【模板】链式前向星

int cnt;

struct Edge
{
    int v, nxt;
    //int w;
}e[maxn];

int head[maxn];

inline void init()
{
 memset(head, -1, sizeof(head));
}

void add(int u, int v/*,int w*/)
{
    e[++cnt].v = v;
    e[cnt].nxt = head[u];
    head[u] = cnt;
    //e[cnt].w = w;
    //add_dinic(v, u);
}