邻接表+链式前向星

（我一个蒟蒻.分不清这两个姐妹qwq

邻接表：

1 -> 2 -> 3 -> 5
2 -> 3
3 -> 4
4 -> 1 -> 5
5 ->^

链式前向星：

edge[0].to = 2;     edge[0].next = -1;     head[1] = 0;

edge[1].to = 3;     edge[1].next = -1;     head[2] = 1;

edge[2].to = 4;     edge[2],next = -1;     head[3] = 2;

edge[3].to = 3;     edge[3].next = 0;      head[1] = 3;

edge[4].to = 1;     edge[4].next = -1;      head[4] = 4;

edge[5].to = 5;    edge[5].next = 3;       head[1] = 5;

edge[6].to = 5;     edge[6].next = 4;       head[4] = 6;

（盗图怪是我了）