hdu 1532 EK模板

我再网上摘的

#include <iostream>
#include <cstdio>
#include <cstring>
#include <queue>
using namespace std;
#define N 300
int m;
int Visited[N];
int Prev[N];
int G[N][N];

unsigned EKmin()
{
    deque<int> q;
    memset(Visited,0,sizeof(Visited));
    memset(Prev,0,sizeof(Prev));
    Prev[1]=0;
    Visited[1]=1;
    q.push_back(1);
    bool bFindPath=false;
    while(!q.empty()) {
        int u=q.front();
        q.pop_front();
        for(int i=1;i<=m;i++) {
            if(G[u][i]>0&&!Visited[i]) {
                Prev[i]=u;
                Visited[i]=1;
                if(i==m) {
                    bFindPath=true;
                    q.clear();
                    break;
                }
                else q.push_back(i);
            }
        }
    }
    if(!bFindPath) return 0;
    int i=m;
    unsigned nMinFlow=999999999;
    while(Prev[i]) {
        if(nMinFlow>G[Prev[i]][i]) nMinFlow=G[Prev[i]][i];
        i=Prev[i];
    }
    i=m;
    while(Prev[i]) {
        G[Prev[i]][i]-=nMinFlow;
        G[i][Prev[i]]+=nMinFlow;
        i=Prev[i];
    }
    return nMinFlow;
}

int main()
{
    int n,i,u,v,val;
    while(scanf("%d%d",&n,&m)!=EOF) {
        memset(G,0,sizeof(G));
        for(i=0;i<n;i++) {
            scanf("%d %d %d",&u,&v,&val);
            G[u][v]+=val;
        }
        unsigned nMinFlow=0;
        unsigned aug;
        while(aug=EKmin()) nMinFlow+=aug;
        printf("%d\n",nMinFlow);

    }
    return 0;
}

  

posted @ 2012-04-09 20:41  shijiwomen  阅读(538)  评论(0编辑  收藏  举报