 |
Goldbach’s |
Conjecture: Every even number greater than two can be written as the sum of two primes |
exercise solution codepad |
| 194 |
17 Dec 2010 |
Polite Numbers: Write numbers as the sum of two or more |
consecutive integers |
exercise solution codepad |
| 207 |
01 Feb 2011 |
Cuckoo Hashing: A hashing system with guaranteed constant-time lookup and amortized |
constant-time insertion |
exercise solution codepad |
| 207 |
01 Feb 2011 |
Cuckoo Hashing: A hashing system with guaranteed |
constant-time lookup and amortized constant-time insertion |
exercise solution codepad |
| 223 |
28 Mar 2011 |
Look And Say, Revisited: Compute Conway’s |
constant |
exercise solution codepad |
| 271 |
13 Sep 2011 |
Tetrahedral Numbers: Find the base of the tetrahedron that |
contains 169179692512835000 balls |
exercise solution codepad |
| 148 |
09 Jul 2010 |
Contents: Permuted Table Of |
Contents: Blog management |
exercise solution codepad |
| 146 |
02 Jul 2010 |
|
Contents: Chronological Listing Of Exercises: Blog management |
exercise solution codepad |
| 148 |
09 Jul 2010 |
|
Contents: Permuted Table Of Contents: Blog management |
exercise solution codepad |
| 150 |
16 Jul 2010 |
|
Contents: Themes: Blog Management |
exercise solution codepad |
| 265 |
23 Aug 2011 |
Knapsack: Fill a knapsack to maximize the value of its |
contents |
exercise solution codepad |
| 117 |
09 Mar 2010 |
Lexicographic Permutations: |
Continually generate the next permutation using an algorithm by Dijkstra |
exercise solution codepad |
| 286 |
08 Nov 2011 |
Improved Standard |
Continuation: An improved version of elliptic curve factorization, widely used in current practice |
exercise solution codepad |
| 49 |
10 Jul 2009 |
The Golden Ratio: Evaluate a |
continued fraction, based on my daughter’s math homework |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The Factorization Of F7: Part 1: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by |
continued fractions |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The Factorization Of F7: Part 2: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by |
continued fractions |
exercise solution codepad |
| 245 |
14 Jun 2011 |
Big Numbers: Input And Output: A library for big integers: input and output with radix |
conversion |
exercise solution codepad |
| 250 |
01 Jul 2011 |
Feet And Inches: |
Convert decimal inches to carpenters’ fractions |
exercise solution codepad |
| 106 |
29 Jan 2010 |
Straddling Checkerboard: An alternative to the Polybius square for ciphers that must |
convert letters to digits |
exercise solution codepad |
| 172 |
01 Oct 2010 |
Oban Numbers: Numbers that omit the letter “o” when spelled, and a function to |
convert numbers to words |
exercise solution codepad |
| 223 |
28 Mar 2011 |
Look And Say, Revisited: Compute |
Conway’s constant |
exercise solution codepad |
| 219 |
15 Mar 2011 |
Look And Say: Calculate John Horton |
Conway’s "Look and Say" sequence |
exercise solution codepad |
| 275 |
27 Sep 2011 |
Statistics: Calculate the mean, standard deviation, linear regression and |
correlation |
exercise solution codepad |
| 69 |
18 Sep 2009 |
Regular Expressions, Part 2: The |
corresponding matcher |
exercise solution codepad |
| 92 |
08 Dec 2009 |
Word |
Count: An implementation of the unix wc program |
exercise solution codepad |
| 206 |
28 Jan 2011 |
Population |
Count: Count the number of set bits (1-bits) in the binary representation of an integer |
exercise solution codepad |
| 259 |
02 Aug 2011 |
The Nth Prime: The n prime, |
counting from p1 = 2 |
exercise solution codepad |
| 200 |
07 Jan 2011 |
Counting Primes: The prime |
counting function and nth-prime function |
exercise solution codepad |
| 257 |
26 Jul 2011 |
More Prime-Counting Functions: Prime |
counting functions by Meissel and Lehmer, based on Legendre’s sum |
exercise solution codepad |
| 200 |
07 Jan 2011 |
|
Counting Primes: The prime counting function and nth-prime function |
exercise solution codepad |
| 256 |
22 Jul 2011 |
|
Counting Primes Using Legendre’s Formula: Recreate Legendre’s two-century old calculation of the number of primes less than a million |
exercise solution codepad |
| 72 |
29 Sep 2009 |
Green Eyes: A |
counting problem from high-school math |
exercise solution codepad |
| 85 |
13 Nov 2009 |
Two linear sorts: |
Count sort and radix sort exploit the structure of integer keys |
exercise solution codepad |
| 206 |
28 Jan 2011 |
Population Count: |
Count the number of set bits (1-bits) in the binary representation of an integer |
exercise solution codepad |
| 285 |
04 Nov 2011 |
|
Craps: Simulate a popular game of gambling with dice |
exercise solution codepad |
| 78 |
20 Oct 2009 |
Shuffle: |
Create random permutations of an array or linked list |
exercise solution codepad |
| 12 |
03 Mar 2009 |
|
Creation: Cryptanalysis of a Vigenère cipher |
exercise solution codepad |
| 226 |
08 Apr 2011 |
|
Credit Card Validation: Validate decimal numbers using the Luhn algorithm |
exercise solution codepad |
| 230 |
22 Apr 2011 |
Xref: Programmer’s |
cross-reference utility |
exercise solution codepad |
| 101 |
12 Jan 2010 |
Calculating Sines: Calculate sines using Taylor series and the triple-angle formula, by Bill |
Cruise |
exercise solution codepad |
| 12 |
03 Mar 2009 |
Creation: |
Cryptanalysis of a Vigenère cipher |
exercise solution codepad |
| 50 |
14 Jul 2009 |
The Daily |
Cryptogram: Solve a monoalphabetic substitution cipher |
exercise solution codepad |
| 60 |
18 Aug 2009 |
Blum Blum Shub: Stream cipher based on a |
cryptographically secure pseudo-random number generator |
exercise solution codepad |
| 94 |
15 Dec 2009 |
Affine-Shift Cipher: A |
cryptographically weak but mathematically interesting cipher |
exercise solution codepad |
| 165 |
07 Sep 2010 |
Data Encryption Standard: Part 3: Triple DES and |
cryptographic hashing |
exercise solution codepad |
| 185 |
16 Nov 2010 |
RSA Cryptography: The original public-key |
cryptographic system, still in wide use |
exercise solution codepad |
| 244 |
10 Jun 2011 |
Steganography: A hand-operable system that combines |
cryptography and steganography |
exercise solution codepad |
| 203 |
18 Jan 2011 |
Solitaire Cipher: Bruce Schneier’s strong |
cryptography based on a deck of playing cards |
exercise solution codepad |
| 185 |
16 Nov 2010 |
RSA |
Cryptography: The original public-key cryptographic system, still in wide use |
exercise solution codepad |
| 246 |
17 Jun 2011 |
Adi Shamir’s Threshold Scheme: Use |
cryptography to share a secret, by Graham Enos |
exercise solution codepad |
| 290 |
22 Nov 2011 |
Rabin’s |
Cryptosystem: Public-key cryptosystem, similar to RSA |
exercise solution codepad |
| 290 |
22 Nov 2011 |
Rabin’s Cryptosystem: Public-key |
cryptosystem, similar to RSA |
exercise solution codepad |
| 283 |
28 Oct 2011 |
|
Crypt: Simple encryption tool from Kernighan and Plauger |
exercise solution codepad |
| 149 |
13 Jul 2010 |
Word |
Cube: A game to form words from a given set of letters |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into two sets of equal size so each subset has the same sum, sum of squares and sum of |
cubes |
exercise solution codepad |
| 207 |
01 Feb 2011 |
|
Cuckoo Hashing: A hashing system with guaranteed constant-time lookup and amortized constant-time insertion |
exercise solution codepad |
| 145 |
29 Jun 2010 |
World |
Cup Prognostication: Simulate the knockout stage using elo ratings |
exercise solution codepad |
| 286 |
08 Nov 2011 |
Improved Standard Continuation: An improved version of elliptic curve factorization, widely used in |
current practice |
exercise solution codepad |
| 55 |
31 Jul 2009 |
Elliptic |
Curve Factorization: A very simple implementation of elliptic curve factorization |
exercise solution codepad |
| 130 |
23 Apr 2010 |
Modern Elliptic |
Curve Factorization, Part 1: Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 131 |
27 Apr 2010 |
Modern Elliptic |
Curve Factorization, Part 2: Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 55 |
31 Jul 2009 |
Elliptic Curve Factorization: A very simple implementation of elliptic |
curve factorization |
exercise solution codepad |
| 56 |
04 Aug 2009 |
Lenstra’s Algorithm: Hendrik Lenstra’s original algorithm for elliptic |
curve factorization |
exercise solution codepad |
| 286 |
08 Nov 2011 |
Improved Standard Continuation: An improved version of elliptic |
curve factorization, widely used in current practice |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer Factorization: Combine trial division, Pollard’s rho and p−1 methods, and elliptic |
curves into a single factorization program |
exercise solution codepad |
| 54 |
28 Jul 2009 |
Elliptic |
Curves: Library of basic functions on elliptic curves |
exercise solution codepad |
| 54 |
28 Jul 2009 |
Elliptic Curves: Library of basic functions on elliptic |
curves |
exercise solution codepad |
| 159 |
17 Aug 2010 |
|
Cut: Select fields or characters from input lines |
exercise solution codepad |
| 5 |
19 Feb 2009 |
Flavius Josephus: Programming a |
cyclical list |
exercise solution codepad |
| 263 |
16 Aug 2011 |
Insert Into A Cyclic Sorted List: Insert a new element into a |
cyclic list, in order |
exercise solution codepad |
| 263 |
16 Aug 2011 |
Insert Into A |
Cyclic Sorted List: Insert a new element into a cyclic list, in order |
exercise solution codepad |
| 50 |
14 Jul 2009 |
The |
Daily Cryptogram: Solve a monoalphabetic substitution cipher |
exercise solution codepad |
| 161 |
24 Aug 2010 |
|
Daniel Shanks’ Square Form Factorization Algorithm: A simple and very fast factorization algorithm for integers between 105 and 1020 |
exercise solution codepad |
| 141 |
15 Jun 2010 |
Natural Join: The fundamental relational |
database operator |
exercise solution codepad |
| 177 |
19 Oct 2010 |
Text File |
Databases: Part 1: Functions to read records with fields in various formats |
exercise solution codepad |
| 178 |
22 Oct 2010 |
Text File |
Databases: Part 2: Various functions to process records with fields |
exercise solution codepad |
| 179 |
26 Oct 2010 |
Benford’s Law: A useful mathematical oddity, and an example of text file |
databases |
exercise solution codepad |
| 163 |
31 Aug 2010 |
|
Data Encryption Standard: Part 1: Basic block enciphering and deciphering using DES |
exercise solution codepad |
| 164 |
03 Sep 2010 |
|
Data Encryption Standard: Part 2: ECB, CBC, CFB and OFB block modes for DES and other block ciphers |
exercise solution codepad |
| 165 |
07 Sep 2010 |
|
Data Encryption Standard: Part 3: Triple DES and cryptographic hashing |
exercise solution codepad |
| 166 |
10 Sep 2010 |
|
Data Encryption Standard: Part 4: DES driver program |
exercise solution codepad |
| 189 |
30 Nov 2010 |
Form Letters: Merge a schema and a |
data file to write form letters |
exercise solution codepad |
| 73 |
02 Oct 2009 |
Red-Black Trees: A purely functional dictionary |
data structure based on approximately-balanced trees |
exercise solution codepad |
| 124 |
02 Apr 2010 |
Disjoint Sets: A |
data structure for storing sets of items in disjoint partitions |
exercise solution codepad |
| 45 |
26 Jun 2009 |
Treaps: A randomized dictionary |
data structure, provides in-order access to key |
exercise solution codepad |
| 116 |
05 Mar 2010 |
Binary Search Tree: Classic |
data structure, providing insert, delete and lookup for ordered datatypes |
exercise solution codepad |
| 171 |
28 Sep 2010 |
Maxiphobic Heaps: A priority-queue |
data structure, similar to leftist heaps, due to Chris Okasaki |
exercise solution codepad |
| 30 |
05 May 2009 |
Priority Queues: A simple library implementation of the priority queue |
data structure |
exercise solution codepad |
| 116 |
05 Mar 2010 |
Binary Search Tree: Classic data structure, providing insert, delete and lookup for ordered |
datatypes |
exercise solution codepad |
| 10 |
24 Feb 2009 |
Mardi Gras: Compute the |
date of Easter |
exercise solution codepad |
| 123 |
30 Mar 2010 |
Passover: Calculate the |
dates of the Jewish holidays Rosh Hashanah and Passover |
exercise solution codepad |
| 40 |
09 Jun 2009 |
Longest Common Subsequence: A classic programming algorithm, with a solution that |
dates to folklore |
exercise solution codepad |
| 174 |
08 Oct 2010 |
Zeller’s Congruence: Calculate the day of the week for a given |
date |
exercise solution codepad |
| 221 |
22 Mar 2011 |
Two Kaprekar Exercises: Kaprekar chains and Kaprekar numbers, from the Indian mathematician |
Dattaraya Ramchandra Kaprekar |
exercise solution codepad |
| 49 |
10 Jul 2009 |
The Golden Ratio: Evaluate a continued fraction, based on my |
daughter’s math homework |
exercise solution codepad |
| 96 |
22 Dec 2009 |
Permuted Index: |
David Parnas’ classic deconstruction of the keyword-in-context index |
exercise solution codepad |
| 88 |
24 Nov 2009 |
Sunrise, Sunset: Calculate the times of sunrise and sunset on any |
day anywhere in the world |
exercise solution codepad |
| 174 |
08 Oct 2010 |
Zeller’s Congruence: Calculate the |
day of the week for a given date |
exercise solution codepad |
| 248 |
24 Jun 2011 |
Thank God It’s Friday!: Three methods to calculate the |
day of the week |
exercise solution codepad |
| 104 |
22 Jan 2010 |
Phases Of The Moon: Calculate the number of |
days since the last new moon |
exercise solution codepad |
| 53 |
24 Jul 2009 |
Let’s Make A |
Deal!: Simulate a tricky probability calculation |
exercise solution codepad |
| 250 |
01 Jul 2011 |
Feet And Inches: Convert |
decimal inches to carpenters’ fractions |
exercise solution codepad |
| 226 |
08 Apr 2011 |
Credit Card Validation: Validate |
decimal numbers using the Luhn algorithm |
exercise solution codepad |
| 163 |
31 Aug 2010 |
Data Encryption Standard: Part 1: Basic block enciphering and |
deciphering using DES |
exercise solution codepad |
| 203 |
18 Jan 2011 |
Solitaire Cipher: Bruce Schneier’s strong cryptography based on a |
deck of playing cards |
exercise solution codepad |
| 96 |
22 Dec 2009 |
Permuted Index: David Parnas’ classic |
deconstruction of the keyword-in-context index |
exercise solution codepad |
| 86 |
17 Nov 2009 |
Master Mind, Part 1: Referee a two-player game of |
deductive logic |
exercise solution codepad |
| 116 |
05 Mar 2010 |
Binary Search Tree: Classic data structure, providing insert, |
delete and lookup for ordered datatypes |
exercise solution codepad |
| 279 |
11 Oct 2011 |
Tower Of Hanoi: Classic |
demonstration of recursion |
exercise solution codepad |
| 269 |
06 Sep 2011 |
|
Deques: Library implementation of double-ended queues |
exercise solution codepad |
| 165 |
07 Sep 2010 |
Data Encryption Standard: Part 3: Triple |
DES and cryptographic hashing |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data Encryption Standard: Part 2: ECB, CBC, CFB and OFB block modes for |
DES and other block ciphers |
exercise solution codepad |
| 33 |
15 May 2009 |
Cellular Automata: Linear cellular automata as |
described by Stephen Wolfram in his book A New Kind of Science |
exercise solution codepad |
| 166 |
10 Sep 2010 |
Data Encryption Standard: Part 4: |
DES driver program |
exercise solution codepad |
| 163 |
31 Aug 2010 |
Data Encryption Standard: Part 1: Basic block enciphering and deciphering using |
DES |
exercise solution codepad |
| 234 |
06 May 2011 |
Entab And |
Detab: expand tabs into spaces, and replace spaces with tabs |
exercise solution codepad |
| 156 |
06 Aug 2010 |
Two Powering Predicates: |
Determine if a number is a square or a prime power |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for big integers: display factorials to 50, |
determine if a number is prime, and compute its prime factors |
exercise solution codepad |
| 187 |
23 Nov 2010 |
String Subsets: |
Determine if one string is a subset of another |
exercise solution codepad |
| 255 |
19 Jul 2011 |
Sum Of Two Integers: |
Determine if two integers in a list sum to a target |
exercise solution codepad |
| 297 |
16 Dec 2011 |
Majority Voting: |
Determine the results of an election |
exercise solution codepad |
| 107 |
02 Feb 2010 |
Proving Primality: A |
deterministic, not probabilistic, method of checking primality |
exercise solution codepad |
| 252 |
08 Jul 2011 |
Vedic Divisibility: Use a method of testing divisibility using the method of osculators |
developed in India |
exercise solution codepad |
| 275 |
27 Sep 2011 |
Statistics: Calculate the mean, standard |
deviation, linear regression and correlation |
exercise solution codepad |
| 285 |
04 Nov 2011 |
Craps: Simulate a popular game of gambling with |
dice |
exercise solution codepad |
| 73 |
02 Oct 2009 |
Red-Black Trees: A purely functional |
dictionary data structure based on approximately-balanced trees |
exercise solution codepad |
| 45 |
26 Jun 2009 |
Treaps: A randomized |
dictionary data structure, provides in-order access to key |
exercise solution codepad |
| 23 |
10 Apr 2009 |
Anagrams: Find anagrams in a |
dictionary |
exercise solution codepad |
| 25 |
17 Apr 2009 |
Spell Checking: A spell-checker in a trie-based |
dictionary |
exercise solution codepad |
| 224 |
01 Apr 2011 |
Maximum |
Difference In An Array: Find maximum Xj &minus Xi, with i ≤ j |
exercise solution codepad |
| 139 |
08 Jun 2010 |
Diff: Find the |
differences between two text files |
exercise solution codepad |
| 139 |
08 Jun 2010 |
|
Diff: Find the differences between two text files |
exercise solution codepad |
| 229 |
19 Apr 2011 |
Same Five |
Digits: A math puzzle from New Scientist, solved by guest author Bob Miller |
exercise solution codepad |
| 181 |
02 Nov 2010 |
Emirps: Prime numbers that are prime when their |
digits are reversed, but not palindromic |
exercise solution codepad |
| 169 |
21 Sep 2010 |
Kaprekar Numbers: Square the number and add the |
digits in halves |
exercise solution codepad |
| 8 |
20 Feb 2009 |
The |
Digits of Pi: A spigot algorithm to calculate the digits of pi |
exercise solution codepad |
| 8 |
20 Feb 2009 |
The Digits of Pi: A spigot algorithm to calculate the |
digits of pi |
exercise solution codepad |
| 129 |
20 Apr 2010 |
145 Puzzle: Build and evaluate expressions using the |
digits one through nine and the simple arithmetic operators |
exercise solution codepad |
| 152 |
23 Jul 2010 |
Happy Numbers: Iterating the sum of the squares of the |
digits terminates with one |
exercise solution codepad |
| 106 |
29 Jan 2010 |
Straddling Checkerboard: An alternative to the Polybius square for ciphers that must convert letters to |
digits |
exercise solution codepad |
| 199 |
04 Jan 2011 |
|
Dijkstra’s Algorithm: Find the shortest path to all vertices of a graph from a single source, guest written by Graham Enos |
exercise solution codepad |
| 117 |
09 Mar 2010 |
Lexicographic Permutations: Continually generate the next permutation using an algorithm by |
Dijkstra |
exercise solution codepad |
| 267 |
30 Aug 2011 |
Hamming Numbers: List the numbers with no factors greater than 5, a classic problem popularized by |
Dijkstra |
exercise solution codepad |
| 99 |
05 Jan 2010 |
The Sum Of Two Squares: A math puzzle with a solution by |
Dijkstra |
exercise solution codepad |
| 124 |
02 Apr 2010 |
Disjoint Sets: A data structure for storing sets of items in |
disjoint partitions |
exercise solution codepad |
| 124 |
02 Apr 2010 |
|
Disjoint Sets: A data structure for storing sets of items in disjoint partitions |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for big integers: |
display factorials to 50, determine if a number is prime, and compute its prime factors |
exercise solution codepad |
| 294 |
06 Dec 2011 |
Pascal’s Triangle: |
Display the binomial coefficients |
exercise solution codepad |
| 289 |
18 Nov 2011 |
Grade School Multiplication: |
Display the steps in the grade school multiplication algorithm |
exercise solution codepad |
| 82 |
03 Nov 2009 |
Quick Sort: Tony Hoare’s |
divide-and-conquer sorting algorithm |
exercise solution codepad |
| 128 |
16 Apr 2010 |
Expression Evaluation: Parse and evaluate an arithmetic expression with plus, minus, times, |
divide and parentheses |
exercise solution codepad |
| 252 |
08 Jul 2011 |
Vedic |
Divisibility: Use a method of testing divisibility using the method of osculators developed in India |
exercise solution codepad |
| 252 |
08 Jul 2011 |
Vedic Divisibility: Use a method of testing |
divisibility using the method of osculators developed in India |
exercise solution codepad |
| 243 |
07 Jun 2011 |
Big Numbers: |
Division: A library for big integers: the grade-school algorithm for long division |
exercise solution codepad |
| 102 |
15 Jan 2010 |
Three Binary Algorithms: Multiplication, |
division and greatest common divisor using binary arithmetic |
exercise solution codepad |
| 48 |
07 Jul 2009 |
Modular Arithmetic: A function library for performing modular addition, subtraction, multiplication, |
division, and square root |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer Factorization: Combine trial |
division, Pollard’s rho and p−1 methods, and elliptic curves into a single factorization program |
exercise solution codepad |
| 243 |
07 Jun 2011 |
Big Numbers: Division: A library for big integers: the grade-school algorithm for long |
division |
exercise solution codepad |
| 273 |
20 Sep 2011 |
Project Euler Problem 3: Thorough explanation of integer factorization by trial |
division |
exercise solution codepad |
| 31 |
08 May 2009 |
Wheel Factorization: Find the factors of a number by a variant of trial |
division |
exercise solution codepad |
| 188 |
26 Nov 2010 |
|
Divisors And Totatives: The number-theoretic functions divisors, numdivs, sumdivs, totatives, and totient |
exercise solution codepad |
| 188 |
26 Nov 2010 |
Divisors And Totatives: The number-theoretic functions |
divisors, numdivs, sumdivs, totatives, and totient |
exercise solution codepad |
| 102 |
15 Jan 2010 |
Three Binary Algorithms: Multiplication, division and greatest common |
divisor using binary arithmetic |
exercise solution codepad |
| 236 |
13 May 2011 |
|
Dixon’s Factorization Algorithm: A slow, but theoretically important, algorithm for integer factorization |
exercise solution codepad |
| 157 |
10 Aug 2010 |
Literate Programming: Structured |
documentation in the style of Donald Knuth |
exercise solution codepad |
| 17 |
20 Mar 2009 |
|
Dodgson's Doublets: A word game invented by the author of Alice in Wonderland |
exercise solution codepad |
| 264 |
19 Aug 2011 |
First Non-Repeating Character: Find the first character in a string that |
doesn’t repeat later in the string |
exercise solution codepad |
| 196 |
24 Dec 2010 |
Tracking Santa: How far |
does Santa travel on his annual journey? |
exercise solution codepad |
| 135 |
25 May 2010 |
GB_FLIP: |
Donald Knuth’s portable, high-quality random-number generator from the Stanford Graphbase |
exercise solution codepad |
| 157 |
10 Aug 2010 |
Literate Programming: Structured documentation in the style of |
Donald Knuth |
exercise solution codepad |
| 28 |
28 Apr 2009 |
Morse Code: Translating the |
dots-and-dashes of Samuel Finley Breese Morse’s telegraph code |
exercise solution codepad |
| 155 |
03 Aug 2010 |
Carl Hewitt’s Same-Fringe Problem: |
Do two trees have the same leaves, solved with streams (lazy lists) |
exercise solution codepad |
| 269 |
06 Sep 2011 |
Deques: Library implementation of |
double-ended queues |
exercise solution codepad |
| 37 |
29 May 2009 |
|
Double Transposition Cipher: A simple and effective cipher, easy to perform by hand |
exercise solution codepad |
| 17 |
20 Mar 2009 |
Dodgson's |
Doublets: A word game invented by the author of Alice in Wonderland |
exercise solution codepad |
| 113 |
23 Feb 2010 |
Engineering A Sort Function: A high-performance quicksort by Jon Bentley and |
Doug McIlroy |
exercise solution codepad |
| 240 |
27 May 2011 |
Upside Up: Numbers that read the same upside |
down |
exercise solution codepad |
| 198 |
31 Dec 2010 |
Arithmetic Drill: Repetitious |
drill for children learning basic arithmetic |
exercise solution codepad |
| 198 |
31 Dec 2010 |
Arithmetic |
Drill: Repetitious drill for children learning basic arithmetic |
exercise solution codepad |
| 166 |
10 Sep 2010 |
Data Encryption Standard: Part 4: DES |
driver program |
exercise solution codepad |
| 171 |
28 Sep 2010 |
Maxiphobic Heaps: A priority-queue data structure, similar to leftist heaps, |
due to Chris Okasaki |
exercise solution codepad |
| 176 |
15 Oct 2010 |
Find The Longest Palindrome In A String: A beautiful linear-time algorithm |
due to Johan Jeuring |
exercise solution codepad |
| 190 |
03 Dec 2010 |
Maximum Sum Subsequence: A classic programming exercise |
due to Jon Bentley |
exercise solution codepad |
| 268 |
02 Sep 2011 |
Two String Exercises: Remove |
duplicate characters, and squish adjacent blanks |
exercise solution codepad |
| 193 |
14 Dec 2010 |
Longest |
Duplicated Substring: Use a sorted suffix list |
exercise solution codepad |
| 274 |
23 Sep 2011 |
Array Duplicates: Find the |
duplicate integer in a large array |
exercise solution codepad |
| 274 |
23 Sep 2011 |
Array |
Duplicates: Find the duplicate integer in a large array |
exercise solution codepad |
| 7 |
20 Feb 2009 |
Multiple |
Dwellings: A simple logic puzzle, solved with the amb non-deterministic operator |
exercise solution codepad |
| 183 |
09 Nov 2010 |
Subset Sums: Third level of the Greplin Programming Challenge, using |
dynamic programming and memoization |
exercise solution codepad |
| 90 |
01 Dec 2009 |
Wolves And Rabbits: Analyze population |
dynamics using the Lotka-Volterra equations |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into two sets of equal size so |
each subset has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 215 |
01 Mar 2011 |
An |
Early LISP Program: A program to flatten a list, from the March 1960 LISP I manual |
exercise solution codepad |
| 158 |
13 Aug 2010 |
|
E: A simple simulation with a surprising ending |
exercise solution codepad |
| 10 |
24 Feb 2009 |
Mardi Gras: Compute the date of |
Easter |
exercise solution codepad |
| 18 |
23 Mar 2009 |
Binary Search: A simple task, |
easy to get wrong |
exercise solution codepad |
| 37 |
29 May 2009 |
Double Transposition Cipher: A simple and effective cipher, |
easy to perform by hand |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data Encryption Standard: Part 2: |
ECB, CBC, CFB and OFB block modes for DES and other block ciphers |
exercise solution codepad |
| 186 |
19 Nov 2010 |
Topological Sort: Order the |
edges of a graph by their precedence relationship |
exercise solution codepad |
| 37 |
29 May 2009 |
Double Transposition Cipher: A simple and |
effective cipher, easy to perform by hand |
exercise solution codepad |
| 76 |
13 Oct 2009 |
Bifid: A simple but |
effective fractionating cipher, never used militarily |
exercise solution codepad |
| 122 |
26 Mar 2010 |
The Next Prime: |
Efficiently find the next prime number larger than a given number |
exercise solution codepad |
| 297 |
16 Dec 2011 |
Majority Voting: Determine the results of an |
election |
exercise solution codepad |
| 263 |
16 Aug 2011 |
Insert Into A Cyclic Sorted List: Insert a new |
element into a cyclic list, in order |
exercise solution codepad |
| 266 |
26 Aug 2011 |
Reverse Every K Nodes Of A Linked List: Reverse the |
elements of a sub-list |
exercise solution codepad |
| 130 |
23 Apr 2010 |
Modern Elliptic Curve Factorization, Part 1: |
Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 131 |
27 Apr 2010 |
Modern Elliptic Curve Factorization, Part 2: |
Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 55 |
31 Jul 2009 |
|
Elliptic Curve Factorization: A very simple implementation of elliptic curve factorization |
exercise solution codepad |
| 130 |
23 Apr 2010 |
Modern |
Elliptic Curve Factorization, Part 1: Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 131 |
27 Apr 2010 |
Modern |
Elliptic Curve Factorization, Part 2: Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 55 |
31 Jul 2009 |
Elliptic Curve Factorization: A very simple implementation of |
elliptic curve factorization |
exercise solution codepad |
| 56 |
04 Aug 2009 |
Lenstra’s Algorithm: Hendrik Lenstra’s original algorithm for |
elliptic curve factorization |
exercise solution codepad |
| 286 |
08 Nov 2011 |
Improved Standard Continuation: An improved version of |
elliptic curve factorization, widely used in current practice |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer Factorization: Combine trial division, Pollard’s rho and p−1 methods, and |
elliptic curves into a single factorization program |
exercise solution codepad |
| 54 |
28 Jul 2009 |
|
Elliptic Curves: Library of basic functions on elliptic curves |
exercise solution codepad |
| 54 |
28 Jul 2009 |
Elliptic Curves: Library of basic functions on |
elliptic curves |
exercise solution codepad |
| 145 |
29 Jun 2010 |
World Cup Prognostication: Simulate the knockout stage using |
elo ratings |
exercise solution codepad |
| 42 |
16 Jun 2009 |
Who Owns The Zebra?: A logic puzzle, solved by |
embedding a Prolog-like logic system in Scheme |
exercise solution codepad |
| 279 |
14 Oct 2011 |
The First N Primes: |
Embedding the Sieve of Eratosthenes in a priority queue instead of an array |
exercise solution codepad |
| 121 |
23 Mar 2010 |
Texas Hold |
‘Em: Find the best poker hand |
exercise solution codepad |
| 181 |
02 Nov 2010 |
|
Emirps: Prime numbers that are prime when their digits are reversed, but not palindromic |
exercise solution codepad |
| 138 |
04 Jun 2010 |
Williams’ |
P+1 Factorization Algorithm: A factorization algorithm, similar to Pollard’s p−1 algorithm |
exercise solution codepad |
| 163 |
31 Aug 2010 |
Data Encryption Standard: Part 1: Basic block |
enciphering and deciphering using DES |
exercise solution codepad |
| 114 |
26 Feb 2010 |
Run Length |
Encoding: A simple compression method for text files |
exercise solution codepad |
| 163 |
31 Aug 2010 |
Data |
Encryption Standard: Part 1: Basic block enciphering and deciphering using DES |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data |
Encryption Standard: Part 2: ECB, CBC, CFB and OFB block modes for DES and other block ciphers |
exercise solution codepad |
| 165 |
07 Sep 2010 |
Data |
Encryption Standard: Part 3: Triple DES and cryptographic hashing |
exercise solution codepad |
| 166 |
10 Sep 2010 |
Data |
Encryption Standard: Part 4: DES driver program |
exercise solution codepad |
| 283 |
28 Oct 2011 |
Crypt: Simple |
encryption tool from Kernighan and Plauger |
exercise solution codepad |
| 158 |
13 Aug 2010 |
E: A simple simulation with a surprising |
ending |
exercise solution codepad |
| 113 |
23 Feb 2010 |
|
Engineering A Sort Function: A high-performance quicksort by Jon Bentley and Doug McIlroy |
exercise solution codepad |
| 209 |
08 Feb 2011 |
The First Computer Program: Ada Lovelace’s program to compute Bernoulli numbers for Charles Babbage’s Analytical |
Engine |
exercise solution codepad |
| 199 |
04 Jan 2011 |
Dijkstra’s Algorithm: Find the shortest path to all vertices of a graph from a single source, guest written by Graham |
Enos |
exercise solution codepad |
| 246 |
17 Jun 2011 |
Adi Shamir’s Threshold Scheme: Use cryptography to share a secret, by Graham |
Enos |
exercise solution codepad |
| 234 |
06 May 2011 |
|
Entab And Detab: expand tabs into spaces, and replace spaces with tabs |
exercise solution codepad |
| 46 |
30 Jun 2009 |
Steve Yegge’s Phone-Screen Coding Exercises: A simple set of programming exercises based on a blog |
entry by Steve Yegge |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into two sets of |
equal size so each subset has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 151 |
20 Jul 2010 |
Solving Systems Of Linear |
Equations: Matrix operations LU-decomposition and LUP-decomposition |
exercise solution codepad |
| 284 |
01 Nov 2011 |
RIP John McCarthy: Implementation of the “Maxwell’s |
equations of software” from the LISP 1.5 Programmer’s Manual |
exercise solution codepad |
| 90 |
01 Dec 2009 |
Wolves And Rabbits: Analyze population dynamics using the Lotka-Volterra |
equations |
exercise solution codepad |
| 111 |
16 Feb 2010 |
Soundex: An algorithm to assign people’s last names to |
equivalence classes based on similar spelling |
exercise solution codepad |
| 2 |
19 Feb 2009 |
Sieve of |
Eratosthenes: A Scheme implementation of an ancient algorithm |
exercise solution codepad |
| 108 |
05 Feb 2010 |
Segmented Sieve Of |
Eratosthenes: Extend the Sieve of Eratosthenes to large ranges of integers |
exercise solution codepad |
| 110 |
12 Feb 2010 |
Sieve of Atkin: A modern alternative to the Sieve of |
Eratosthenes for computing prime numbers |
exercise solution codepad |
| 279 |
14 Oct 2011 |
The First N Primes: Embedding the Sieve of |
Eratosthenes in a priority queue instead of an array |
exercise solution codepad |
| 108 |
05 Feb 2010 |
Segmented Sieve Of Eratosthenes: Extend the Sieve of |
Eratosthenes to large ranges of integers |
exercise solution codepad |
| 84 |
10 Nov 2009 |
Merge Sort: A fast, stable sorting algorithm, |
especially well-suited to linked lists |
exercise solution codepad |
| 212 |
18 Feb 2011 |
Two Factoring Games: Home primes and the |
Euclid-Mullin sequence |
exercise solution codepad |
| 214 |
25 Feb 2011 |
Sieve Of |
Euler: An alternate, and slow, method of sieving for primes |
exercise solution codepad |
| 273 |
20 Sep 2011 |
Project |
Euler Problem 3: Thorough explanation of integer factorization by trial division |
exercise solution codepad |
| 95 |
18 Dec 2009 |
Calculating Logarithms: Use the methods of Newton and |
Euler to calculate square roots and logarithms |
exercise solution codepad |
| 49 |
10 Jul 2009 |
The Golden Ratio: |
Evaluate a continued fraction, based on my daughter’s math homework |
exercise solution codepad |
| 128 |
16 Apr 2010 |
Expression Evaluation: Parse and |
evaluate an arithmetic expression with plus, minus, times, divide and parentheses |
exercise solution codepad |
| 129 |
20 Apr 2010 |
145 Puzzle: Build and |
evaluate expressions using the digits one through nine and the simple arithmetic operators |
exercise solution codepad |
| 1 |
19 Feb 2009 |
RPN Calculator: |
Evaluate numeric expressions at the command line |
exercise solution codepad |
| 128 |
16 Apr 2010 |
Expression |
Evaluation: Parse and evaluate an arithmetic expression with plus, minus, times, divide and parentheses |
exercise solution codepad |
| 115 |
02 Mar 2010 |
Goldbach’s Conjecture: Every |
even number greater than two can be written as the sum of two primes |
exercise solution codepad |
| 4 |
19 Feb 2009 |
Sudoku: A backtracking solution to |
everybody’s favorite puzzle |
exercise solution codepad |
| 115 |
02 Mar 2010 |
Goldbach’s Conjecture: |
Every even number greater than two can be written as the sum of two primes |
exercise solution codepad |
| 266 |
26 Aug 2011 |
Reverse |
Every K Nodes Of A Linked List: Reverse the elements of a sub-list |
exercise solution codepad |
| 118 |
12 Mar 2010 |
Traveling Salesman: Brute Force: |
Examine all possible permutations to find the least-cost tour |
exercise solution codepad |
| 179 |
26 Oct 2010 |
Benford’s Law: A useful mathematical oddity, and an |
example of text file databases |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: |
Examples: A library for big integers: display factorials to 50, determine if a number is prime, and compute its prime factors |
exercise solution codepad |
| 208 |
04 Feb 2011 |
Excel Columns: Numbers as in |
Excel column names, A=1, Z=26, IV=256 |
exercise solution codepad |
| 208 |
04 Feb 2011 |
|
Excel Columns: Numbers as in Excel column names, A=1, Z=26, IV=256 |
exercise solution codepad |
| 190 |
03 Dec 2010 |
Maximum Sum Subsequence: A classic programming |
exercise due to Jon Bentley |
exercise solution codepad |
| 170 |
24 Sep 2010 |
Alien Numbers: An |
exercise from Google Code Jam |
exercise solution codepad |
| 195 |
21 Dec 2010 |
Interval Arithmetic: An |
exercise from SICP |
exercise solution codepad |
| 296 |
13 Dec 2011 |
Validating Telephone Numbers: An |
exercise in input validation |
exercise solution codepad |
| 137 |
01 Jun 2010 |
Unwrapping A Spiral: An |
exercise in recursion |
exercise solution codepad |
| 144 |
25 Jun 2010 |
Learn A New Language: Solve the |
exercise of your choice in an unfamiliar language |
exercise solution codepad |
| 46 |
30 Jun 2009 |
Steve Yegge’s Phone-Screen Coding |
Exercises: A simple set of programming exercises based on a blog entry by Steve Yegge |
