HDU 3549 Flow Problem ( 最大流 -EK 算法)

C++，G++的读取速度差距也太大了

Flow Problem

题意：n，m表示n个点m条有向带权边

问：从1-n最大流多少

裸最大流，拿来练手，挺不错的

#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <queue>
#include <algorithm>
const int N = 210;
#define MIN INT_MIN
#define MAX INT_MAX
#define LL long long
using namespace std;
int max(int a,int b){if(a>b)return a; else return b;}
int min(int a,int b){if(a<b)return a; else return b;}
int c[100][100];
int re[100];
int f[100][100];
int p[100],n,m;
void init()
{
    for(int i = 0;i<=n;i++)
    {
        for(int j = 0;j<=n;j++)
        {
            c[i][j] = f[i][j] = 0;
        }
        p[i] = 0;
    }
}
void EK(int s,int t)
{
    queue<int >q;
    while(q.empty()==false) q.pop();
    int sum = 0;
    while(1)
    {
        memset(re,0,sizeof(re));
        q.push(s);
        re[s] = MAX;
        p[s] = -1;
        while(!q.empty())
        {
            int u = q.front();
            q.pop();
            for(int i = 1;i<=n;i++)
            {
                if(!re[i] && f[u][i] < c[u][i])
                {
                    q.push(i);
                    p[i] = u;
                    re[i] = min(re[u],c[u][i]-f[u][i]);
                }
            }
        }
        if(re[t]==0) break;
        for(int st = t;st!=s;st = p[st])
        {
            f[p[st]][st] += re[t];
            f[st][p[st]] -= re[t];
        }
        sum += re[t];
    }
    printf("%d\n",sum);
}

int main()
{
    int t,C=0,a,b,w;
    scanf("%d",&t);
    while(t--)
    {
        C++;
        scanf("%d%d",&n,&m);
        init();
        for(int i = 0;i<m;i++)
        {
            scanf("%d%d%d",&a,&b,&w);
            c[a][b] += w;
        }
        printf("Case %d: ",C);
        EK(1,n);
    }
    return 0;
}

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