设无向图G有n个点e条边，编写算法建立G的邻接表，并按照深度优先搜索输出顶点间。-Let undirected graph G with n vertices e edges, G to write algorithms to establish the adjacency table, and depth-first search in accordance with the output vertex requires time complexity of the algorithm is O (n+e), and in addition to the space occupied by the adjacent multi-table itself outside only O (1) auxiliary space.