邻接表模板

struct Node

{

    int from,to,next;

}edge[MAXM];

int tol;

int head[MAXN];

void init()

{

    tol=0;

    memset(head,-1,sizeof(head));

}

void addedge(int u,int v)

{

    edge[tol].from=u;

    edge[tol].to=v;

    edge[tol].next=head[u];

    head[u]=tol++;

}

for(int i=head[u];i!=-1;i=edge[i].next)

{

}