缺省源&一些常用的码头

#include <bits/stdc++.h>
#define N 1000010
#define M 2000010
#define pii pair<int,int>
#define mkp make_pair
#define pb push_back
#define fi first
#define se second
//#define int long long
//#define MOD
#define INF 1000000000
#define int_edge int to[M],nxt[M],head[N],cnt=0;
using namespace std;

//int_edge;void add_edge(int x,int y ){to[++cnt]=y;nxt[cnt]=head[x];head[x]=cnt;}
//int_edge;int val[M];void add_edge(int x,int y,int z){to[++cnt]=y;val[cnt]=z;nxt[cnt]=head[x];head[x]=cnt;}
signed main()
{

	return 0;
}