[Template] Minimum Cost Maximum

#include<bits/stdc++.h>
using namespace std;
const int nmaxn=5000+8,mmaxn=50000+7;
bool vis[nmaxn];
int h[nmaxn],dis[nmaxn],ef[nmaxn],pre[nmaxn],num[nmaxn];
struct edge{
    int to,nex,fl,co;
}e[mmaxn<<1];
int s,t,cnt=0;
void add(int u,int v,int cos,int flo){
    e[cnt]=(edge){v,h[u],flo,cos};
    h[u]=cnt++;
}
bool spfa(){
    memset(dis,0x3f3f3f3f,sizeof(dis));
    ef[s]=0x3f3f3f3f;
    dis[s]=0,vis[s]=1;
    pre[t]=0;
    queue<int> q;
    q.push(s);
    while(!q.empty()){
        int u=q.front();
        q.pop();vis[u]=0;
        for(int i=h[u];i!=-1;i=e[i].nex){
            int v=e[i].to;
            if(e[i].fl&&dis[v]>dis[u]+e[i].co){
                dis[v]=dis[u]+e[i].co;
                pre[v]=u;num[v]=i;
                ef[v]=min(ef[u],e[i].fl);
                if(!vis[v]){
                    q.push(v);
                    vis[v]=1;
                }
            }
        }
    }
    return pre[t];
}
int main(){
    int n,m;scanf("%d%d%d%d",&n,&m,&s,&t);
    memset(h,-1,sizeof(h));
    for(int i=1;i<=m;++i){
        int u,v,w,f;scanf("%d%d%d%d",&u,&v,&w,&f);
        add(u,v,f,w);add(v,u,-f,0);
    }
    int ansf=0,ansc=0;
    while(spfa()){
        ansf+=ef[t];
        ansc+=ef[t]*dis[t];
        for(int i=t;i!=s;i=pre[i]){
            e[num[i]].fl-=ef[t];
            e[num[i]^1].fl+=ef[t];
        }
    }
    printf("%d %d",ansf,ansc);
    return 0;
}

 

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Origin www.cnblogs.com/xiaobuxie/p/11391904.html