最小费用最大流模板

#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<queue>
#define inf 2147483647
using namespace std;
struct data
{
    int from,to,next,cup,flow,cost;
    data(){from=-1,to=-1,next=-1,cup=-1,flow=-1,cost=-1;}
}e[200];
int vis[200],head[200],d[200],p[200],a[200];
int cnt,flow,cost;
int n,m;
void add(int u,int v,int w,int c)
{e[cnt].from=u,e[cnt].to=v,e[cnt].next=head[u],head[u]=cnt,e[cnt].cup=w,e[cnt].flow=0,e[cnt].cost=c,cnt++;}
bool spfa(int s,int t)
{
    memset(vis,0,sizeof(vis));
    for(int i=1;i<=n;i++) d[i]=inf;
    queue<int>q;
    q.push(s);
    d[s]=0,vis[s]=1,p[s]=0,a[s]=inf;
    while(!q.empty())
    {
        int now=q.front();
        q.pop();
        vis[now]=0;
        for(int i=head[now];i>=0;i=e[i].next)
        {
            if(e[i].cup>e[i].flow&&d[e[i].from]<inf&&d[e[i].to]>d[e[i].from]+e[i].cost)
            {
                d[e[i].to]=d[e[i].from]+e[i].cost;
                p[e[i].to]=i;
                a[e[i].to]=min(a[e[i].from],e[i].cup-e[i].flow);
                if(!vis[e[i].to])
                {
                    q.push(e[i].to);
                    vis[e[i].to]=1;
                }
            }
        }
    }
    if(d[t]==inf) return false;
    flow+=a[t];
    cost+=d[t]*a[t];
    int now=t;
    while(now!=s)
    {
        e[p[now]].flow+=a[t];
        e[p[now]^1].flow-=a[t];
        now=e[p[now]].from;
    }
    return true;
}
int main()
{
    memset(head,-1,sizeof(head));
    
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++)
    {
        int u,v,w,c;
        scanf("%d%d%d%d",&u,&v,&w,&c);
        add(u,v,w,c);
        add(v,u,0,-c);
    }
    int s,t;
    scanf("%d%d",&s,&t);
    while(spfa(s,t));
    cout<<flow<<' '<<cost;
}