poj 1273

////网络流算法的模板！！！

E K算法

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<cctype>
#include<queue>
#include<stack>
#include<vector>
#include<algorithm>

using namespace std;
typedef long long LL;
#define N 210
#define INF 0x3f3f3f3f

int maps[N][N], pre[N], n, m, vis[N], ans;

int solve()
{
    int f=0;
    queue<int> Q;
    memset(pre, 0, sizeof(pre));
    Q.push(1);

    while(Q.size())
    {
        int q=Q.front();
        Q.pop();
        if(q==m)
        {
            f=1;
            break;
        }
        for(int i=1; i<=m; i++)
        {
            if(maps[q][i]>0&&!pre[i])
            {
                pre[i]=q;
                Q.push(i);
            }
        }
    }
    if(f==0)
        return 0;

    int k=m;
    int bian=INF;
    while(pre[k]&&k!=1)
    {
        bian=min(bian, maps[pre[k]][k]);
        k=pre[k];
    }

    k=m;
    while(pre[k]&&k!=1)
    {
        maps[pre[k]][k]-=bian;
        maps[k][pre[k]]+=bian;
        k=pre[k];
    }
    return bian;
}

int main()
{
    int a, b, c, x;
    while(~scanf("%d%d", &n, &m))
    {
        memset(maps, 0, sizeof(maps));
        for(int i=1; i<=n; i++)
        {
            scanf("%d%d%d", &a, &b, &c);
            maps[a][b]+=c;
        }

        ans=0;
        while(x=solve())
            ans+=x;

        printf("%d
", ans);
    }
    return 0 ;
}