分别用floyd 和dijkstra算法计算城市间最短路径的简单例子，地图由固定格式的文件输入，参考压缩包中的sample.txt,地图文件名要作为main参数-Floyd were Dijkstra algorithm and the shortest path between cities in the simple example, the map by a fixed format file input, reference compression package sample.txt, map file name to as a main parameter