边集数组

struct Edge{
    int from,to,w;
};
int first[MAX_V];
int next[MAX_E];

void init()
{
    memset(first,-1,sizeof(first));
    memset(next,-1,sizeof(next));
}

void read_edge(int u,int v,int w)
{
    static int id = 0;
    edges[id].from = u;edges[id].to = v;edges[id].weight =w;

    next[id] = first[u];
    first[u] = id++;

}