dijitetra 和 floyd 算法，单步执行或连续，过程全部显示在界面上，并可以计算最小生成树和连通区域，有向图保存为.mpg,学习算法可以参考-dijitetra and floyd algorithm,step by step or go all through,process is printed in the program,minimal spanning tree is all calculate and saved,the graph is saved in .mpg pat