DFS on the above undigraph with A as the starting point, and the neighbors of the same vertex are in order of a~z. The order in which the vertices are accessed is: 以A为起点对以上无向图进行DFS，同一顶点的邻居以a~z为序，各顶点被访问的顺序为：
Aa, e, b, c, f, g, h, j, i, d
Ba, b, c, f, g, d, i, h, j, e
Ca, b, e, c, f, h, g, i, d, j
Da, e, b, c, f, h, g, i, d, j