TLE $30pts$

我怀疑我学了个假的 dinic，第二组样例本地要跑整整 $14$ 秒。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
#define MAXN 400010
#define MAXM 1000010
using namespace std;
const int inf=0x3f3f3f3f;
struct Edge
{
	int to;
	int dis;
	int nxt;
}
edge[MAXM<<1];
int head[MAXN],size=1;
void add(int from,int to,int dis)
{
	edge[++size].nxt=head[from];
	edge[size].to=to;
	edge[size].dis=dis;
	head[from]=size;
}
void init()
{
	memset(head,-1,sizeof(head));
	memset(edge,-1,sizeof(edge));
}
int n1,n2,n3,m1,m2,N,s,t;
int u,v;
int ans;
int lv[MAXN];
int now[MAXN];
bool bfs()
{
	for(int i=1;i<=N;i++)
		lv[i]=inf;
	queue<int> q;
	q.push(s);
	lv[s]=0;
	now[s]=head[s];
	while(!q.empty())
	{
		int x=q.front();
		q.pop();
		for(int i=head[x];~i;i=edge[i].nxt)
		{
			int v=edge[i].to;
			if(edge[i].dis>0&&lv[v]==inf)
			{
				lv[v]=lv[x]+1;
				now[v]=head[v];
				if(v==t)
					return 1;
				q.push(v);
			}
		}
	}
	return 0;
}
int dfs(int x,int val)
{
	if(x==t)
		return val;
	int res=0,k;
	for(int i=now[x];~i;i=edge[i].nxt)
	{
		now[x]=i;
		int v=edge[i].to;
		if(edge[i].dis>0&&lv[v]==lv[x]+1)
		{
			k=dfs(v,min(val,edge[i].dis));
			if(k==0)
				lv[v]=inf;
			edge[i].dis-=k;
			edge[i^1].dis+=k;
			res+=k;
			val-=k;
		}
	}
	return res;
}
int main()
{
	init();
	scanf("%d%d%d",&n1,&n2,&n3);
	s=n1+n1+n2+n3+1,t=n1+n1+n2+n3+2,N=n1+n1+n2+n3+2;
	for(int i=1;i<=n2;i++)
	{
		add(s,i,1);
		add(i,s,0);
	}
	scanf("%d",&m1);
	for(int i=1;i<=m1;i++)
	{
		scanf("%d%d",&u,&v);
		add(v,n2+u,1);
		add(n2+u,v,0);
	}
	for(int i=1;i<=n1;i++)
	{
		add(n2+i,n2+n1+i,1);
		add(n2+n1+i,n2+i,0);
	}
	scanf("%d",&m2);
	for(int i=1;i<=m2;i++)
	{
		scanf("%d%d",&u,&v);
		add(n2+n1+u,n2+n1+n1+v,1);
		add(n2+n1+n1+v,n2+n1+u,0);
	}
	for(int i=1;i<=n3;i++)
	{
		add(n2+n1+n1+i,t,1);
		add(t,n2+n1+n1+i,0);
	}
	while(bfs())
		ans+=dfs(s,inf);
	printf("%d",ans);
	return 0;
}