hdu 3879 最大权闭合图(裸题)

/*
裸的最大权闭合图
解:参见胡波涛的《最小割模型在信息学竞赛中的应用
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<queue>
using namespace std;
#define N  55100//刚开始开的是5100一直越界应该是n+m
#define NN  510000
#define inf 0x3fffffff
struct node {
int u,v,w,next;
}bian[NN*8];
int head[N],yong,dis[N],work[N];
void init() {
yong=0;
memset(head,-1,sizeof(head));
}
void addedge(int u,int v,int w) {
bian[yong].v=v;
bian[yong].w=w;
bian[yong].next=head[u];
head[u]=yong++;
}
int bfs(int s,int t)
{
    memset(dis,-1,sizeof(dis));
    queue<int>q;
    q.push(s);
    dis[s]=0;
    while(!q.empty())
    {
        int u=q.front();
        q.pop();
        for(int i=head[u];i!=-1;i=bian[i].next)
        {
            int v=bian[i].v;
            if(bian[i].w&&dis[v]==-1)
            {
                dis[v]=dis[u]+1;
                q.push(v);
                if(v==t)
                    return 1;
            }
        }
    }
    return 0;
}
int dfs(int  s,int limit,int t)
{
    if(s==t)return limit;
    for(int &i=work[s];i!=-1;i=bian[i].next)
    {
        int v=bian[i].v;
        if(bian[i].w&&dis[v]==dis[s]+1)
        {
            int tt=dfs(v,min(limit,bian[i].w),t);
            if(tt)
            {
                bian[i].w-=tt;
                bian[i^1].w+=tt;
                return tt;
            }
        }
    }
    return 0;
}
int dinic(int s,int t)
{
    int ans=0;
    while(bfs(s,t))
    {
        memcpy(work,head,sizeof(head));
        while(int tt=dfs(s,inf,t))
            ans+=tt;
    }
    return ans;
}
int main(){
    int n,m,i,k,sum,u,v,w,s,t;
    while(scanf("%d%d",&n,&m)!=EOF) {
        init();
        s=0;t=n+m+1;
        for(i=1;i<=n;i++) {
            scanf("%d",&k);
           addedge(i,t,k);
           addedge(t,i,0);
        }
        sum=0;
        for(i=1;i<=m;i++) {
            scanf("%d%d%d",&u,&v,&w);
            addedge(s,i+n,w);
            addedge(i+n,s,0);
            addedge(i+n,u,inf);
            addedge(u,i+n,0);
            addedge(i+n,v,inf);
            addedge(v,i+n,0);
            sum+=w;
        }
        printf("%d
",sum-dinic(s,t));
    }
return 0;}

原文地址:https://www.cnblogs.com/thefirstfeeling/p/4410551.html