You may also find Sphere Online Judge: http://www.spoj.pl http://www.spoj.pl and http://acm.uva.es/archive/nuevoportal/ http://acm.uva.es/archive/nuevoportal/ u

You may also find Sphere Online Judge: http://www.spoj.pl http://www.spoj.pl and http://acm.uva.es/archive/nuevoportal/ http://acm.uva.es/archive/nuevoportal/ useful. Both contain problems from a multitude of sources, namely ACM-ICPC. I've never participated in the Google Code Jam, but presumably, these problems should serve you well.