warshall算法，解决了图的连通性问题,输入一个矩阵，输出的两个矩阵，一个表示连通性的判断，另一个表示连通分支的表示。-Warshall method, which solves the problem of the graph connectivity, while entering a matrix, there will output two matrix, one said connectivity judgment, the other branch of the said connected said.