exercise solution codepad |
| 46 |
30 Jun 2009 |
Steve Yegge’s Phone-Screen Coding Exercises: A simple set of programming |
exercises based on a blog entry by Steve Yegge |
exercise solution codepad |
| 146 |
02 Jul 2010 |
Contents: Chronological Listing Of |
Exercises: Blog management |
exercise solution codepad |
| 51 |
17 Jul 2009 |
International Mathematical Olympiad: Three |
exercises from 1960s math competitions |
exercise solution codepad |
| 221 |
22 Mar 2011 |
Two Kaprekar |
Exercises: Kaprekar chains and Kaprekar numbers, from the Indian mathematician Dattaraya Ramchandra Kaprekar |
exercise solution codepad |
| 175 |
12 Oct 2010 |
Rotate An Array: A simple but tricky |
exercise solved by an algorithm from the folklore of computing |
exercise solution codepad |
| 268 |
02 Sep 2011 |
Two String |
Exercises: Remove duplicate characters, and squish adjacent blanks |
exercise solution codepad |
| 211 |
15 Feb 2011 |
Google Code Jam Qualification Round Africa 2010: Three simple |
exercises |
exercise solution codepad |
| 38 |
02 Jun 2009 |
Pig Latin: A simple |
exercise to solve a children’s game |
exercise solution codepad |
| 140 |
11 Jun 2010 |
N-Queens: Our version of a classic algorithmic |
exercise |
exercise solution codepad |
| 280 |
18 Oct 2011 |
The Wall: Ray Panko’s spreadsheet |
exercise |
exercise solution codepad |
| 58 |
11 Aug 2009 |
Uncle Bob’s Bowling Game Kata: Use pattern-matching on lists to solve a classic object-oriented programming |
exercise |
exercise solution codepad |
| 44 |
23 Jun 2009 |
The Mod Out System: |
Expand a series of ranges |
exercise solution codepad |
| 234 |
06 May 2011 |
Entab And Detab: |
expand tabs into spaces, and replace spaces with tabs |
exercise solution codepad |
| 273 |
20 Sep 2011 |
Project Euler Problem 3: Thorough |
explanation of integer factorization by trial division |
exercise solution codepad |
| 85 |
13 Nov 2009 |
Two linear sorts: Count sort and radix sort |
exploit the structure of integer keys |
exercise solution codepad |
| 201 |
11 Jan 2011 |
Two Integrals: The |
exponential and logarithmic integral, and an approximation for prime-pi |
exercise solution codepad |
| 154 |
30 Jul 2010 |
Fibonacci Numbers: Three algorithms taking |
exponential time, linear time, and logarithmic time |
exercise solution codepad |
| 74 |
06 Oct 2009 |
MapReduce: Google’s famous system for parallelizing computations |
expressed as a programming idiom |
exercise solution codepad |
| 128 |
16 Apr 2010 |
|
Expression Evaluation: Parse and evaluate an arithmetic expression with plus, minus, times, divide and parentheses |
exercise solution codepad |
| 1 |
19 Feb 2009 |
RPN Calculator: Evaluate numeric |
expressions at the command line |
exercise solution codepad |
| 68 |
15 Sep 2009 |
Regular |
Expressions, Part 1: A parser for regular expressions |
exercise solution codepad |
| 69 |
18 Sep 2009 |
Regular |
Expressions, Part 2: The corresponding matcher |
exercise solution codepad |
| 70 |
22 Sep 2009 |
Regular |
Expressions, Part 3: A regular expression test suite |
exercise solution codepad |
| 68 |
15 Sep 2009 |
Regular Expressions, Part 1: A parser for regular |
expressions |
exercise solution codepad |
| 129 |
20 Apr 2010 |
145 Puzzle: Build and evaluate |
expressions using the digits one through nine and the simple arithmetic operators |
exercise solution codepad |
| 70 |
22 Sep 2009 |
Regular Expressions, Part 3: A regular |
expression test suite |
exercise solution codepad |
| 128 |
16 Apr 2010 |
Expression Evaluation: Parse and evaluate an arithmetic |
expression with plus, minus, times, divide and parentheses |
exercise solution codepad |
| 292 |
29 Nov 2011 |
AVL Trees, |
Extended: Add additional functionality to AVL trees |
exercise solution codepad |
| 120 |
19 Mar 2010 |
|
Extending Pollard’s P−1 Factorization Algorithm: Add a second stage to allow larger factorizations |
exercise solution codepad |
| 108 |
05 Feb 2010 |
Segmented Sieve Of Eratosthenes: |
Extend the Sieve of Eratosthenes to large ranges of integers |
exercise solution codepad |
| 72 |
29 Sep 2009 |
Green |
Eyes: A counting problem from high-school math |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The Factorization Of |
F7: Part 1: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The Factorization Of |
F7: Part 2: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for big integers: display |
factorials to 50, determine if a number is prime, and compute its prime factors |
exercise solution codepad |
| 212 |
18 Feb 2011 |
Two |
Factoring Games: Home primes and the Euclid-Mullin sequence |
exercise solution codepad |
| 120 |
19 Mar 2010 |
Extending Pollard’s P−1 |
Factorization Algorithm: Add a second stage to allow larger factorizations |
exercise solution codepad |
| 138 |
04 Jun 2010 |
Williams’ P+1 |
Factorization Algorithm: A factorization algorithm, similar to Pollard’s p−1 algorithm |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel Shanks’ Square Form |
Factorization Algorithm: A simple and very fast factorization algorithm for integers between 105 and 1020 |
exercise solution codepad |
| 52 |
21 Jul 2009 |
Pollard’s P−1 |
Factorization Algorithm: A simple factorization algorithm by John Pollard |
exercise solution codepad |
| 236 |
13 May 2011 |
Dixon’s |
Factorization Algorithm: A slow, but theoretically important, algorithm for integer factorization |
exercise solution codepad |
| 52 |
21 Jul 2009 |
Pollard’s P−1 Factorization Algorithm: A simple |
factorization algorithm by John Pollard |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel Shanks’ Square Form Factorization Algorithm: A simple and very fast |
factorization algorithm for integers between 105 and 1020 |
exercise solution codepad |
| 272 |
16 Sep 2011 |
Pollard’s P−1 |
Factorization Algoritihm, Revisited: An improved second stage that is much faster than the original |
exercise solution codepad |
| 138 |
04 Jun 2010 |
Williams’ P+1 Factorization Algorithm: A |
factorization algorithm, similar to Pollard’s p−1 algorithm |
exercise solution codepad |
| 55 |
31 Jul 2009 |
Elliptic Curve |
Factorization: A very simple implementation of elliptic curve factorization |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The Factorization Of F7: Part 1: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer |
factorization by continued fractions |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The Factorization Of F7: Part 2: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer |
factorization by continued fractions |
exercise solution codepad |
| 34 |
19 May 2009 |
Fermat’s Method: Integer |
factorization by Fermat’s algorithm |
exercise solution codepad |
| 273 |
20 Sep 2011 |
Project Euler Problem 3: Thorough explanation of integer |
factorization by trial division |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer |
Factorization: Combine trial division, Pollard’s rho and p−1 methods, and elliptic curves into a single factorization program |
exercise solution codepad |
| 31 |
08 May 2009 |
Wheel |
Factorization: Find the factors of a number by a variant of trial division |
exercise solution codepad |
| 43 |
19 Jun 2009 |
Monte Carlo |
Factorization: Integer factorization via Pollard’s rho algorithm |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The |
Factorization Of F7: Part 1: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The |
Factorization Of F7: Part 2: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 130 |
23 Apr 2010 |
Modern Elliptic Curve |
Factorization, Part 1: Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 131 |
27 Apr 2010 |
Modern Elliptic Curve |
Factorization, Part 2: Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer Factorization: Combine trial division, Pollard’s rho and p−1 methods, and elliptic curves into a single |
factorization program |
exercise solution codepad |
| 120 |
19 Mar 2010 |
Extending Pollard’s P−1 Factorization Algorithm: Add a second stage to allow larger |
factorizations |
exercise solution codepad |
| 204 |
21 Jan 0 |
Pollard Rho, Revisited: Richard Brent’s variant of John Pollard’s rho algorithm for integer |
factorization |
exercise solution codepad |
| 236 |
13 May 2011 |
Dixon’s Factorization Algorithm: A slow, but theoretically important, algorithm for integer |
factorization |
exercise solution codepad |
| 55 |
31 Jul 2009 |
Elliptic Curve Factorization: A very simple implementation of elliptic curve |
factorization |
exercise solution codepad |
| 56 |
04 Aug 2009 |
Lenstra’s Algorithm: Hendrik Lenstra’s original algorithm for elliptic curve |
factorization |
exercise solution codepad |
| 43 |
19 Jun 2009 |
Monte Carlo Factorization: Integer |
factorization via Pollard’s rho algorithm |
exercise solution codepad |
| 286 |
08 Nov 2011 |
Improved Standard Continuation: An improved version of elliptic curve |
factorization, widely used in current practice |
exercise solution codepad |
| 127 |
13 Apr 2010 |
Traveling Salesman: Minimum Spanning Tree: Heuristic guarantees solution within |
factor of two of optimal tour |
exercise solution codepad |
| 267 |
30 Aug 2011 |
Hamming Numbers: List the numbers with no |
factors greater than 5, a classic problem popularized by Dijkstra |
exercise solution codepad |
| 31 |
08 May 2009 |
Wheel Factorization: Find the |
factors of a number by a variant of trial division |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for big integers: display factorials to 50, determine if a number is prime, and compute its prime |
factors |
exercise solution codepad |
| 74 |
06 Oct 2009 |
MapReduce: Google’s |
famous system for parallelizing computations expressed as a programming idiom |
exercise solution codepad |
| 196 |
24 Dec 2010 |
Tracking Santa: How |
far does Santa travel on his annual journey? |
exercise solution codepad |
| 63 |
28 Aug 2009 |
String Search: Boyer-Moore: Search for a pattern in a text using a |
fast and simple algorithm |
exercise solution codepad |
| 272 |
16 Sep 2011 |
Pollard’s P−1 Factorization Algoritihm, Revisited: An improved second stage that is much |
faster than the original |
exercise solution codepad |
| 112 |
19 Feb 2010 |
Sieve Of Atkin, Improved: A |
faster version of the Sieve of Atkin |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel Shanks’ Square Form Factorization Algorithm: A simple and very |
fast factorization algorithm for integers between 105 and 1020 |
exercise solution codepad |
| 84 |
10 Nov 2009 |
Merge Sort: A |
fast, stable sorting algorithm, especially well-suited to linked lists |
exercise solution codepad |
| 4 |
19 Feb 2009 |
Sudoku: A backtracking solution to everybody’s |
favorite puzzle |
exercise solution codepad |
| 250 |
01 Jul 2011 |
|
Feet And Inches: Convert decimal inches to carpenters’ fractions |
exercise solution codepad |
| 34 |
19 May 2009 |
Fermat’s Method: Integer factorization by |
Fermat’s algorithm |
exercise solution codepad |
| 34 |
19 May 2009 |
|
Fermat’s Method: Integer factorization by Fermat’s algorithm |
exercise solution codepad |
| 238 |
20 May 0 |
ISBN Validation: Validate ISBN book numbers, and |
fetch author and title from the internet |
exercise solution codepad |
| 182 |
05 Nov 2010 |
Weather Forecast: |
Fetch the weather forecast from the internet |
exercise solution codepad |
| 41 |
12 Jun 2009 |
|
Feynman’s Puzzle: A simple logic puzzle |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci Primes: Find primes among the |
fibonacci numbers; includes the Park-Miller random number generator and Miller-Rabin primality checker |
exercise solution codepad |
| 154 |
30 Jul 2010 |
|
Fibonacci Numbers: Three algorithms taking exponential time, linear time, and logarithmic time |
exercise solution codepad |
| 180 |
29 Oct 2010 |
|
Fibonacci Primes: Find primes among the fibonacci numbers; includes the Park-Miller random number generator and Miller-Rabin primality checker |
exercise solution codepad |
| 57 |
07 Aug 2009 |
ADFGX: A classic German military |
field cipher from the First World War |
exercise solution codepad |
| 47 |
03 Jul 2009 |
The Playfair Cipher: A classic military |
field cipher |
exercise solution codepad |
| 177 |
19 Oct 2010 |
Text File Databases: Part 1: Functions to read records with |
fields in various formats |
exercise solution codepad |
| 159 |
17 Aug 2010 |
Cut: Select |
fields or characters from input lines |
exercise solution codepad |
| 178 |
22 Oct 2010 |
Text File Databases: Part 2: Various functions to process records with |
fields |
exercise solution codepad |
| 222 |
25 Mar 2011 |
Sum: The standard Unix V7 |
file-checksum command |
exercise solution codepad |
| 177 |
19 Oct 2010 |
Text |
File Databases: Part 1: Functions to read records with fields in various formats |
exercise solution codepad |
| 178 |
22 Oct 2010 |
Text |
File Databases: Part 2: Various functions to process records with fields |
exercise solution codepad |
| 179 |
26 Oct 2010 |
Benford’s Law: A useful mathematical oddity, and an example of text |
file databases |
exercise solution codepad |
| 136 |
28 May 2010 |
Printing |
Files: A simple program to list files, similar to the unix pr program |
exercise solution codepad |
| 136 |
28 May 2010 |
Printing Files: A simple program to list |
files, similar to the unix pr program |
exercise solution codepad |
| 114 |
26 Feb 2010 |
Run Length Encoding: A simple compression method for text |
files |
exercise solution codepad |
| 139 |
08 Jun 2010 |
Diff: Find the differences between two text |
files |
exercise solution codepad |
| 235 |
10 May 2011 |
Comm: select or reject lines common to two sorted |
files |
exercise solution codepad |
| 189 |
30 Nov 2010 |
Form Letters: Merge a schema and a data |
file to write form letters |
exercise solution codepad |
| 225 |
05 Apr 2011 |
Fortune: Print a random aphorism from a |
file |
exercise solution codepad |
| 16 |
17 Mar 2009 |
Comma-Separated Values: Retrieve records from a comma-separated values |
file using a finite-state machine |
exercise solution codepad |
| 265 |
23 Aug 2011 |
Knapsack: |
Fill a knapsack to maximize the value of its contents |
exercise solution codepad |
| 26 |
21 Apr 2009 |
Probabilistic Spell Checking: A probabilistic spell-checker based on a Bloom |
filter |
exercise solution codepad |
| 64 |
01 Sep 2009 |
String Search: Rabin-Karp: Our |
final classic string-search algorithm |
exercise solution codepad |
| 23 |
10 Apr 2009 |
Anagrams: |
Find anagrams in a dictionary |
exercise solution codepad |
| 224 |
01 Apr 2011 |
Maximum Difference In An Array: |
Find maximum Xj &minus Xi, with i ≤ j |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci Primes: |
Find primes among the fibonacci numbers; includes the Park-Miller random number generator and Miller-Rabin primality checker |
exercise solution codepad |
| 271 |
13 Sep 2011 |
Tetrahedral Numbers: |
Find the base of the tetrahedron that contains 169179692512835000 balls |
exercise solution codepad |
| 121 |
23 Mar 2010 |
Texas Hold ‘Em: |
Find the best poker hand |
exercise solution codepad |
| 139 |
08 Jun 2010 |
Diff: |
Find the differences between two text files |
exercise solution codepad |
| 274 |
23 Sep 2011 |
Array Duplicates: |
Find the duplicate integer in a large array |
exercise solution codepad |
| 31 |
08 May 2009 |
Wheel Factorization: |
Find the factors of a number by a variant of trial division |
exercise solution codepad |
| 264 |
19 Aug 2011 |
First Non-Repeating Character: |
Find the first character in a string that doesn’t repeat later in the string |
exercise solution codepad |
| 93 |
11 Dec 2009 |
Selection: |
Find the kth-largest item in a list |
exercise solution codepad |
| 118 |
12 Mar 2010 |
Traveling Salesman: Brute Force: Examine all possible permutations to |
find the least-cost tour |
exercise solution codepad |
| 176 |
15 Oct 2010 |
|
Find The Longest Palindrome In A String: A beautiful linear-time algorithm due to Johan Jeuring |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest Common Ancestor: |
Find the lowest node in a binary search tree that is a common ancestor to two given nodes |
exercise solution codepad |
| 125 |
06 Apr 2010 |
Minimum Spanning Tree: Kruskal’s Algorithm: |
Find the minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 126 |
09 Apr 2010 |
Minimum Spanning Tree: Prim’s Algorithm: |
Find the minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 35 |
22 May 2009 |
The Next Palindrome: |
Find the next palindromic number greater than the input number |
exercise solution codepad |
| 122 |
26 Mar 2010 |
The Next Prime: Efficiently |
find the next prime number larger than a given number |
exercise solution codepad |
| 199 |
04 Jan 2011 |
Dijkstra’s Algorithm: |
Find the shortest path to all vertices of a graph from a single source, guest written by Graham Enos |
exercise solution codepad |
| 16 |
17 Mar 2009 |
Comma-Separated Values: Retrieve records from a comma-separated values file using a |
finite-state machine |
exercise solution codepad |
| 28 |
28 Apr 2009 |
Morse Code: Translating the dots-and-dashes of Samuel |
Finley Breese Morse’s telegraph code |
exercise solution codepad |
| 264 |
19 Aug 2011 |
First Non-Repeating Character: Find the |
first character in a string that doesn’t repeat later in the string |
exercise solution codepad |
| 209 |
08 Feb 2011 |
The |
First Computer Program: Ada Lovelace’s program to compute Bernoulli numbers for Charles Babbage’s Analytical Engine |
exercise solution codepad |
| 147 |
06 Jul 2010 |
Chaocipher: |
First look at a ninety-two year old autokey-type cipher |
exercise solution codepad |
| 264 |
19 Aug 2011 |
|
First Non-Repeating Character: Find the first character in a string that doesn’t repeat later in the string |
exercise solution codepad |
| 279 |
14 Oct 2011 |
The |
First N Primes: Embedding the Sieve of Eratosthenes in a priority queue instead of an array |
exercise solution codepad |
| 57 |
07 Aug 2009 |
ADFGX: A classic German military field cipher from the |
First World War |
exercise solution codepad |
| 229 |
19 Apr 2011 |
Same |
Five Digits: A math puzzle from New Scientist, solved by guest author Bob Miller |
exercise solution codepad |
| 87 |
20 Nov 2009 |
Master Mind, Part 2: Solve a Master Mind puzzle in |
five probes or less |
exercise solution codepad |
| 231 |
26 Apr 2011 |
Miscellanea: |
FizzBuzz, Prime Words, and Split A List |
exercise solution codepad |
| 215 |
01 Mar 2011 |
An Early LISP Program: A program to |
flatten a list, from the March 1960 LISP I manual |
exercise solution codepad |
| 5 |
19 Feb 2009 |
|
Flavius Josephus: Programming a cyclical list |
exercise solution codepad |
| 103 |
19 Jan 2010 |
|
Flight Planning: Computing the navigation triangle, by Jos Koot |
exercise solution codepad |
| 22 |
07 Apr 2009 |
|
Flipping Pancakes: A sorting method analyzed by Bill Gates |
exercise solution codepad |
| 175 |
12 Oct 2010 |
Rotate An Array: A simple but tricky exercise solved by an algorithm from the |
folklore of computing |
exercise solution codepad |
| 40 |
09 Jun 2009 |
Longest Common Subsequence: A classic programming algorithm, with a solution that dates to |
folklore |
exercise solution codepad |
| 118 |
12 Mar 2010 |
Traveling Salesman: Brute |
Force: Examine all possible permutations to find the least-cost tour |
exercise solution codepad |
| 61 |
21 Aug 2009 |
String Search: Brute |
Force: Search for a pattern in a text by comparing the pattern to the text at all possible positions |
exercise solution codepad |
| 182 |
05 Nov 2010 |
Weather |
Forecast: Fetch the weather forecast from the internet |
exercise solution codepad |
| 182 |
05 Nov 2010 |
Weather Forecast: Fetch the weather |
forecast from the internet |
exercise solution codepad |
| 242 |
03 Jun 2011 |
Mersenne Primes: The Lucas-Lehmer test for identifying primes of the |
form 2n−1 |
exercise solution codepad |
| 177 |
19 Oct 2010 |
Text File Databases: Part 1: Functions to read records with fields in various |
formats |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel Shanks’ Square |
Form Factorization Algorithm: A simple and very fast factorization algorithm for integers between 105 and 1020 |
exercise solution codepad |
| 189 |
30 Nov 2010 |
|
Form Letters: Merge a schema and a data file to write form letters |
exercise solution codepad |
| 189 |
30 Nov 2010 |
Form Letters: Merge a schema and a data file to write |
form letters |
exercise solution codepad |
| 91 |
04 Dec 2009 |
Autokey: A cipher in which the input text |
forms part of the key |
exercise solution codepad |
| 101 |
12 Jan 2010 |
Calculating Sines: Calculate sines using Taylor series and the triple-angle |
formula, by Bill Cruise |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting Primes Using Legendre’s |
Formula: Recreate Legendre’s two-century old calculation of the number of primes less than a million |
exercise solution codepad |
| 149 |
13 Jul 2010 |
Word Cube: A game to |
form words from a given set of letters |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The Factorization Of F7: Part 1: Our |
fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The Factorization Of F7: Part 2: Our |
fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 225 |
05 Apr 2011 |
|
Fortune: Print a random aphorism from a file |
exercise solution codepad |
| 192 |
10 Dec 2010 |
Two Random Selections: Use random number to select |
fortunes and lotto winners |
exercise solution codepad |
| 76 |
13 Oct 2009 |
Bifid: A simple but effective |
fractionating cipher, never used militarily |
exercise solution codepad |
| 49 |
10 Jul 2009 |
The Golden Ratio: Evaluate a continued |
fraction, based on my daughter’s math homework |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The Factorization Of F7: Part 1: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued |
fractions |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The Factorization Of F7: Part 2: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued |
fractions |
exercise solution codepad |
| 205 |
25 Jan 2011 |
Rational Numbers: A library of basic arithmetic and comparison of |
fractions |
exercise solution codepad |
| 250 |
01 Jul 2011 |
Feet And Inches: Convert decimal inches to carpenters’ |
fractions |
exercise solution codepad |
| 27 |
24 Apr 2009 |
Word Hy-phen-a-tion By Com-pu-ter: |
Frank Liang’s hyphenation algorithm, used in TeX |
exercise solution codepad |
| 14 |
10 Mar 2009 |
Word |
Frequencies: Our interpretation of a problem solved by a classic unix pipeline |
exercise solution codepad |
| 15 |
13 Mar 2009 |
|
Friday, the Thirteenth: A small calendar library, and a simple use of it |
exercise solution codepad |
| 248 |
24 Jun 2011 |
Thank God It’s |
Friday!: Three methods to calculate the day of the week |
exercise solution codepad |
| 113 |
23 Feb 2010 |
Engineering A Sort |
Function: A high-performance quicksort by Jon Bentley and Doug McIlroy |
exercise solution codepad |
| 73 |
02 Oct 2009 |
Red-Black Trees: A purely |
functional dictionary data structure based on approximately-balanced trees |
exercise solution codepad |
| 292 |
29 Nov 2011 |
AVL Trees, Extended: Add additional |
functionality to AVL trees |
exercise solution codepad |
| 200 |
07 Jan 2011 |
Counting Primes: The prime counting |
function and nth-prime function |
exercise solution codepad |
| 184 |
12 Nov 2010 |
Rowland’s Prime-Generating |
Function: A sequence of ones and primes |
exercise solution codepad |
| 39 |
05 Jun 2009 |
Ternary Search Tries: Build a |
function library for handling ternary search tries |
exercise solution codepad |
| 48 |
07 Jul 2009 |
Modular Arithmetic: A |
function library for performing modular addition, subtraction, multiplication, division, and square root |
exercise solution codepad |
| 249 |
28 Jun 2011 |
Big Numbers: |
Functions: A library for big integers: gcd, powering, square root, random numbers |
exercise solution codepad |
| 257 |
26 Jul 2011 |
More Prime-Counting Functions: Prime counting |
functions by Meissel and Lehmer, based on Legendre’s sum |
exercise solution codepad |
| 188 |
26 Nov 2010 |
Divisors And Totatives: The number-theoretic |
functions divisors, numdivs, sumdivs, totatives, and totient |
exercise solution codepad |
| 54 |
28 Jul 2009 |
Elliptic Curves: Library of basic |
functions on elliptic curves |
exercise solution codepad |
| 257 |
26 Jul 2011 |
More Prime-Counting |
Functions: Prime counting functions by Meissel and Lehmer, based on Legendre’s sum |
exercise solution codepad |
| 287 |
11 Nov 2011 |
Generators: Write |
functions that yield a value, but can then be re-entered |
exercise solution codepad |
| 178 |
22 Oct 2010 |
Text File Databases: Part 2: Various |
functions to process records with fields |
exercise solution codepad |
| 177 |
19 Oct 2010 |
Text File Databases: Part 1: |
Functions to read records with fields in various formats |
exercise solution codepad |
| 239 |
24 May 2011 |
Big Numbers: Getting Started: A library for big integers: representation, comparison, simple |
functions |
exercise solution codepad |
| 172 |
01 Oct 2010 |
Oban Numbers: Numbers that omit the letter “o” when spelled, and a |
function to convert numbers to words |
exercise solution codepad |
| 142 |
18 Jun 0 |
Parsing Command-Line Arguments: An old-style getopt |
function |
exercise solution codepad |
| 200 |
07 Jan 2011 |
Counting Primes: The prime counting function and nth-prime |
function |
exercise solution codepad |
| 258 |
29 Jul 2011 |
Approximating Pi: Approximating pi with the logarithmic integral and Riemann’s R |
function |
exercise solution codepad |
| 141 |
15 Jun 2010 |
Natural Join: The |
fundamental relational database operator |
exercise solution codepad |
| 285 |
04 Nov 2011 |
Craps: Simulate a popular game of |
gambling with dice |
exercise solution codepad |
| 216 |
04 Mar 2011 |
Chutes And Ladders: Simulate a child’s |
game, and compute its statistics |
exercise solution codepad |
| 17 |
20 Mar 2009 |
Dodgson's Doublets: A word |
game invented by the author of Alice in Wonderland |
exercise solution codepad |
| 58 |
11 Aug 2009 |
Uncle Bob’s Bowling |
Game Kata: Use pattern-matching on lists to solve a classic object-oriented programming exercise |
exercise solution codepad |
| 86 |
17 Nov 2009 |
Master Mind, Part 1: Referee a two-player |
game of deductive logic |
exercise solution codepad |
| 285 |
04 Nov 2011 |
Craps: Simulate a popular |
game of gambling with dice |
exercise solution codepad |
| 100 |
08 Jan 2010 |
Nim: A two-player |
game of mathematical logic |
exercise solution codepad |
| 233 |
03 May 2011 |
Squaring The Bishop: Charles Babbage’s |
game of word squares |
exercise solution codepad |
| 212 |
18 Feb 2011 |
Two Factoring |
Games: Home primes and the Euclid-Mullin sequence |
exercise solution codepad |
| 149 |
13 Jul 2010 |
Word Cube: A |
game to form words from a given set of letters |
exercise solution codepad |
| 38 |
02 Jun 2009 |
Pig Latin: A simple exercise to solve a children’s |
game |
exercise solution codepad |
| 29 |
01 May 2009 |
Primality Checking: A probabilistic primality checker by |
Gary Miller and Michael Rabin |
exercise solution codepad |
| 22 |
07 Apr 2009 |
Flipping Pancakes: A sorting method analyzed by Bill |
Gates |
exercise solution codepad |
| 135 |
25 May 2010 |
|
GB_FLIP: Donald Knuth’s portable, high-quality random-number generator from the Stanford Graphbase |
exercise solution codepad |
| 249 |
28 Jun 2011 |
Big Numbers: Functions: A library for big integers: |
gcd, powering, square root, random numbers |
exercise solution codepad |
| 11 |
27 Feb 2009 |
Mark V. Shaney: |
Generate parodies of a text using a Markov chain |
exercise solution codepad |
| 117 |
09 Mar 2010 |
Lexicographic Permutations: Continually |
generate the next permutation using an algorithm by Dijkstra |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci Primes: Find primes among the fibonacci numbers; includes the Park-Miller random number |
generator and Miller-Rabin primality checker |
exercise solution codepad |
| 232 |
29 Apr 2011 |
Rule 30 RNG: The random number |
generator from Mathematica, based on Stephen Wolfram’s Rule 30 cellular automata |
exercise solution codepad |
| 135 |
25 May 2010 |
GB_FLIP: Donald Knuth’s portable, high-quality random-number |
generator from the Stanford Graphbase |
exercise solution codepad |
| 173 |
05 Oct 2010 |
George Marsaglia’s Random Number |
Generators: Nine high-quality RNGs in nineteen lines of code |
exercise solution codepad |
| 287 |
11 Nov 2011 |
|
Generators: Write functions that yield a value, but can then be re-entered |
exercise solution codepad |
| 60 |
18 Aug 2009 |
Blum Blum Shub: Stream cipher based on a cryptographically secure pseudo-random number |
generator |
exercise solution codepad |
| 270 |
09 Sep 2011 |
Mersenne Twister: Random number |
generator with very long period, useful for simulations |
exercise solution codepad |
| 173 |
05 Oct 2010 |
|
George Marsaglia’s Random Number Generators: Nine high-quality RNGs in nineteen lines of code |
exercise solution codepad |
| 57 |
07 Aug 2009 |
ADFGX: A classic |
German military field cipher from the First World War |
exercise solution codepad |
| 142 |
18 Jun 0 |
Parsing Command-Line Arguments: An old-style |
getopt function |
exercise solution codepad |
| 239 |
24 May 2011 |
Big Numbers: |
Getting Started: A library for big integers: representation, comparison, simple functions |
exercise solution codepad |
| 18 |
23 Mar 2009 |
Binary Search: A simple task, easy to |
get wrong |
exercise solution codepad |
| 174 |
08 Oct 2010 |
Zeller’s Congruence: Calculate the day of the week for a |
given date |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest Common Ancestor: Find the lowest node in a binary search tree that is a common ancestor to two |
given nodes |
exercise solution codepad |
| 122 |
26 Mar 2010 |
The Next Prime: Efficiently find the next prime number larger than a |
given number |
exercise solution codepad |
| 149 |
13 Jul 2010 |
Word Cube: A game to form words from a |
given set of letters |
exercise solution codepad |
| 248 |
24 Jun 2011 |
Thank |
God It’s Friday!: Three methods to calculate the day of the week |
exercise solution codepad |
| 115 |
02 Mar 2010 |
|
Goldbach’s Conjecture: Every even number greater than two can be written as the sum of two primes |
exercise solution codepad |
| 49 |
10 Jul 2009 |
The |
Golden Ratio: Evaluate a continued fraction, based on my daughter’s math homework |
exercise solution codepad |
| 211 |
15 Feb 2011 |
|
Google Code Jam Qualification Round Africa 2010: Three simple exercises |
exercise solution codepad |
| 170 |
24 Sep 2010 |
Alien Numbers: An exercise from |
Google Code Jam |
exercise solution codepad |
| 74 |
06 Oct 2009 |
MapReduce: |
Google’s famous system for parallelizing computations expressed as a programming idiom |
exercise solution codepad |
| 97 |
29 Dec 2009 |
A Statisticle Speling Korrecter: Peter Norvig’s version of the |
Google spelling suggester |
exercise solution codepad |
| 24 |
14 Apr 2009 |
|
Google Treasure Hunt 2008 Puzzle 4: A prime-number puzzle |
exercise solution codepad |
| 243 |
07 Jun 2011 |
Big Numbers: Division: A library for big integers: the |
grade-school algorithm for long division |
exercise solution codepad |
| 241 |
31 May 2011 |
Big Numbers: Addition, Subtraction And Multiplication: A library for big integers: |
grade-school algorithms for addition, subtraction, and multiplication |
exercise solution codepad |
| 289 |
18 Nov 2011 |
Grade School Multiplication: Display the steps in the |
grade school multiplication algorithm |
exercise solution codepad |
| 289 |
18 Nov 2011 |
|
Grade School Multiplication: Display the steps in the grade school multiplication algorithm |
exercise solution codepad |
| 199 |
04 Jan 2011 |
Dijkstra’s Algorithm: Find the shortest path to all vertices of a graph from a single source, guest written by |
Graham Enos |
exercise solution codepad |
| 246 |
17 Jun 2011 |
Adi Shamir’s Threshold Scheme: Use cryptography to share a secret, by |
Graham Enos |
exercise solution codepad |
| 153 |
27 Jul 2010 |
HAMURABI.BAS: Manage |
grain and land in ancient Sumeria |
exercise solution codepad |
| 135 |
25 May 2010 |
GB_FLIP: Donald Knuth’s portable, high-quality random-number generator from the Stanford |
Graphbase |
exercise solution codepad |
| 186 |
19 Nov 2010 |
Topological Sort: Order the edges of a |
graph by their precedence relationship |
exercise solution codepad |
| 199 |
04 Jan 2011 |
Dijkstra’s Algorithm: Find the shortest path to all vertices of a |
graph from a single source, guest written by Graham Enos |
exercise solution codepad |
| 125 |
06 Apr 2010 |
Minimum Spanning Tree: Kruskal’s Algorithm: Find the minimum-cost tree that includes all the nodes in a |
graph |
exercise solution codepad |
| 126 |
09 Apr 2010 |
Minimum Spanning Tree: Prim’s Algorithm: Find the minimum-cost tree that includes all the nodes in a |
graph |
exercise solution codepad |
| 10 |
24 Feb 2009 |
Mardi |
Gras: Compute the date of Easter |
exercise solution codepad |
| 267 |
30 Aug 2011 |
Hamming Numbers: List the numbers with no factors |
greater than 5, a classic problem popularized by Dijkstra |
exercise solution codepad |
| 35 |
22 May 2009 |
The Next Palindrome: Find the next palindromic number |
greater than the input number |
exercise solution codepad |
| 115 |
02 Mar 2010 |
Goldbach’s Conjecture: Every even number |
greater than two can be written as the sum of two primes |
exercise solution codepad |
| 102 |
15 Jan 2010 |
Three Binary Algorithms: Multiplication, division and |
greatest common divisor using binary arithmetic |
exercise solution codepad |
| 119 |
16 Mar 2010 |
Traveling Salesman: Nearest Neighbor: A |
greedy heuristic that builds a path by always choosing the nearest unvisited point |
exercise solution codepad |
| 72 |
29 Sep 2009 |
|
Green Eyes: A counting problem from high-school math |
exercise solution codepad |
| 183 |
09 Nov 2010 |
Subset Sums: Third level of the |
Greplin Programming Challenge, using dynamic programming and memoization |
exercise solution codepad |
| 71 |
25 Sep 2009 |
|
Grep: Simple version of the classic unix regular-expression matching utility |
exercise solution codepad |
| 77 |
16 Oct 2009 |
|
Growable Arrays: Arrays that grow and shrink at run-time, with O(log n) complexity per operation |
exercise solution codepad |
| 77 |
16 Oct 2009 |
Growable Arrays: Arrays that |
grow and shrink at run-time, with O(log n) complexity per operation |
exercise solution codepad |
| 228 |
15 Apr 2011 |
Partition Numbers: Calculate the partition numbers, using memoization via |
growing arrays |
exercise solution codepad |
| 207 |
01 Feb 2011 |
Cuckoo Hashing: A hashing system with |
guaranteed constant-time lookup and amortized constant-time insertion |
exercise solution codepad |
| 83 |
06 Nov 2009 |
Heap Sort: A |
guaranteed O(log n) sorting method based on priority queues |
exercise solution codepad |
| 127 |
13 Apr 2010 |
Traveling Salesman: Minimum Spanning Tree: Heuristic |
guarantees solution within factor of two of optimal tour |
exercise solution codepad |
| 229 |
19 Apr 2011 |
Same Five Digits: A math puzzle from New Scientist, solved by |
guest author Bob Miller |
exercise solution codepad |
| 199 |
04 Jan 2011 |
Dijkstra’s Algorithm: Find the shortest path to all vertices of a graph from a single source, |
guest written by Graham Enos |
exercise solution codepad |
| 169 |
21 Sep 2010 |
Kaprekar Numbers: Square the number and add the digits in |
halves |
exercise solution codepad |
| 267 |
30 Aug 2011 |
|
Hamming Numbers: List the numbers with no factors greater than 5, a classic problem popularized by Dijkstra |
exercise solution codepad |
| 153 |
27 Jul 2010 |
|
HAMURABI.BAS: Manage grain and land in ancient Sumeria |
exercise solution codepad |
| 39 |
05 Jun 2009 |
Ternary Search Tries: Build a function library for |
handling ternary search tries |
exercise solution codepad |
| 244 |
10 Jun 2011 |
Steganography: A |
hand-operable system that combines cryptography and steganography |
exercise solution codepad |
| 121 |
23 Mar 2010 |
Texas Hold ‘Em: Find the best poker |
hand |
exercise solution codepad |
| 37 |
29 May 2009 |
Double Transposition Cipher: A simple and effective cipher, easy to perform by |
hand |
exercise solution codepad |
| 279 |
11 Oct 2011 |
Tower Of |
Hanoi: Classic demonstration of recursion |
exercise solution codepad |
| 152 |
23 Jul 2010 |
|
