【图】最小费用最大流MCMF

struct Edge
{
	int from,to,cap,flow,cost;
};

struct MCMF
{
	int n,m,s,t;
	vector<Edge> edges;
	vector<int> G[maxn];
	int inq[maxn];
	int d[maxn];
	int p[maxn];
	int a[maxn];
	
	void init(int n)
	{
		this->n=n;
		for(int i=0;i<n;i++) G[i].clear();
		edges.clear();
	}
	void AddEdge(int from,int to,int cap,int cost)
	{
		edges.push_back((Edge){from,to,cap,0,cost});
		edges.push_back((Edge){to,from,0,0,-cost});
		m=edges.size();
		G[from].push_back(m-2);
		G[to].push_back(m-1);
	}
	bool BellmanFord(int s,int t,int &flow,int& cost)
	{
		for(int i=0;i<n;i++) d[i]=INF;
		memset(inq,0,sizeof(inq));
		d[s]=0;inq[s]=1;p[s]=0;a[s]=INF;
		
		queue<int> Q;
		Q.push(s);
		while(!Q.empty())
		{
			int u=Q.front();q.pop();
			inq[u]=0;
			for(int i=0;i<G[u].size();i++)
			{
				Edge& e=edges[G[u][i]];
				if(e.cap>e.flow&&d[e.to]>d[u]+e.cost)
				{
					d[e.to]=d[u]+e.cost;
					p[e.to]=G[u][i];
					a[e.to]=min(a[u],e.cap-e.flow);
					if(!inq[e.to])
					{
						Q.push(e.to);
						inq[e.to]=1;
					}
				}
			}
		}
		if(d[t]==INF)	return false;
		flow+=a[t];
		cost+=d[t]*a[t];
		int u=t;
		while(u!=s)
		{
			edges[p[u]].flow+=a[t];
			edges[p[u]^1].flow-=a[t];
			u=edges[p[u]].from;
		}
		return false;
	}
	int Mincost(int s,int t)
	{
		int flow=0,cost=0;
		while(Bellmanford(s,t,flow,cost));
		return cost;
	}
}