有时仅对赋权有向图上从任意一个顶点到另外任意一个顶点之间有没有路感兴趣。试修改Floyd算法，计算出图的道路矩阵P，使得从顶点i到顶点j有路时P[i,j]= 1,否则P[i,j]= 0。-sometimes only to empower a map from any one vertex to another arbitrary point between a road not interested. Try to amend Floyd algorithm calculated the ro