图的建立以及深度遍历，该代码很简单，是用链式存储的-Map-building, as well as the depth of traversal, the code is very simple, with chain store

利用邻接表存储无向图,并深度遍历和广度遍历图-Storage without the use of the adjacent table to the map, and the depth and breadth traversal graph traversal