说明：  弗洛伊德算法是解决任意两点间的最短路径的一种算法，可以正确处理有向图或有向图或负权（但不可存在负权回路)的最短路径问题，同时也被用于计算有向图的传递闭包。
(Freud algorithm is an algorithm to solve the shortest path between any two points. It can correctly handle the shortest path problem of directed graph or directed graph or negative weight (but can not exist negative weight loop), and it is also used to calculate transitive closure of directed graph.)