中文说明：matlab练习程序（单源最短路径Bellman-Ford） 该算法可以用来解决一般（边的权值为负）的单源最短路径问题，而dijkstra只能解决权值非负的情况。此算法使用松弛技术，对每一个顶点，逐步减少源到该顶点的路径的估计值，直到达到最短的路径。
English Description：
MATLAB training program (single source shortest path Bellman-Ford) this algorithm can be used to solve General (a negative edge weights) the single-source shortest path problem, Dijkstra will only solve the situation of non-negative weights. This algorithm uses a relaxation technique, for each vertex, gradually reduce the estimate of source to the vertex of the path until it reaches the shortest possible path.