Definition:
Vertices v and w are srongly connected if there is a directed path from v to w and a directed path from w to v.
Algorithm:
Phase 1, Compute reverse postorder of the reverse graph of graph G, refer to my blog Topological Sort to know how to compute this.
Phase 2, Run DFS in the order of the results from Phase 1.
原文：http://www.cnblogs.com/dingjunnan/p/5450265.html