Competitive Solutions Solutions to competitive programming problems from some online judges. Online Judges Hackerrank https://www.hackerrank.com/ Donald E. Knuth https://www.facebook.com/events/570806507134708 Codeforces https://codeforces.com/ Interview-cake https://www.interviewcake.com/ OmegaUp https://omegaup.com/ Leetcode https://leetcode.com/