### Index * [Competitive Programming](#competitive-programming) * [Data science](#data-science) * [Problem Sets](#problem-sets) ### Competitive Programming * [4Clojure](http://www.4clojure.com) * [Codeabbey](http://www.codeabbey.com) * [Codechef](https://www.codechef.com/contests) * [Codeeval](https://www.codeeval.com) * [CodeFights](https://codefights.com) * [Codeforces](http://codeforces.com) * [Coderbyte](https://coderbyte.com) * [Codewars](http://www.codewars.com) * [Codingame](https://www.codingame.com/start) * [Facebook Hackercup](https://www.facebook.com/hackercup) * [Hackerrank](https://www.hackerrank.com) * [Hello World Open](https://helloworldopen.com) * [Internet Problem Solving Contest](http://ipsc.ksp.sk) * [Just another Golf Coding](http://jagc.org) * [Microcorruption](https://microcorruption.com/login) * [Saratov State University](http://acm.sgu.ru/index.php) * [Topcoder](https://www.topcoder.com) ### Data science * [Kaggle](https://www.kaggle.com) ### Problem Sets * [Advent Of Code](http://adventofcode.com) * [Anarchy Golf](http://golf.shinh.org) * [CareerCup](http://www.careercup.com) * [CheckIO](http://www.checkio.org) * [CodeHunt](https://www.codehunt.com) * [Codility](https://codility.com/programmers/) * [Coding Bat](http://codingbat.com/java) * [Exercism](http://exercism.io) * [Geeks For Geeks](http://www.geeksforgeeks.org) * [Google Code Jam - Practise](https://code.google.com/codejam/contests.html) * [Hacker.org](http://www.hacker.org) * [HackerEarth](https://www.hackerearth.com) * [InterviewBit](https://www.interviewbit.com) * [Leetcode](https://leetcode.com) * [Mathproblem of the Month - Bilkent University](http://www.fen.bilkent.edu.tr/~cvmath/prob-month.html) * [PEG Judge](http://wcipeg.com) * [PKU Online Judge](http://poj.org) * [Ponder This!](https://www.research.ibm.com/haifa/ponderthis/index.shtml) * [ProblemBook.NET](http://problembook.net/content/en/index.html) * [Project Euler](https://projecteuler.net) * [Python Practice Projects](http://pythonpracticeprojects.com) * [Rosalind](http://rosalind.info/problems/locations/) * [Sphere Online Judge](http://www.spoj.com) * [TalentBuddy](http://www.talentbuddy.co/blog/) * [Timus Online Judge](http://acm.timus.ru) * [URI Online Judge](https://www.urionlinejudge.com.br/judge/login) * [UVa Online Judge](https://uva.onlinejudge.org/index.php?Itemid=8&option=com_onlinejudge)