Happy Numbers: Iterating the sum of the squares of the digits terminates with one |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil |
Harvey’s Puzle: partition {1,…,16} into two sets of equal size so each subset has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 123 |
30 Mar 2010 |
Passover: Calculate the dates of the Jewish holidays Rosh |
Hashanah and Passover |
exercise solution codepad |
| 207 |
01 Feb 2011 |
Cuckoo |
Hashing: A hashing system with guaranteed constant-time lookup and amortized constant-time insertion |
exercise solution codepad |
| 207 |
01 Feb 2011 |
Cuckoo Hashing: A |
hashing system with guaranteed constant-time lookup and amortized constant-time insertion |
exercise solution codepad |
| 165 |
07 Sep 2010 |
Data Encryption Standard: Part 3: Triple DES and cryptographic |
hashing |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into two sets of equal size so each subset |
has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 155 |
03 Aug 2010 |
Carl Hewitt’s Same-Fringe Problem: Do two trees |
have the same leaves, solved with streams (lazy lists) |
exercise solution codepad |
| 171 |
28 Sep 2010 |
Maxiphobic |
Heaps: A priority-queue data structure, similar to leftist heaps, due to Chris Okasaki |
exercise solution codepad |
| 59 |
14 Aug 2009 |
Pairing |
Heaps: A standard algorithm for maintaining priority queues |
exercise solution codepad |
| 171 |
28 Sep 2010 |
Maxiphobic Heaps: A priority-queue data structure, similar to leftist |
heaps, due to Chris Okasaki |
exercise solution codepad |
| 83 |
06 Nov 2009 |
|
Heap Sort: A guaranteed O(log n) sorting method based on priority queues |
exercise solution codepad |
| 56 |
04 Aug 2009 |
Lenstra’s Algorithm: |
Hendrik Lenstra’s original algorithm for elliptic curve factorization |
exercise solution codepad |
| 261 |
09 Aug 2011 |
|
Hett’s Problem 1.28: Sorting a list of lists according to length of sublists |
exercise solution codepad |
| 127 |
13 Apr 2010 |
Traveling Salesman: Minimum Spanning Tree: |
Heuristic guarantees solution within factor of two of optimal tour |
exercise solution codepad |
| 119 |
16 Mar 2010 |
Traveling Salesman: Nearest Neighbor: A greedy |
heuristic that builds a path by always choosing the nearest unvisited point |
exercise solution codepad |
| 155 |
03 Aug 2010 |
Carl |
Hewitt’s Same-Fringe Problem: Do two trees have the same leaves, solved with streams (lazy lists) |
exercise solution codepad |
| 113 |
23 Feb 2010 |
Engineering A Sort Function: A |
high-performance quicksort by Jon Bentley and Doug McIlroy |
exercise solution codepad |
| 135 |
25 May 2010 |
GB_FLIP: Donald Knuth’s portable, |
high-quality random-number generator from the Stanford Graphbase |
exercise solution codepad |
| 173 |
05 Oct 2010 |
George Marsaglia’s Random Number Generators: Nine |
high-quality RNGs in nineteen lines of code |
exercise solution codepad |
| 72 |
29 Sep 2009 |
Green Eyes: A counting problem from |
high-school math |
exercise solution codepad |
| 82 |
03 Nov 2009 |
Quick Sort: Tony |
Hoare’s divide-and-conquer sorting algorithm |
exercise solution codepad |
| 121 |
23 Mar 2010 |
Texas |
Hold ‘Em: Find the best poker hand |
exercise solution codepad |
| 123 |
30 Mar 2010 |
Passover: Calculate the dates of the Jewish |
holidays Rosh Hashanah and Passover |
exercise solution codepad |
| 212 |
18 Feb 2011 |
Two Factoring Games: |
Home primes and the Euclid-Mullin sequence |
exercise solution codepad |
| 49 |
10 Jul 2009 |
The Golden Ratio: Evaluate a continued fraction, based on my daughter’s math |
homework |
exercise solution codepad |
| 219 |
15 Mar 2011 |
Look And Say: Calculate John |
Horton Conway’s "Look and Say" sequence |
exercise solution codepad |
| 227 |
12 Apr 2011 |
|
House Of Representatives: Apportion representatives by the Huntington-Hill method |
exercise solution codepad |
| 196 |
24 Dec 2010 |
Tracking Santa: |
How far does Santa travel on his annual journey? |
exercise solution codepad |
| 24 |
14 Apr 2009 |
Google Treasure |
Hunt 2008 Puzzle 4: A prime-number puzzle |
exercise solution codepad |
| 227 |
12 Apr 2011 |
House Of Representatives: Apportion representatives by the |
Huntington-Hill method |
exercise solution codepad |
| 191 |
07 Dec 2010 |
Ullman’s Puzzle: It never |
hurts to sort |
exercise solution codepad |
| 27 |
24 Apr 2009 |
Word Hy-phen-a-tion By Com-pu-ter: Frank Liang’s |
hyphenation algorithm, used in TeX |
exercise solution codepad |
| 27 |
24 Apr 2009 |
Word |
Hy-phen-a-tion By Com-pu-ter: Frank Liang’s hyphenation algorithm, used in TeX |
exercise solution codepad |
| 242 |
03 Jun 2011 |
Mersenne Primes: The Lucas-Lehmer test for |
identifying primes of the form 2n−1 |
exercise solution codepad |
| 74 |
06 Oct 2009 |
MapReduce: Google’s famous system for parallelizing computations expressed as a programming |
idiom |
exercise solution codepad |
| 197 |
28 Dec 2010 |
Carmichael Numbers: Composite numbers such that an-1 ≡ 1 (mod n) |
if a is prime to n |
exercise solution codepad |
| 156 |
06 Aug 2010 |
Two Powering Predicates: Determine |
if a number is a square or a prime power |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for big integers: display factorials to 50, determine |
if a number is prime, and compute its prime factors |
exercise solution codepad |
| 187 |
23 Nov 2010 |
String Subsets: Determine |
if one string is a subset of another |
exercise solution codepad |
| 255 |
19 Jul 2011 |
Sum Of Two Integers: Determine |
if two integers in a list sum to a target |
exercise solution codepad |
| 224 |
01 Apr 2011 |
Maximum Difference In An Array: Find maximum Xj &minus Xi, with |
i ≤ j |
exercise solution codepad |
| 215 |
01 Mar 2011 |
An Early LISP Program: A program to flatten a list, from the March 1960 LISP |
I manual |
exercise solution codepad |
| 2 |
19 Feb 2009 |
Sieve of Eratosthenes: A Scheme |
implementation of an ancient algorithm |
exercise solution codepad |
| 36 |
26 May 2009 |
Word Search Solver: A computerized |
implementation of a popular time-waster |
exercise solution codepad |
| 269 |
06 Sep 2011 |
Deques: Library |
implementation of double-ended queues |
exercise solution codepad |
| 55 |
31 Jul 2009 |
Elliptic Curve Factorization: A very simple |
implementation of elliptic curve factorization |
exercise solution codepad |
| 284 |
01 Nov 2011 |
RIP John McCarthy: |
Implementation of the “Maxwell’s equations of software” from the LISP 1.5 Programmer’s Manual |
exercise solution codepad |
| 291 |
25 Nov 2011 |
AVL Trees: Basic |
implementation of the original balanced-tree algorithm |
exercise solution codepad |
| 30 |
05 May 2009 |
Priority Queues: A simple library |
implementation of the priority queue data structure |
exercise solution codepad |
| 92 |
08 Dec 2009 |
Word Count: An |
implementation of the unix wc program |
exercise solution codepad |
| 236 |
13 May 2011 |
Dixon’s Factorization Algorithm: A slow, but theoretically |
important, algorithm for integer factorization |
exercise solution codepad |
| 112 |
19 Feb 2010 |
Sieve Of Atkin, |
Improved: A faster version of the Sieve of Atkin |
exercise solution codepad |
| 134 |
07 May 2010 |
Integer Logarithms: An |
improved algorithm is O(log n) instead of O(n) |
exercise solution codepad |
| 272 |
16 Sep 2011 |
Pollard’s P−1 Factorization Algoritihm, Revisited: An |
improved second stage that is much faster than the original |
exercise solution codepad |
| 286 |
08 Nov 2011 |
|
Improved Standard Continuation: An improved version of elliptic curve factorization, widely used in current practice |
exercise solution codepad |
| 286 |
08 Nov 2011 |
Improved Standard Continuation: An |
improved version of elliptic curve factorization, widely used in current practice |
exercise solution codepad |
| 250 |
01 Jul 2011 |
Feet And |
Inches: Convert decimal inches to carpenters’ fractions |
exercise solution codepad |
| 250 |
01 Jul 2011 |
Feet And Inches: Convert decimal |
inches to carpenters’ fractions |
exercise solution codepad |
| 125 |
06 Apr 2010 |
Minimum Spanning Tree: Kruskal’s Algorithm: Find the minimum-cost tree that |
includes all the nodes in a graph |
exercise solution codepad |
| 126 |
09 Apr 2010 |
Minimum Spanning Tree: Prim’s Algorithm: Find the minimum-cost tree that |
includes all the nodes in a graph |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci Primes: Find primes among the fibonacci numbers; |
includes the Park-Miller random number generator and Miller-Rabin primality checker |
exercise solution codepad |
| 109 |
09 Feb 2010 |
Numerical Integration: Quadrature by the rectangular, trapezoidal and Simpson’s method, |
including adaptive quadrature |
exercise solution codepad |
| 96 |
22 Dec 2009 |
Permuted |
Index: David Parnas’ classic deconstruction of the keyword-in-context index |
exercise solution codepad |
| 96 |
22 Dec 2009 |
Permuted Index: David Parnas’ classic deconstruction of the keyword-in-context |
index |
exercise solution codepad |
| 221 |
22 Mar 2011 |
Two Kaprekar Exercises: Kaprekar chains and Kaprekar numbers, from the |
Indian mathematician Dattaraya Ramchandra Kaprekar |
exercise solution codepad |
| 252 |
08 Jul 2011 |
Vedic Divisibility: Use a method of testing divisibility using the method of osculators developed in |
India |
exercise solution codepad |
| 278 |
07 Oct 2011 |
Sieve of Sundaram: Sieving for prime numbers using a method from |
India |
exercise solution codepad |
| 45 |
26 Jun 2009 |
Treaps: A randomized dictionary data structure, provides |
in-order access to key |
exercise solution codepad |
| 245 |
14 Jun 2011 |
Big Numbers: |
Input And Output: A library for big integers: input and output with radix conversion |
exercise solution codepad |
| 245 |
14 Jun 2011 |
Big Numbers: Input And Output: A library for big integers: |
input and output with radix conversion |
exercise solution codepad |
| 159 |
17 Aug 2010 |
Cut: Select fields or characters from |
input lines |
exercise solution codepad |
| 213 |
22 Feb 2011 |
Sliding Window Minimum: List of minimums sliding across an |
input list |
exercise solution codepad |
| 35 |
22 May 2009 |
The Next Palindrome: Find the next palindromic number greater than the |
input number |
exercise solution codepad |
| 253 |
12 Jul 2011 |
JSON: Parsing |
Input: Parse JSON input |
exercise solution codepad |
| 217 |
08 Mar 2011 |
Reverse Words: Reverse the words in an |
input string |
exercise solution codepad |
| 91 |
04 Dec 2009 |
Autokey: A cipher in which the |
input text forms part of the key |
exercise solution codepad |
| 253 |
12 Jul 2011 |
JSON: Parsing Input: Parse JSON |
input |
exercise solution codepad |
| 296 |
13 Dec 2011 |
Validating Telephone Numbers: An exercise in |
input validation |
exercise solution codepad |
| 263 |
16 Aug 2011 |
Insert Into A Cyclic Sorted List: |
Insert a new element into a cyclic list, in order |
exercise solution codepad |
| 116 |
05 Mar 2010 |
Binary Search Tree: Classic data structure, providing |
insert, delete and lookup for ordered datatypes |
exercise solution codepad |
| 263 |
16 Aug 2011 |
|
Insert Into A Cyclic Sorted List: Insert a new element into a cyclic list, in order |
exercise solution codepad |
| 80 |
27 Oct 2009 |
Three Quadratic Sorts: Bubble sort, selection sort and |
insertion sort |
exercise solution codepad |
| 207 |
01 Feb 2011 |
Cuckoo Hashing: A hashing system with guaranteed constant-time lookup and amortized constant-time |
insertion |
exercise solution codepad |
| 262 |
12 Aug 2011 |
Word Breaks: |
Insert spaces between words: applepie => apple pie |
exercise solution codepad |
| 279 |
14 Oct 2011 |
The First N Primes: Embedding the Sieve of Eratosthenes in a priority queue |
instead of an array |
exercise solution codepad |
| 134 |
07 May 2010 |
Integer Logarithms: An improved algorithm is O(log n) |
instead of O(n) |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The Factorization Of F7: Part 1: Our fortieth anniversary celebration of Morrison and Brillhart’s method of |
integer factorization by continued fractions |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The Factorization Of F7: Part 2: Our fortieth anniversary celebration of Morrison and Brillhart’s method of |
integer factorization by continued fractions |
exercise solution codepad |
| 34 |
19 May 2009 |
Fermat’s Method: |
Integer factorization by Fermat’s algorithm |
exercise solution codepad |
| 273 |
20 Sep 2011 |
Project Euler Problem 3: Thorough explanation of |
integer factorization by trial division |
exercise solution codepad |
| 132 |
30 Apr 2010 |
|
Integer Factorization: Combine trial division, Pollard’s rho and p−1 methods, and elliptic curves into a single factorization program |
exercise solution codepad |
| 204 |
21 Jan 0 |
Pollard Rho, Revisited: Richard Brent’s variant of John Pollard’s rho algorithm for |
integer factorization |
exercise solution codepad |
| 236 |
13 May 2011 |
Dixon’s Factorization Algorithm: A slow, but theoretically important, algorithm for |
integer factorization |
exercise solution codepad |
| 43 |
19 Jun 2009 |
Monte Carlo Factorization: |
Integer factorization via Pollard’s rho algorithm |
exercise solution codepad |
| 274 |
23 Sep 2011 |
Array Duplicates: Find the duplicate |
integer in a large array |
exercise solution codepad |
| 85 |
13 Nov 2009 |
Two linear sorts: Count sort and radix sort exploit the structure of |
integer keys |
exercise solution codepad |
| 134 |
07 May 2010 |
|
Integer Logarithms: An improved algorithm is O(log n) instead of O(n) |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel Shanks’ Square Form Factorization Algorithm: A simple and very fast factorization algorithm for |
integers between 105 and 1020 |
exercise solution codepad |
| 255 |
19 Jul 2011 |
Sum Of Two |
Integers: Determine if two integers in a list sum to a target |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for big |
integers: display factorials to 50, determine if a number is prime, and compute its prime factors |
exercise solution codepad |
| 249 |
28 Jun 2011 |
Big Numbers: Functions: A library for big |
integers: gcd, powering, square root, random numbers |
exercise solution codepad |
| 241 |
31 May 2011 |
Big Numbers: Addition, Subtraction And Multiplication: A library for big |
integers: grade-school algorithms for addition, subtraction, and multiplication |
exercise solution codepad |
| 255 |
19 Jul 2011 |
Sum Of Two Integers: Determine if two |
integers in a list sum to a target |
exercise solution codepad |
| 245 |
14 Jun 2011 |
Big Numbers: Input And Output: A library for big |
integers: input and output with radix conversion |
exercise solution codepad |
| 239 |
24 May 2011 |
Big Numbers: Getting Started: A library for big |
integers: representation, comparison, simple functions |
exercise solution codepad |
| 247 |
21 Jun 2011 |
Big Numbers: Testing: A library for big |
integers: testing |
exercise solution codepad |
| 243 |
07 Jun 2011 |
Big Numbers: Division: A library for big |
integers: the grade-school algorithm for long division |
exercise solution codepad |
| 108 |
05 Feb 2010 |
Segmented Sieve Of Eratosthenes: Extend the Sieve of Eratosthenes to large ranges of |
integers |
exercise solution codepad |
| 194 |
17 Dec 2010 |
Polite Numbers: Write numbers as the sum of two or more consecutive |
integers |
exercise solution codepad |
| 206 |
28 Jan 2011 |
Population Count: Count the number of set bits (1-bits) in the binary representation of an |
integer |
exercise solution codepad |
| 201 |
11 Jan 2011 |
Two Integrals: The exponential and logarithmic |
integral, and an approximation for prime-pi |
exercise solution codepad |
| 258 |
29 Jul 2011 |
Approximating Pi: Approximating pi with the logarithmic |
integral and Riemann’s R function |
exercise solution codepad |
| 201 |
11 Jan 2011 |
Two |
Integrals: The exponential and logarithmic integral, and an approximation for prime-pi |
exercise solution codepad |
| 109 |
09 Feb 2010 |
Numerical |
Integration: Quadrature by the rectangular, trapezoidal and Simpson’s method, including adaptive quadrature |
exercise solution codepad |
| 94 |
15 Dec 2009 |
Affine-Shift Cipher: A cryptographically weak but mathematically |
interesting cipher |
exercise solution codepad |
| 51 |
17 Jul 2009 |
|
International Mathematical Olympiad: Three exercises from 1960s math competitions |
exercise solution codepad |
| 182 |
05 Nov 2010 |
Weather Forecast: Fetch the weather forecast from the |
internet |
exercise solution codepad |
| 238 |
20 May 0 |
ISBN Validation: Validate ISBN book numbers, and fetch author and title from the |
internet |
exercise solution codepad |
| 14 |
10 Mar 2009 |
Word Frequencies: Our |
interpretation of a problem solved by a classic unix pipeline |
exercise solution codepad |
| 19 |
27 Mar 2009 |
A Turing Machine Simulator: An |
interpreter for a single-tape, multi-symbol turing machine |
exercise solution codepad |
| 277 |
04 Oct 2011 |
Brainfuck: |
Interpreter for a Turing-line language |
exercise solution codepad |
| 195 |
21 Dec 2010 |
|
Interval Arithmetic: An exercise from SICP |
exercise solution codepad |
| 263 |
16 Aug 2011 |
Insert Into A Cyclic Sorted List: Insert a new element |
into a cyclic list, in order |
exercise solution codepad |
| 263 |
16 Aug 2011 |
Insert |
Into A Cyclic Sorted List: Insert a new element into a cyclic list, in order |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer Factorization: Combine trial division, Pollard’s rho and p−1 methods, and elliptic curves |
into a single factorization program |
exercise solution codepad |
| 234 |
06 May 2011 |
Entab And Detab: expand tabs |
into spaces, and replace spaces with tabs |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} |
into two sets of equal size so each subset has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 17 |
20 Mar 2009 |
Dodgson's Doublets: A word game |
invented by the author of Alice in Wonderland |
exercise solution codepad |
| 162 |
27 Aug 2010 |
Chinese Remainders: An ancient application of modular |
inverses |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest Common Ancestor: Find the lowest node in a binary search tree that |
is a common ancestor to two given nodes |
exercise solution codepad |
| 156 |
06 Aug 2010 |
Two Powering Predicates: Determine if a number |
is a square or a prime power |
exercise solution codepad |
| 187 |
23 Nov 2010 |
String Subsets: Determine if one string |
is a subset of another |
exercise solution codepad |
| 238 |
20 May 0 |
ISBN Validation: Validate |
ISBN book numbers, and fetch author and title from the internet |
exercise solution codepad |
| 238 |
20 May 0 |
|
ISBN Validation: Validate ISBN book numbers, and fetch author and title from the internet |
exercise solution codepad |
| 272 |
16 Sep 2011 |
Pollard’s P−1 Factorization Algoritihm, Revisited: An improved second stage that |
is much faster than the original |
exercise solution codepad |
| 134 |
07 May 2010 |
Integer Logarithms: An improved algorithm |
is O(log n) instead of O(n) |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for big integers: display factorials to 50, determine if a number |
is prime, and compute its prime factors |
exercise solution codepad |
| 197 |
28 Dec 2010 |
Carmichael Numbers: Composite numbers such that an-1 ≡ 1 (mod n) if a |
is prime to n |
exercise solution codepad |
| 93 |
11 Dec 2009 |
Selection: Find the kth-largest |
item in a list |
exercise solution codepad |
| 124 |
02 Apr 2010 |
Disjoint Sets: A data structure for storing sets of |
items in disjoint partitions |
exercise solution codepad |
| 152 |
23 Jul 2010 |
Happy Numbers: |
Iterating the sum of the squares of the digits terminates with one |
exercise solution codepad |
| 191 |
07 Dec 2010 |
Ullman’s Puzzle: |
It never hurts to sort |
exercise solution codepad |
| 265 |
23 Aug 2011 |
Knapsack: Fill a knapsack to maximize the value of |
its contents |
exercise solution codepad |
| 248 |
24 Jun 2011 |
Thank God |
It’s Friday!: Three methods to calculate the day of the week |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for big integers: display factorials to 50, determine if a number is prime, and compute |
its prime factors |
exercise solution codepad |
| 216 |
04 Mar 2011 |
Chutes And Ladders: Simulate a child’s game, and compute |
its statistics |
exercise solution codepad |
| 15 |
13 Mar 2009 |
Friday, the Thirteenth: A small calendar library, and a simple use of |
it |
exercise solution codepad |
| 208 |
04 Feb 2011 |
Excel Columns: Numbers as in Excel column names, A=1, Z=26, |
IV=256 |
exercise solution codepad |
| 133 |
04 May 2010 |
Spectacular Seven: Compute the odds at |
jai alai |
exercise solution codepad |
| 211 |
15 Feb 2011 |
Google Code |
Jam Qualification Round Africa 2010: Three simple exercises |
exercise solution codepad |
| 170 |
24 Sep 2010 |
Alien Numbers: An exercise from Google Code |
Jam |
exercise solution codepad |
| 176 |
15 Oct 2010 |
Find The Longest Palindrome In A String: A beautiful linear-time algorithm due to Johan |
Jeuring |
exercise solution codepad |
| 123 |
30 Mar 2010 |
Passover: Calculate the dates of the |
Jewish holidays Rosh Hashanah and Passover |
exercise solution codepad |
| 176 |
15 Oct 2010 |
Find The Longest Palindrome In A String: A beautiful linear-time algorithm due to |
Johan Jeuring |
exercise solution codepad |
| 219 |
15 Mar 2011 |
Look And Say: Calculate |
John Horton Conway’s "Look and Say" sequence |
exercise solution codepad |
| 284 |
01 Nov 2011 |
RIP |
John McCarthy: Implementation of the “Maxwell’s equations of software” from the LISP 1.5 Programmer’s Manual |
exercise solution codepad |
| 79 |
23 Oct 2009 |
Mr. S. and Mr. P.: A logic puzzle popularized by |
John McCarthy |
exercise solution codepad |
| 204 |
21 Jan 0 |
Pollard Rho, Revisited: Richard Brent’s variant of |
John Pollard’s rho algorithm for integer factorization |
exercise solution codepad |
| 52 |
21 Jul 2009 |
Pollard’s P−1 Factorization Algorithm: A simple factorization algorithm by |
John Pollard |
exercise solution codepad |
| 141 |
15 Jun 2010 |
Natural |
Join: The fundamental relational database operator |
exercise solution codepad |
| 113 |
23 Feb 2010 |
Engineering A Sort Function: A high-performance quicksort by |
Jon Bentley and Doug McIlroy |
exercise solution codepad |
| 190 |
03 Dec 2010 |
Maximum Sum Subsequence: A classic programming exercise due to |
Jon Bentley |
exercise solution codepad |
| 5 |
19 Feb 2009 |
Flavius |
Josephus: Programming a cyclical list |
exercise solution codepad |
| 103 |
19 Jan 2010 |
Flight Planning: Computing the navigation triangle, by |
Jos Koot |
exercise solution codepad |
| 196 |
24 Dec 2010 |
Tracking Santa: How far does Santa travel on his annual |
journey? |
exercise solution codepad |
| 254 |
15 Jul 2011 |
JSON: Writing Output: The other side of |
JSAON |
exercise solution codepad |
| 253 |
12 Jul 2011 |
JSON: Parsing Input: Parse |
JSON input |
exercise solution codepad |
| 253 |
12 Jul 2011 |
|
JSON: Parsing Input: Parse JSON input |
exercise solution codepad |
| 254 |
15 Jul 2011 |
|
JSON: Writing Output: The other side of JSAON |
exercise solution codepad |
| 224 |
01 Apr 2011 |
Maximum Difference In An Array: Find maximum Xj &minus Xi, with i ≤ |
j |
exercise solution codepad |
| 224 |
01 Apr 2011 |
Maximum Difference In An Array: Find maximum Xj &minus Xi, with i |
≤ j |
exercise solution codepad |
| 221 |
22 Mar 2011 |
Two Kaprekar Exercises: |
Kaprekar chains and Kaprekar numbers, from the Indian mathematician Dattaraya Ramchandra Kaprekar |
exercise solution codepad |
| 221 |
22 Mar 2011 |
Two |
Kaprekar Exercises: Kaprekar chains and Kaprekar numbers, from the Indian mathematician Dattaraya Ramchandra Kaprekar |
exercise solution codepad |
| 221 |
22 Mar 2011 |
Two Kaprekar Exercises: Kaprekar chains and |
Kaprekar numbers, from the Indian mathematician Dattaraya Ramchandra Kaprekar |
exercise solution codepad |
| 169 |
21 Sep 2010 |
|
Kaprekar Numbers: Square the number and add the digits in halves |
exercise solution codepad |
| 221 |
22 Mar 2011 |
Two Kaprekar Exercises: Kaprekar chains and Kaprekar numbers, from the Indian mathematician Dattaraya Ramchandra |
Kaprekar |
exercise solution codepad |
| 58 |
11 Aug 2009 |
Uncle Bob’s Bowling Game |
Kata: Use pattern-matching on lists to solve a classic object-oriented programming exercise |
exercise solution codepad |
| 283 |
28 Oct 2011 |
Crypt: Simple encryption tool from |
Kernighan and Plauger |
exercise solution codepad |
| 85 |
13 Nov 2009 |
Two linear sorts: Count sort and radix sort exploit the structure of integer |
keys |
exercise solution codepad |
| 45 |
26 Jun 2009 |
Treaps: A randomized dictionary data structure, provides in-order access to |
key |
exercise solution codepad |
| 91 |
04 Dec 2009 |
Autokey: A cipher in which the input text forms part of the |
key |
exercise solution codepad |
| 96 |
22 Dec 2009 |
Permuted Index: David Parnas’ classic deconstruction of the |
keyword-in-context index |
exercise solution codepad |
| 33 |
15 May 2009 |
Cellular Automata: Linear cellular automata as described by Stephen Wolfram in his book A New |
Kind of Science |
exercise solution codepad |
| 265 |
23 Aug 2011 |
|
Knapsack: Fill a knapsack to maximize the value of its contents |
exercise solution codepad |
| 265 |
23 Aug 2011 |
Knapsack: Fill a |
knapsack to maximize the value of its contents |
exercise solution codepad |
| 293 |
02 Dec 2011 |
|
Knight Rider: Classic problem of the knight’s tour |
exercise solution codepad |
| 293 |
02 Dec 2011 |
Knight Rider: Classic problem of the |
knight’s tour |
exercise solution codepad |
| 145 |
29 Jun 2010 |
World Cup Prognostication: Simulate the |
knockout stage using elo ratings |
exercise solution codepad |
| 266 |
26 Aug 2011 |
Reverse Every |
K Nodes Of A Linked List: Reverse the elements of a sub-list |
exercise solution codepad |
| 62 |
25 Aug 2009 |
String Search: |
Knuth-Morris-Pratt: Search for a pattern in a text using an O(n) algorithm |
exercise solution codepad |
| 135 |
25 May 2010 |
GB_FLIP: Donald |
Knuth’s portable, high-quality random-number generator from the Stanford Graphbase |
exercise solution codepad |
| 157 |
10 Aug 2010 |
Literate Programming: Structured documentation in the style of Donald |
Knuth |
exercise solution codepad |
| 103 |
19 Jan 2010 |
Flight Planning: Computing the navigation triangle, by Jos |
Koot |
exercise solution codepad |
| 97 |
29 Dec 2009 |
A Statisticle Speling |
Korrecter: Peter Norvig’s version of the Google spelling suggester |
exercise solution codepad |
| 125 |
06 Apr 2010 |
Minimum Spanning Tree: |
Kruskal’s Algorithm: Find the minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 93 |
11 Dec 2009 |
Selection: Find the |
kth-largest item in a list |
exercise solution codepad |
| 216 |
04 Mar 2011 |
Chutes And |
Ladders: Simulate a child’s game, and compute its statistics |
exercise solution codepad |
| 153 |
27 Jul 2010 |
HAMURABI.BAS: Manage grain and |
land in ancient Sumeria |
exercise solution codepad |
| 144 |
25 Jun 2010 |
Learn A New |
Language: Solve the exercise of your choice in an unfamiliar language |
exercise solution codepad |
| 144 |
25 Jun 2010 |
Learn A New Language: Solve the exercise of your choice in an unfamiliar |
language |
exercise solution codepad |
| 277 |
04 Oct 2011 |
Brainfuck: Interpreter for a Turing-line |
language |
exercise solution codepad |
| 274 |
23 Sep 2011 |
Array Duplicates: Find the duplicate integer in a |
large array |
exercise solution codepad |
| 108 |
05 Feb 2010 |
Segmented Sieve Of Eratosthenes: Extend the Sieve of Eratosthenes to |
large ranges of integers |
exercise solution codepad |
| 120 |
19 Mar 2010 |
Extending Pollard’s P−1 Factorization Algorithm: Add a second stage to allow |
larger factorizations |
exercise solution codepad |
| 122 |
26 Mar 2010 |
The Next Prime: Efficiently find the next prime number |
larger than a given number |
exercise solution codepad |
| 111 |
16 Feb 2010 |
Soundex: An algorithm to assign people’s |
last names to equivalence classes based on similar spelling |
exercise solution codepad |
| 104 |
22 Jan 2010 |
Phases Of The Moon: Calculate the number of days since the |
last new moon |
exercise solution codepad |
| 264 |
19 Aug 2011 |
First Non-Repeating Character: Find the first character in a string that doesn’t repeat |
later in the string |
exercise solution codepad |
| 38 |
02 Jun 2009 |
Pig |
Latin: A simple exercise to solve a children’s game |
exercise solution codepad |
| 179 |
26 Oct 2010 |
Benford’s |
Law: A useful mathematical oddity, and an example of text file databases |
exercise solution codepad |
| 155 |
03 Aug 2010 |
Carl Hewitt’s Same-Fringe Problem: Do two trees have the same leaves, solved with streams |
(lazy lists) |
exercise solution codepad |
| 144 |
25 Jun 2010 |
|
Learn A New Language: Solve the exercise of your choice in an unfamiliar language |
exercise solution codepad |
| 198 |
31 Dec 2010 |
Arithmetic Drill: Repetitious drill for children |
learning basic arithmetic |
exercise solution codepad |
| 118 |
12 Mar 2010 |
Traveling Salesman: Brute Force: Examine all possible permutations to find the |
least-cost tour |
exercise solution codepad |
| 155 |
03 Aug 2010 |
Carl Hewitt’s Same-Fringe Problem: Do two trees have the same |
leaves, solved with streams (lazy lists) |
exercise solution codepad |
| 171 |
28 Sep 2010 |
Maxiphobic Heaps: A priority-queue data structure, similar to |
leftist heaps, due to Chris Okasaki |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting Primes Using |
Legendre’s Formula: Recreate Legendre’s two-century old calculation of the number of primes less than a million |
exercise solution codepad |
| 257 |
26 Jul 2011 |
More Prime-Counting Functions: Prime counting functions by Meissel and Lehmer, based on |
Legendre’s sum |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting Primes Using Legendre’s Formula: Recreate |
Legendre’s two-century old calculation of the number of primes less than a million |
exercise solution codepad |
| 257 |
26 Jul 2011 |
More Prime-Counting Functions: Prime counting functions by Meissel and |
Lehmer, based on Legendre’s sum |
exercise solution codepad |
| 114 |
26 Feb 2010 |
Run |
Length Encoding: A simple compression method for text files |
exercise solution codepad |
| 261 |
09 Aug 2011 |
Hett’s Problem 1.28: Sorting a list of lists according to |
length of sublists |
exercise solution codepad |
| 56 |
04 Aug 2009 |
|
Lenstra’s Algorithm: Hendrik Lenstra’s original algorithm for elliptic curve factorization |
exercise solution codepad |
| 56 |
04 Aug 2009 |
Lenstra’s Algorithm: Hendrik |
Lenstra’s original algorithm for elliptic curve factorization |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting Primes Using Legendre’s Formula: Recreate Legendre’s two-century old calculation of the number of primes |
less than a million |
exercise solution codepad |
| 87 |
20 Nov 2009 |
Master Mind, Part 2: Solve a Master Mind puzzle in five probes or |
less |
exercise solution codepad |
| 53 |
24 Jul 2009 |
|
Let’s Make A Deal!: Simulate a tricky probability calculation |
exercise solution codepad |
| 172 |
01 Oct 2010 |
Oban Numbers: Numbers that omit the |
letter “o” when spelled, and a function to convert numbers to words |
exercise solution codepad |
| 189 |
30 Nov 2010 |
Form |
Letters: Merge a schema and a data file to write form letters |
exercise solution codepad |
| 106 |
29 Jan 2010 |
Straddling Checkerboard: An alternative to the Polybius square for ciphers that must convert |
letters to digits |
exercise solution codepad |
| 149 |
13 Jul 2010 |
Word Cube: A game to form words from a given set of |
letters |
exercise solution codepad |
| 189 |
30 Nov 2010 |
Form Letters: Merge a schema and a data file to write form |
letters |
exercise solution codepad |
| 183 |
09 Nov 2010 |
Subset Sums: Third |
level of the Greplin Programming Challenge, using dynamic programming and memoization |
exercise solution codepad |
| 117 |
09 Mar 2010 |
|
Lexicographic Permutations: Continually generate the next permutation using an algorithm by Dijkstra |
exercise solution codepad |
| 27 |
24 Apr 2009 |
Word Hy-phen-a-tion By Com-pu-ter: Frank |
Liang’s hyphenation algorithm, used in TeX |
exercise solution codepad |
| 15 |
13 Mar 2009 |
Friday, the Thirteenth: A small calendar |
library, and a simple use of it |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A |
library for big integers: display factorials to 50, determine if a number is prime, and compute its prime factors |
exercise solution codepad |
| 249 |
28 Jun 2011 |
Big Numbers: Functions: A |
library for big integers: gcd, powering, square root, random numbers |
exercise solution codepad |
| 241 |
31 May 2011 |
Big Numbers: Addition, Subtraction And Multiplication: A |
library for big integers: grade-school algorithms for addition, subtraction, and multiplication |
exercise solution codepad |
| 245 |
14 Jun 2011 |
Big Numbers: Input And Output: A |
library for big integers: input and output with radix conversion |
exercise solution codepad |
| 239 |
24 May 2011 |
Big Numbers: Getting Started: A |
library for big integers: representation, comparison, simple functions |
exercise solution codepad |
| 247 |
21 Jun 2011 |
Big Numbers: Testing: A |
library for big integers: testing |
exercise solution codepad |
| 243 |
07 Jun 2011 |
Big Numbers: Division: A |
library for big integers: the grade-school algorithm for long division |
exercise solution codepad |
| 39 |
05 Jun 2009 |
Ternary Search Tries: Build a function |
library for handling ternary search tries |
exercise solution codepad |
| 48 |
07 Jul 2009 |
Modular Arithmetic: A function |
library for performing modular addition, subtraction, multiplication, division, and square root |
exercise solution codepad |
| 269 |
06 Sep 2011 |
Deques: |
Library implementation of double-ended queues |
exercise solution codepad |
| 30 |
05 May 2009 |
Priority Queues: A simple |
library implementation of the priority queue data structure |
exercise solution codepad |
| 205 |
25 Jan 2011 |
Rational Numbers: A |
library of basic arithmetic and comparison of fractions |
exercise solution codepad |
| 54 |
28 Jul 2009 |
Elliptic Curves: |
Library of basic functions on elliptic curves |
exercise solution codepad |
| 13 |
06 Mar 2009 |
Roman Numerals: A |
library to read and write Roman numerals |
exercise solution codepad |
| 33 |
15 May 2009 |
Cellular Automata: |
Linear cellular automata as described by Stephen Wolfram in his book A New Kind of Science |
exercise solution codepad |
| 151 |
20 Jul 2010 |
Solving Systems Of |
Linear Equations: Matrix operations LU-decomposition and LUP-decomposition |
exercise solution codepad |
| 275 |
27 Sep 2011 |
Statistics: Calculate the mean, standard deviation, |
linear regression and correlation |
exercise solution codepad |
| 85 |
13 Nov 2009 |
Two |
linear sorts: Count sort and radix sort exploit the structure of integer keys |
exercise solution codepad |
| 176 |
15 Oct 2010 |
Find The Longest Palindrome In A String: A beautiful |
linear-time algorithm due to Johan Jeuring |
exercise solution codepad |
| 154 |
30 Jul 2010 |
Fibonacci Numbers: Three algorithms taking exponential time, |
linear time, and logarithmic time |
exercise solution codepad |
| 235 |
10 May 2011 |
Comm: select or reject |
lines common to two sorted files |
exercise solution codepad |
| 173 |
05 Oct 2010 |
George Marsaglia’s Random Number Generators: Nine high-quality RNGs in nineteen |
lines of code |
exercise solution codepad |
| 159 |
17 Aug 2010 |
Cut: Select fields or characters from input |
lines |
exercise solution codepad |
| 1 |
19 Feb 2009 |
RPN Calculator: Evaluate numeric expressions at the command |
line |
exercise solution codepad |
| 266 |
26 Aug 2011 |
Reverse Every K Nodes Of A |
Linked List: Reverse the elements of a sub-list |
exercise solution codepad |
| 84 |
10 Nov 2009 |
Merge Sort: A fast, stable sorting algorithm, especially well-suited to |
linked lists |
exercise solution codepad |
| 78 |
20 Oct 2009 |
Shuffle: Create random permutations of an array or |
linked list |
exercise solution codepad |
| 284 |
01 Nov 2011 |
RIP John McCarthy: Implementation of the “Maxwell’s equations of software” from the |
LISP 1.5 Programmer’s Manual |
exercise solution codepad |
| 215 |
01 Mar 2011 |
An Early LISP Program: A program to flatten a list, from the March 1960 |
LISP I manual |
exercise solution codepad |
| 215 |
01 Mar 2011 |
An Early |
LISP Program: A program to flatten a list, from the March 1960 LISP I manual |
