以下是引用HJin在2007-9-5 7:33:57的发言：
burte force is an applicable way, but it takes O(e^n) time.
As Yu3Zhon2gFei1Yan4 said we may need some graph algorithm here for a polynomial time soln.
我E文太差了,谁能帮我解释下,谢谢.....
