code jam source
https://code.google.com/codejam
https://www.facebook.com/hackercup
http://codeforces.com/
https://www.hackerrank.com/
http://www.topcoder.com/
https://icpc.baylor.edu/
https://www.codechef.com/
https://leetcode.com/
http://ipsc.ksp.sk/
https://www.algospot.com/