图的邻接表存储

struct Edge{    int v;    ll w;    Edge *next;};Edge e[maxn*10];void add_edge(int u,int v,ll w) ///插入邻接表的首部而非尾部，避免遍历{    Edge *pre=&e[u];    Edge *p=(Edge*)malloc(sizeof(Edge));    p->v=v;p->w=w;    p->next=pre->next;    pre->next=p;}    //遍历        for(Edge *p=e[u].next;p!=NULL;p=p->next)//遍历结点u的每条出边