好资源

https://class.coursera.org/algorithms-001/lecture

http://open.163.com/special/opencourse/algorithms.html

 http://www.comp.nus.edu.sg/~stevenha/programming/acmoj.html#Q7

http://www.algorithmist.com/index.php/Main_Page

http://acm.timus.ru/problem.aspx?space=1&num=1306

http://hzwer.com/1234.html

http://xsy.gdgzez.com.cn/JudgeOnline/