最小费用最大流模版

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;
            CL(inq,0);
        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 true;
    }
    int Mincost(int s,int t){
        int flow=0,cost=0;
        while(BellmanFord(s,t,flow,cost));
        return cost;
    }
};