最大流模板

const int MAXN = ;
const int INF = 0x3f3f3f3f;
 
struct Edge{
	int flow,to,rev;
	Edge(){}
	Edge(int a,int b,int c):to(a),flow(b),rev(c){}
};
 
vector<Edge> E[MAXN];
 
inline void Add(int from,int to,int flow){
	E[from].push_back(Edge(to,1,E[to].size()));
	E[to].push_back(Edge(from,0,E[from].size()-1));
}

int deep[MAXN];
 
bool BFS(int from,int to){
	memset(deep,-1,sizeof deep);
	deep[from] = 0;
	queue<int> Q;
	Q.push(from);
	while(!Q.empty()){
		int t = Q.front();
		Q.pop();
		for(int i=0 ; i<E[t].size() ; ++i){
			Edge& e = E[t][i];
			if(e.flow > 0 && deep[e.to] == -1){
				deep[e.to] = deep[t] + 1;
				Q.push(e.to);
			}
		}
	}
	return deep[to] != -1;
}
 
int iter[MAXN];
 
int DFS(int from,int to,int flow){
	if(from == to || flow == 0)return flow;
	for(int &i=iter[from] ; i<E[from].size() ; ++i){
		Edge &e = E[from][i];
		if(e.flow > 0 && deep[e.to] == deep[from]+1){
			int nowflow = DFS(e.to,to,min(flow,e.flow));
			if(nowflow > 0){
				e.flow -= nowflow;
				E[e.to][e.rev].flow += nowflow;
				return nowflow;
			}
		}
	}
	return 0;
}
 
int Dinic(int from,int to){
	int sumflow = 0;
	while(BFS(from,to)){
		memset(iter,0,sizeof iter);
		int t;
		while((t=DFS(from,to,INF)) > 0)sumflow += t;
	}
	return sumflow;
}