Competition Sites to practice

1 UVA:http://acm.uva.es/p - The Valladolid University Online Judge.

Over N problems, for a reasonable value of N. The problems are culled

from old contests, and online contests.

2.ZJU:Zhejiang University Online Judge - http://acm.zju.edu.cn

3.SGU:Saratov State University Online Contester - http://acm.sgu.ru

4.PKU: Peking University Judge Online of ACM ICPC -

http://acm.pku.edu.cn/JudgeOnline

5.topcoder

6.codeforces