exercise solution codepad |
| 136 |
28 May 2010 |
Printing Files: A simple program to |
list files, similar to the unix pr program |
exercise solution codepad |
| 215 |
01 Mar 2011 |
An Early LISP Program: A program to flatten a |
list, from the March 1960 LISP I manual |
exercise solution codepad |
| 146 |
02 Jul 2010 |
Contents: Chronological |
Listing Of Exercises: Blog management |
exercise solution codepad |
| 263 |
16 Aug 2011 |
Insert Into A Cyclic Sorted List: Insert a new element into a cyclic |
list, in order |
exercise solution codepad |
| 263 |
16 Aug 2011 |
Insert Into A Cyclic Sorted |
List: Insert a new element into a cyclic list, in order |
exercise solution codepad |
| 261 |
09 Aug 2011 |
Hett’s Problem 1.28: Sorting a |
list of lists according to length of sublists |
exercise solution codepad |
| 213 |
22 Feb 2011 |
Sliding Window Minimum: |
List of minimums sliding across an input list |
exercise solution codepad |
| 266 |
26 Aug 2011 |
Reverse Every K Nodes Of A Linked |
List: Reverse the elements of a sub-list |
exercise solution codepad |
| 261 |
09 Aug 2011 |
Hett’s Problem 1.28: Sorting a list of |
lists according to length of sublists |
exercise solution codepad |
| 58 |
11 Aug 2009 |
Uncle Bob’s Bowling Game Kata: Use pattern-matching on |
lists to solve a classic object-oriented programming exercise |
exercise solution codepad |
| 155 |
03 Aug 2010 |
Carl Hewitt’s Same-Fringe Problem: Do two trees have the same leaves, solved with streams (lazy |
lists) |
exercise solution codepad |
| 84 |
10 Nov 2009 |
Merge Sort: A fast, stable sorting algorithm, especially well-suited to linked |
lists |
exercise solution codepad |
| 255 |
19 Jul 2011 |
Sum Of Two Integers: Determine if two integers in a |
list sum to a target |
exercise solution codepad |
| 267 |
30 Aug 2011 |
Hamming Numbers: |
List the numbers with no factors greater than 5, a classic problem popularized by Dijkstra |
exercise solution codepad |
| 193 |
14 Dec 2010 |
Longest Duplicated Substring: Use a sorted suffix |
list |
exercise solution codepad |
| 213 |
22 Feb 2011 |
Sliding Window Minimum: List of minimums sliding across an input |
list |
exercise solution codepad |
| 231 |
26 Apr 2011 |
Miscellanea: FizzBuzz, Prime Words, and Split A |
List |
exercise solution codepad |
| 5 |
19 Feb 2009 |
Flavius Josephus: Programming a cyclical |
list |
exercise solution codepad |
| 78 |
20 Oct 2009 |
Shuffle: Create random permutations of an array or linked |
list |
exercise solution codepad |
| 93 |
11 Dec 2009 |
Selection: Find the kth-largest item in a |
list |
exercise solution codepad |
| 157 |
10 Aug 2010 |
|
Literate Programming: Structured documentation in the style of Donald Knuth |
exercise solution codepad |
| 32 |
12 May 2009 |
|
Loan Amortization: Calculate and print a simple loan amortization table |
exercise solution codepad |
| 32 |
12 May 2009 |
Loan Amortization: Calculate and print a simple |
loan amortization table |
exercise solution codepad |
| 201 |
11 Jan 2011 |
Two Integrals: The exponential and |
logarithmic integral, and an approximation for prime-pi |
exercise solution codepad |
| 258 |
29 Jul 2011 |
Approximating Pi: Approximating pi with the |
logarithmic integral and Riemann’s R function |
exercise solution codepad |
| 154 |
30 Jul 2010 |
Fibonacci Numbers: Three algorithms taking exponential time, linear time, and |
logarithmic time |
exercise solution codepad |
| 276 |
30 Sep 2011 |
Logarithm Tables: Print old-fashioned tables of |
logarithms and anti-logarithms |
exercise solution codepad |
| 134 |
07 May 2010 |
Integer |
Logarithms: An improved algorithm is O(log n) instead of O(n) |
exercise solution codepad |
| 95 |
18 Dec 2009 |
Calculating Logarithms: Use the methods of Newton and Euler to calculate square roots and |
logarithms |
exercise solution codepad |
| 95 |
18 Dec 2009 |
Calculating |
Logarithms: Use the methods of Newton and Euler to calculate square roots and logarithms |
exercise solution codepad |
| 276 |
30 Sep 2011 |
|
Logarithm Tables: Print old-fashioned tables of logarithms and anti-logarithms |
exercise solution codepad |
| 79 |
23 Oct 2009 |
Mr. S. and Mr. P.: A |
logic puzzle popularized by John McCarthy |
exercise solution codepad |
| 42 |
16 Jun 2009 |
Who Owns The Zebra?: A |
logic puzzle, solved by embedding a Prolog-like logic system in Scheme |
exercise solution codepad |
| 7 |
20 Feb 2009 |
Multiple Dwellings: A simple |
logic puzzle, solved with the amb non-deterministic operator |
exercise solution codepad |
| 41 |
12 Jun 2009 |
Feynman’s Puzzle: A simple |
logic puzzle |
exercise solution codepad |
| 42 |
16 Jun 2009 |
Who Owns The Zebra?: A logic puzzle, solved by embedding a Prolog-like |
logic system in Scheme |
exercise solution codepad |
| 100 |
08 Jan 2010 |
Nim: A two-player game of mathematical |
logic |
exercise solution codepad |
| 86 |
17 Nov 2009 |
Master Mind, Part 1: Referee a two-player game of deductive |
logic |
exercise solution codepad |
| 243 |
07 Jun 2011 |
Big Numbers: Division: A library for big integers: the grade-school algorithm for |
long division |
exercise solution codepad |
| 40 |
09 Jun 2009 |
|
Longest Common Subsequence: A classic programming algorithm, with a solution that dates to folklore |
exercise solution codepad |
| 193 |
14 Dec 2010 |
|
Longest Duplicated Substring: Use a sorted suffix list |
exercise solution codepad |
| 176 |
15 Oct 2010 |
Find The |
Longest Palindrome In A String: A beautiful linear-time algorithm due to Johan Jeuring |
exercise solution codepad |
| 270 |
09 Sep 2011 |
Mersenne Twister: Random number generator with very |
long period, useful for simulations |
exercise solution codepad |
| 219 |
15 Mar 2011 |
|
Look And Say: Calculate John Horton Conway’s "Look and Say" sequence |
exercise solution codepad |
| 223 |
28 Mar 2011 |
|
Look And Say, Revisited: Compute Conway’s constant |
exercise solution codepad |
| 219 |
15 Mar 2011 |
Look And Say: Calculate John Horton Conway’s |
"Look and Say" sequence |
exercise solution codepad |
| 147 |
06 Jul 2010 |
Chaocipher: First |
look at a ninety-two year old autokey-type cipher |
exercise solution codepad |
| 207 |
01 Feb 2011 |
Cuckoo Hashing: A hashing system with guaranteed constant-time |
lookup and amortized constant-time insertion |
exercise solution codepad |
| 116 |
05 Mar 2010 |
Binary Search Tree: Classic data structure, providing insert, delete and |
lookup for ordered datatypes |
exercise solution codepad |
| 220 |
18 Mar 2011 |
Loopy Loops: Print the numbers from 1 to 1000 without using |
loops or conditionals |
exercise solution codepad |
| 220 |
18 Mar 2011 |
Loopy |
Loops: Print the numbers from 1 to 1000 without using loops or conditionals |
exercise solution codepad |
| 220 |
18 Mar 2011 |
|
Loopy Loops: Print the numbers from 1 to 1000 without using loops or conditionals |
exercise solution codepad |
| 90 |
01 Dec 2009 |
Wolves And Rabbits: Analyze population dynamics using the |
Lotka-Volterra equations |
exercise solution codepad |
| 192 |
10 Dec 2010 |
Two Random Selections: Use random number to select fortunes and |
lotto winners |
exercise solution codepad |
| 209 |
08 Feb 2011 |
The First Computer Program: Ada |
Lovelace’s program to compute Bernoulli numbers for Charles Babbage’s Analytical Engine |
exercise solution codepad |
| 218 |
11 Mar 2011 |
|
Lowest Common Ancestor: Find the lowest node in a binary search tree that is a common ancestor to two given nodes |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest Common Ancestor: Find the |
lowest node in a binary search tree that is a common ancestor to two given nodes |
exercise solution codepad |
| 242 |
03 Jun 2011 |
Mersenne Primes: The |
Lucas-Lehmer test for identifying primes of the form 2n−1 |
exercise solution codepad |
| 151 |
20 Jul 2010 |
Solving Systems Of Linear Equations: Matrix operations |
LU-decomposition and LUP-decomposition |
exercise solution codepad |
| 226 |
08 Apr 2011 |
Credit Card Validation: Validate decimal numbers using the |
Luhn algorithm |
exercise solution codepad |
| 151 |
20 Jul 2010 |
Solving Systems Of Linear Equations: Matrix operations LU-decomposition and |
LUP-decomposition |
exercise solution codepad |
| 21 |
03 Apr 2009 |
Programming the Turing |
Machine: A turing-machine program to multiply two numbers |
exercise solution codepad |
| 19 |
27 Mar 2009 |
A Turing |
Machine Simulator: An interpreter for a single-tape, multi-symbol turing machine |
exercise solution codepad |
| 16 |
17 Mar 2009 |
Comma-Separated Values: Retrieve records from a comma-separated values file using a finite-state |
machine |
exercise solution codepad |
| 19 |
27 Mar 2009 |
A Turing Machine Simulator: An interpreter for a single-tape, multi-symbol turing |
machine |
exercise solution codepad |
| 202 |
14 Jan 2011 |
Slots: Simulate a slot |
machine |
exercise solution codepad |
| 59 |
14 Aug 2009 |
Pairing Heaps: A standard algorithm for |
maintaining priority queues |
exercise solution codepad |
| 297 |
16 Dec 2011 |
|
Majority Voting: Determine the results of an election |
exercise solution codepad |
| 53 |
24 Jul 2009 |
Let’s |
Make A Deal!: Simulate a tricky probability calculation |
exercise solution codepad |
| 153 |
27 Jul 2010 |
HAMURABI.BAS: |
Manage grain and land in ancient Sumeria |
exercise solution codepad |
| 146 |
02 Jul 2010 |
Contents: Chronological Listing Of Exercises: Blog |
management |
exercise solution codepad |
| 148 |
09 Jul 2010 |
Contents: Permuted Table Of Contents: Blog |
management |
exercise solution codepad |
| 150 |
16 Jul 2010 |
Contents: Themes: Blog |
Management |
exercise solution codepad |
| 215 |
01 Mar 2011 |
An Early LISP Program: A program to flatten a list, from the March 1960 LISP I |
manual |
exercise solution codepad |
| 284 |
01 Nov 2011 |
RIP John McCarthy: Implementation of the “Maxwell’s equations of software” from the LISP 1.5 Programmer’s |
Manual |
exercise solution codepad |
| 74 |
06 Oct 2009 |
|
MapReduce: Google’s famous system for parallelizing computations expressed as a programming idiom |
exercise solution codepad |
| 215 |
01 Mar 2011 |
An Early LISP Program: A program to flatten a list, from the |
March 1960 LISP I manual |
exercise solution codepad |
| 10 |
24 Feb 2009 |
|
Mardi Gras: Compute the date of Easter |
exercise solution codepad |
| 11 |
27 Feb 2009 |
Mark V. Shaney: Generate parodies of a text using a |
Markov chain |
exercise solution codepad |
| 11 |
27 Feb 2009 |
|
Mark V. Shaney: Generate parodies of a text using a Markov chain |
exercise solution codepad |
| 160 |
20 Aug 0 |
|
Marriage Sort: A sub-quadratic sort similar to shell sort or comb sort |
exercise solution codepad |
| 173 |
05 Oct 2010 |
George |
Marsaglia’s Random Number Generators: Nine high-quality RNGs in nineteen lines of code |
exercise solution codepad |
| 66 |
08 Sep 2009 |
Porter Stemming: |
Martin Porter’s algorithm for removing suffices from word stems |
exercise solution codepad |
| 86 |
17 Nov 2009 |
|
Master Mind, Part 1: Referee a two-player game of deductive logic |
exercise solution codepad |
| 87 |
20 Nov 2009 |
|
Master Mind, Part 2: Solve a Master Mind puzzle in five probes or less |
exercise solution codepad |
| 87 |
20 Nov 2009 |
Master Mind, Part 2: Solve a |
Master Mind puzzle in five probes or less |
exercise solution codepad |
| 67 |
11 Sep 2009 |
Beautiful Code: A simple regular-expression |
matcher by Rob Pike |
exercise solution codepad |
| 69 |
18 Sep 2009 |
Regular Expressions, Part 2: The corresponding |
matcher |
exercise solution codepad |
| 71 |
25 Sep 2009 |
Grep: Simple version of the classic unix regular-expression |
matching utility |
exercise solution codepad |
| 51 |
17 Jul 2009 |
International Mathematical Olympiad: Three exercises from 1960s |
math competitions |
exercise solution codepad |
| 232 |
29 Apr 2011 |
Rule 30 RNG: The random number generator from |
Mathematica, based on Stephen Wolfram’s Rule 30 cellular automata |
exercise solution codepad |
| 100 |
08 Jan 2010 |
Nim: A two-player game of |
mathematical logic |
exercise solution codepad |
| 94 |
15 Dec 2009 |
Affine-Shift Cipher: A cryptographically weak but |
mathematically interesting cipher |
exercise solution codepad |
| 179 |
26 Oct 2010 |
Benford’s Law: A useful |
mathematical oddity, and an example of text file databases |
exercise solution codepad |
| 51 |
17 Jul 2009 |
International |
Mathematical Olympiad: Three exercises from 1960s math competitions |
exercise solution codepad |
| 221 |
22 Mar 2011 |
Two Kaprekar Exercises: Kaprekar chains and Kaprekar numbers, from the Indian |
mathematician Dattaraya Ramchandra Kaprekar |
exercise solution codepad |
| 49 |
10 Jul 2009 |
The Golden Ratio: Evaluate a continued fraction, based on my daughter’s |
math homework |
exercise solution codepad |
| 89 |
27 Nov 2009 |
$7.11: A |
math puzzle: a+b+c+d = a×b×c×d = 7.11 |
exercise solution codepad |
| 229 |
19 Apr 2011 |
Same Five Digits: A |
math puzzle from New Scientist, solved by guest author Bob Miller |
exercise solution codepad |
| 99 |
05 Jan 2010 |
The Sum Of Two Squares: A |
math puzzle with a solution by Dijkstra |
exercise solution codepad |
| 72 |
29 Sep 2009 |
Green Eyes: A counting problem from high-school |
math |
exercise solution codepad |
| 143 |
22 Jun 2010 |
Matrix Operations: |
Matrix addition, scalar multiplication, multiplication and transposition |
exercise solution codepad |
| 151 |
20 Jul 2010 |
Solving Systems Of Linear Equations: |
Matrix operations LU-decomposition and LUP-decomposition |
exercise solution codepad |
| 143 |
22 Jun 2010 |
|
Matrix Operations: Matrix addition, scalar multiplication, multiplication and transposition |
exercise solution codepad |
| 265 |
23 Aug 2011 |
Knapsack: Fill a knapsack to |
maximize the value of its contents |
exercise solution codepad |
| 224 |
01 Apr 2011 |
|
Maximum Difference In An Array: Find maximum Xj &minus Xi, with i ≤ j |
exercise solution codepad |
| 190 |
03 Dec 2010 |
|
Maximum Sum Subsequence: A classic programming exercise due to Jon Bentley |
exercise solution codepad |
| 224 |
01 Apr 2011 |
Maximum Difference In An Array: Find |
maximum Xj &minus Xi, with i ≤ j |
exercise solution codepad |
| 171 |
28 Sep 2010 |
|
Maxiphobic Heaps: A priority-queue data structure, similar to leftist heaps, due to Chris Okasaki |
exercise solution codepad |
| 284 |
01 Nov 2011 |
RIP John McCarthy: Implementation of the |
“Maxwell’s equations of software” from the LISP 1.5 Programmer’s Manual |
exercise solution codepad |
| 284 |
01 Nov 2011 |
RIP John |
McCarthy: Implementation of the “Maxwell’s equations of software” from the LISP 1.5 Programmer’s Manual |
exercise solution codepad |
| 79 |
23 Oct 2009 |
Mr. S. and Mr. P.: A logic puzzle popularized by John |
McCarthy |
exercise solution codepad |
| 113 |
23 Feb 2010 |
Engineering A Sort Function: A high-performance quicksort by Jon Bentley and Doug |
McIlroy |
exercise solution codepad |
| 295 |
09 Dec 2011 |
|
McNugget Numbers: A simple problem, worked out on a napkin |
exercise solution codepad |
| 275 |
27 Sep 2011 |
Statistics: Calculate the |
mean, standard deviation, linear regression and correlation |
exercise solution codepad |
| 257 |
26 Jul 2011 |
More Prime-Counting Functions: Prime counting functions by |
Meissel and Lehmer, based on Legendre’s sum |
exercise solution codepad |
| 183 |
09 Nov 2010 |
Subset Sums: Third level of the Greplin Programming Challenge, using dynamic programming and |
memoization |
exercise solution codepad |
| 228 |
15 Apr 2011 |
Partition Numbers: Calculate the partition numbers, using |
memoization via growing arrays |
exercise solution codepad |
| 189 |
30 Nov 2010 |
Form Letters: |
Merge a schema and a data file to write form letters |
exercise solution codepad |
| 84 |
10 Nov 2009 |
|
Merge Sort: A fast, stable sorting algorithm, especially well-suited to linked lists |
exercise solution codepad |
| 242 |
03 Jun 2011 |
|
Mersenne Primes: The Lucas-Lehmer test for identifying primes of the form 2n−1 |
exercise solution codepad |
| 270 |
09 Sep 2011 |
|
Mersenne Twister: Random number generator with very long period, useful for simulations |
exercise solution codepad |
| 22 |
07 Apr 2009 |
Flipping Pancakes: A sorting |
method analyzed by Bill Gates |
exercise solution codepad |
| 83 |
06 Nov 2009 |
Heap Sort: A guaranteed O(log n) sorting |
method based on priority queues |
exercise solution codepad |
| 114 |
26 Feb 2010 |
Run Length Encoding: A simple compression |
method for text files |
exercise solution codepad |
| 278 |
07 Oct 2011 |
Sieve of Sundaram: Sieving for prime numbers using a |
method from India |
exercise solution codepad |
| 109 |
09 Feb 2010 |
Numerical Integration: Quadrature by the rectangular, trapezoidal and Simpson’s |
method, including adaptive quadrature |
exercise solution codepad |
| 34 |
19 May 2009 |
Fermat’s |
Method: Integer factorization by Fermat’s algorithm |
exercise solution codepad |
| 107 |
02 Feb 2010 |
Proving Primality: A deterministic, not probabilistic, |
method of checking primality |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The Factorization Of F7: Part 1: Our fortieth anniversary celebration of Morrison and Brillhart’s |
method of integer factorization by continued fractions |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The Factorization Of F7: Part 2: Our fortieth anniversary celebration of Morrison and Brillhart’s |
method of integer factorization by continued fractions |
exercise solution codepad |
| 252 |
08 Jul 2011 |
Vedic Divisibility: Use a method of testing divisibility using the |
method of osculators developed in India |
exercise solution codepad |
| 214 |
25 Feb 2011 |
Sieve Of Euler: An alternate, and slow, |
method of sieving for primes |
exercise solution codepad |
| 252 |
08 Jul 2011 |
Vedic Divisibility: Use a |
method of testing divisibility using the method of osculators developed in India |
exercise solution codepad |
| 75 |
09 Oct 2009 |
Calculating Pi: Calculate the value of π by monte-carlo |
methods and by an Archimedean method |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer Factorization: Combine trial division, Pollard’s rho and p−1 |
methods, and elliptic curves into a single factorization program |
exercise solution codepad |
| 95 |
18 Dec 2009 |
Calculating Logarithms: Use the |
methods of Newton and Euler to calculate square roots and logarithms |
exercise solution codepad |
| 248 |
24 Jun 2011 |
Thank God It’s Friday!: Three |
methods to calculate the day of the week |
exercise solution codepad |
| 227 |
12 Apr 2011 |
House Of Representatives: Apportion representatives by the Huntington-Hill |
method |
exercise solution codepad |
| 75 |
09 Oct 2009 |
Calculating Pi: Calculate the value of π by monte-carlo methods and by an Archimedean |
method |
exercise solution codepad |
| 29 |
01 May 2009 |
Primality Checking: A probabilistic primality checker by Gary Miller and |
Michael Rabin |
exercise solution codepad |
| 76 |
13 Oct 2009 |
Bifid: A simple but effective fractionating cipher, never used |
militarily |
exercise solution codepad |
| 57 |
07 Aug 2009 |
ADFGX: A classic German |
military field cipher from the First World War |
exercise solution codepad |
| 47 |
03 Jul 2009 |
The Playfair Cipher: A classic |
military field cipher |
exercise solution codepad |
| 29 |
01 May 2009 |
Primality Checking: A probabilistic primality checker by Gary |
Miller and Michael Rabin |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci Primes: Find primes among the fibonacci numbers; includes the Park-Miller random number generator and |
Miller-Rabin primality checker |
exercise solution codepad |
| 229 |
19 Apr 2011 |
Same Five Digits: A math puzzle from New Scientist, solved by guest author Bob |
Miller |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting Primes Using Legendre’s Formula: Recreate Legendre’s two-century old calculation of the number of primes less than a |
million |
exercise solution codepad |
| 86 |
17 Nov 2009 |
Master |
Mind, Part 1: Referee a two-player game of deductive logic |
exercise solution codepad |
| 87 |
20 Nov 2009 |
Master |
Mind, Part 2: Solve a Master Mind puzzle in five probes or less |
exercise solution codepad |
| 87 |
20 Nov 2009 |
Master Mind, Part 2: Solve a Master |
Mind puzzle in five probes or less |
exercise solution codepad |
| 125 |
06 Apr 2010 |
Minimum Spanning Tree: Kruskal’s Algorithm: Find the |
minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 126 |
09 Apr 2010 |
Minimum Spanning Tree: Prim’s Algorithm: Find the |
minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 213 |
22 Feb 2011 |
Sliding Window |
Minimum: List of minimums sliding across an input list |
exercise solution codepad |
| 127 |
13 Apr 2010 |
Traveling Salesman: |
Minimum Spanning Tree: Heuristic guarantees solution within factor of two of optimal tour |
exercise solution codepad |
| 125 |
06 Apr 2010 |
|
Minimum Spanning Tree: Kruskal’s Algorithm: Find the minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 126 |
09 Apr 2010 |
|
Minimum Spanning Tree: Prim’s Algorithm: Find the minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 213 |
22 Feb 2011 |
Sliding Window Minimum: List of |
minimums sliding across an input list |
exercise solution codepad |
| 128 |
16 Apr 2010 |
Expression Evaluation: Parse and evaluate an arithmetic expression with plus, |
minus, times, divide and parentheses |
exercise solution codepad |
| 231 |
26 Apr 2011 |
|
Miscellanea: FizzBuzz, Prime Words, and Split A List |
exercise solution codepad |
| 110 |
12 Feb 2010 |
Sieve of Atkin: A |
modern alternative to the Sieve of Eratosthenes for computing prime numbers |
exercise solution codepad |
| 130 |
23 Apr 2010 |
|
Modern Elliptic Curve Factorization, Part 1: Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 131 |
27 Apr 2010 |
|
Modern Elliptic Curve Factorization, Part 2: Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data Encryption Standard: Part 2: ECB, CBC, CFB and OFB block |
modes for DES and other block ciphers |
exercise solution codepad |
| 197 |
28 Dec 2010 |
Carmichael Numbers: Composite numbers such that an-1 ≡ 1 |
(mod n) if a is prime to n |
exercise solution codepad |
| 44 |
23 Jun 2009 |
The |
Mod Out System: Expand a series of ranges |
exercise solution codepad |
| 48 |
07 Jul 2009 |
Modular Arithmetic: A function library for performing |
modular addition, subtraction, multiplication, division, and square root |
exercise solution codepad |
| 48 |
07 Jul 2009 |
|
Modular Arithmetic: A function library for performing modular addition, subtraction, multiplication, division, and square root |
exercise solution codepad |
| 162 |
27 Aug 2010 |
Chinese Remainders: An ancient application of |
modular inverses |
exercise solution codepad |
| 50 |
14 Jul 2009 |
The Daily Cryptogram: Solve a |
monoalphabetic substitution cipher |
exercise solution codepad |
| 43 |
19 Jun 2009 |
|
Monte Carlo Factorization: Integer factorization via Pollard’s rho algorithm |
exercise solution codepad |
| 75 |
09 Oct 2009 |
Calculating Pi: Calculate the value of π by |
monte-carlo methods and by an Archimedean method |
exercise solution codepad |
| 130 |
23 Apr 2010 |
Modern Elliptic Curve Factorization, Part 1: Elliptic arithmetic using |
Montgomery’s parameterization |
exercise solution codepad |
| 131 |
27 Apr 2010 |
Modern Elliptic Curve Factorization, Part 2: Elliptic arithmetic using |
Montgomery’s parameterization |
exercise solution codepad |
| 104 |
22 Jan 2010 |
Phases Of The |
Moon: Calculate the number of days since the last new moon |
exercise solution codepad |
| 104 |
22 Jan 2010 |
Phases Of The Moon: Calculate the number of days since the last new |
moon |
exercise solution codepad |
| 194 |
17 Dec 2010 |
Polite Numbers: Write numbers as the sum of two or |
more consecutive integers |
exercise solution codepad |
| 257 |
26 Jul 2011 |
|
More Prime-Counting Functions: Prime counting functions by Meissel and Lehmer, based on Legendre’s sum |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The Factorization Of F7: Part 1: Our fortieth anniversary celebration of |
Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The Factorization Of F7: Part 2: Our fortieth anniversary celebration of |
Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 28 |
28 Apr 2009 |
|
Morse Code: Translating the dots-and-dashes of Samuel Finley Breese Morse’s telegraph code |
exercise solution codepad |
| 28 |
28 Apr 2009 |
Morse Code: Translating the dots-and-dashes of Samuel Finley Breese |
Morse’s telegraph code |
exercise solution codepad |
| 79 |
23 Oct 2009 |
Mr. S. and |
Mr. P.: A logic puzzle popularized by John McCarthy |
exercise solution codepad |
| 79 |
23 Oct 2009 |
|
Mr. S. and Mr. P.: A logic puzzle popularized by John McCarthy |
exercise solution codepad |
| 272 |
16 Sep 2011 |
Pollard’s P−1 Factorization Algoritihm, Revisited: An improved second stage that is |
much faster than the original |
exercise solution codepad |
| 7 |
20 Feb 2009 |
|
Multiple Dwellings: A simple logic puzzle, solved with the amb non-deterministic operator |
exercise solution codepad |
| 289 |
18 Nov 2011 |
Grade School Multiplication: Display the steps in the grade school |
multiplication algorithm |
exercise solution codepad |
| 241 |
31 May 2011 |
Big Numbers: Addition, Subtraction And |
Multiplication: A library for big integers: grade-school algorithms for addition, subtraction, and multiplication |
exercise solution codepad |
| 143 |
22 Jun 2010 |
Matrix Operations: Matrix addition, scalar multiplication, |
multiplication and transposition |
exercise solution codepad |
| 289 |
18 Nov 2011 |
Grade School |
Multiplication: Display the steps in the grade school multiplication algorithm |
exercise solution codepad |
| 102 |
15 Jan 2010 |
Three Binary Algorithms: |
Multiplication, division and greatest common divisor using binary arithmetic |
exercise solution codepad |
| 48 |
07 Jul 2009 |
Modular Arithmetic: A function library for performing modular addition, subtraction, |
multiplication, division, and square root |
exercise solution codepad |
| 143 |
22 Jun 2010 |
Matrix Operations: Matrix addition, scalar |
multiplication, multiplication and transposition |
exercise solution codepad |
| 241 |
31 May 2011 |
Big Numbers: Addition, Subtraction And Multiplication: A library for big integers: grade-school algorithms for addition, subtraction, and |
multiplication |
exercise solution codepad |
| 21 |
03 Apr 2009 |
Programming the Turing Machine: A turing-machine program to |
multiply two numbers |
exercise solution codepad |
| 19 |
27 Mar 2009 |
A Turing Machine Simulator: An interpreter for a single-tape, |
multi-symbol turing machine |
exercise solution codepad |
| 106 |
29 Jan 2010 |
Straddling Checkerboard: An alternative to the Polybius square for ciphers that |
must convert letters to digits |
exercise solution codepad |
| 208 |
04 Feb 2011 |
Excel Columns: Numbers as in Excel column |
names, A=1, Z=26, IV=256 |
exercise solution codepad |
| 111 |
16 Feb 2010 |
Soundex: An algorithm to assign people’s last |
names to equivalence classes based on similar spelling |
exercise solution codepad |
| 295 |
09 Dec 2011 |
McNugget Numbers: A simple problem, worked out on a |
napkin |
exercise solution codepad |
| 141 |
15 Jun 2010 |
|
Natural Join: The fundamental relational database operator |
exercise solution codepad |
| 103 |
19 Jan 2010 |
Flight Planning: Computing the |
navigation triangle, by Jos Koot |
exercise solution codepad |
| 77 |
16 Oct 2009 |
Growable Arrays: Arrays that grow and shrink at run-time, with O(log |
n) complexity per operation |
exercise solution codepad |
| 119 |
16 Mar 2010 |
Traveling Salesman: |
Nearest Neighbor: A greedy heuristic that builds a path by always choosing the nearest unvisited point |
exercise solution codepad |
| 119 |
16 Mar 2010 |
Traveling Salesman: Nearest Neighbor: A greedy heuristic that builds a path by always choosing the |
nearest unvisited point |
exercise solution codepad |
| 119 |
16 Mar 2010 |
Traveling Salesman: Nearest |
Neighbor: A greedy heuristic that builds a path by always choosing the nearest unvisited point |
exercise solution codepad |
| 191 |
07 Dec 2010 |
Ullman’s Puzzle: It |
never hurts to sort |
exercise solution codepad |
| 76 |
13 Oct 2009 |
Bifid: A simple but effective fractionating cipher, |
never used militarily |
exercise solution codepad |
| 263 |
16 Aug 2011 |
Insert Into A Cyclic Sorted List: Insert a |
new element into a cyclic list, in order |
exercise solution codepad |
| 33 |
15 May 2009 |
Cellular Automata: Linear cellular automata as described by Stephen Wolfram in his book A |
New Kind of Science |
exercise solution codepad |
| 144 |
25 Jun 2010 |
Learn A |
New Language: Solve the exercise of your choice in an unfamiliar language |
exercise solution codepad |
| 104 |
22 Jan 2010 |
Phases Of The Moon: Calculate the number of days since the last |
new moon |
exercise solution codepad |
| 229 |
19 Apr 2011 |
Same Five Digits: A math puzzle from |
New Scientist, solved by guest author Bob Miller |
exercise solution codepad |
| 95 |
18 Dec 2009 |
Calculating Logarithms: Use the methods of |
Newton and Euler to calculate square roots and logarithms |
exercise solution codepad |
| 35 |
22 May 2009 |
The |
Next Palindrome: Find the next palindromic number greater than the input number |
exercise solution codepad |
| 35 |
22 May 2009 |
The Next Palindrome: Find the |
next palindromic number greater than the input number |
exercise solution codepad |
| 117 |
09 Mar 2010 |
Lexicographic Permutations: Continually generate the |
next permutation using an algorithm by Dijkstra |
exercise solution codepad |
| 122 |
26 Mar 2010 |
The |
Next Prime: Efficiently find the next prime number larger than a given number |
exercise solution codepad |
| 122 |
26 Mar 2010 |
The Next Prime: Efficiently find the |
next prime number larger than a given number |
exercise solution codepad |
| 197 |
28 Dec 2010 |
Carmichael Numbers: Composite numbers such that an-1 ≡ 1 (mod |
n) if a is prime to n |
exercise solution codepad |
| 100 |
08 Jan 2010 |
|
Nim: A two-player game of mathematical logic |
exercise solution codepad |
| 129 |
20 Apr 2010 |
145 Puzzle: Build and evaluate expressions using the digits one through |
nine and the simple arithmetic operators |
exercise solution codepad |
| 173 |
05 Oct 2010 |
George Marsaglia’s Random Number Generators: |
Nine high-quality RNGs in nineteen lines of code |
exercise solution codepad |
| 173 |
05 Oct 2010 |
George Marsaglia’s Random Number Generators: Nine high-quality RNGs in |
nineteen lines of code |
exercise solution codepad |
| 260 |
05 Aug 2011 |
|
Ninety-Nine Bottles Of Beer: The popular song |
exercise solution codepad |
| 147 |
06 Jul 2010 |
Chaocipher: First look at a |
ninety-two year old autokey-type cipher |
exercise solution codepad |
| 134 |
07 May 2010 |
Integer Logarithms: An improved algorithm is O(log |
n) instead of O(n) |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest Common Ancestor: Find the lowest |
node in a binary search tree that is a common ancestor to two given nodes |
exercise solution codepad |
| 125 |
06 Apr 2010 |
Minimum Spanning Tree: Kruskal’s Algorithm: Find the minimum-cost tree that includes all the |
nodes in a graph |
exercise solution codepad |
| 126 |
09 Apr 2010 |
Minimum Spanning Tree: Prim’s Algorithm: Find the minimum-cost tree that includes all the |
nodes in a graph |
exercise solution codepad |
| 266 |
26 Aug 2011 |
Reverse Every K |
Nodes Of A Linked List: Reverse the elements of a sub-list |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest Common Ancestor: Find the lowest node in a binary search tree that is a common ancestor to two given |
nodes |
exercise solution codepad |
| 267 |
30 Aug 2011 |
Hamming Numbers: List the numbers with |
no factors greater than 5, a classic problem popularized by Dijkstra |
exercise solution codepad |
| 7 |
20 Feb 2009 |
Multiple Dwellings: A simple logic puzzle, solved with the amb |
non-deterministic operator |
exercise solution codepad |
| 264 |
19 Aug 2011 |
First |
Non-Repeating Character: Find the first character in a string that doesn’t repeat later in the string |
exercise solution codepad |
| 97 |
29 Dec 2009 |
A Statisticle Speling Korrecter: Peter |
Norvig’s version of the Google spelling suggester |
exercise solution codepad |
| 181 |
02 Nov 2010 |
Emirps: Prime numbers that are prime when their digits are reversed, but |
not palindromic |
exercise solution codepad |
| 107 |
02 Feb 2010 |
Proving Primality: A deterministic, |
not probabilistic, method of checking primality |
exercise solution codepad |
| 279 |
14 Oct 2011 |
The First |
N Primes: Embedding the Sieve of Eratosthenes in a priority queue instead of an array |
exercise solution codepad |
| 140 |
11 Jun 2010 |
|
N-Queens: Our version of a classic algorithmic exercise |
exercise solution codepad |
| 83 |
06 Nov 2009 |
Heap Sort: A guaranteed O(log |
n) sorting method based on priority queues |
exercise solution codepad |
| 259 |
02 Aug 2011 |
The Nth Prime: The |
n prime, counting from p1 = 2 |
exercise solution codepad |
| 200 |
07 Jan 2011 |
Counting Primes: The prime counting function and |
nth-prime function |
exercise solution codepad |
| 259 |
02 Aug 2011 |
The |
Nth Prime: The n prime, counting from p1 = 2 |
exercise solution codepad |
| 197 |
28 Dec 2010 |
Carmichael Numbers: Composite numbers such that an-1 ≡ 1 (mod n) if a is prime to |
n |
exercise solution codepad |
| 169 |
21 Sep 2010 |
Kaprekar Numbers: Square the |
number and add the digits in halves |
exercise solution codepad |
| 31 |
08 May 2009 |
Wheel Factorization: Find the factors of a |
number by a variant of trial division |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci Primes: Find primes among the fibonacci numbers; includes the Park-Miller random |
number generator and Miller-Rabin primality checker |
exercise solution codepad |
| 232 |
29 Apr 2011 |
Rule 30 RNG: The random |
number generator from Mathematica, based on Stephen Wolfram’s Rule 30 cellular automata |
exercise solution codepad |
| 173 |
05 Oct 2010 |
George Marsaglia’s Random |
Number Generators: Nine high-quality RNGs in nineteen lines of code |
exercise solution codepad |
| 60 |
18 Aug 2009 |
Blum Blum Shub: Stream cipher based on a cryptographically secure pseudo-random |
number generator |
exercise solution codepad |
| 270 |
09 Sep 2011 |
Mersenne Twister: Random |
number generator with very long period, useful for simulations |
exercise solution codepad |
| 35 |
22 May 2009 |
The Next Palindrome: Find the next palindromic |
number greater than the input number |
exercise solution codepad |
| 115 |
02 Mar 2010 |
Goldbach’s Conjecture: Every even |
number greater than two can be written as the sum of two primes |
exercise solution codepad |
| 156 |
06 Aug 2010 |
Two Powering Predicates: Determine if a |
number is a square or a prime power |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for big integers: display factorials to 50, determine if a |
number is prime, and compute its prime factors |
exercise solution codepad |
| 122 |
26 Mar 2010 |
The Next Prime: Efficiently find the next prime |
number larger than a given number |
exercise solution codepad |
| 104 |
22 Jan 2010 |
Phases Of The Moon: Calculate the |
number of days since the last new moon |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting Primes Using Legendre’s Formula: Recreate Legendre’s two-century old calculation of the |
number of primes less than a million |
exercise solution codepad |
| 206 |
28 Jan 2011 |
Population Count: Count the |
number of set bits (1-bits) in the binary representation of an integer |
exercise solution codepad |
| 241 |
31 May 2011 |
Big |
Numbers: Addition, Subtraction And Multiplication: A library for big integers: grade-school algorithms for addition, subtraction, and multiplication |
exercise solution codepad |
| 205 |
25 Jan 2011 |
Rational |
Numbers: A library of basic arithmetic and comparison of fractions |
exercise solution codepad |
| 238 |
20 May 0 |
ISBN Validation: Validate ISBN book |
numbers, and fetch author and title from the internet |
exercise solution codepad |
| 170 |
24 Sep 2010 |
Alien |
Numbers: An exercise from Google Code Jam |
exercise solution codepad |
| 296 |
13 Dec 2011 |
Validating Telephone |
Numbers: An exercise in input validation |
exercise solution codepad |
| 295 |
09 Dec 2011 |
McNugget |
Numbers: A simple problem, worked out on a napkin |
