24Jun/090
Contests, problemsets and challenges
Not for a long time, I have been detected online judge's, which give's problem. Your mission is to find solution in C++/Java/Pascal, and online judje will check it with multiple tests. Tests are hidden, you can't view it, but system give's you 1 test, and problem description. Most of problems are difficult. Main thing is algorithm, not a programming technique.
http://acm.timus.ru - Russian Online Judge. Interface is multilanguage.
http://uva.onlinejudge.org - Nice interface with statistics.
If you need help, I will give you wiki pages, where you can find hints & tricks.
http://www.comp.nus.edu.sg/~stevenha/index.html
http://www.algorithmist.com/index.php/
