Nines And Zeros
June 19, 2015
We have today an interview question that so stumped an interviewee that he asked for help on the internet:
Given an integer n, find the smallest number consisting only of the digits zero and nine that is divisible by n. For instance, given n = 23, the smallest number consisting only of the digits zero and nine that is divisible by 23 is 990909.
Your task is to write a program that finds the number described above. When you are finished, you are welcome to read or run a suggested solution, or to post your own solution or discuss the exercise in the comments below.
Programming Praxis 