exercise solution codepad |
| 208 |
04 Feb 2011 |
Excel Columns: |
Numbers as in Excel column names, A=1, Z=26, IV=256 |
exercise solution codepad |
| 194 |
17 Dec 2010 |
Polite Numbers: Write |
numbers as the sum of two or more consecutive integers |
exercise solution codepad |
| 228 |
15 Apr 2011 |
Partition |
Numbers: Calculate the partition numbers, using memoization via growing arrays |
exercise solution codepad |
| 197 |
28 Dec 2010 |
Carmichael |
Numbers: Composite numbers such that an-1 ≡ 1 (mod n) if a is prime to n |
exercise solution codepad |
| 243 |
07 Jun 2011 |
Big |
Numbers: Division: A library for big integers: the grade-school algorithm for long division |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big |
Numbers: Examples: A library for big integers: display factorials to 50, determine if a number is prime, and compute its prime factors |
exercise solution codepad |
| 271 |
13 Sep 2011 |
Tetrahedral |
Numbers: Find the base of the tetrahedron that contains 169179692512835000 balls |
exercise solution codepad |
| 209 |
08 Feb 2011 |
The First Computer Program: Ada Lovelace’s program to compute Bernoulli |
numbers for Charles Babbage’s Analytical Engine |
exercise solution codepad |
| 220 |
18 Mar 2011 |
Loopy Loops: Print the |
numbers from 1 to 1000 without using loops or conditionals |
exercise solution codepad |
| 221 |
22 Mar 2011 |
Two Kaprekar Exercises: Kaprekar chains and Kaprekar |
numbers, from the Indian mathematician Dattaraya Ramchandra Kaprekar |
exercise solution codepad |
| 249 |
28 Jun 2011 |
Big |
Numbers: Functions: A library for big integers: gcd, powering, square root, random numbers |
exercise solution codepad |
| 239 |
24 May 2011 |
Big |
Numbers: Getting Started: A library for big integers: representation, comparison, simple functions |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci Primes: Find primes among the fibonacci |
numbers; includes the Park-Miller random number generator and Miller-Rabin primality checker |
exercise solution codepad |
| 245 |
14 Jun 2011 |
Big |
Numbers: Input And Output: A library for big integers: input and output with radix conversion |
exercise solution codepad |
| 152 |
23 Jul 2010 |
Happy |
Numbers: Iterating the sum of the squares of the digits terminates with one |
exercise solution codepad |
| 267 |
30 Aug 2011 |
Hamming |
Numbers: List the numbers with no factors greater than 5, a classic problem popularized by Dijkstra |
exercise solution codepad |
| 172 |
01 Oct 2010 |
Oban |
Numbers: Numbers that omit the letter “o” when spelled, and a function to convert numbers to words |
exercise solution codepad |
| 169 |
21 Sep 2010 |
Kaprekar |
Numbers: Square the number and add the digits in halves |
exercise solution codepad |
| 197 |
28 Dec 2010 |
Carmichael Numbers: Composite |
numbers such that an-1 ≡ 1 (mod n) if a is prime to n |
exercise solution codepad |
| 247 |
21 Jun 2011 |
Big |
Numbers: Testing: A library for big integers: testing |
exercise solution codepad |
| 181 |
02 Nov 2010 |
Emirps: Prime |
numbers that are prime when their digits are reversed, but not palindromic |
exercise solution codepad |
| 172 |
01 Oct 2010 |
Oban Numbers: |
Numbers that omit the letter “o” when spelled, and a function to convert numbers to words |
exercise solution codepad |
| 240 |
27 May 2011 |
Upside Up: |
Numbers that read the same upside down |
exercise solution codepad |
| 154 |
30 Jul 2010 |
Fibonacci |
Numbers: Three algorithms taking exponential time, linear time, and logarithmic time |
exercise solution codepad |
| 210 |
11 Feb 2011 |
Sums Of Powers: Use Bernoulli |
numbers to quickly compute sums of powers |
exercise solution codepad |
| 172 |
01 Oct 2010 |
Oban Numbers: Numbers that omit the letter “o” when spelled, and a function to convert |
numbers to words |
exercise solution codepad |
| 110 |
12 Feb 2010 |
Sieve of Atkin: A modern alternative to the Sieve of Eratosthenes for computing prime |
numbers |
exercise solution codepad |
| 21 |
03 Apr 2009 |
Programming the Turing Machine: A turing-machine program to multiply two |
numbers |
exercise solution codepad |
| 249 |
28 Jun 2011 |
Big Numbers: Functions: A library for big integers: gcd, powering, square root, random |
numbers |
exercise solution codepad |
| 278 |
07 Oct 2011 |
Sieve of Sundaram: Sieving for prime |
numbers using a method from India |
exercise solution codepad |
| 228 |
15 Apr 2011 |
Partition Numbers: Calculate the partition |
numbers, using memoization via growing arrays |
exercise solution codepad |
| 226 |
08 Apr 2011 |
Credit Card Validation: Validate decimal |
numbers using the Luhn algorithm |
exercise solution codepad |
| 267 |
30 Aug 2011 |
Hamming Numbers: List the |
numbers with no factors greater than 5, a classic problem popularized by Dijkstra |
exercise solution codepad |
| 194 |
17 Dec 2010 |
Polite |
Numbers: Write numbers as the sum of two or more consecutive integers |
exercise solution codepad |
| 188 |
26 Nov 2010 |
Divisors And Totatives: The |
number-theoretic functions divisors, numdivs, sumdivs, totatives, and totient |
exercise solution codepad |
| 192 |
10 Dec 2010 |
Two Random Selections: Use random |
number to select fortunes and lotto winners |
exercise solution codepad |
| 122 |
26 Mar 2010 |
The Next Prime: Efficiently find the next prime number larger than a given |
number |
exercise solution codepad |
| 35 |
22 May 2009 |
The Next Palindrome: Find the next palindromic number greater than the input |
number |
exercise solution codepad |
| 188 |
26 Nov 2010 |
Divisors And Totatives: The number-theoretic functions divisors, |
numdivs, sumdivs, totatives, and totient |
exercise solution codepad |
| 13 |
06 Mar 2009 |
Roman |
Numerals: A library to read and write Roman numerals |
exercise solution codepad |
| 13 |
06 Mar 2009 |
Roman Numerals: A library to read and write Roman |
numerals |
exercise solution codepad |
| 109 |
09 Feb 2010 |
|
Numerical Integration: Quadrature by the rectangular, trapezoidal and Simpson’s method, including adaptive quadrature |
exercise solution codepad |
| 1 |
19 Feb 2009 |
RPN Calculator: Evaluate |
numeric expressions at the command line |
exercise solution codepad |
| 172 |
01 Oct 2010 |
|
Oban Numbers: Numbers that omit the letter “o” when spelled, and a function to convert numbers to words |
exercise solution codepad |
| 58 |
11 Aug 2009 |
Uncle Bob’s Bowling Game Kata: Use pattern-matching on lists to solve a classic |
object-oriented programming exercise |
exercise solution codepad |
| 179 |
26 Oct 2010 |
Benford’s Law: A useful mathematical |
oddity, and an example of text file databases |
exercise solution codepad |
| 133 |
04 May 2010 |
Spectacular Seven: Compute the |
odds at jai alai |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data Encryption Standard: Part 2: ECB, CBC, CFB and |
OFB block modes for DES and other block ciphers |
exercise solution codepad |
| 171 |
28 Sep 2010 |
Maxiphobic Heaps: A priority-queue data structure, similar to leftist heaps, due to Chris |
Okasaki |
exercise solution codepad |
| 147 |
06 Jul 2010 |
Chaocipher: First look at a ninety-two year |
old autokey-type cipher |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting Primes Using Legendre’s Formula: Recreate Legendre’s two-century |
old calculation of the number of primes less than a million |
exercise solution codepad |
| 276 |
30 Sep 2011 |
Logarithm Tables: Print |
old-fashioned tables of logarithms and anti-logarithms |
exercise solution codepad |
| 142 |
18 Jun 0 |
Parsing Command-Line Arguments: An |
old-style getopt function |
exercise solution codepad |
| 77 |
16 Oct 2009 |
Growable Arrays: Arrays that grow and shrink at run-time, with |
O(log n) complexity per operation |
exercise solution codepad |
| 134 |
07 May 2010 |
Integer Logarithms: An improved algorithm is |
O(log n) instead of O(n) |
exercise solution codepad |
| 83 |
06 Nov 2009 |
Heap Sort: A guaranteed |
O(log n) sorting method based on priority queues |
exercise solution codepad |
| 51 |
17 Jul 2009 |
International Mathematical |
Olympiad: Three exercises from 1960s math competitions |
exercise solution codepad |
| 172 |
01 Oct 2010 |
Oban Numbers: Numbers that |
omit the letter “o” when spelled, and a function to convert numbers to words |
exercise solution codepad |
| 62 |
25 Aug 2009 |
String Search: Knuth-Morris-Pratt: Search for a pattern in a text using an |
O(n) algorithm |
exercise solution codepad |
| 184 |
12 Nov 2010 |
Rowland’s Prime-Generating Function: A sequence of |
ones and primes |
exercise solution codepad |
| 187 |
23 Nov 2010 |
String Subsets: Determine if |
one string is a subset of another |
exercise solution codepad |
| 129 |
20 Apr 2010 |
145 Puzzle: Build and evaluate expressions using the digits |
one through nine and the simple arithmetic operators |
exercise solution codepad |
| 152 |
23 Jul 2010 |
Happy Numbers: Iterating the sum of the squares of the digits terminates with |
one |
exercise solution codepad |
| 134 |
07 May 2010 |
Integer Logarithms: An improved algorithm is O(log n) instead of |
O(n) |
exercise solution codepad |
| 151 |
20 Jul 2010 |
Solving Systems Of Linear Equations: Matrix |
operations LU-decomposition and LUP-decomposition |
exercise solution codepad |
| 143 |
22 Jun 2010 |
Matrix |
Operations: Matrix addition, scalar multiplication, multiplication and transposition |
exercise solution codepad |
| 77 |
16 Oct 2009 |
Growable Arrays: Arrays that grow and shrink at run-time, with O(log n) complexity per |
operation |
exercise solution codepad |
| 129 |
20 Apr 2010 |
145 Puzzle: Build and evaluate expressions using the digits one through nine and the simple arithmetic |
operators |
exercise solution codepad |
| 141 |
15 Jun 2010 |
Natural Join: The fundamental relational database |
operator |
exercise solution codepad |
| 7 |
20 Feb 2009 |
Multiple Dwellings: A simple logic puzzle, solved with the amb non-deterministic |
operator |
exercise solution codepad |
| 127 |
13 Apr 2010 |
Traveling Salesman: Minimum Spanning Tree: Heuristic guarantees solution within factor of two of |
optimal tour |
exercise solution codepad |
| 116 |
05 Mar 2010 |
Binary Search Tree: Classic data structure, providing insert, delete and lookup for |
ordered datatypes |
exercise solution codepad |
| 186 |
19 Nov 2010 |
Topological Sort: |
Order the edges of a graph by their precedence relationship |
exercise solution codepad |
| 263 |
16 Aug 2011 |
Insert Into A Cyclic Sorted List: Insert a new element into a cyclic list, in |
order |
exercise solution codepad |
| 56 |
04 Aug 2009 |
Lenstra’s Algorithm: Hendrik Lenstra’s |
original algorithm for elliptic curve factorization |
exercise solution codepad |
| 291 |
25 Nov 2011 |
AVL Trees: Basic implementation of the |
original balanced-tree algorithm |
exercise solution codepad |
| 185 |
16 Nov 2010 |
RSA Cryptography: The |
original public-key cryptographic system, still in wide use |
exercise solution codepad |
| 272 |
16 Sep 2011 |
Pollard’s P−1 Factorization Algoritihm, Revisited: An improved second stage that is much faster than the |
original |
exercise solution codepad |
| 252 |
08 Jul 2011 |
Vedic Divisibility: Use a method of testing divisibility using the method of |
osculators developed in India |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data Encryption Standard: Part 2: ECB, CBC, CFB and OFB block modes for DES and |
other block ciphers |
exercise solution codepad |
| 254 |
15 Jul 2011 |
JSON: Writing Output: The |
other side of JSAON |
exercise solution codepad |
| 295 |
09 Dec 2011 |
McNugget Numbers: A simple problem, worked |
out on a napkin |
exercise solution codepad |
| 245 |
14 Jun 2011 |
Big Numbers: Input And |
Output: A library for big integers: input and output with radix conversion |
exercise solution codepad |
| 254 |
15 Jul 2011 |
JSON: Writing |
Output: The other side of JSAON |
exercise solution codepad |
| 245 |
14 Jun 2011 |
Big Numbers: Input And Output: A library for big integers: input and |
output with radix conversion |
exercise solution codepad |
| 44 |
23 Jun 2009 |
The Mod |
Out System: Expand a series of ranges |
exercise solution codepad |
| 172 |
01 Oct 2010 |
Oban Numbers: Numbers that omit the letter |
“o” when spelled, and a function to convert numbers to words |
exercise solution codepad |
| 42 |
16 Jun 2009 |
Who |
Owns The Zebra?: A logic puzzle, solved by embedding a Prolog-like logic system in Scheme |
exercise solution codepad |
| 259 |
02 Aug 2011 |
The Nth Prime: The n prime, counting from |
p1 = 2 |
exercise solution codepad |
| 138 |
04 Jun 2010 |
Williams’ P+1 Factorization Algorithm: A factorization algorithm, similar to Pollard’s |
p−1 algorithm |
exercise solution codepad |
| 120 |
19 Mar 2010 |
Extending Pollard’s |
P−1 Factorization Algorithm: Add a second stage to allow larger factorizations |
exercise solution codepad |
| 52 |
21 Jul 2009 |
Pollard’s |
P−1 Factorization Algorithm: A simple factorization algorithm by John Pollard |
exercise solution codepad |
| 272 |
16 Sep 2011 |
Pollard’s |
P−1 Factorization Algoritihm, Revisited: An improved second stage that is much faster than the original |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer Factorization: Combine trial division, Pollard’s rho and |
p−1 methods, and elliptic curves into a single factorization program |
exercise solution codepad |
| 59 |
14 Aug 2009 |
|
Pairing Heaps: A standard algorithm for maintaining priority queues |
exercise solution codepad |
| 35 |
22 May 2009 |
The Next |
Palindrome: Find the next palindromic number greater than the input number |
exercise solution codepad |
| 176 |
15 Oct 2010 |
Find The Longest |
Palindrome In A String: A beautiful linear-time algorithm due to Johan Jeuring |
exercise solution codepad |
| 35 |
22 May 2009 |
The Next Palindrome: Find the next |
palindromic number greater than the input number |
exercise solution codepad |
| 181 |
02 Nov 2010 |
Emirps: Prime numbers that are prime when their digits are reversed, but not |
palindromic |
exercise solution codepad |
| 79 |
23 Oct 2009 |
Mr. S. and Mr. |
P.: A logic puzzle popularized by John McCarthy |
exercise solution codepad |
| 22 |
07 Apr 2009 |
Flipping |
Pancakes: A sorting method analyzed by Bill Gates |
exercise solution codepad |
| 280 |
18 Oct 2011 |
The Wall: Ray |
Panko’s spreadsheet exercise |
exercise solution codepad |
| 74 |
06 Oct 2009 |
MapReduce: Google’s famous system for |
parallelizing computations expressed as a programming idiom |
exercise solution codepad |
| 130 |
23 Apr 2010 |
Modern Elliptic Curve Factorization, Part 1: Elliptic arithmetic using Montgomery’s |
parameterization |
exercise solution codepad |
| 131 |
27 Apr 2010 |
Modern Elliptic Curve Factorization, Part 2: Elliptic arithmetic using Montgomery’s |
parameterization |
exercise solution codepad |
| 128 |
16 Apr 2010 |
Expression Evaluation: Parse and evaluate an arithmetic expression with plus, minus, times, divide and |
parentheses |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci Primes: Find primes among the fibonacci numbers; includes the |
Park-Miller random number generator and Miller-Rabin primality checker |
exercise solution codepad |
| 96 |
22 Dec 2009 |
Permuted Index: David |
Parnas’ classic deconstruction of the keyword-in-context index |
exercise solution codepad |
| 11 |
27 Feb 2009 |
Mark V. Shaney: Generate |
parodies of a text using a Markov chain |
exercise solution codepad |
| 128 |
16 Apr 2010 |
Expression Evaluation: |
Parse and evaluate an arithmetic expression with plus, minus, times, divide and parentheses |
exercise solution codepad |
| 253 |
12 Jul 2011 |
JSON: Parsing Input: |
Parse JSON input |
exercise solution codepad |
| 68 |
15 Sep 2009 |
Regular Expressions, Part 1: A |
parser for regular expressions |
exercise solution codepad |
| 142 |
18 Jun 0 |
|
Parsing Command-Line Arguments: An old-style getopt function |
exercise solution codepad |
| 253 |
12 Jul 2011 |
JSON: |
Parsing Input: Parse JSON input |
exercise solution codepad |
| 68 |
15 Sep 2009 |
Regular Expressions, |
Part 1: A parser for regular expressions |
exercise solution codepad |
| 163 |
31 Aug 2010 |
Data Encryption Standard: |
Part 1: Basic block enciphering and deciphering using DES |
exercise solution codepad |
| 130 |
23 Apr 2010 |
Modern Elliptic Curve Factorization, |
Part 1: Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 177 |
19 Oct 2010 |
Text File Databases: |
Part 1: Functions to read records with fields in various formats |
exercise solution codepad |
| 167 |
14 Sep 2010 |
The Factorization Of F7: |
Part 1: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 86 |
17 Nov 2009 |
Master Mind, |
Part 1: Referee a two-player game of deductive logic |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data Encryption Standard: |
Part 2: ECB, CBC, CFB and OFB block modes for DES and other block ciphers |
exercise solution codepad |
| 131 |
27 Apr 2010 |
Modern Elliptic Curve Factorization, |
Part 2: Elliptic arithmetic using Montgomery’s parameterization |
exercise solution codepad |
| 168 |
17 Sep 2010 |
The Factorization Of F7: |
Part 2: Our fortieth anniversary celebration of Morrison and Brillhart’s method of integer factorization by continued fractions |
exercise solution codepad |
| 87 |
20 Nov 2009 |
Master Mind, |
Part 2: Solve a Master Mind puzzle in five probes or less |
exercise solution codepad |
| 69 |
18 Sep 2009 |
Regular Expressions, |
Part 2: The corresponding matcher |
exercise solution codepad |
| 178 |
22 Oct 2010 |
Text File Databases: |
Part 2: Various functions to process records with fields |
exercise solution codepad |
| 70 |
22 Sep 2009 |
Regular Expressions, |
Part 3: A regular expression test suite |
exercise solution codepad |
| 165 |
07 Sep 2010 |
Data Encryption Standard: |
Part 3: Triple DES and cryptographic hashing |
exercise solution codepad |
| 166 |
10 Sep 2010 |
Data Encryption Standard: |
Part 4: DES driver program |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: |
partition {1,…,16} into two sets of equal size so each subset has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 228 |
15 Apr 2011 |
|
Partition Numbers: Calculate the partition numbers, using memoization via growing arrays |
exercise solution codepad |
| 228 |
15 Apr 2011 |
Partition Numbers: Calculate the |
partition numbers, using memoization via growing arrays |
exercise solution codepad |
| 124 |
02 Apr 2010 |
Disjoint Sets: A data structure for storing sets of items in disjoint |
partitions |
exercise solution codepad |
| 91 |
04 Dec 2009 |
Autokey: A cipher in which the input text forms |
part of the key |
exercise solution codepad |
| 294 |
06 Dec 2011 |
|
Pascal’s Triangle: Display the binomial coefficients |
exercise solution codepad |
| 123 |
30 Mar 2010 |
|
Passover: Calculate the dates of the Jewish holidays Rosh Hashanah and Passover |
exercise solution codepad |
| 123 |
30 Mar 2010 |
Passover: Calculate the dates of the Jewish holidays Rosh Hashanah and |
Passover |
exercise solution codepad |
| 119 |
16 Mar 2010 |
Traveling Salesman: Nearest Neighbor: A greedy heuristic that builds a |
path by always choosing the nearest unvisited point |
exercise solution codepad |
| 199 |
04 Jan 2011 |
Dijkstra’s Algorithm: Find the shortest |
path to all vertices of a graph from a single source, guest written by Graham Enos |
exercise solution codepad |
| 61 |
21 Aug 2009 |
String Search: Brute Force: Search for a |
pattern in a text by comparing the pattern to the text at all possible positions |
exercise solution codepad |
| 63 |
28 Aug 2009 |
String Search: Boyer-Moore: Search for a |
pattern in a text using a fast and simple algorithm |
exercise solution codepad |
| 62 |
25 Aug 2009 |
String Search: Knuth-Morris-Pratt: Search for a |
pattern in a text using an O(n) algorithm |
exercise solution codepad |
| 58 |
11 Aug 2009 |
Uncle Bob’s Bowling Game Kata: Use |
pattern-matching on lists to solve a classic object-oriented programming exercise |
exercise solution codepad |
| 61 |
21 Aug 2009 |
String Search: Brute Force: Search for a pattern in a text by comparing the |
pattern to the text at all possible positions |
exercise solution codepad |
| 111 |
16 Feb 2010 |
Soundex: An algorithm to assign |
people’s last names to equivalence classes based on similar spelling |
exercise solution codepad |
| 37 |
29 May 2009 |
Double Transposition Cipher: A simple and effective cipher, easy to |
perform by hand |
exercise solution codepad |
| 48 |
07 Jul 2009 |
Modular Arithmetic: A function library for |
performing modular addition, subtraction, multiplication, division, and square root |
exercise solution codepad |
| 270 |
09 Sep 2011 |
Mersenne Twister: Random number generator with very long |
period, useful for simulations |
exercise solution codepad |
| 117 |
09 Mar 2010 |
Lexicographic |
Permutations: Continually generate the next permutation using an algorithm by Dijkstra |
exercise solution codepad |
| 78 |
20 Oct 2009 |
Shuffle: Create random |
permutations of an array or linked list |
exercise solution codepad |
| 118 |
12 Mar 2010 |
Traveling Salesman: Brute Force: Examine all possible |
permutations to find the least-cost tour |
exercise solution codepad |
| 117 |
09 Mar 2010 |
Lexicographic Permutations: Continually generate the next |
permutation using an algorithm by Dijkstra |
exercise solution codepad |
| 96 |
22 Dec 2009 |
|
Permuted Index: David Parnas’ classic deconstruction of the keyword-in-context index |
exercise solution codepad |
| 148 |
09 Jul 2010 |
Contents: |
Permuted Table Of Contents: Blog management |
exercise solution codepad |
| 97 |
29 Dec 2009 |
A Statisticle Speling Korrecter: |
Peter Norvig’s version of the Google spelling suggester |
exercise solution codepad |
| 104 |
22 Jan 2010 |
|
Phases Of The Moon: Calculate the number of days since the last new moon |
exercise solution codepad |
| 288 |
15 Nov 2011 |
|
Phil Harvey’s Puzle: partition {1,…,16} into two sets of equal size so each subset has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 46 |
30 Jun 2009 |
Steve Yegge’s |
Phone-Screen Coding Exercises: A simple set of programming exercises based on a blog entry by Steve Yegge |
exercise solution codepad |
| 258 |
29 Jul 2011 |
Approximating |
Pi: Approximating pi with the logarithmic integral and Riemann’s R function |
exercise solution codepad |
| 8 |
20 Feb 2009 |
The Digits of |
Pi: A spigot algorithm to calculate the digits of pi |
exercise solution codepad |
| 75 |
09 Oct 2009 |
Calculating Pi: Calculate the value of |
π by monte-carlo methods and by an Archimedean method |
exercise solution codepad |
| 75 |
09 Oct 2009 |
Calculating |
Pi: Calculate the value of π by monte-carlo methods and by an Archimedean method |
exercise solution codepad |
| 262 |
12 Aug 2011 |
Word Breaks: Insert spaces between words: applepie => apple |
pie |
exercise solution codepad |
| 38 |
02 Jun 2009 |
|
Pig Latin: A simple exercise to solve a children’s game |
exercise solution codepad |
| 67 |
11 Sep 2009 |
Beautiful Code: A simple regular-expression matcher by Rob |
Pike |
exercise solution codepad |
| 14 |
10 Mar 2009 |
Word Frequencies: Our interpretation of a problem solved by a classic unix |
pipeline |
exercise solution codepad |
| 8 |
20 Feb 2009 |
The Digits of Pi: A spigot algorithm to calculate the digits of |
pi |
exercise solution codepad |
| 258 |
29 Jul 2011 |
Approximating Pi: Approximating |
pi with the logarithmic integral and Riemann’s R function |
exercise solution codepad |
| 103 |
19 Jan 2010 |
Flight |
Planning: Computing the navigation triangle, by Jos Koot |
exercise solution codepad |
| 283 |
28 Oct 2011 |
Crypt: Simple encryption tool from Kernighan and |
Plauger |
exercise solution codepad |
| 47 |
03 Jul 2009 |
The |
Playfair Cipher: A classic military field cipher |
exercise solution codepad |
| 203 |
18 Jan 2011 |
Solitaire Cipher: Bruce Schneier’s strong cryptography based on a deck of |
playing cards |
exercise solution codepad |
| 128 |
16 Apr 2010 |
Expression Evaluation: Parse and evaluate an arithmetic expression with |
plus, minus, times, divide and parentheses |
exercise solution codepad |
| 119 |
16 Mar 2010 |
Traveling Salesman: Nearest Neighbor: A greedy heuristic that builds a path by always choosing the nearest unvisited |
point |
exercise solution codepad |
| 121 |
23 Mar 2010 |
Texas Hold ‘Em: Find the best |
poker hand |
exercise solution codepad |
| 194 |
17 Dec 2010 |
|
Polite Numbers: Write numbers as the sum of two or more consecutive integers |
exercise solution codepad |
| 204 |
21 Jan 0 |
|
Pollard Rho, Revisited: Richard Brent’s variant of John Pollard’s rho algorithm for integer factorization |
exercise solution codepad |
| 138 |
04 Jun 2010 |
Williams’ P+1 Factorization Algorithm: A factorization algorithm, similar to |
Pollard’s p−1 algorithm |
exercise solution codepad |
| 120 |
19 Mar 2010 |
Extending |
Pollard’s P−1 Factorization Algorithm: Add a second stage to allow larger factorizations |
exercise solution codepad |
| 52 |
21 Jul 2009 |
|
Pollard’s P−1 Factorization Algorithm: A simple factorization algorithm by John Pollard |
exercise solution codepad |
| 272 |
16 Sep 2011 |
|
Pollard’s P−1 Factorization Algoritihm, Revisited: An improved second stage that is much faster than the original |
exercise solution codepad |
| 204 |
21 Jan 0 |
Pollard Rho, Revisited: Richard Brent’s variant of John |
Pollard’s rho algorithm for integer factorization |
exercise solution codepad |
| 43 |
19 Jun 2009 |
Monte Carlo Factorization: Integer factorization via |
Pollard’s rho algorithm |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer Factorization: Combine trial division, |
Pollard’s rho and p−1 methods, and elliptic curves into a single factorization program |
exercise solution codepad |
| 52 |
21 Jul 2009 |
Pollard’s P−1 Factorization Algorithm: A simple factorization algorithm by John |
Pollard |
exercise solution codepad |
| 106 |
29 Jan 2010 |
Straddling Checkerboard: An alternative to the |
Polybius square for ciphers that must convert letters to digits |
exercise solution codepad |
| 285 |
04 Nov 2011 |
Craps: Simulate a |
popular game of gambling with dice |
exercise solution codepad |
| 267 |
30 Aug 2011 |
Hamming Numbers: List the numbers with no factors greater than 5, a classic problem |
popularized by Dijkstra |
exercise solution codepad |
| 79 |
23 Oct 2009 |
Mr. S. and Mr. P.: A logic puzzle |
popularized by John McCarthy |
exercise solution codepad |
| 260 |
05 Aug 2011 |
Ninety-Nine Bottles Of Beer: The |
popular song |
exercise solution codepad |
| 36 |
26 May 2009 |
Word Search Solver: A computerized implementation of a |
popular time-waster |
exercise solution codepad |
| 206 |
28 Jan 2011 |
|
Population Count: Count the number of set bits (1-bits) in the binary representation of an integer |
exercise solution codepad |
| 90 |
01 Dec 2009 |
Wolves And Rabbits: Analyze |
population dynamics using the Lotka-Volterra equations |
exercise solution codepad |
| 135 |
25 May 2010 |
GB_FLIP: Donald Knuth’s |
portable, high-quality random-number generator from the Stanford Graphbase |
exercise solution codepad |
| 66 |
08 Sep 2009 |
Porter Stemming: Martin |
Porter’s algorithm for removing suffices from word stems |
exercise solution codepad |
| 66 |
08 Sep 2009 |
|
Porter Stemming: Martin Porter’s algorithm for removing suffices from word stems |
exercise solution codepad |
| 61 |
21 Aug 2009 |
String Search: Brute Force: Search for a pattern in a text by comparing the pattern to the text at all possible |
positions |
exercise solution codepad |
| 118 |
12 Mar 2010 |
Traveling Salesman: Brute Force: Examine all |
possible permutations to find the least-cost tour |
exercise solution codepad |
| 61 |
21 Aug 2009 |
String Search: Brute Force: Search for a pattern in a text by comparing the pattern to the text at all |
possible positions |
exercise solution codepad |
| 156 |
06 Aug 2010 |
Two |
Powering Predicates: Determine if a number is a square or a prime power |
exercise solution codepad |
| 249 |
28 Jun 2011 |
Big Numbers: Functions: A library for big integers: gcd, |
powering, square root, random numbers |
exercise solution codepad |
| 210 |
11 Feb 2011 |
Sums Of Powers: Use Bernoulli numbers to quickly compute sums of |
powers |
exercise solution codepad |
| 210 |
11 Feb 2011 |
Sums Of |
Powers: Use Bernoulli numbers to quickly compute sums of powers |
exercise solution codepad |
| 156 |
06 Aug 2010 |
Two Powering Predicates: Determine if a number is a square or a prime |
power |
exercise solution codepad |
| 286 |
08 Nov 2011 |
Improved Standard Continuation: An improved version of elliptic curve factorization, widely used in current |
practice |
exercise solution codepad |
| 186 |
19 Nov 2010 |
Topological Sort: Order the edges of a graph by their |
precedence relationship |
exercise solution codepad |
| 156 |
06 Aug 2010 |
Two Powering |
Predicates: Determine if a number is a square or a prime power |
exercise solution codepad |
| 107 |
02 Feb 2010 |
Proving |
Primality: A deterministic, not probabilistic, method of checking primality |
exercise solution codepad |
| 29 |
01 May 2009 |
Primality Checking: A probabilistic |
primality checker by Gary Miller and Michael Rabin |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci Primes: Find primes among the fibonacci numbers; includes the Park-Miller random number generator and Miller-Rabin |
primality checker |
exercise solution codepad |
| 29 |
01 May 2009 |
|
Primality Checking: A probabilistic primality checker by Gary Miller and Michael Rabin |
exercise solution codepad |
| 105 |
26 Jan 2010 |
|
Primality Checking, Revisited: The Baillie-Wagstaff algorithm for primality checking |
exercise solution codepad |
| 105 |
26 Jan 2010 |
Primality Checking, Revisited: The Baillie-Wagstaff algorithm for |
primality checking |
exercise solution codepad |
| 107 |
02 Feb 2010 |
Proving Primality: A deterministic, not probabilistic, method of checking |
primality |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for big integers: display factorials to 50, determine if a number is |
prime, and compute its prime factors |
exercise solution codepad |
| 259 |
02 Aug 2011 |
The Nth Prime: The n |
prime, counting from p1 = 2 |
exercise solution codepad |
| 200 |
07 Jan 2011 |
Counting Primes: The |
prime counting function and nth-prime function |
exercise solution codepad |
| 257 |
26 Jul 2011 |
More Prime-Counting Functions: |
Prime counting functions by Meissel and Lehmer, based on Legendre’s sum |
exercise solution codepad |
| 257 |
26 Jul 2011 |
More |
Prime-Counting Functions: Prime counting functions by Meissel and Lehmer, based on Legendre’s sum |
exercise solution codepad |
| 122 |
26 Mar 2010 |
The Next |
Prime: Efficiently find the next prime number larger than a given number |
exercise solution codepad |
| 251 |
05 Jul 2011 |
Big Numbers: Examples: A library for big integers: display factorials to 50, determine if a number is prime, and compute its |
prime factors |
exercise solution codepad |
| 184 |
12 Nov 2010 |
Rowland’s |
Prime-Generating Function: A sequence of ones and primes |
exercise solution codepad |
| 122 |
26 Mar 2010 |
The Next Prime: Efficiently find the next |
prime number larger than a given number |
exercise solution codepad |
| 24 |
14 Apr 2009 |
Google Treasure Hunt 2008 Puzzle 4: A |
prime-number puzzle |
exercise solution codepad |
| 181 |
02 Nov 2010 |
Emirps: |
Prime numbers that are prime when their digits are reversed, but not palindromic |
exercise solution codepad |
| 110 |
12 Feb 2010 |
Sieve of Atkin: A modern alternative to the Sieve of Eratosthenes for computing |
prime numbers |
exercise solution codepad |
| 278 |
07 Oct 2011 |
Sieve of Sundaram: Sieving for |
prime numbers using a method from India |
exercise solution codepad |
| 201 |
11 Jan 2011 |
Two Integrals: The exponential and logarithmic integral, and an approximation for |
prime-pi |
exercise solution codepad |
| 156 |
06 Aug 2010 |
Two Powering Predicates: Determine if a number is a square or a |
prime power |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci Primes: Find |
primes among the fibonacci numbers; includes the Park-Miller random number generator and Miller-Rabin primality checker |
exercise solution codepad |
| 212 |
18 Feb 2011 |
Two Factoring Games: Home |
primes and the Euclid-Mullin sequence |
exercise solution codepad |
| 279 |
14 Oct 2011 |
The First N |
Primes: Embedding the Sieve of Eratosthenes in a priority queue instead of an array |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci |
Primes: Find primes among the fibonacci numbers; includes the Park-Miller random number generator and Miller-Rabin primality checker |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting Primes Using Legendre’s Formula: Recreate Legendre’s two-century old calculation of the number of |
primes less than a million |
exercise solution codepad |
| 242 |
03 Jun 2011 |
Mersenne Primes: The Lucas-Lehmer test for identifying |
primes of the form 2n−1 |
exercise solution codepad |
| 242 |
03 Jun 2011 |
Mersenne |
Primes: The Lucas-Lehmer test for identifying primes of the form 2n−1 |
exercise solution codepad |
| 200 |
07 Jan 2011 |
Counting |
Primes: The prime counting function and nth-prime function |
exercise solution codepad |
| 115 |
02 Mar 2010 |
Goldbach’s Conjecture: Every even number greater than two can be written as the sum of two |
primes |
exercise solution codepad |
| 184 |
12 Nov 2010 |
Rowland’s Prime-Generating Function: A sequence of ones and |
primes |
exercise solution codepad |
| 214 |
25 Feb 2011 |
Sieve Of Euler: An alternate, and slow, method of sieving for |
primes |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting |
Primes Using Legendre’s Formula: Recreate Legendre’s two-century old calculation of the number of primes less than a million |
exercise solution codepad |
| 259 |
02 Aug 2011 |
The Nth |
Prime: The n prime, counting from p1 = 2 |
exercise solution codepad |
| 197 |
28 Dec 2010 |
Carmichael Numbers: Composite numbers such that an-1 ≡ 1 (mod n) if a is |
prime to n |
exercise solution codepad |
| 181 |
02 Nov 2010 |
Emirps: Prime numbers that are |
prime when their digits are reversed, but not palindromic |
exercise solution codepad |
| 231 |
26 Apr 2011 |
Miscellanea: FizzBuzz, |
Prime Words, and Split A List |
exercise solution codepad |
| 126 |
09 Apr 2010 |
Minimum Spanning Tree: |
Prim’s Algorithm: Find the minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 225 |
05 Apr 2011 |
Fortune: |
Print a random aphorism from a file |
exercise solution codepad |
| 32 |
12 May 2009 |
Loan Amortization: Calculate and |
print a simple loan amortization table |
exercise solution codepad |
| 98 |
01 Jan 2010 |
Cal: |
Print a twelve-month calendar |
exercise solution codepad |
| 136 |
28 May 2010 |
|
Printing Files: A simple program to list files, similar to the unix pr program |
exercise solution codepad |
| 276 |
30 Sep 2011 |
Logarithm Tables: |
Print old-fashioned tables of logarithms and anti-logarithms |
exercise solution codepad |
| 220 |
18 Mar 2011 |
Loopy Loops: |
Print the numbers from 1 to 1000 without using loops or conditionals |
exercise solution codepad |
| 171 |
28 Sep 2010 |
Maxiphobic Heaps: A |
priority-queue data structure, similar to leftist heaps, due to Chris Okasaki |
exercise solution codepad |
| 30 |
05 May 2009 |
Priority Queues: A simple library implementation of the |
priority queue data structure |
exercise solution codepad |
| 279 |
14 Oct 2011 |
The First N Primes: Embedding the Sieve of Eratosthenes in a |
priority queue instead of an array |
exercise solution codepad |
| 30 |
05 May 2009 |
|
Priority Queues: A simple library implementation of the priority queue data structure |
exercise solution codepad |
| 59 |
14 Aug 2009 |
Pairing Heaps: A standard algorithm for maintaining |
priority queues |
exercise solution codepad |
| 83 |
06 Nov 2009 |
Heap Sort: A guaranteed O(log n) sorting method based on |
priority queues |
exercise solution codepad |
| 107 |
02 Feb 2010 |
Proving Primality: A deterministic, not |
probabilistic, method of checking primality |
exercise solution codepad |
| 29 |
01 May 2009 |
Primality Checking: A |
probabilistic primality checker by Gary Miller and Michael Rabin |
exercise solution codepad |
| 26 |
21 Apr 2009 |
Probabilistic Spell Checking: A |
probabilistic spell-checker based on a Bloom filter |
exercise solution codepad |
