Three In A Row
January 9, 2018
In today’s exercise we are given a file and asked to find the userid’s of customers that appeared on three successive days. The input file contains a date in MM/DD/YYYY format, a tab character, and a userid (a four-digit integer):
01/11/2018\t0003 01/12/2018\t0003 01/13/2018\t0004 01/13/2018\t0003
In this case, customer 3 appeared on three successive days, 1/11, 1/12 and 1/13. You may assume the input is properly formed.
Your task is to write a program that finds customers who appeared on three successive days. 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 