| 26 |
21 Apr 2009 |
|
Probabilistic Spell Checking: A probabilistic spell-checker based on a Bloom filter |
exercise solution codepad |
| 53 |
24 Jul 2009 |
Let’s Make A Deal!: Simulate a tricky |
probability calculation |
exercise solution codepad |
| 3 |
19 Feb 2009 |
Bingo: Calculate the |
probability of winning at Bingo |
exercise solution codepad |
| 87 |
20 Nov 2009 |
Master Mind, Part 2: Solve a Master Mind puzzle in five |
probes or less |
exercise solution codepad |
| 261 |
09 Aug 2011 |
Hett’s |
Problem 1.28: Sorting a list of lists according to length of sublists |
exercise solution codepad |
| 273 |
20 Sep 2011 |
Project Euler |
Problem 3: Thorough explanation of integer factorization by trial division |
exercise solution codepad |
| 155 |
03 Aug 2010 |
Carl Hewitt’s Same-Fringe |
Problem: Do two trees have the same leaves, solved with streams (lazy lists) |
exercise solution codepad |
| 72 |
29 Sep 2009 |
Green Eyes: A counting |
problem from high-school math |
exercise solution codepad |
| 293 |
02 Dec 2011 |
Knight Rider: Classic |
problem of the knight’s tour |
exercise solution codepad |
| 267 |
30 Aug 2011 |
Hamming Numbers: List the numbers with no factors greater than 5, a classic |
problem popularized by Dijkstra |
exercise solution codepad |
| 14 |
10 Mar 2009 |
Word Frequencies: Our interpretation of a |
problem solved by a classic unix pipeline |
exercise solution codepad |
| 295 |
09 Dec 2011 |
McNugget Numbers: A simple |
problem, worked out on a napkin |
exercise solution codepad |
| 178 |
22 Oct 2010 |
Text File Databases: Part 2: Various functions to |
process records with fields |
exercise solution codepad |
| 145 |
29 Jun 2010 |
World Cup |
Prognostication: Simulate the knockout stage using elo ratings |
exercise solution codepad |
| 209 |
08 Feb 2011 |
The First Computer |
Program: Ada Lovelace’s program to compute Bernoulli numbers for Charles Babbage’s Analytical Engine |
exercise solution codepad |
| 215 |
01 Mar 2011 |
An Early LISP |
Program: A program to flatten a list, from the March 1960 LISP I manual |
exercise solution codepad |
| 230 |
22 Apr 2011 |
Xref: |
Programmer’s cross-reference utility |
exercise solution codepad |
| 284 |
01 Nov 2011 |
RIP John McCarthy: Implementation of the “Maxwell’s equations of software” from the LISP 1.5 |
Programmer’s Manual |
exercise solution codepad |
| 5 |
19 Feb 2009 |
Flavius Josephus: |
Programming a cyclical list |
exercise solution codepad |
| 40 |
09 Jun 2009 |
Longest Common Subsequence: A classic |
programming algorithm, with a solution that dates to folklore |
exercise solution codepad |
| 183 |
09 Nov 2010 |
Subset Sums: Third level of the Greplin Programming Challenge, using dynamic |
programming and memoization |
exercise solution codepad |
| 183 |
09 Nov 2010 |
Subset Sums: Third level of the Greplin |
Programming Challenge, using dynamic programming and memoization |
exercise solution codepad |
| 190 |
03 Dec 2010 |
Maximum Sum Subsequence: A classic |
programming exercise due to Jon Bentley |
exercise solution codepad |
| 46 |
30 Jun 2009 |
Steve Yegge’s Phone-Screen Coding Exercises: A simple set of |
programming exercises based on a blog entry by Steve Yegge |
exercise solution codepad |
| 58 |
11 Aug 2009 |
Uncle Bob’s Bowling Game Kata: Use pattern-matching on lists to solve a classic object-oriented |
programming exercise |
exercise solution codepad |
| 74 |
06 Oct 2009 |
MapReduce: Google’s famous system for parallelizing computations expressed as a |
programming idiom |
exercise solution codepad |
| 157 |
10 Aug 2010 |
Literate |
Programming: Structured documentation in the style of Donald Knuth |
exercise solution codepad |
| 21 |
03 Apr 2009 |
|
Programming the Turing Machine: A turing-machine program to multiply two numbers |
exercise solution codepad |
| 9 |
20 Feb 2009 |
A Self-Reproducing |
Program: The quintessential quine |
exercise solution codepad |
| 209 |
08 Feb 2011 |
The First Computer Program: Ada Lovelace’s |
program to compute Bernoulli numbers for Charles Babbage’s Analytical Engine |
exercise solution codepad |
| 215 |
01 Mar 2011 |
An Early LISP Program: A |
program to flatten a list, from the March 1960 LISP I manual |
exercise solution codepad |
| 136 |
28 May 2010 |
Printing Files: A simple |
program to list files, similar to the unix pr program |
exercise solution codepad |
| 21 |
03 Apr 2009 |
Programming the Turing Machine: A turing-machine |
program to multiply two numbers |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer Factorization: Combine trial division, Pollard’s rho and p−1 methods, and elliptic curves into a single factorization |
program |
exercise solution codepad |
| 136 |
28 May 2010 |
Printing Files: A simple program to list files, similar to the unix pr |
program |
exercise solution codepad |
| 166 |
10 Sep 2010 |
Data Encryption Standard: Part 4: DES driver |
program |
exercise solution codepad |
| 92 |
08 Dec 2009 |
Word Count: An implementation of the unix wc |
program |
exercise solution codepad |
| 273 |
20 Sep 2011 |
|
Project Euler Problem 3: Thorough explanation of integer factorization by trial division |
exercise solution codepad |
| 42 |
16 Jun 2009 |
Who Owns The Zebra?: A logic puzzle, solved by embedding a |
Prolog-like logic system in Scheme |
exercise solution codepad |
| 65 |
04 Sep 2009 |
Ron’s Cipher #4: Stream cipher by Ron Rivest that underlies the SSL and WEP |
protocols |
exercise solution codepad |
| 45 |
26 Jun 2009 |
Treaps: A randomized dictionary data structure, |
provides in-order access to key |
exercise solution codepad |
| 116 |
05 Mar 2010 |
Binary Search Tree: Classic data structure, |
providing insert, delete and lookup for ordered datatypes |
exercise solution codepad |
| 107 |
02 Feb 2010 |
|
Proving Primality: A deterministic, not probabilistic, method of checking primality |
exercise solution codepad |
| 136 |
28 May 2010 |
Printing Files: A simple program to list files, similar to the unix |
pr program |
exercise solution codepad |
| 60 |
18 Aug 2009 |
Blum Blum Shub: Stream cipher based on a cryptographically secure |
pseudo-random number generator |
exercise solution codepad |
| 185 |
16 Nov 2010 |
RSA Cryptography: The original |
public-key cryptographic system, still in wide use |
exercise solution codepad |
| 290 |
22 Nov 2011 |
Rabin’s Cryptosystem: |
Public-key cryptosystem, similar to RSA |
exercise solution codepad |
| 73 |
02 Oct 2009 |
Red-Black Trees: A |
purely functional dictionary data structure based on approximately-balanced trees |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s |
Puzle: partition {1,…,16} into two sets of equal size so each subset has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 24 |
14 Apr 2009 |
Google Treasure Hunt 2008 |
Puzzle 4: A prime-number puzzle |
exercise solution codepad |
| 89 |
27 Nov 2009 |
$7.11: A math |
puzzle: a+b+c+d = a×b×c×d = 7.11 |
exercise solution codepad |
| 41 |
12 Jun 2009 |
Feynman’s |
Puzzle: A simple logic puzzle |
exercise solution codepad |
| 129 |
20 Apr 2010 |
145 |
Puzzle: Build and evaluate expressions using the digits one through nine and the simple arithmetic operators |
exercise solution codepad |
| 229 |
19 Apr 2011 |
Same Five Digits: A math |
puzzle from New Scientist, solved by guest author Bob Miller |
exercise solution codepad |
| 87 |
20 Nov 2009 |
Master Mind, Part 2: Solve a Master Mind |
puzzle in five probes or less |
exercise solution codepad |
| 191 |
07 Dec 2010 |
Ullman’s |
Puzzle: It never hurts to sort |
exercise solution codepad |
| 79 |
23 Oct 2009 |
Mr. S. and Mr. P.: A logic |
puzzle popularized by John McCarthy |
exercise solution codepad |
| 42 |
16 Jun 2009 |
Who Owns The Zebra?: A logic |
puzzle, solved by embedding a Prolog-like logic system in Scheme |
exercise solution codepad |
| 7 |
20 Feb 2009 |
Multiple Dwellings: A simple logic |
puzzle, solved with the amb non-deterministic operator |
exercise solution codepad |
| 24 |
14 Apr 2009 |
Google Treasure Hunt 2008 Puzzle 4: A prime-number |
puzzle |
exercise solution codepad |
| 41 |
12 Jun 2009 |
Feynman’s Puzzle: A simple logic |
puzzle |
exercise solution codepad |
| 4 |
19 Feb 2009 |
Sudoku: A backtracking solution to everybody’s favorite |
puzzle |
exercise solution codepad |
| 99 |
05 Jan 2010 |
The Sum Of Two Squares: A math |
puzzle with a solution by Dijkstra |
exercise solution codepad |
| 80 |
27 Oct 2009 |
Three |
Quadratic Sorts: Bubble sort, selection sort and insertion sort |
exercise solution codepad |
| 237 |
17 May 2011 |
Two Bad Sorts: Stooge sort and bogosort are worse than |
quadratic |
exercise solution codepad |
| 109 |
09 Feb 2010 |
Numerical Integration: |
Quadrature by the rectangular, trapezoidal and Simpson’s method, including adaptive quadrature |
exercise solution codepad |
| 109 |
09 Feb 2010 |
Numerical Integration: Quadrature by the rectangular, trapezoidal and Simpson’s method, including adaptive |
quadrature |
exercise solution codepad |
| 211 |
15 Feb 2011 |
Google Code Jam |
Qualification Round Africa 2010: Three simple exercises |
exercise solution codepad |
| 30 |
05 May 2009 |
Priority Queues: A simple library implementation of the priority |
queue data structure |
exercise solution codepad |
| 279 |
14 Oct 2011 |
The First N Primes: Embedding the Sieve of Eratosthenes in a priority |
queue instead of an array |
exercise solution codepad |
| 30 |
05 May 2009 |
Priority |
Queues: A simple library implementation of the priority queue data structure |
exercise solution codepad |
| 269 |
06 Sep 2011 |
Deques: Library implementation of double-ended |
queues |
exercise solution codepad |
| 59 |
14 Aug 2009 |
Pairing Heaps: A standard algorithm for maintaining priority |
queues |
exercise solution codepad |
| 83 |
06 Nov 2009 |
Heap Sort: A guaranteed O(log n) sorting method based on priority |
queues |
exercise solution codepad |
| 210 |
11 Feb 2011 |
Sums Of Powers: Use Bernoulli numbers to |
quickly compute sums of powers |
exercise solution codepad |
| 113 |
23 Feb 2010 |
Engineering A Sort Function: A high-performance |
quicksort by Jon Bentley and Doug McIlroy |
exercise solution codepad |
| 82 |
03 Nov 2009 |
|
Quick Sort: Tony Hoare’s divide-and-conquer sorting algorithm |
exercise solution codepad |
| 9 |
20 Feb 2009 |
A Self-Reproducing Program: The quintessential |
quine |
exercise solution codepad |
| 9 |
20 Feb 2009 |
A Self-Reproducing Program: The |
quintessential quine |
exercise solution codepad |
| 90 |
01 Dec 2009 |
Wolves And |
Rabbits: Analyze population dynamics using the Lotka-Volterra equations |
exercise solution codepad |
| 64 |
01 Sep 2009 |
String Search: |
Rabin-Karp: Our final classic string-search algorithm |
exercise solution codepad |
| 290 |
22 Nov 2011 |
|
Rabin’s Cryptosystem: Public-key cryptosystem, similar to RSA |
exercise solution codepad |
| 29 |
01 May 2009 |
Primality Checking: A probabilistic primality checker by Gary Miller and Michael |
Rabin |
exercise solution codepad |
| 245 |
14 Jun 2011 |
Big Numbers: Input And Output: A library for big integers: input and output with |
radix conversion |
exercise solution codepad |
| 85 |
13 Nov 2009 |
Two linear sorts: Count sort and |
radix sort exploit the structure of integer keys |
exercise solution codepad |
| 20 |
31 Mar 2009 |
|
Rail-Fence Cipher: A simple transposition cipher |
exercise solution codepad |
| 221 |
22 Mar 2011 |
Two Kaprekar Exercises: Kaprekar chains and Kaprekar numbers, from the Indian mathematician Dattaraya |
Ramchandra Kaprekar |
exercise solution codepad |
| 225 |
05 Apr 2011 |
Fortune: Print a |
random aphorism from a file |
exercise solution codepad |
| 45 |
26 Jun 2009 |
Treaps: A |
randomized dictionary data structure, provides in-order access to key |
exercise solution codepad |
| 180 |
29 Oct 2010 |
Fibonacci Primes: Find primes among the fibonacci numbers; includes the Park-Miller |
random number generator and Miller-Rabin primality checker |
exercise solution codepad |
| 232 |
29 Apr 2011 |
Rule 30 RNG: The |
random number generator from Mathematica, based on Stephen Wolfram’s Rule 30 cellular automata |
exercise solution codepad |
| 135 |
25 May 2010 |
GB_FLIP: Donald Knuth’s portable, high-quality |
random-number generator from the Stanford Graphbase |
exercise solution codepad |
| 173 |
05 Oct 2010 |
George Marsaglia’s |
Random Number Generators: Nine high-quality RNGs in nineteen lines of code |
exercise solution codepad |
| 270 |
09 Sep 2011 |
Mersenne Twister: |
Random number generator with very long period, useful for simulations |
exercise solution codepad |
| 249 |
28 Jun 2011 |
Big Numbers: Functions: A library for big integers: gcd, powering, square root, |
random numbers |
exercise solution codepad |
| 192 |
10 Dec 2010 |
Two Random Selections: Use |
random number to select fortunes and lotto winners |
exercise solution codepad |
| 78 |
20 Oct 2009 |
Shuffle: Create |
random permutations of an array or linked list |
exercise solution codepad |
| 192 |
10 Dec 2010 |
Two |
Random Selections: Use random number to select fortunes and lotto winners |
exercise solution codepad |
| 108 |
05 Feb 2010 |
Segmented Sieve Of Eratosthenes: Extend the Sieve of Eratosthenes to large |
ranges of integers |
exercise solution codepad |
| 44 |
23 Jun 2009 |
The Mod Out System: Expand a series of |
ranges |
exercise solution codepad |
| 145 |
29 Jun 2010 |
World Cup Prognostication: Simulate the knockout stage using elo |
ratings |
exercise solution codepad |
| 49 |
10 Jul 2009 |
The Golden |
Ratio: Evaluate a continued fraction, based on my daughter’s math homework |
exercise solution codepad |
| 205 |
25 Jan 2011 |
|
Rational Numbers: A library of basic arithmetic and comparison of fractions |
exercise solution codepad |
| 280 |
18 Oct 2011 |
The Wall: |
Ray Panko’s spreadsheet exercise |
exercise solution codepad |
| 13 |
06 Mar 2009 |
Roman Numerals: A library to |
read and write Roman numerals |
exercise solution codepad |
| 177 |
19 Oct 2010 |
Text File Databases: Part 1: Functions to |
read records with fields in various formats |
exercise solution codepad |
| 240 |
27 May 2011 |
Upside Up: Numbers that |
read the same upside down |
exercise solution codepad |
| 16 |
17 Mar 2009 |
Comma-Separated Values: Retrieve |
records from a comma-separated values file using a finite-state machine |
exercise solution codepad |
| 177 |
19 Oct 2010 |
Text File Databases: Part 1: Functions to read |
records with fields in various formats |
exercise solution codepad |
| 178 |
22 Oct 2010 |
Text File Databases: Part 2: Various functions to process |
records with fields |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting Primes Using Legendre’s Formula: |
Recreate Legendre’s two-century old calculation of the number of primes less than a million |
exercise solution codepad |
| 109 |
09 Feb 2010 |
Numerical Integration: Quadrature by the |
rectangular, trapezoidal and Simpson’s method, including adaptive quadrature |
exercise solution codepad |
| 137 |
01 Jun 2010 |
Unwrapping A Spiral: An exercise in |
recursion |
exercise solution codepad |
| 279 |
11 Oct 2011 |
Tower Of Hanoi: Classic demonstration of |
recursion |
exercise solution codepad |
| 73 |
02 Oct 2009 |
|
Red-Black Trees: A purely functional dictionary data structure based on approximately-balanced trees |
exercise solution codepad |
| 287 |
11 Nov 2011 |
Generators: Write functions that yield a value, but can then be |
re-entered |
exercise solution codepad |
| 86 |
17 Nov 2009 |
Master Mind, Part 1: |
Referee a two-player game of deductive logic |
exercise solution codepad |
| 275 |
27 Sep 2011 |
Statistics: Calculate the mean, standard deviation, linear |
regression and correlation |
exercise solution codepad |
| 67 |
11 Sep 2009 |
Beautiful Code: A simple |
regular-expression matcher by Rob Pike |
exercise solution codepad |
| 71 |
25 Sep 2009 |
Grep: Simple version of the classic unix |
regular-expression matching utility |
exercise solution codepad |
| 68 |
15 Sep 2009 |
|
Regular Expressions, Part 1: A parser for regular expressions |
exercise solution codepad |
| 69 |
18 Sep 2009 |
|
Regular Expressions, Part 2: The corresponding matcher |
exercise solution codepad |
| 70 |
22 Sep 2009 |
|
Regular Expressions, Part 3: A regular expression test suite |
exercise solution codepad |
| 68 |
15 Sep 2009 |
Regular Expressions, Part 1: A parser for |
regular expressions |
exercise solution codepad |
| 70 |
22 Sep 2009 |
Regular Expressions, Part 3: A |
regular expression test suite |
exercise solution codepad |
| 235 |
10 May 2011 |
Comm: select or |
reject lines common to two sorted files |
exercise solution codepad |
| 141 |
15 Jun 2010 |
Natural Join: The fundamental |
relational database operator |
exercise solution codepad |
| 186 |
19 Nov 2010 |
Topological Sort: Order the edges of a graph by their precedence |
relationship |
exercise solution codepad |
| 162 |
27 Aug 2010 |
Chinese |
Remainders: An ancient application of modular inverses |
exercise solution codepad |
| 268 |
02 Sep 2011 |
Two String Exercises: |
Remove duplicate characters, and squish adjacent blanks |
exercise solution codepad |
| 66 |
08 Sep 2009 |
Porter Stemming: Martin Porter’s algorithm for |
removing suffices from word stems |
exercise solution codepad |
| 264 |
19 Aug 2011 |
First Non-Repeating Character: Find the first character in a string that doesn’t |
repeat later in the string |
exercise solution codepad |
| 198 |
31 Dec 2010 |
Arithmetic Drill: |
Repetitious drill for children learning basic arithmetic |
exercise solution codepad |
| 234 |
06 May 2011 |
Entab And Detab: expand tabs into spaces, and |
replace spaces with tabs |
exercise solution codepad |
| 239 |
24 May 2011 |
Big Numbers: Getting Started: A library for big integers: |
representation, comparison, simple functions |
exercise solution codepad |
| 206 |
28 Jan 2011 |
Population Count: Count the number of set bits (1-bits) in the binary |
representation of an integer |
exercise solution codepad |
| 227 |
12 Apr 2011 |
House Of |
Representatives: Apportion representatives by the Huntington-Hill method |
exercise solution codepad |
| 227 |
12 Apr 2011 |
House Of Representatives: Apportion |
representatives by the Huntington-Hill method |
exercise solution codepad |
| 297 |
16 Dec 2011 |
Majority Voting: Determine the |
results of an election |
exercise solution codepad |
| 16 |
17 Mar 2009 |
Comma-Separated Values: |
Retrieve records from a comma-separated values file using a finite-state machine |
exercise solution codepad |
| 181 |
02 Nov 2010 |
Emirps: Prime numbers that are prime when their digits are |
reversed, but not palindromic |
exercise solution codepad |
| 266 |
26 Aug 2011 |
|
Reverse Every K Nodes Of A Linked List: Reverse the elements of a sub-list |
exercise solution codepad |
| 266 |
26 Aug 2011 |
Reverse Every K Nodes Of A Linked List: |
Reverse the elements of a sub-list |
exercise solution codepad |
| 217 |
08 Mar 2011 |
Reverse Words: |
Reverse the words in an input string |
exercise solution codepad |
| 217 |
08 Mar 2011 |
|
Reverse Words: Reverse the words in an input string |
exercise solution codepad |
| 272 |
16 Sep 2011 |
Pollard’s P−1 Factorization Algoritihm, |
Revisited: An improved second stage that is much faster than the original |
exercise solution codepad |
| 223 |
28 Mar 2011 |
Look And Say, |
Revisited: Compute Conway’s constant |
exercise solution codepad |
| 204 |
21 Jan 0 |
Pollard Rho, |
Revisited: Richard Brent’s variant of John Pollard’s rho algorithm for integer factorization |
exercise solution codepad |
| 281 |
21 Oct 2011 |
Sum, |
Revisited: SysV and Berkeley versions of the Unix V7 sum command |
exercise solution codepad |
| 105 |
26 Jan 2010 |
Primality Checking, |
Revisited: The Baillie-Wagstaff algorithm for primality checking |
exercise solution codepad |
| 258 |
29 Jul 2011 |
Approximating Pi: Approximating pi with the logarithmic integral and Riemann’s |
R function |
exercise solution codepad |
| 204 |
21 Jan 0 |
Pollard Rho, Revisited: Richard Brent’s variant of John Pollard’s |
rho algorithm for integer factorization |
exercise solution codepad |
| 43 |
19 Jun 2009 |
Monte Carlo Factorization: Integer factorization via Pollard’s |
rho algorithm |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer Factorization: Combine trial division, Pollard’s |
rho and p−1 methods, and elliptic curves into a single factorization program |
exercise solution codepad |
| 204 |
21 Jan 0 |
Pollard |
Rho, Revisited: Richard Brent’s variant of John Pollard’s rho algorithm for integer factorization |
exercise solution codepad |
| 204 |
21 Jan 0 |
Pollard Rho, Revisited: |
Richard Brent’s variant of John Pollard’s rho algorithm for integer factorization |
exercise solution codepad |
| 293 |
02 Dec 2011 |
Knight |
Rider: Classic problem of the knight’s tour |
exercise solution codepad |
| 258 |
29 Jul 2011 |
Approximating Pi: Approximating pi with the logarithmic integral and |
Riemann’s R function |
exercise solution codepad |
| 284 |
01 Nov 2011 |
|
RIP John McCarthy: Implementation of the “Maxwell’s equations of software” from the LISP 1.5 Programmer’s Manual |
exercise solution codepad |
| 65 |
04 Sep 2009 |
Ron’s Cipher #4: Stream cipher by Ron |
Rivest that underlies the SSL and WEP protocols |
exercise solution codepad |
| 173 |
05 Oct 2010 |
George Marsaglia’s Random Number Generators: Nine high-quality |
RNGs in nineteen lines of code |
exercise solution codepad |
| 232 |
29 Apr 2011 |
Rule 30 |
RNG: The random number generator from Mathematica, based on Stephen Wolfram’s Rule 30 cellular automata |
exercise solution codepad |
| 67 |
11 Sep 2009 |
Beautiful Code: A simple regular-expression matcher by |
Rob Pike |
exercise solution codepad |
| 13 |
06 Mar 2009 |
|
Roman Numerals: A library to read and write Roman numerals |
exercise solution codepad |
| 13 |
06 Mar 2009 |
Roman Numerals: A library to read and write |
Roman numerals |
exercise solution codepad |
| 65 |
04 Sep 2009 |
Ron’s Cipher #4: Stream cipher by |
Ron Rivest that underlies the SSL and WEP protocols |
exercise solution codepad |
| 65 |
04 Sep 2009 |
|
Ron’s Cipher #4: Stream cipher by Ron Rivest that underlies the SSL and WEP protocols |
exercise solution codepad |
| 249 |
28 Jun 2011 |
Big Numbers: Functions: A library for big integers: gcd, powering, square |
root, random numbers |
exercise solution codepad |
| 95 |
18 Dec 2009 |
Calculating Logarithms: Use the methods of Newton and Euler to calculate square |
roots and logarithms |
exercise solution codepad |
| 48 |
07 Jul 2009 |
Modular Arithmetic: A function library for performing modular addition, subtraction, multiplication, division, and square |
root |
exercise solution codepad |
| 123 |
30 Mar 2010 |
Passover: Calculate the dates of the Jewish holidays |
Rosh Hashanah and Passover |
exercise solution codepad |
| 6 |
20 Feb 2009 |
|
ROT13: A simple Caesar-shift cipher |
exercise solution codepad |
| 175 |
12 Oct 2010 |
|
Rotate An Array: A simple but tricky exercise solved by an algorithm from the folklore of computing |
exercise solution codepad |
| 211 |
15 Feb 2011 |
Google Code Jam Qualification |
Round Africa 2010: Three simple exercises |
exercise solution codepad |
| 184 |
12 Nov 2010 |
|
Rowland’s Prime-Generating Function: A sequence of ones and primes |
exercise solution codepad |
| 1 |
19 Feb 2009 |
|
RPN Calculator: Evaluate numeric expressions at the command line |
exercise solution codepad |
| 185 |
16 Nov 2010 |
|
RSA Cryptography: The original public-key cryptographic system, still in wide use |
exercise solution codepad |
| 290 |
22 Nov 2011 |
Rabin’s Cryptosystem: Public-key cryptosystem, similar to |
RSA |
exercise solution codepad |
| 232 |
29 Apr 2011 |
Rule 30 RNG: The random number generator from Mathematica, based on Stephen Wolfram’s |
Rule 30 cellular automata |
exercise solution codepad |
| 232 |
29 Apr 2011 |
|
Rule 30 RNG: The random number generator from Mathematica, based on Stephen Wolfram’s Rule 30 cellular automata |
exercise solution codepad |
| 114 |
26 Feb 2010 |
|
Run Length Encoding: A simple compression method for text files |
exercise solution codepad |
| 77 |
16 Oct 2009 |
Growable Arrays: Arrays that grow and shrink at |
run-time, with O(log n) complexity per operation |
exercise solution codepad |
| 118 |
12 Mar 2010 |
Traveling |
Salesman: Brute Force: Examine all possible permutations to find the least-cost tour |
exercise solution codepad |
| 127 |
13 Apr 2010 |
Traveling |
Salesman: Minimum Spanning Tree: Heuristic guarantees solution within factor of two of optimal tour |
exercise solution codepad |
| 119 |
16 Mar 2010 |
Traveling |
Salesman: Nearest Neighbor: A greedy heuristic that builds a path by always choosing the nearest unvisited point |
exercise solution codepad |
| 229 |
19 Apr 2011 |
|
Same Five Digits: A math puzzle from New Scientist, solved by guest author Bob Miller |
exercise solution codepad |
| 155 |
03 Aug 2010 |
Carl Hewitt’s |
Same-Fringe Problem: Do two trees have the same leaves, solved with streams (lazy lists) |
exercise solution codepad |
| 155 |
03 Aug 2010 |
Carl Hewitt’s Same-Fringe Problem: Do two trees have the |
same leaves, solved with streams (lazy lists) |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into two sets of equal size so each subset has the |
same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 240 |
27 May 2011 |
Upside Up: Numbers that read the |
same upside down |
exercise solution codepad |
| 28 |
28 Apr 2009 |
Morse Code: Translating the dots-and-dashes of |
Samuel Finley Breese Morse’s telegraph code |
exercise solution codepad |
| 79 |
23 Oct 2009 |
Mr. |
S. and Mr. P.: A logic puzzle popularized by John McCarthy |
exercise solution codepad |
| 196 |
24 Dec 2010 |
Tracking |
Santa: How far does Santa travel on his annual journey? |
exercise solution codepad |
| 196 |
24 Dec 2010 |
Tracking Santa: How far does |
Santa travel on his annual journey? |
exercise solution codepad |
| 219 |
15 Mar 2011 |
Look And |
Say: Calculate John Horton Conway’s "Look and Say" sequence |
exercise solution codepad |
| 223 |
28 Mar 2011 |
Look And |
Say, Revisited: Compute Conway’s constant |
exercise solution codepad |
| 219 |
15 Mar 2011 |
Look And Say: Calculate John Horton Conway’s "Look and |
Say" sequence |
exercise solution codepad |
| 143 |
22 Jun 2010 |
Matrix Operations: Matrix addition, |
scalar multiplication, multiplication and transposition |
exercise solution codepad |
| 189 |
30 Nov 2010 |
Form Letters: Merge a |
schema and a data file to write form letters |
exercise solution codepad |
| 2 |
19 Feb 2009 |
Sieve of Eratosthenes: A |
Scheme implementation of an ancient algorithm |
exercise solution codepad |
| 42 |
16 Jun 2009 |
Who Owns The Zebra?: A logic puzzle, solved by embedding a Prolog-like logic system in |
Scheme |
exercise solution codepad |
| 246 |
17 Jun 2011 |
Adi Shamir’s Threshold |
Scheme: Use cryptography to share a secret, by Graham Enos |
exercise solution codepad |
| 203 |
18 Jan 2011 |
Solitaire Cipher: Bruce |
Schneier’s strong cryptography based on a deck of playing cards |
exercise solution codepad |
| 289 |
18 Nov 2011 |
Grade School Multiplication: Display the steps in the grade |
school multiplication algorithm |
exercise solution codepad |
| 289 |
18 Nov 2011 |
Grade |
School Multiplication: Display the steps in the grade school multiplication algorithm |
exercise solution codepad |
| 33 |
15 May 2009 |
Cellular Automata: Linear cellular automata as described by Stephen Wolfram in his book A New Kind of |
Science |
exercise solution codepad |
| 229 |
19 Apr 2011 |
Same Five Digits: A math puzzle from New |
Scientist, solved by guest author Bob Miller |
exercise solution codepad |
| 18 |
23 Mar 2009 |
Binary |
Search: A simple task, easy to get wrong |
exercise solution codepad |
| 63 |
28 Aug 2009 |
String |
Search: Boyer-Moore: Search for a pattern in a text using a fast and simple algorithm |
exercise solution codepad |
| 61 |
21 Aug 2009 |
String |
Search: Brute Force: Search for a pattern in a text by comparing the pattern to the text at all possible positions |
exercise solution codepad |
| 61 |
21 Aug 2009 |
String Search: Brute Force: |
Search for a pattern in a text by comparing the pattern to the text at all possible positions |
exercise solution codepad |
| 63 |
28 Aug 2009 |
String Search: Boyer-Moore: |
Search for a pattern in a text using a fast and simple algorithm |
exercise solution codepad |
| 62 |
25 Aug 2009 |
String Search: Knuth-Morris-Pratt: |
Search for a pattern in a text using an O(n) algorithm |
exercise solution codepad |
| 62 |
25 Aug 2009 |
String |
Search: Knuth-Morris-Pratt: Search for a pattern in a text using an O(n) algorithm |
exercise solution codepad |
| 64 |
01 Sep 2009 |
String |
Search: Rabin-Karp: Our final classic string-search algorithm |
exercise solution codepad |
| 36 |
26 May 2009 |
Word |
Search Solver: A computerized implementation of a popular time-waster |
exercise solution codepad |
| 116 |
05 Mar 2010 |
Binary |
Search Tree: Classic data structure, providing insert, delete and lookup for ordered datatypes |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest Common Ancestor: Find the lowest node in a binary |
search tree that is a common ancestor to two given nodes |
exercise solution codepad |
| 39 |
05 Jun 2009 |
Ternary |
Search Tries: Build a function library for handling ternary search tries |
exercise solution codepad |
| 39 |
05 Jun 2009 |
Ternary Search Tries: Build a function library for handling ternary |
search tries |
exercise solution codepad |
| 272 |
16 Sep 2011 |
Pollard’s P−1 Factorization Algoritihm, Revisited: An improved |
second stage that is much faster than the original |
exercise solution codepad |
| 120 |
19 Mar 2010 |
Extending Pollard’s P−1 Factorization Algorithm: Add a |
second stage to allow larger factorizations |
exercise solution codepad |
| 246 |
17 Jun 2011 |
Adi Shamir’s Threshold Scheme: Use cryptography to share a |
secret, by Graham Enos |
exercise solution codepad |
| 60 |
18 Aug 2009 |
Blum Blum Shub: Stream cipher based on a cryptographically |
secure pseudo-random number generator |
exercise solution codepad |
| 108 |
05 Feb 2010 |
|
Segmented Sieve Of Eratosthenes: Extend the Sieve of Eratosthenes to large ranges of integers |
exercise solution codepad |
| 159 |
17 Aug 2010 |
Cut: |
Select fields or characters from input lines |
exercise solution codepad |
| 192 |
10 Dec 2010 |
Two Random Selections: Use random number to |
select fortunes and lotto winners |
exercise solution codepad |
| 93 |
11 Dec 2009 |
|
Selection: Find the kth-largest item in a list |
exercise solution codepad |
| 80 |
27 Oct 2009 |
Three Quadratic Sorts: Bubble sort, |
selection sort and insertion sort |
exercise solution codepad |
| 192 |
10 Dec 2010 |
Two Random |
Selections: Use random number to select fortunes and lotto winners |
exercise solution codepad |
| 235 |
10 May 2011 |
Comm: |
select or reject lines common to two sorted files |
exercise solution codepad |
| 9 |
20 Feb 2009 |
A |
Self-Reproducing Program: The quintessential quine |
exercise solution codepad |
| 184 |
12 Nov 2010 |
Rowland’s Prime-Generating Function: A |
sequence of ones and primes |
exercise solution codepad |
| 212 |
18 Feb 2011 |
Two Factoring Games: Home primes and the Euclid-Mullin |
sequence |
exercise solution codepad |
| 219 |
15 Mar 2011 |
Look And Say: Calculate John Horton Conway’s "Look and Say" |
sequence |
exercise solution codepad |
| 101 |
12 Jan 2010 |
Calculating Sines: Calculate sines using Taylor |
series and the triple-angle formula, by Bill Cruise |
exercise solution codepad |
| 44 |
23 Jun 2009 |
The Mod Out System: Expand a |
series of ranges |
exercise solution codepad |
| 206 |
28 Jan 2011 |
Population Count: Count the number of |
set bits (1-bits) in the binary representation of an integer |
exercise solution codepad |
| 149 |
13 Jul 2010 |
Word Cube: A game to form words from a given |
set of letters |
exercise solution codepad |
| 46 |
30 Jun 2009 |
Steve Yegge’s Phone-Screen Coding Exercises: A simple |
set of programming exercises based on a blog entry by Steve Yegge |
exercise solution codepad |
| 124 |
02 Apr 2010 |
Disjoint |
Sets: A data structure for storing sets of items in disjoint partitions |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into two |
sets of equal size so each subset has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 124 |
02 Apr 2010 |
Disjoint Sets: A data structure for storing |
sets of items in disjoint partitions |
exercise solution codepad |
| 133 |
04 May 2010 |
Spectacular |
Seven: Compute the odds at jai alai |
exercise solution codepad |
| 246 |
17 Jun 2011 |
Adi |
Shamir’s Threshold Scheme: Use cryptography to share a secret, by Graham Enos |
exercise solution codepad |
| 11 |
27 Feb 2009 |
Mark V. |
Shaney: Generate parodies of a text using a Markov chain |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel |
Shanks’ Square Form Factorization Algorithm: A simple and very fast factorization algorithm for integers between 105 and 1020 |
exercise solution codepad |
| 246 |
17 Jun 2011 |
Adi Shamir’s Threshold Scheme: Use cryptography to |
share a secret, by Graham Enos |
exercise solution codepad |
| 160 |
20 Aug 0 |
Marriage Sort: A sub-quadratic sort similar to |
shell sort or comb sort |
exercise solution codepad |
| 81 |
30 Oct 2009 |
Two Sub-Quadratic Sorts: Comb sort and |
shell sort |
exercise solution codepad |
| 199 |
04 Jan 2011 |
Dijkstra’s Algorithm: Find the |
shortest path to all vertices of a graph from a single source, guest written by Graham Enos |
exercise solution codepad |
| 77 |
16 Oct 2009 |
Growable Arrays: Arrays that grow and |
shrink at run-time, with O(log n) complexity per operation |
exercise solution codepad |
| 60 |
18 Aug 2009 |
Blum Blum |
Shub: Stream cipher based on a cryptographically secure pseudo-random number generator |
exercise solution codepad |
| 78 |
20 Oct 2009 |
|
Shuffle: Create random permutations of an array or linked list |
exercise solution codepad |
| 195 |
21 Dec 2010 |
Interval Arithmetic: An exercise from |
SICP |
exercise solution codepad |
| 254 |
15 Jul 2011 |
JSON: Writing Output: The other |
side of JSAON |
exercise solution codepad |
| 110 |
12 Feb 2010 |
|
Sieve of Atkin: A modern alternative to the Sieve of Eratosthenes for computing prime numbers |
exercise solution codepad |
| 112 |
19 Feb 2010 |
|
Sieve Of Atkin, Improved: A faster version of the Sieve of Atkin |
exercise solution codepad |
| 112 |
19 Feb 2010 |
Sieve Of Atkin, Improved: A faster version of the |
Sieve of Atkin |
exercise solution codepad |
| 2 |
19 Feb 2009 |
|
Sieve of Eratosthenes: A Scheme implementation of an ancient algorithm |
exercise solution codepad |
| 108 |
05 Feb 2010 |
Segmented |
Sieve Of Eratosthenes: Extend the Sieve of Eratosthenes to large ranges of integers |
exercise solution codepad |
| 110 |
12 Feb 2010 |
Sieve of Atkin: A modern alternative to the |
Sieve of Eratosthenes for computing prime numbers |
exercise solution codepad |
| 279 |
14 Oct 2011 |
The First N Primes: Embedding the |
Sieve of Eratosthenes in a priority queue instead of an array |
exercise solution codepad |
| 108 |
05 Feb 2010 |
Segmented Sieve Of Eratosthenes: Extend the |
Sieve of Eratosthenes to large ranges of integers |
exercise solution codepad |
| 214 |
25 Feb 2011 |
|
Sieve Of Euler: An alternate, and slow, method of sieving for primes |
exercise solution codepad |
| 278 |
07 Oct 2011 |
|
Sieve of Sundaram: Sieving for prime numbers using a method from India |
exercise solution codepad |
| 278 |
07 Oct 2011 |
Sieve of Sundaram: |
Sieving for prime numbers using a method from India |
exercise solution codepad |
| 214 |
25 Feb 2011 |
Sieve Of Euler: An alternate, and slow, method of |
sieving for primes |
exercise solution codepad |
| 111 |
16 Feb 2010 |
Soundex: An algorithm to assign people’s last names to equivalence classes based on |
similar spelling |
exercise solution codepad |
| 171 |
28 Sep 2010 |
Maxiphobic Heaps: A priority-queue data structure, |
similar to leftist heaps, due to Chris Okasaki |
exercise solution codepad |
| 138 |
04 Jun 2010 |
Williams’ P+1 Factorization Algorithm: A factorization algorithm, |
similar to Pollard’s p−1 algorithm |
exercise solution codepad |
| 290 |
22 Nov 2011 |
Rabin’s Cryptosystem: Public-key cryptosystem, |
similar to RSA |
exercise solution codepad |
| 160 |
20 Aug 0 |
Marriage Sort: A sub-quadratic sort |
similar to shell sort or comb sort |
exercise solution codepad |
| 136 |
28 May 2010 |
Printing Files: A simple program to list files, |
similar to the unix pr program |
exercise solution codepad |
| 63 |
28 Aug 2009 |
String Search: Boyer-Moore: Search for a pattern in a text using a fast and |
simple algorithm |
exercise solution codepad |
| 37 |
29 May 2009 |
Double Transposition Cipher: A |
simple and effective cipher, easy to perform by hand |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel Shanks’ Square Form Factorization Algorithm: A |
simple and very fast factorization algorithm for integers between 105 and 1020 |
exercise solution codepad |
| 129 |
20 Apr 2010 |
145 Puzzle: Build and evaluate expressions using the digits one through nine and the |
simple arithmetic operators |
exercise solution codepad |
| 76 |
13 Oct 2009 |
Bifid: A |
simple but effective fractionating cipher, never used militarily |
exercise solution codepad |
| 175 |
12 Oct 2010 |
Rotate An Array: A |
simple but tricky exercise solved by an algorithm from the folklore of computing |
exercise solution codepad |
| 6 |
20 Feb 2009 |
ROT13: A |
simple Caesar-shift cipher |
exercise solution codepad |
| 114 |
26 Feb 2010 |
Run Length Encoding: A |
simple compression method for text files |
exercise solution codepad |
| 283 |
28 Oct 2011 |
Crypt: |
Simple encryption tool from Kernighan and Plauger |
exercise solution codepad |
| 211 |
15 Feb 2011 |
Google Code Jam Qualification Round Africa 2010: Three |
simple exercises |
exercise solution codepad |
| 38 |
02 Jun 2009 |
Pig Latin: A |
simple exercise to solve a children’s game |
exercise solution codepad |
| 52 |
21 Jul 2009 |
Pollard’s P−1 Factorization Algorithm: A |
simple factorization algorithm by John Pollard |
exercise solution codepad |
| 239 |
24 May 2011 |
Big Numbers: Getting Started: A library for big integers: representation, comparison, |
simple functions |
exercise solution codepad |
| 55 |
31 Jul 2009 |
Elliptic Curve Factorization: A very |
simple implementation of elliptic curve factorization |
exercise solution codepad |
| 30 |
05 May 2009 |
Priority Queues: A |
simple library implementation of the priority queue data structure |
exercise solution codepad |
| 32 |
12 May 2009 |
Loan Amortization: Calculate and print a |
simple loan amortization table |
exercise solution codepad |
| 7 |
20 Feb 2009 |
Multiple Dwellings: A |
simple logic puzzle, solved with the amb non-deterministic operator |
exercise solution codepad |
| 41 |
12 Jun 2009 |
Feynman’s Puzzle: A |
simple logic puzzle |
exercise solution codepad |
| 295 |
09 Dec 2011 |
McNugget Numbers: A |
simple problem, worked out on a napkin |
exercise solution codepad |
| 136 |
28 May 2010 |
Printing Files: A |
simple program to list files, similar to the unix pr program |
exercise solution codepad |
| 67 |
11 Sep 2009 |
Beautiful Code: A |
simple regular-expression matcher by Rob Pike |
exercise solution codepad |
| 46 |
30 Jun 2009 |
Steve Yegge’s Phone-Screen Coding Exercises: A |
simple set of programming exercises based on a blog entry by Steve Yegge |
exercise solution codepad |
| 158 |
13 Aug 2010 |
E: A |
simple simulation with a surprising ending |
exercise solution codepad |
| 18 |
23 Mar 2009 |
Binary Search: A |
simple task, easy to get wrong |
exercise solution codepad |
| 20 |
31 Mar 2009 |
Rail-Fence Cipher: A |
simple transposition cipher |
exercise solution codepad |
| 15 |
13 Mar 2009 |
Friday, the Thirteenth: A small calendar library, and a |
simple use of it |
exercise solution codepad |
| 71 |
25 Sep 2009 |
Grep: |
Simple version of the classic unix regular-expression matching utility |
exercise solution codepad |
| 109 |
09 Feb 2010 |
Numerical Integration: Quadrature by the rectangular, trapezoidal and |
Simpson’s method, including adaptive quadrature |
exercise solution codepad |
| 216 |
04 Mar 2011 |
Chutes And Ladders: |
Simulate a child’s game, and compute its statistics |
exercise solution codepad |
| 285 |
04 Nov 2011 |
Craps: |
Simulate a popular game of gambling with dice |
exercise solution codepad |
| 202 |
14 Jan 2011 |
Slots: |
Simulate a slot machine |
exercise solution codepad |
| 53 |
24 Jul 2009 |
Let’s Make A Deal!: |
Simulate a tricky probability calculation |
exercise solution codepad |
| 145 |
29 Jun 2010 |
World Cup Prognostication: |
Simulate the knockout stage using elo ratings |
exercise solution codepad |
| 270 |
09 Sep 2011 |
Mersenne Twister: Random number generator with very long period, useful for |
simulations |
exercise solution codepad |
| 158 |
13 Aug 2010 |
E: A simple |
simulation with a surprising ending |
exercise solution codepad |
| 19 |
27 Mar 2009 |
A Turing Machine |
Simulator: An interpreter for a single-tape, multi-symbol turing machine |
exercise solution codepad |
| 104 |
22 Jan 2010 |
Phases Of The Moon: Calculate the number of days |
since the last new moon |
exercise solution codepad |
| 101 |
12 Jan 2010 |
Calculating |
Sines: Calculate sines using Taylor series and the triple-angle formula, by Bill Cruise |
exercise solution codepad |
| 101 |
12 Jan 2010 |
Calculating Sines: Calculate |
sines using Taylor series and the triple-angle formula, by Bill Cruise |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer Factorization: Combine trial division, Pollard’s rho and p−1 methods, and elliptic curves into a |
single factorization program |
exercise solution codepad |
| 199 |
04 Jan 2011 |
Dijkstra’s Algorithm: Find the shortest path to all vertices of a graph from a |
single source, guest written by Graham Enos |
exercise solution codepad |
| 19 |
27 Mar 2009 |
A Turing Machine Simulator: An interpreter for a |
single-tape, multi-symbol turing machine |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into two sets of equal |
size so each subset has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 213 |
22 Feb 2011 |
Sliding Window Minimum: List of minimums |
sliding across an input list |
exercise solution codepad |
| 213 |
22 Feb 2011 |
|
Sliding Window Minimum: List of minimums sliding across an input list |
exercise solution codepad |
| 202 |
14 Jan 2011 |
Slots: Simulate a |
slot machine |
exercise solution codepad |
| 202 |
14 Jan 2011 |
|
Slots: Simulate a slot machine |
exercise solution codepad |
| 236 |
13 May 2011 |
Dixon’s Factorization Algorithm: A |
slow, but theoretically important, algorithm for integer factorization |
exercise solution codepad |
| 214 |
25 Feb 2011 |
Sieve Of Euler: An alternate, and |
slow, method of sieving for primes |
exercise solution codepad |
| 15 |
13 Mar 2009 |
Friday, the Thirteenth: A |
small calendar library, and a simple use of it |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into two sets of equal size |
so each subset has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 284 |
01 Nov 2011 |
RIP John McCarthy: Implementation of the “Maxwell’s equations of |
software” from the LISP 1.5 Programmer’s Manual |
exercise solution codepad |
| 203 |
18 Jan 2011 |
|
Solitaire Cipher: Bruce Schneier’s strong cryptography based on a deck of playing cards |
exercise solution codepad |
| 99 |
05 Jan 2010 |
The Sum Of Two Squares: A math puzzle with a |
solution by Dijkstra |
exercise solution codepad |
| 40 |
09 Jun 2009 |
Longest Common Subsequence: A classic programming algorithm, with a |
solution that dates to folklore |
exercise solution codepad |
| 4 |
19 Feb 2009 |
Sudoku: A backtracking |
solution to everybody’s favorite puzzle |
exercise solution codepad |
| 127 |
13 Apr 2010 |
Traveling Salesman: Minimum Spanning Tree: Heuristic guarantees |
solution within factor of two of optimal tour |
exercise solution codepad |
| 38 |
02 Jun 2009 |
Pig Latin: A simple exercise to |
solve a children’s game |
exercise solution codepad |
| 58 |
11 Aug 2009 |
Uncle Bob’s Bowling Game Kata: Use pattern-matching on lists to |
solve a classic object-oriented programming exercise |
exercise solution codepad |
| 87 |
20 Nov 2009 |
Master Mind, Part 2: |
Solve a Master Mind puzzle in five probes or less |
exercise solution codepad |
| 50 |
14 Jul 2009 |
The Daily Cryptogram: |
Solve a monoalphabetic substitution cipher |
exercise solution codepad |
| 14 |
10 Mar 2009 |
Word Frequencies: Our interpretation of a problem |
solved by a classic unix pipeline |
exercise solution codepad |
| 175 |
12 Oct 2010 |
Rotate An Array: A simple but tricky exercise |
solved by an algorithm from the folklore of computing |
exercise solution codepad |
| 42 |
16 Jun 2009 |
Who Owns The Zebra?: A logic puzzle, |
solved by embedding a Prolog-like logic system in Scheme |
exercise solution codepad |
| 229 |
19 Apr 2011 |
Same Five Digits: A math puzzle from New Scientist, |
solved by guest author Bob Miller |
exercise solution codepad |
| 155 |
03 Aug 2010 |
Carl Hewitt’s Same-Fringe Problem: Do two trees have the same leaves, |
solved with streams (lazy lists) |
exercise solution codepad |
| 7 |
20 Feb 2009 |
Multiple Dwellings: A simple logic puzzle, |
solved with the amb non-deterministic operator |
exercise solution codepad |
| 36 |
26 May 2009 |
Word Search |
Solver: A computerized implementation of a popular time-waster |
exercise solution codepad |
| 144 |
25 Jun 2010 |
Learn A New Language: |
Solve the exercise of your choice in an unfamiliar language |
exercise solution codepad |
| 151 |
20 Jul 2010 |
|
Solving Systems Of Linear Equations: Matrix operations LU-decomposition and LUP-decomposition |
exercise solution codepad |
| 260 |
05 Aug 2011 |
Ninety-Nine Bottles Of Beer: The popular |
song |
exercise solution codepad |
| 84 |
10 Nov 2009 |
Merge |
Sort: A fast, stable sorting algorithm, especially well-suited to linked lists |
exercise solution codepad |
| 83 |
06 Nov 2009 |
Heap |
Sort: A guaranteed O(log n) sorting method based on priority queues |
exercise solution codepad |
| 237 |
17 May 2011 |
Two Bad Sorts: Stooge |
sort and bogosort are worse than quadratic |
exercise solution codepad |
| 80 |
27 Oct 2009 |
Three Quadratic Sorts: Bubble sort, selection |
sort and insertion sort |
exercise solution codepad |
| 85 |
13 Nov 2009 |
Two linear sorts: Count |
sort and radix sort exploit the structure of integer keys |
exercise solution codepad |
| 81 |
30 Oct 2009 |
Two Sub-Quadratic Sorts: Comb |
sort and shell sort |
exercise solution codepad |
| 160 |
20 Aug 0 |
Marriage |
Sort: A sub-quadratic sort similar to shell sort or comb sort |
exercise solution codepad |
| 235 |
10 May 2011 |
Comm: select or reject lines common to two |
sorted files |
exercise solution codepad |
| 263 |
16 Aug 2011 |
Insert Into A Cyclic |
Sorted List: Insert a new element into a cyclic list, in order |
exercise solution codepad |
| 193 |
14 Dec 2010 |
Longest Duplicated Substring: Use a |
sorted suffix list |
exercise solution codepad |
| 85 |
13 Nov 2009 |
Two linear sorts: Count sort and radix |
sort exploit the structure of integer keys |
exercise solution codepad |
| 113 |
23 Feb 2010 |
Engineering A |
Sort Function: A high-performance quicksort by Jon Bentley and Doug McIlroy |
exercise solution codepad |
| 84 |
10 Nov 2009 |
Merge Sort: A fast, stable |
sorting algorithm, especially well-suited to linked lists |
exercise solution codepad |
| 82 |
03 Nov 2009 |
Quick Sort: Tony Hoare’s divide-and-conquer |
sorting algorithm |
exercise solution codepad |
| 261 |
09 Aug 2011 |
Hett’s Problem 1.28: |
Sorting a list of lists according to length of sublists |
exercise solution codepad |
| 22 |
07 Apr 2009 |
Flipping Pancakes: A |
sorting method analyzed by Bill Gates |
exercise solution codepad |
| 83 |
06 Nov 2009 |
Heap Sort: A guaranteed O(log n) |
sorting method based on priority queues |
exercise solution codepad |
| 160 |
20 Aug 0 |
Marriage Sort: A sub-quadratic sort similar to shell |
sort or comb sort |
exercise solution codepad |
| 186 |
19 Nov 2010 |
Topological |
Sort: Order the edges of a graph by their precedence relationship |
exercise solution codepad |
| 80 |
27 Oct 2009 |
Three Quadratic |
Sorts: Bubble sort, selection sort and insertion sort |
exercise solution codepad |
| 81 |
30 Oct 2009 |
Two Sub-Quadratic |
Sorts: Comb sort and shell sort |
exercise solution codepad |
| 85 |
13 Nov 2009 |
Two linear |
sorts: Count sort and radix sort exploit the structure of integer keys |
exercise solution codepad |
| 80 |
27 Oct 2009 |
Three Quadratic Sorts: Bubble |
sort, selection sort and insertion sort |
exercise solution codepad |
| 160 |
20 Aug 0 |
Marriage Sort: A sub-quadratic |
sort similar to shell sort or comb sort |
exercise solution codepad |
| 237 |
17 May 2011 |
Two Bad |
Sorts: Stooge sort and bogosort are worse than quadratic |
exercise solution codepad |
| 82 |
03 Nov 2009 |
Quick |
Sort: Tony Hoare’s divide-and-conquer sorting algorithm |
exercise solution codepad |
| 160 |
20 Aug 0 |
Marriage Sort: A sub-quadratic sort similar to shell sort or comb |
sort |
exercise solution codepad |
| 191 |
07 Dec 2010 |
Ullman’s Puzzle: It never hurts to |
sort |
exercise solution codepad |
| 80 |
27 Oct 2009 |
Three Quadratic Sorts: Bubble sort, selection sort and insertion |
sort |
exercise solution codepad |
| 81 |
30 Oct 2009 |
Two Sub-Quadratic Sorts: Comb sort and shell |
sort |
exercise solution codepad |
| 111 |
16 Feb 2010 |
|
Soundex: An algorithm to assign people’s last names to equivalence classes based on similar spelling |
exercise solution codepad |
| 199 |
04 Jan 2011 |
Dijkstra’s Algorithm: Find the shortest path to all vertices of a graph from a single |
source, guest written by Graham Enos |
exercise solution codepad |
| 234 |
06 May 2011 |
Entab And Detab: expand tabs into |
spaces, and replace spaces with tabs |
exercise solution codepad |
| 262 |
12 Aug 2011 |
Word Breaks: Insert |
spaces between words: applepie => apple pie |
exercise solution codepad |
| 234 |
06 May 2011 |
Entab And Detab: expand tabs into spaces, and replace |
spaces with tabs |
exercise solution codepad |
| 127 |
13 Apr 2010 |
Traveling Salesman: Minimum |
Spanning Tree: Heuristic guarantees solution within factor of two of optimal tour |
exercise solution codepad |
| 125 |
06 Apr 2010 |
Minimum |
Spanning Tree: Kruskal’s Algorithm: Find the minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 126 |
09 Apr 2010 |
Minimum |
Spanning Tree: Prim’s Algorithm: Find the minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 133 |
04 May 2010 |
|
Spectacular Seven: Compute the odds at jai alai |
exercise solution codepad |
| 97 |
29 Dec 2009 |
A Statisticle |
Speling Korrecter: Peter Norvig’s version of the Google spelling suggester |
exercise solution codepad |
| 26 |
21 Apr 2009 |
Probabilistic Spell Checking: A probabilistic |
spell-checker based on a Bloom filter |
exercise solution codepad |
| 25 |
17 Apr 2009 |
Spell Checking: A |
spell-checker in a trie-based dictionary |
exercise solution codepad |
| 26 |
21 Apr 2009 |
Probabilistic |
Spell Checking: A probabilistic spell-checker based on a Bloom filter |
exercise solution codepad |
| 25 |
17 Apr 2009 |
|
Spell Checking: A spell-checker in a trie-based dictionary |
exercise solution codepad |
| 172 |
01 Oct 2010 |
Oban Numbers: Numbers that omit the letter “o” when |
spelled, and a function to convert numbers to words |
exercise solution codepad |
| 97 |
29 Dec 2009 |
A Statisticle Speling Korrecter: Peter Norvig’s version of the Google |
spelling suggester |
exercise solution codepad |
| 111 |
16 Feb 2010 |
Soundex: An algorithm to assign people’s last names to equivalence classes based on similar |
spelling |
exercise solution codepad |
| 8 |
20 Feb 2009 |
The Digits of Pi: A |
spigot algorithm to calculate the digits of pi |
exercise solution codepad |
| 137 |
01 Jun 2010 |
Unwrapping A |
Spiral: An exercise in recursion |
exercise solution codepad |
| 231 |
26 Apr 2011 |
Miscellanea: FizzBuzz, Prime Words, and |
Split A List |
exercise solution codepad |
| 280 |
18 Oct 2011 |
The Wall: Ray Panko’s |
spreadsheet exercise |
exercise solution codepad |
| 106 |
29 Jan 2010 |
Straddling Checkerboard: An alternative to the Polybius |
square for ciphers that must convert letters to digits |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel Shanks’ |
Square Form Factorization Algorithm: A simple and very fast factorization algorithm for integers between 105 and 1020 |
exercise solution codepad |
| 156 |
06 Aug 2010 |
Two Powering Predicates: Determine if a number is a |
square or a prime power |
exercise solution codepad |
| 249 |
28 Jun 2011 |
Big Numbers: Functions: A library for big integers: gcd, powering, |
square root, random numbers |
exercise solution codepad |
| 95 |
18 Dec 2009 |
Calculating Logarithms: Use the methods of Newton and Euler to calculate |
square roots and logarithms |
exercise solution codepad |
| 48 |
07 Jul 2009 |
Modular Arithmetic: A function library for performing modular addition, subtraction, multiplication, division, and |
square root |
exercise solution codepad |
| 99 |
05 Jan 2010 |
The Sum Of Two |
Squares: A math puzzle with a solution by Dijkstra |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into two sets of equal size so each subset has the same sum, sum of |
squares and sum of cubes |
exercise solution codepad |
| 152 |
23 Jul 2010 |
Happy Numbers: Iterating the sum of the |
squares of the digits terminates with one |
exercise solution codepad |
| 233 |
03 May 2011 |
Squaring The Bishop: Charles Babbage’s game of word |
squares |
exercise solution codepad |
| 169 |
21 Sep 2010 |
Kaprekar Numbers: |
Square the number and add the digits in halves |
exercise solution codepad |
| 233 |
03 May 2011 |
|
Squaring The Bishop: Charles Babbage’s game of word squares |
exercise solution codepad |
| 268 |
02 Sep 2011 |
Two String Exercises: Remove duplicate characters, and |
squish adjacent blanks |
exercise solution codepad |
| 65 |
04 Sep 2009 |
Ron’s Cipher #4: Stream cipher by Ron Rivest that underlies the |
SSL and WEP protocols |
exercise solution codepad |
| 84 |
10 Nov 2009 |
Merge Sort: A fast, |
stable sorting algorithm, especially well-suited to linked lists |
exercise solution codepad |
| 272 |
16 Sep 2011 |
Pollard’s P−1 Factorization Algoritihm, Revisited: An improved second |
stage that is much faster than the original |
exercise solution codepad |
| 120 |
19 Mar 2010 |
Extending Pollard’s P−1 Factorization Algorithm: Add a second |
stage to allow larger factorizations |
exercise solution codepad |
| 145 |
29 Jun 2010 |
World Cup Prognostication: Simulate the knockout |
stage using elo ratings |
exercise solution codepad |
| 59 |
14 Aug 2009 |
Pairing Heaps: A |
standard algorithm for maintaining priority queues |
exercise solution codepad |
| 286 |
08 Nov 2011 |
Improved |
Standard Continuation: An improved version of elliptic curve factorization, widely used in current practice |
exercise solution codepad |
| 275 |
27 Sep 2011 |
Statistics: Calculate the mean, |
standard deviation, linear regression and correlation |
exercise solution codepad |
| 163 |
31 Aug 2010 |
Data Encryption |
Standard: Part 1: Basic block enciphering and deciphering using DES |
exercise solution codepad |
| 164 |
03 Sep 2010 |
Data Encryption |
Standard: Part 2: ECB, CBC, CFB and OFB block modes for DES and other block ciphers |
exercise solution codepad |
| 165 |
07 Sep 2010 |
Data Encryption |
Standard: Part 3: Triple DES and cryptographic hashing |
exercise solution codepad |
| 166 |
10 Sep 2010 |
Data Encryption |
Standard: Part 4: DES driver program |
exercise solution codepad |
| 222 |
25 Mar 2011 |
Sum: The |
standard Unix V7 file-checksum command |
exercise solution codepad |
| 135 |
25 May 2010 |
GB_FLIP: Donald Knuth’s portable, high-quality random-number generator from the |
Stanford Graphbase |
exercise solution codepad |
| 239 |
24 May 2011 |
Big Numbers: Getting |
Started: A library for big integers: representation, comparison, simple functions |
exercise solution codepad |
| 97 |
29 Dec 2009 |
A |
Statisticle Speling Korrecter: Peter Norvig’s version of the Google spelling suggester |
exercise solution codepad |
| 275 |
27 Sep 2011 |
|
Statistics: Calculate the mean, standard deviation, linear regression and correlation |
exercise solution codepad |
| 216 |
04 Mar 2011 |
Chutes And Ladders: Simulate a child’s game, and compute its |
statistics |
exercise solution codepad |
| 244 |
10 Jun 2011 |
|
Steganography: A hand-operable system that combines cryptography and steganography |
exercise solution codepad |
| 244 |
10 Jun 2011 |
Steganography: A hand-operable system that combines cryptography and |
steganography |
exercise solution codepad |
| 66 |
08 Sep 2009 |
Porter |
Stemming: Martin Porter’s algorithm for removing suffices from word stems |
exercise solution codepad |
| 66 |
08 Sep 2009 |
Porter Stemming: Martin Porter’s algorithm for removing suffices from word |
stems |
exercise solution codepad |
| 33 |
15 May 2009 |
Cellular Automata: Linear cellular automata as described by |
Stephen Wolfram in his book A New Kind of Science |
exercise solution codepad |
| 232 |
29 Apr 2011 |
Rule 30 RNG: The random number generator from Mathematica, based on |
Stephen Wolfram’s Rule 30 cellular automata |
exercise solution codepad |
| 289 |
18 Nov 2011 |
Grade School Multiplication: Display the |
steps in the grade school multiplication algorithm |
exercise solution codepad |
| 46 |
30 Jun 2009 |
|
Steve Yegge’s Phone-Screen Coding Exercises: A simple set of programming exercises based on a blog entry by Steve Yegge |
exercise solution codepad |
| 46 |
30 Jun 2009 |
Steve Yegge’s Phone-Screen Coding Exercises: A simple set of programming exercises based on a blog entry by |
Steve Yegge |
exercise solution codepad |
| 185 |
16 Nov 2010 |
RSA Cryptography: The original public-key cryptographic system, |
still in wide use |
exercise solution codepad |
| 237 |
17 May 2011 |
Two Bad Sorts: |
Stooge sort and bogosort are worse than quadratic |
exercise solution codepad |
| 124 |
02 Apr 2010 |
Disjoint Sets: A data structure for |
storing sets of items in disjoint partitions |
exercise solution codepad |
| 106 |
29 Jan 2010 |
|
Straddling Checkerboard: An alternative to the Polybius square for ciphers that must convert letters to digits |
exercise solution codepad |
| 60 |
18 Aug 2009 |
Blum Blum Shub: |
Stream cipher based on a cryptographically secure pseudo-random number generator |
exercise solution codepad |
| 65 |
04 Sep 2009 |
Ron’s Cipher #4: |
Stream cipher by Ron Rivest that underlies the SSL and WEP protocols |
exercise solution codepad |
| 155 |
03 Aug 2010 |
Carl Hewitt’s Same-Fringe Problem: Do two trees have the same leaves, solved with |
streams (lazy lists) |
exercise solution codepad |
| 176 |
15 Oct 2010 |
Find The Longest Palindrome In A |
String: A beautiful linear-time algorithm due to Johan Jeuring |
exercise solution codepad |
| 268 |
02 Sep 2011 |
Two |
String Exercises: Remove duplicate characters, and squish adjacent blanks |
exercise solution codepad |
| 187 |
23 Nov 2010 |
String Subsets: Determine if one |
string is a subset of another |
exercise solution codepad |
| 64 |
01 Sep 2009 |
String Search: Rabin-Karp: Our final classic |
string-search algorithm |
exercise solution codepad |
| 63 |
28 Aug 2009 |
|
String Search: Boyer-Moore: Search for a pattern in a text using a fast and simple algorithm |
exercise solution codepad |
| 61 |
21 Aug 2009 |
|
String Search: Brute Force: Search for a pattern in a text by comparing the pattern to the text at all possible positions |
exercise solution codepad |
| 62 |
25 Aug 2009 |
|
String Search: Knuth-Morris-Pratt: Search for a pattern in a text using an O(n) algorithm |
exercise solution codepad |
| 64 |
01 Sep 2009 |
|
String Search: Rabin-Karp: Our final classic string-search algorithm |
exercise solution codepad |
| 187 |
23 Nov 2010 |
|
String Subsets: Determine if one string is a subset of another |
exercise solution codepad |
| 264 |
19 Aug 2011 |
First Non-Repeating Character: Find the first character in a |
string that doesn’t repeat later in the string |
exercise solution codepad |
| 217 |
08 Mar 2011 |
Reverse Words: Reverse the words in an input |
string |
exercise solution codepad |
| 264 |
19 Aug 2011 |
First Non-Repeating Character: Find the first character in a string that doesn’t repeat later in the |
string |
exercise solution codepad |
| 203 |
18 Jan 2011 |
Solitaire Cipher: Bruce Schneier’s |
strong cryptography based on a deck of playing cards |
exercise solution codepad |
| 73 |
02 Oct 2009 |
Red-Black Trees: A purely functional dictionary data |
structure based on approximately-balanced trees |
exercise solution codepad |
| 157 |
10 Aug 2010 |
Literate Programming: |
Structured documentation in the style of Donald Knuth |
exercise solution codepad |
| 124 |
02 Apr 2010 |
Disjoint Sets: A data |
structure for storing sets of items in disjoint partitions |
exercise solution codepad |
| 85 |
13 Nov 2009 |
Two linear sorts: Count sort and radix sort exploit the |
structure of integer keys |
exercise solution codepad |
| 45 |
26 Jun 2009 |
Treaps: A randomized dictionary data |
structure, provides in-order access to key |
exercise solution codepad |
| 116 |
05 Mar 2010 |
Binary Search Tree: Classic data |
structure, providing insert, delete and lookup for ordered datatypes |
exercise solution codepad |
| 171 |
28 Sep 2010 |
Maxiphobic Heaps: A priority-queue data |
structure, similar to leftist heaps, due to Chris Okasaki |
exercise solution codepad |
| 30 |
05 May 2009 |
Priority Queues: A simple library implementation of the priority queue data |
structure |
exercise solution codepad |
| 157 |
10 Aug 2010 |
Literate Programming: Structured documentation in the |
style of Donald Knuth |
exercise solution codepad |
| 261 |
09 Aug 2011 |
Hett’s Problem 1.28: Sorting a list of lists according to length of |
sublists |
exercise solution codepad |
| 266 |
26 Aug 2011 |
Reverse Every K Nodes Of A Linked List: Reverse the elements of a |
sub-list |
exercise solution codepad |
| 81 |
30 Oct 2009 |
Two |
Sub-Quadratic Sorts: Comb sort and shell sort |
exercise solution codepad |
| 160 |
20 Aug 0 |
Marriage Sort: A |
sub-quadratic sort similar to shell sort or comb sort |
exercise solution codepad |
| 40 |
09 Jun 2009 |
Longest Common |
Subsequence: A classic programming algorithm, with a solution that dates to folklore |
exercise solution codepad |
| 190 |
03 Dec 2010 |
Maximum Sum |
Subsequence: A classic programming exercise due to Jon Bentley |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into two sets of equal size so each |
subset has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 187 |
23 Nov 2010 |
String Subsets: Determine if one string is a |
subset of another |
exercise solution codepad |
| 187 |
23 Nov 2010 |
String |
Subsets: Determine if one string is a subset of another |
exercise solution codepad |
| 183 |
09 Nov 2010 |
|
Subset Sums: Third level of the Greplin Programming Challenge, using dynamic programming and memoization |
exercise solution codepad |
| 50 |
14 Jul 2009 |
The Daily Cryptogram: Solve a monoalphabetic |
substitution cipher |
exercise solution codepad |
| 193 |
14 Dec 2010 |
Longest Duplicated |
Substring: Use a sorted suffix list |
exercise solution codepad |
| 241 |
31 May 2011 |
Big Numbers: Addition, |
Subtraction And Multiplication: A library for big integers: grade-school algorithms for addition, subtraction, and multiplication |
exercise solution codepad |
| 241 |
31 May 2011 |
Big Numbers: Addition, Subtraction And Multiplication: A library for big integers: grade-school algorithms for addition, |
subtraction, and multiplication |
exercise solution codepad |
| 48 |
07 Jul 2009 |
Modular Arithmetic: A function library for performing modular addition, |
subtraction, multiplication, division, and square root |
exercise solution codepad |
| 197 |
28 Dec 2010 |
Carmichael Numbers: Composite numbers |
such that an-1 ≡ 1 (mod n) if a is prime to n |
exercise solution codepad |
| 4 |
19 Feb 2009 |
|
Sudoku: A backtracking solution to everybody’s favorite puzzle |
exercise solution codepad |
| 66 |
08 Sep 2009 |
Porter Stemming: Martin Porter’s algorithm for removing |
suffices from word stems |
exercise solution codepad |
| 193 |
14 Dec 2010 |
Longest Duplicated Substring: Use a sorted |
suffix list |
exercise solution codepad |
| 97 |
29 Dec 2009 |
A Statisticle Speling Korrecter: Peter Norvig’s version of the Google spelling |
suggester |
exercise solution codepad |
| 70 |
22 Sep 2009 |
Regular Expressions, Part 3: A regular expression test |
suite |
exercise solution codepad |
| 281 |
21 Oct 2011 |
Sum, Revisited: SysV and Berkeley versions of the Unix V7 |
sum command |
exercise solution codepad |
| 188 |
26 Nov 2010 |
Divisors And Totatives: The number-theoretic functions divisors, numdivs, |
sumdivs, totatives, and totient |
exercise solution codepad |
| 153 |
27 Jul 2010 |
HAMURABI.BAS: Manage grain and land in ancient |
Sumeria |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into two sets of equal size so each subset has the same sum, sum of squares and |
sum of cubes |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into two sets of equal size so each subset has the same sum, |
sum of squares and sum of cubes |
exercise solution codepad |
| 152 |
23 Jul 2010 |
Happy Numbers: Iterating the |
sum of the squares of the digits terminates with one |
exercise solution codepad |
| 255 |
19 Jul 2011 |
|
Sum Of Two Integers: Determine if two integers in a list sum to a target |
exercise solution codepad |
| 194 |
17 Dec 2010 |
Polite Numbers: Write numbers as the |
sum of two or more consecutive integers |
exercise solution codepad |
| 115 |
02 Mar 2010 |
Goldbach’s Conjecture: Every even number greater than two can be written as the |
sum of two primes |
exercise solution codepad |
| 99 |
05 Jan 2010 |
The |
Sum Of Two Squares: A math puzzle with a solution by Dijkstra |
exercise solution codepad |
| 281 |
21 Oct 2011 |
|
Sum, Revisited: SysV and Berkeley versions of the Unix V7 sum command |
exercise solution codepad |
| 210 |
11 Feb 2011 |
Sums Of Powers: Use Bernoulli numbers to quickly compute |
sums of powers |
exercise solution codepad |
| 210 |
11 Feb 2011 |
|
Sums Of Powers: Use Bernoulli numbers to quickly compute sums of powers |
exercise solution codepad |
| 183 |
09 Nov 2010 |
Subset |
Sums: Third level of the Greplin Programming Challenge, using dynamic programming and memoization |
exercise solution codepad |
| 190 |
03 Dec 2010 |
Maximum |
Sum Subsequence: A classic programming exercise due to Jon Bentley |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into two sets of equal size so each subset has the same |
sum, sum of squares and sum of cubes |
exercise solution codepad |
| 222 |
25 Mar 2011 |
|
Sum: The standard Unix V7 file-checksum command |
exercise solution codepad |
| 255 |
19 Jul 2011 |
Sum Of Two Integers: Determine if two integers in a list |
sum to a target |
exercise solution codepad |
| 257 |
26 Jul 2011 |
More Prime-Counting Functions: Prime counting functions by Meissel and Lehmer, based on Legendre’s |
sum |
exercise solution codepad |
| 278 |
07 Oct 2011 |
Sieve of |
Sundaram: Sieving for prime numbers using a method from India |
exercise solution codepad |
| 88 |
24 Nov 2009 |
Sunrise, Sunset: Calculate the times of |
sunrise and sunset on any day anywhere in the world |
exercise solution codepad |
| 88 |
24 Nov 2009 |
|
Sunrise, Sunset: Calculate the times of sunrise and sunset on any day anywhere in the world |
exercise solution codepad |
| 88 |
24 Nov 2009 |
Sunrise, |
Sunset: Calculate the times of sunrise and sunset on any day anywhere in the world |
exercise solution codepad |
| 88 |
24 Nov 2009 |
Sunrise, Sunset: Calculate the times of sunrise and |
sunset on any day anywhere in the world |
exercise solution codepad |
| 158 |
13 Aug 2010 |
E: A simple simulation with a |
surprising ending |
exercise solution codepad |
| 44 |
23 Jun 2009 |
The Mod Out |
System: Expand a series of ranges |
exercise solution codepad |
| 74 |
06 Oct 2009 |
MapReduce: Google’s famous |
system for parallelizing computations expressed as a programming idiom |
exercise solution codepad |
| 42 |
16 Jun 2009 |
Who Owns The Zebra?: A logic puzzle, solved by embedding a Prolog-like logic |
system in Scheme |
exercise solution codepad |
| 151 |
20 Jul 2010 |
Solving |
Systems Of Linear Equations: Matrix operations LU-decomposition and LUP-decomposition |
exercise solution codepad |
| 185 |
16 Nov 2010 |
RSA Cryptography: The original public-key cryptographic |
system, still in wide use |
exercise solution codepad |
| 244 |
10 Jun 2011 |
Steganography: A hand-operable |
system that combines cryptography and steganography |
exercise solution codepad |
| 207 |
01 Feb 2011 |
Cuckoo Hashing: A hashing |
system with guaranteed constant-time lookup and amortized constant-time insertion |
exercise solution codepad |
| 281 |
21 Oct 2011 |
Sum, Revisited: |
SysV and Berkeley versions of the Unix V7 sum command |
exercise solution codepad |
| 148 |
09 Jul 2010 |
Contents: Permuted |
Table Of Contents: Blog management |
exercise solution codepad |
| 276 |
30 Sep 2011 |
Logarithm Tables: Print old-fashioned |
tables of logarithms and anti-logarithms |
exercise solution codepad |
| 276 |
30 Sep 2011 |
Logarithm |
Tables: Print old-fashioned tables of logarithms and anti-logarithms |
exercise solution codepad |
| 32 |
12 May 2009 |
Loan Amortization: Calculate and print a simple loan amortization |
table |
exercise solution codepad |
| 234 |
06 May 2011 |
Entab And Detab: expand |
tabs into spaces, and replace spaces with tabs |
exercise solution codepad |
| 234 |
06 May 2011 |
Entab And Detab: expand tabs into spaces, and replace spaces with |
tabs |
exercise solution codepad |
| 154 |
30 Jul 2010 |
Fibonacci Numbers: Three algorithms |
taking exponential time, linear time, and logarithmic time |
exercise solution codepad |
| 255 |
19 Jul 2011 |
Sum Of Two Integers: Determine if two integers in a list sum to a |
target |
exercise solution codepad |
| 18 |
23 Mar 2009 |
Binary Search: A simple |
task, easy to get wrong |
exercise solution codepad |
| 101 |
12 Jan 2010 |
Calculating Sines: Calculate sines using |
Taylor series and the triple-angle formula, by Bill Cruise |
exercise solution codepad |
| 28 |
28 Apr 2009 |
Morse Code: Translating the dots-and-dashes of Samuel Finley Breese Morse’s |
telegraph code |
exercise solution codepad |
| 296 |
13 Dec 2011 |
Validating |
Telephone Numbers: An exercise in input validation |
exercise solution codepad |
| 152 |
23 Jul 2010 |
Happy Numbers: Iterating the sum of the squares of the digits |
terminates with one |
exercise solution codepad |
| 39 |
05 Jun 2009 |
|
Ternary Search Tries: Build a function library for handling ternary search tries |
exercise solution codepad |
| 39 |
05 Jun 2009 |
Ternary Search Tries: Build a function library for handling |
ternary search tries |
exercise solution codepad |
| 242 |
03 Jun 2011 |
Mersenne Primes: The Lucas-Lehmer |
test for identifying primes of the form 2n−1 |
exercise solution codepad |
| 247 |
21 Jun 2011 |
Big Numbers: |
Testing: A library for big integers: testing |
exercise solution codepad |
| 252 |
08 Jul 2011 |
Vedic Divisibility: Use a method of |
testing divisibility using the method of osculators developed in India |
exercise solution codepad |
| 247 |
21 Jun 2011 |
Big Numbers: Testing: A library for big integers: |
testing |
exercise solution codepad |
| 70 |
22 Sep 2009 |
Regular Expressions, Part 3: A regular expression |
test suite |
exercise solution codepad |
| 271 |
13 Sep 2011 |
|
Tetrahedral Numbers: Find the base of the tetrahedron that contains 169179692512835000 balls |
exercise solution codepad |
| 271 |
13 Sep 2011 |
Tetrahedral Numbers: Find the base of the |
tetrahedron that contains 169179692512835000 balls |
exercise solution codepad |
| 121 |
23 Mar 2010 |
|
Texas Hold ‘Em: Find the best poker hand |
exercise solution codepad |
| 61 |
21 Aug 2009 |
String Search: Brute Force: Search for a pattern in a text by comparing the pattern to the |
text at all possible positions |
exercise solution codepad |
| 61 |
21 Aug 2009 |
String Search: Brute Force: Search for a pattern in a |
text by comparing the pattern to the text at all possible positions |
exercise solution codepad |
| 177 |
19 Oct 2010 |
|
Text File Databases: Part 1: Functions to read records with fields in various formats |
exercise solution codepad |
| 178 |
22 Oct 2010 |
|
Text File Databases: Part 2: Various functions to process records with fields |
exercise solution codepad |
| 179 |
26 Oct 2010 |
Benford’s Law: A useful mathematical oddity, and an example of |
text file databases |
exercise solution codepad |
| 114 |
26 Feb 2010 |
Run Length Encoding: A simple compression method for |
text files |
exercise solution codepad |
| 139 |
08 Jun 2010 |
Diff: Find the differences between two |
text files |
exercise solution codepad |
| 91 |
04 Dec 2009 |
Autokey: A cipher in which the input |
text forms part of the key |
exercise solution codepad |
| 27 |
24 Apr 2009 |
Word Hy-phen-a-tion By Com-pu-ter: Frank Liang’s hyphenation algorithm, used in |
TeX |
exercise solution codepad |
| 63 |
28 Aug 2009 |
String Search: Boyer-Moore: Search for a pattern in a |
text using a fast and simple algorithm |
exercise solution codepad |
| 11 |
27 Feb 2009 |
Mark V. Shaney: Generate parodies of a |
text using a Markov chain |
exercise solution codepad |
| 62 |
25 Aug 2009 |
String Search: Knuth-Morris-Pratt: Search for a pattern in a |
text using an O(n) algorithm |
exercise solution codepad |
| 267 |
30 Aug 2011 |
Hamming Numbers: List the numbers with no factors greater |
than 5, a classic problem popularized by Dijkstra |
exercise solution codepad |
| 122 |
26 Mar 2010 |
The Next Prime: Efficiently find the next prime number larger |
than a given number |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting Primes Using Legendre’s Formula: Recreate Legendre’s two-century old calculation of the number of primes less |
than a million |
exercise solution codepad |
| 248 |
24 Jun 2011 |
|
Thank God It’s Friday!: Three methods to calculate the day of the week |
exercise solution codepad |
| 237 |
17 May 2011 |
Two Bad Sorts: Stooge sort and bogosort are worse |
than quadratic |
exercise solution codepad |
| 35 |
22 May 2009 |
The Next Palindrome: Find the next palindromic number greater |
than the input number |
exercise solution codepad |
| 272 |
16 Sep 2011 |
Pollard’s P−1 Factorization Algoritihm, Revisited: An improved second stage that is much faster |
than the original |
exercise solution codepad |
| 115 |
02 Mar 2010 |
Goldbach’s Conjecture: Every even number greater |
than two can be written as the sum of two primes |
exercise solution codepad |
| 181 |
02 Nov 2010 |
Emirps: Prime numbers that are prime when |
their digits are reversed, but not palindromic |
exercise solution codepad |
| 186 |
19 Nov 2010 |
Topological Sort: Order the edges of a graph by |
their precedence relationship |
exercise solution codepad |
| 150 |
16 Jul 2010 |
Contents: |
Themes: Blog Management |
exercise solution codepad |
| 287 |
11 Nov 2011 |
Generators: Write functions that yield a value, but can |
then be re-entered |
exercise solution codepad |
| 236 |
13 May 2011 |
Dixon’s Factorization Algorithm: A slow, but |
theoretically important, algorithm for integer factorization |
exercise solution codepad |
| 183 |
09 Nov 2010 |
Subset Sums: |
Third level of the Greplin Programming Challenge, using dynamic programming and memoization |
exercise solution codepad |
| 15 |
13 Mar 2009 |
Friday, the |
Thirteenth: A small calendar library, and a simple use of it |
exercise solution codepad |
| 273 |
20 Sep 2011 |
Project Euler Problem 3: |
Thorough explanation of integer factorization by trial division |
exercise solution codepad |
| 154 |
30 Jul 2010 |
Fibonacci Numbers: |
Three algorithms taking exponential time, linear time, and logarithmic time |
exercise solution codepad |
| 102 |
15 Jan 2010 |
|
Three Binary Algorithms: Multiplication, division and greatest common divisor using binary arithmetic |
exercise solution codepad |
| 51 |
17 Jul 2009 |
International Mathematical Olympiad: |
Three exercises from 1960s math competitions |
exercise solution codepad |
| 248 |
24 Jun 2011 |
Thank God It’s Friday!: |
Three methods to calculate the day of the week |
exercise solution codepad |
| 80 |
27 Oct 2009 |
|
Three Quadratic Sorts: Bubble sort, selection sort and insertion sort |
exercise solution codepad |
| 211 |
15 Feb 2011 |
Google Code Jam Qualification Round Africa 2010: |
Three simple exercises |
exercise solution codepad |
| 246 |
17 Jun 2011 |
Adi Shamir’s |
Threshold Scheme: Use cryptography to share a secret, by Graham Enos |
exercise solution codepad |
| 129 |
20 Apr 2010 |
145 Puzzle: Build and evaluate expressions using the digits one |
through nine and the simple arithmetic operators |
exercise solution codepad |
| 154 |
30 Jul 2010 |
Fibonacci Numbers: Three algorithms taking exponential time, linear |
time, and logarithmic time |
exercise solution codepad |
| 154 |
30 Jul 2010 |
Fibonacci Numbers: Three algorithms taking exponential |
time, linear time, and logarithmic time |
exercise solution codepad |
| 128 |
16 Apr 2010 |
Expression Evaluation: Parse and evaluate an arithmetic expression with plus, minus, |
times, divide and parentheses |
exercise solution codepad |
| 88 |
24 Nov 2009 |
Sunrise, Sunset: Calculate the |
times of sunrise and sunset on any day anywhere in the world |
exercise solution codepad |
| 154 |
30 Jul 2010 |
Fibonacci Numbers: Three algorithms taking exponential time, linear time, and logarithmic |
time |
exercise solution codepad |
| 36 |
26 May 2009 |
Word Search Solver: A computerized implementation of a popular |
time-waster |
exercise solution codepad |
| 238 |
20 May 0 |
ISBN Validation: Validate ISBN book numbers, and fetch author and |
title from the internet |
exercise solution codepad |
| 82 |
03 Nov 2009 |
Quick Sort: |
Tony Hoare’s divide-and-conquer sorting algorithm |
exercise solution codepad |
| 283 |
28 Oct 2011 |
Crypt: Simple encryption |
tool from Kernighan and Plauger |
exercise solution codepad |
| 186 |
19 Nov 2010 |
|
Topological Sort: Order the edges of a graph by their precedence relationship |
exercise solution codepad |
| 188 |
26 Nov 2010 |
Divisors And Totatives: The number-theoretic functions divisors, numdivs, sumdivs, |
totatives, and totient |
exercise solution codepad |
| 188 |
26 Nov 2010 |
Divisors And |
Totatives: The number-theoretic functions divisors, numdivs, sumdivs, totatives, and totient |
exercise solution codepad |
| 188 |
26 Nov 2010 |
Divisors And Totatives: The number-theoretic functions divisors, numdivs, sumdivs, totatives, and |
totient |
exercise solution codepad |
| 118 |
12 Mar 2010 |
Traveling Salesman: Brute Force: Examine all possible permutations to find the least-cost |
tour |
exercise solution codepad |
| 127 |
13 Apr 2010 |
Traveling Salesman: Minimum Spanning Tree: Heuristic guarantees solution within factor of two of optimal |
tour |
exercise solution codepad |
| 293 |
02 Dec 2011 |
Knight Rider: Classic problem of the knight’s |
tour |
exercise solution codepad |
| 279 |
11 Oct 2011 |
|
Tower Of Hanoi: Classic demonstration of recursion |
exercise solution codepad |
| 196 |
24 Dec 2010 |
|
Tracking Santa: How far does Santa travel on his annual journey? |
exercise solution codepad |
| 28 |
28 Apr 2009 |
Morse Code: |
Translating the dots-and-dashes of Samuel Finley Breese Morse’s telegraph code |
exercise solution codepad |
| 37 |
29 May 2009 |
Double |
Transposition Cipher: A simple and effective cipher, easy to perform by hand |
exercise solution codepad |
| 20 |
31 Mar 2009 |
Rail-Fence Cipher: A simple |
transposition cipher |
exercise solution codepad |
| 143 |
22 Jun 2010 |
Matrix Operations: Matrix addition, scalar multiplication, multiplication and |
transposition |
exercise solution codepad |
| 109 |
09 Feb 2010 |
Numerical Integration: Quadrature by the rectangular, |
trapezoidal and Simpson’s method, including adaptive quadrature |
exercise solution codepad |
| 118 |
12 Mar 2010 |
|
Traveling Salesman: Brute Force: Examine all possible permutations to find the least-cost tour |
exercise solution codepad |
| 127 |
13 Apr 2010 |
|
Traveling Salesman: Minimum Spanning Tree: Heuristic guarantees solution within factor of two of optimal tour |
exercise solution codepad |
| 119 |
16 Mar 2010 |
|
Traveling Salesman: Nearest Neighbor: A greedy heuristic that builds a path by always choosing the nearest unvisited point |
exercise solution codepad |
| 196 |
24 Dec 2010 |
Tracking Santa: How far does Santa |
travel on his annual journey? |
exercise solution codepad |
| 45 |
26 Jun 2009 |
|
Treaps: A randomized dictionary data structure, provides in-order access to key |
exercise solution codepad |
| 24 |
14 Apr 2009 |
Google |
Treasure Hunt 2008 Puzzle 4: A prime-number puzzle |
exercise solution codepad |
| 116 |
05 Mar 2010 |
Binary Search |
Tree: Classic data structure, providing insert, delete and lookup for ordered datatypes |
exercise solution codepad |
| 127 |
13 Apr 2010 |
Traveling Salesman: Minimum Spanning |
Tree: Heuristic guarantees solution within factor of two of optimal tour |
exercise solution codepad |
| 125 |
06 Apr 2010 |
Minimum Spanning |
Tree: Kruskal’s Algorithm: Find the minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 126 |
09 Apr 2010 |
Minimum Spanning |
Tree: Prim’s Algorithm: Find the minimum-cost tree that includes all the nodes in a graph |
exercise solution codepad |
| 73 |
02 Oct 2009 |
Red-Black |
Trees: A purely functional dictionary data structure based on approximately-balanced trees |
exercise solution codepad |
| 291 |
25 Nov 2011 |
AVL |
Trees: Basic implementation of the original balanced-tree algorithm |
exercise solution codepad |
| 292 |
29 Nov 2011 |
AVL |
Trees, Extended: Add additional functionality to AVL trees |
exercise solution codepad |
| 155 |
03 Aug 2010 |
Carl Hewitt’s Same-Fringe Problem: Do two |
trees have the same leaves, solved with streams (lazy lists) |
exercise solution codepad |
| 292 |
29 Nov 2011 |
AVL Trees, Extended: Add additional functionality to AVL |
trees |
exercise solution codepad |
| 73 |
02 Oct 2009 |
Red-Black Trees: A purely functional dictionary data structure based on approximately-balanced |
trees |
exercise solution codepad |
| 125 |
06 Apr 2010 |
Minimum Spanning Tree: Kruskal’s Algorithm: Find the minimum-cost |
tree that includes all the nodes in a graph |
exercise solution codepad |
| 126 |
09 Apr 2010 |
Minimum Spanning Tree: Prim’s Algorithm: Find the minimum-cost |
tree that includes all the nodes in a graph |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest Common Ancestor: Find the lowest node in a binary search |
tree that is a common ancestor to two given nodes |
exercise solution codepad |
| 132 |
30 Apr 2010 |
Integer Factorization: Combine |
trial division, Pollard’s rho and p−1 methods, and elliptic curves into a single factorization program |
exercise solution codepad |
| 273 |
20 Sep 2011 |
Project Euler Problem 3: Thorough explanation of integer factorization by |
trial division |
exercise solution codepad |
| 31 |
08 May 2009 |
Wheel Factorization: Find the factors of a number by a variant of |
trial division |
exercise solution codepad |
| 103 |
19 Jan 2010 |
Flight Planning: Computing the navigation |
triangle, by Jos Koot |
exercise solution codepad |
| 294 |
06 Dec 2011 |
Pascal’s |
Triangle: Display the binomial coefficients |
exercise solution codepad |
| 175 |
12 Oct 2010 |
Rotate An Array: A simple but |
tricky exercise solved by an algorithm from the folklore of computing |
exercise solution codepad |
| 53 |
24 Jul 2009 |
Let’s Make A Deal!: Simulate a |
tricky probability calculation |
exercise solution codepad |
| 25 |
17 Apr 2009 |
Spell Checking: A spell-checker in a |
trie-based dictionary |
exercise solution codepad |
| 39 |
05 Jun 2009 |
Ternary Search |
Tries: Build a function library for handling ternary search tries |
exercise solution codepad |
| 39 |
05 Jun 2009 |
Ternary Search Tries: Build a function library for handling ternary search |
tries |
exercise solution codepad |
| 101 |
12 Jan 2010 |
Calculating Sines: Calculate sines using Taylor series and the |
triple-angle formula, by Bill Cruise |
exercise solution codepad |
| 165 |
07 Sep 2010 |
Data Encryption Standard: Part 3: |
Triple DES and cryptographic hashing |
exercise solution codepad |
| 277 |
04 Oct 2011 |
Brainfuck: Interpreter for a |
Turing-line language |
exercise solution codepad |
| 21 |
03 Apr 2009 |
Programming the |
Turing Machine: A turing-machine program to multiply two numbers |
exercise solution codepad |
| 21 |
03 Apr 2009 |
Programming the Turing Machine: A |
turing-machine program to multiply two numbers |
exercise solution codepad |
| 19 |
27 Mar 2009 |
A |
Turing Machine Simulator: An interpreter for a single-tape, multi-symbol turing machine |
exercise solution codepad |
| 19 |
27 Mar 2009 |
A Turing Machine Simulator: An interpreter for a single-tape, multi-symbol |
turing machine |
exercise solution codepad |
| 98 |
01 Jan 2010 |
Cal: Print a |
twelve-month calendar |
exercise solution codepad |
| 270 |
09 Sep 2011 |
Mersenne |
Twister: Random number generator with very long period, useful for simulations |
exercise solution codepad |
| 237 |
17 May 2011 |
|
Two Bad Sorts: Stooge sort and bogosort are worse than quadratic |
exercise solution codepad |
| 115 |
02 Mar 2010 |
Goldbach’s Conjecture: Every even number greater than |
two can be written as the sum of two primes |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting Primes Using Legendre’s Formula: Recreate Legendre’s |
two-century old calculation of the number of primes less than a million |
exercise solution codepad |
| 212 |
18 Feb 2011 |
|
Two Factoring Games: Home primes and the Euclid-Mullin sequence |
exercise solution codepad |
| 218 |
11 Mar 2011 |
Lowest Common Ancestor: Find the lowest node in a binary search tree that is a common ancestor to |
two given nodes |
exercise solution codepad |
| 255 |
19 Jul 2011 |
Sum Of |
Two Integers: Determine if two integers in a list sum to a target |
exercise solution codepad |
| 255 |
19 Jul 2011 |
Sum Of Two Integers: Determine if |
two integers in a list sum to a target |
exercise solution codepad |
| 201 |
11 Jan 2011 |
|
Two Integrals: The exponential and logarithmic integral, and an approximation for prime-pi |
exercise solution codepad |
| 221 |
22 Mar 2011 |
|
Two Kaprekar Exercises: Kaprekar chains and Kaprekar numbers, from the Indian mathematician Dattaraya Ramchandra Kaprekar |
exercise solution codepad |
| 85 |
13 Nov 2009 |
|
Two linear sorts: Count sort and radix sort exploit the structure of integer keys |
exercise solution codepad |
| 21 |
03 Apr 2009 |
Programming the Turing Machine: A turing-machine program to multiply |
two numbers |
exercise solution codepad |
| 127 |
13 Apr 2010 |
Traveling Salesman: Minimum Spanning Tree: Heuristic guarantees solution within factor of |
two of optimal tour |
exercise solution codepad |
| 194 |
17 Dec 2010 |
Polite Numbers: Write numbers as the sum of |
two or more consecutive integers |
exercise solution codepad |
| 86 |
17 Nov 2009 |
Master Mind, Part 1: Referee a |
two-player game of deductive logic |
exercise solution codepad |
| 100 |
08 Jan 2010 |
Nim: A |
two-player game of mathematical logic |
exercise solution codepad |
| 156 |
06 Aug 2010 |
|
Two Powering Predicates: Determine if a number is a square or a prime power |
exercise solution codepad |
| 115 |
02 Mar 2010 |
Goldbach’s Conjecture: Every even number greater than two can be written as the sum of |
two primes |
exercise solution codepad |
| 192 |
10 Dec 2010 |
|
Two Random Selections: Use random number to select fortunes and lotto winners |
exercise solution codepad |
| 288 |
15 Nov 2011 |
Phil Harvey’s Puzle: partition {1,…,16} into |
two sets of equal size so each subset has the same sum, sum of squares and sum of cubes |
exercise solution codepad |
| 235 |
10 May 2011 |
Comm: select or reject lines common to |
two sorted files |
exercise solution codepad |
| 99 |
05 Jan 2010 |
The Sum Of |
Two Squares: A math puzzle with a solution by Dijkstra |
exercise solution codepad |
| 268 |
02 Sep 2011 |
|
Two String Exercises: Remove duplicate characters, and squish adjacent blanks |
exercise solution codepad |
| 81 |
30 Oct 2009 |
|
Two Sub-Quadratic Sorts: Comb sort and shell sort |
exercise solution codepad |
| 139 |
08 Jun 2010 |
Diff: Find the differences between |
two text files |
exercise solution codepad |
| 155 |
03 Aug 2010 |
Carl Hewitt’s Same-Fringe Problem: Do |
two trees have the same leaves, solved with streams (lazy lists) |
exercise solution codepad |
| 191 |
07 Dec 2010 |
|
Ullman’s Puzzle: It never hurts to sort |
exercise solution codepad |
| 58 |
11 Aug 2009 |
|
Uncle Bob’s Bowling Game Kata: Use pattern-matching on lists to solve a classic object-oriented programming exercise |
exercise solution codepad |
| 65 |
04 Sep 2009 |
Ron’s Cipher #4: Stream cipher by Ron Rivest that |
underlies the SSL and WEP protocols |
exercise solution codepad |
| 144 |
25 Jun 2010 |
Learn A New Language: Solve the exercise of your choice in an |
unfamiliar language |
exercise solution codepad |
| 282 |
25 Oct 2011 |
Cksum: |
Unix checksum utility |
exercise solution codepad |
| 14 |
10 Mar 2009 |
Word Frequencies: Our interpretation of a problem solved by a classic |
unix pipeline |
exercise solution codepad |
| 136 |
28 May 2010 |
Printing Files: A simple program to list files, similar to the |
unix pr program |
exercise solution codepad |
| 71 |
25 Sep 2009 |
Grep: Simple version of the classic |
unix regular-expression matching utility |
exercise solution codepad |
| 222 |
25 Mar 2011 |
Sum: The standard |
Unix V7 file-checksum command |
exercise solution codepad |
| 281 |
21 Oct 2011 |
Sum, Revisited: SysV and Berkeley versions of the |
Unix V7 sum command |
exercise solution codepad |
| 92 |
08 Dec 2009 |
Word Count: An implementation of the |
unix wc program |
exercise solution codepad |
| 119 |
16 Mar 2010 |
Traveling Salesman: Nearest Neighbor: A greedy heuristic that builds a path by always choosing the nearest |
unvisited point |
exercise solution codepad |
| 137 |
01 Jun 2010 |
|
Unwrapping A Spiral: An exercise in recursion |
exercise solution codepad |
| 240 |
27 May 2011 |
Upside |
Up: Numbers that read the same upside down |
exercise solution codepad |
| 240 |
27 May 2011 |
Upside Up: Numbers that read the same |
upside down |
exercise solution codepad |
| 240 |
27 May 2011 |
|
Upside Up: Numbers that read the same upside down |
exercise solution codepad |
| 252 |
08 Jul 2011 |
Vedic Divisibility: |
Use a method of testing divisibility using the method of osculators developed in India |
exercise solution codepad |
| 193 |
14 Dec 2010 |
Longest Duplicated Substring: |
Use a sorted suffix list |
exercise solution codepad |
| 210 |
11 Feb 2011 |
Sums Of Powers: |
Use Bernoulli numbers to quickly compute sums of powers |
exercise solution codepad |
| 246 |
17 Jun 2011 |
Adi Shamir’s Threshold Scheme: |
Use cryptography to share a secret, by Graham Enos |
exercise solution codepad |
| 286 |
08 Nov 2011 |
Improved Standard Continuation: An improved version of elliptic curve factorization, widely |
used in current practice |
exercise solution codepad |
| 27 |
24 Apr 2009 |
Word Hy-phen-a-tion By Com-pu-ter: Frank Liang’s hyphenation algorithm, |
used in TeX |
exercise solution codepad |
| 76 |
13 Oct 2009 |
Bifid: A simple but effective fractionating cipher, never |
used militarily |
exercise solution codepad |
| 270 |
09 Sep 2011 |
Mersenne Twister: Random number generator with very long period, |
useful for simulations |
exercise solution codepad |
| 179 |
26 Oct 2010 |
Benford’s Law: A |
useful mathematical oddity, and an example of text file databases |
exercise solution codepad |
| 15 |
13 Mar 2009 |
Friday, the Thirteenth: A small calendar library, and a simple |
use of it |
exercise solution codepad |
| 58 |
11 Aug 2009 |
Uncle Bob’s Bowling Game Kata: |
Use pattern-matching on lists to solve a classic object-oriented programming exercise |
exercise solution codepad |
| 192 |
10 Dec 2010 |
Two Random Selections: |
Use random number to select fortunes and lotto winners |
exercise solution codepad |
| 95 |
18 Dec 2009 |
Calculating Logarithms: |
Use the methods of Newton and Euler to calculate square roots and logarithms |
exercise solution codepad |
| 185 |
16 Nov 2010 |
RSA Cryptography: The original public-key cryptographic system, still in wide |
use |
exercise solution codepad |
| 63 |
28 Aug 2009 |
String Search: Boyer-Moore: Search for a pattern in a text |
using a fast and simple algorithm |
exercise solution codepad |
| 16 |
17 Mar 2009 |
Comma-Separated Values: Retrieve records from a comma-separated values file |
using a finite-state machine |
exercise solution codepad |
| 11 |
27 Feb 2009 |
Mark V. Shaney: Generate parodies of a text |
using a Markov chain |
exercise solution codepad |
| 278 |
07 Oct 2011 |
Sieve of Sundaram: Sieving for prime numbers |
using a method from India |
exercise solution codepad |
| 117 |
09 Mar 2010 |
Lexicographic Permutations: Continually generate the next permutation |
using an algorithm by Dijkstra |
exercise solution codepad |
| 62 |
25 Aug 2009 |
String Search: Knuth-Morris-Pratt: Search for a pattern in a text |
using an O(n) algorithm |
exercise solution codepad |
| 102 |
15 Jan 2010 |
Three Binary Algorithms: Multiplication, division and greatest common divisor |
using binary arithmetic |
exercise solution codepad |
| 163 |
31 Aug 2010 |
Data Encryption Standard: Part 1: Basic block enciphering and deciphering |
using DES |
exercise solution codepad |
| 183 |
09 Nov 2010 |
Subset Sums: Third level of the Greplin Programming Challenge, |
using dynamic programming and memoization |
exercise solution codepad |
| 145 |
29 Jun 2010 |
World Cup Prognostication: Simulate the knockout stage |
using elo ratings |
exercise solution codepad |
| 256 |
22 Jul 2011 |
Counting Primes |
Using Legendre’s Formula: Recreate Legendre’s two-century old calculation of the number of primes less than a million |
exercise solution codepad |
| 220 |
18 Mar 2011 |
Loopy Loops: Print the numbers from 1 to 1000 without |
using loops or conditionals |
exercise solution codepad |
| 228 |
15 Apr 2011 |
Partition Numbers: Calculate the partition numbers, |
using memoization via growing arrays |
exercise solution codepad |
| 130 |
23 Apr 2010 |
Modern Elliptic Curve Factorization, Part 1: Elliptic arithmetic |
using Montgomery’s parameterization |
exercise solution codepad |
| 131 |
27 Apr 2010 |
Modern Elliptic Curve Factorization, Part 2: Elliptic arithmetic |
using Montgomery’s parameterization |
exercise solution codepad |
| 101 |
12 Jan 2010 |
Calculating Sines: Calculate sines |
using Taylor series and the triple-angle formula, by Bill Cruise |
exercise solution codepad |
| 129 |
20 Apr 2010 |
145 Puzzle: Build and evaluate expressions |
using the digits one through nine and the simple arithmetic operators |
exercise solution codepad |
| 90 |
01 Dec 2009 |
Wolves And Rabbits: Analyze population dynamics |
using the Lotka-Volterra equations |
exercise solution codepad |
| 226 |
08 Apr 2011 |
Credit Card Validation: Validate decimal numbers |
using the Luhn algorithm |
exercise solution codepad |
| 252 |
08 Jul 2011 |
Vedic Divisibility: Use a method of testing divisibility |
using the method of osculators developed in India |
exercise solution codepad |
| 230 |
22 Apr 2011 |
Xref: Programmer’s cross-reference |
utility |
exercise solution codepad |
| 282 |
25 Oct 2011 |
Cksum: Unix checksum |
utility |
exercise solution codepad |
| 71 |
25 Sep 2009 |
Grep: Simple version of the classic unix regular-expression matching |
utility |
exercise solution codepad |
| 222 |
25 Mar 2011 |
Sum: The standard Unix |
V7 file-checksum command |
exercise solution codepad |
| 281 |
21 Oct 2011 |
Sum, Revisited: SysV and Berkeley versions of the Unix |
V7 sum command |
exercise solution codepad |
| 226 |
08 Apr 2011 |
Credit Card Validation: |
Validate decimal numbers using the Luhn algorithm |
exercise solution codepad |
| 238 |
20 May 0 |
ISBN Validation: |
Validate ISBN book numbers, and fetch author and title from the internet |
exercise solution codepad |
| 296 |
13 Dec 2011 |
|
Validating Telephone Numbers: An exercise in input validation |
exercise solution codepad |
| 296 |
13 Dec 2011 |
Validating Telephone Numbers: An exercise in input |
validation |
exercise solution codepad |
| 226 |
08 Apr 2011 |
Credit Card |
Validation: Validate decimal numbers using the Luhn algorithm |
exercise solution codepad |
| 238 |
20 May 0 |
ISBN |
Validation: Validate ISBN book numbers, and fetch author and title from the internet |
exercise solution codepad |
| 287 |
11 Nov 2011 |
Generators: Write functions that yield a |
value, but can then be re-entered |
exercise solution codepad |
| 265 |
23 Aug 2011 |
Knapsack: Fill a knapsack to maximize the |
value of its contents |
exercise solution codepad |
| 75 |
09 Oct 2009 |
Calculating Pi: Calculate the |
value of π by monte-carlo methods and by an Archimedean method |
exercise solution codepad |
| 16 |
17 Mar 2009 |
Comma-Separated Values: Retrieve records from a comma-separated |
values file using a finite-state machine |
exercise solution codepad |
| 16 |
17 Mar 2009 |
Comma-Separated |
Values: Retrieve records from a comma-separated values file using a finite-state machine |
exercise solution codepad |
| 204 |
21 Jan 0 |
Pollard Rho, Revisited: Richard Brent’s |
variant of John Pollard’s rho algorithm for integer factorization |
exercise solution codepad |
| 31 |
08 May 2009 |
Wheel Factorization: Find the factors of a number by a |
variant of trial division |
exercise solution codepad |
| 177 |
19 Oct 2010 |
Text File Databases: Part 1: Functions to read records with fields in |
various formats |
exercise solution codepad |
| 178 |
22 Oct 2010 |
Text File Databases: Part 2: |
Various functions to process records with fields |
exercise solution codepad |
| 252 |
08 Jul 2011 |
|
Vedic Divisibility: Use a method of testing divisibility using the method of osculators developed in India |
exercise solution codepad |
| 140 |
11 Jun 2010 |
N-Queens: Our |
version of a classic algorithmic exercise |
exercise solution codepad |
| 286 |
08 Nov 2011 |
Improved Standard Continuation: An improved |
version of elliptic curve factorization, widely used in current practice |
exercise solution codepad |
| 71 |
25 Sep 2009 |
Grep: Simple |
version of the classic unix regular-expression matching utility |
exercise solution codepad |
| 97 |
29 Dec 2009 |
A Statisticle Speling Korrecter: Peter Norvig’s |
version of the Google spelling suggester |
exercise solution codepad |
| 112 |
19 Feb 2010 |
Sieve Of Atkin, Improved: A faster |
version of the Sieve of Atkin |
exercise solution codepad |
| 281 |
21 Oct 2011 |
Sum, Revisited: SysV and Berkeley |
versions of the Unix V7 sum command |
exercise solution codepad |
| 199 |
04 Jan 2011 |
Dijkstra’s Algorithm: Find the shortest path to all |
vertices of a graph from a single source, guest written by Graham Enos |
exercise solution codepad |
| 161 |
24 Aug 2010 |
Daniel Shanks’ Square Form Factorization Algorithm: A simple and |
very fast factorization algorithm for integers between 105 and 1020 |
exercise solution codepad |
| 270 |
09 Sep 2011 |
Mersenne Twister: Random number generator with |
very long period, useful for simulations |
exercise solution codepad |
| 55 |
31 Jul 2009 |
Elliptic Curve Factorization: A |
very simple implementation of elliptic curve factorization |
exercise solution codepad |
| 228 |
15 Apr 2011 |
Partition Numbers: Calculate the partition numbers, using memoization |
via growing arrays |
exercise solution codepad |
| 43 |
19 Jun 2009 |
Monte Carlo Factorization: Integer factorization |
via Pollard’s rho algorithm |
exercise solution codepad |
| 12 |
03 Mar 2009 |
Creation: Cryptanalysis of a |
Vigenère cipher |
exercise solution codepad |
| 297 |
16 Dec 2011 |
Majority |
Voting: Determine the results of an election |
exercise solution codepad |
| 11 |
27 Feb 2009 |
Mark |
V. Shaney: Generate parodies of a text using a Markov chain |
exercise solution codepad |
| 280 |
18 Oct 2011 |
The |
Wall: Ray Panko’s spreadsheet exercise |
exercise solution codepad |
| 57 |
07 Aug 2009 |
ADFGX: A classic German military field cipher from the First World |
War |
exercise solution codepad |
| 92 |
08 Dec 2009 |
Word Count: An implementation of the unix |
wc program |
exercise solution codepad |
| 94 |
15 Dec 2009 |
Affine-Shift Cipher: A cryptographically |
weak but mathematically interesting cipher |
exercise solution codepad |
| 182 |
05 Nov 2010 |
|
Weather Forecast: Fetch the weather forecast from the internet |
exercise solution codepad |
| 182 |
05 Nov 2010 |
Weather Forecast: Fetch the |
weather forecast from the internet |
exercise solution codepad |
| 174 |
08 Oct 2010 |
Zeller’s Congruence: Calculate the day of the |
week for a given date |
exercise solution codepad |
| 248 |
24 Jun 2011 |
Thank God It’s Friday!: Three methods to calculate the day of the |
week |
exercise solution codepad |
| 84 |
10 Nov 2009 |
Merge Sort: A fast, stable sorting algorithm, especially |
well-suited to linked lists |
exercise solution codepad |
| 65 |
04 Sep 2009 |
Ron’s Cipher #4: Stream cipher by Ron Rivest that underlies the SSL and |
WEP protocols |
exercise solution codepad |
| 31 |
08 May 2009 |
|
Wheel Factorization: Find the factors of a number by a variant of trial division |
exercise solution codepad |
| 172 |
01 Oct 2010 |
Oban Numbers: Numbers that omit the letter “o” |
when spelled, and a function to convert numbers to words |
exercise solution codepad |
| 181 |
02 Nov 2010 |
Emirps: Prime numbers that are prime |
when their digits are reversed, but not palindromic |
exercise solution codepad |
| 42 |
16 Jun 2009 |
|
Who Owns The Zebra?: A logic puzzle, solved by embedding a Prolog-like logic system in Scheme |
exercise solution codepad |
| 286 |
08 Nov 2011 |
Improved Standard Continuation: An improved version of elliptic curve factorization, |
widely used in current practice |
exercise solution codepad |
| 185 |
16 Nov 2010 |
RSA Cryptography: The original public-key cryptographic system, still in |
wide use |
exercise solution codepad |
| 138 |
04 Jun 2010 |
|
Williams’ P+1 Factorization Algorithm: A factorization algorithm, similar to Pollard’s p−1 algorithm |
exercise solution codepad |
| 213 |
22 Feb 2011 |
Sliding |
Window Minimum: List of minimums sliding across an input list |
exercise solution codepad |
| 192 |
10 Dec 2010 |
Two Random Selections: Use random number to select fortunes and lotto |
winners |
exercise solution codepad |
| 3 |
19 Feb 2009 |
Bingo: Calculate the probability of |
winning at Bingo |
exercise solution codepad |
| 127 |
13 Apr 2010 |
Traveling Salesman: Minimum Spanning Tree: Heuristic guarantees solution |
within factor of two of optimal tour |
exercise solution codepad |
| 220 |
18 Mar 2011 |
Loopy Loops: Print the numbers from 1 to 1000 |
without using loops or conditionals |
exercise solution codepad |
| 33 |
15 May 2009 |
Cellular Automata: Linear cellular automata as described by Stephen |
Wolfram in his book A New Kind of Science |
exercise solution codepad |
| 232 |
29 Apr 2011 |
Rule 30 RNG: The random number generator from Mathematica, based on Stephen |
Wolfram’s Rule 30 cellular automata |
exercise solution codepad |
| 90 |
01 Dec 2009 |
|
Wolves And Rabbits: Analyze population dynamics using the Lotka-Volterra equations |
exercise solution codepad |
| 17 |
20 Mar 2009 |
Dodgson's Doublets: A word game invented by the author of Alice in |
Wonderland |
exercise solution codepad |
| 262 |
12 Aug 2011 |
|
Word Breaks: Insert spaces between words: applepie => apple pie |
exercise solution codepad |
| 92 |
08 Dec 2009 |
|
Word Count: An implementation of the unix wc program |
exercise solution codepad |
| 149 |
13 Jul 2010 |
|
Word Cube: A game to form words from a given set of letters |
exercise solution codepad |
| 14 |
10 Mar 2009 |
|
Word Frequencies: Our interpretation of a problem solved by a classic unix pipeline |
exercise solution codepad |
| 17 |
20 Mar 2009 |
Dodgson's Doublets: A |
word game invented by the author of Alice in Wonderland |
exercise solution codepad |
| 27 |
24 Apr 2009 |
|
Word Hy-phen-a-tion By Com-pu-ter: Frank Liang’s hyphenation algorithm, used in TeX |
exercise solution codepad |
| 231 |
26 Apr 2011 |
Miscellanea: FizzBuzz, Prime |
Words, and Split A List |
exercise solution codepad |
| 262 |
12 Aug 2011 |
Word Breaks: Insert spaces between |
words: applepie => apple pie |
exercise solution codepad |
| 36 |
26 May 2009 |
|
Word Search Solver: A computerized implementation of a popular time-waster |
exercise solution codepad |
| 149 |
13 Jul 2010 |
Word Cube: A game to form |
words from a given set of letters |
exercise solution codepad |
| 217 |
08 Mar 2011 |
Reverse Words: Reverse the |
words in an input string |
exercise solution codepad |
| 233 |
03 May 2011 |
Squaring The Bishop: Charles Babbage’s game of |
word squares |
exercise solution codepad |
| 217 |
08 Mar 2011 |
Reverse |
Words: Reverse the words in an input string |
exercise solution codepad |
| 66 |
08 Sep 2009 |
Porter Stemming: Martin Porter’s algorithm for removing suffices from |
word stems |
exercise solution codepad |
| 172 |
01 Oct 2010 |
Oban Numbers: Numbers that omit the letter “o” when spelled, and a function to convert numbers to |
words |
exercise solution codepad |
| 295 |
09 Dec 2011 |
McNugget Numbers: A simple problem, |
worked out on a napkin |
exercise solution codepad |
| 145 |
29 Jun 2010 |
|
World Cup Prognostication: Simulate the knockout stage using elo ratings |
exercise solution codepad |
| 88 |
24 Nov 2009 |
Sunrise, Sunset: Calculate the times of sunrise and sunset on any day anywhere in the |
world |
exercise solution codepad |
| 57 |
07 Aug 2009 |
ADFGX: A classic German military field cipher from the First |
World War |
exercise solution codepad |
| 237 |
17 May 2011 |
Two Bad Sorts: Stooge sort and bogosort are |
worse than quadratic |
exercise solution codepad |
| 189 |
30 Nov 2010 |
Form Letters: Merge a schema and a data file to |
write form letters |
exercise solution codepad |
| 287 |
11 Nov 2011 |
Generators: |
Write functions that yield a value, but can then be re-entered |
exercise solution codepad |
| 194 |
17 Dec 2010 |
Polite Numbers: |
Write numbers as the sum of two or more consecutive integers |
exercise solution codepad |
| 13 |
06 Mar 2009 |
Roman Numerals: A library to read and |
write Roman numerals |
exercise solution codepad |
| 254 |
15 Jul 2011 |
JSON: |
Writing Output: The other side of JSAON |
exercise solution codepad |
| 115 |
02 Mar 2010 |
Goldbach’s Conjecture: Every even number greater than two can be |
written as the sum of two primes |
exercise solution codepad |
| 199 |
04 Jan 2011 |
Dijkstra’s Algorithm: Find the shortest path to all vertices of a graph from a single source, guest |
written by Graham Enos |
exercise solution codepad |
| 18 |
23 Mar 2009 |
Binary Search: A simple task, easy to get |
wrong |
exercise solution codepad |
| 224 |
01 Apr 2011 |
Maximum Difference In An Array: Find maximum Xj &minus |
Xi, with i ≤ j |
exercise solution codepad |
| 224 |
01 Apr 2011 |
Maximum Difference In An Array: Find maximum Xj |
&minus Xi, with i ≤ j |
exercise solution codepad |
| 224 |
01 Apr 2011 |
Maximum Difference In An Array: Find maximum |
Xj &minus Xi, with i ≤ j |
exercise solution codepad |
| 230 |
22 Apr 2011 |
|
Xref: Programmer’s cross-reference utility |
exercise solution codepad |
| 147 |
06 Jul 2010 |
Chaocipher: First look at a ninety-two |
year old autokey-type cipher |
exercise solution codepad |
| 46 |
30 Jun 2009 |
Steve |
Yegge’s Phone-Screen Coding Exercises: A simple set of programming exercises based on a blog entry by Steve Yegge |
exercise solution codepad |
| 46 |
30 Jun 2009 |
Steve Yegge’s Phone-Screen Coding Exercises: A simple set of programming exercises based on a blog entry by Steve |
Yegge |
exercise solution codepad |
| 287 |
11 Nov 2011 |
Generators: Write functions that |
yield a value, but can then be re-entered |
exercise solution codepad |
| 144 |
25 Jun 2010 |
Learn A New Language: Solve the exercise of |
your choice in an unfamiliar language |
exercise solution codepad |
| 208 |
04 Feb 2011 |
Excel Columns: Numbers as in Excel column names, A=1, |
Z=26, IV=256 |
exercise solution codepad |
| 42 |
16 Jun 2009 |
Who Owns The |
Zebra?: A logic puzzle, solved by embedding a Prolog-like logic system in Scheme |
exercise solution codepad |
| 174 |
08 Oct 2010 |
|
Zeller’s Congruence: Calculate the day of the week for a given date |
exercise solution codepad |
