最大流流模板题hdu_1532

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模板如下，注意是先输入的边数，后输入的点数，勿错。

#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<vector>
#define MAXX 205
#define INF 0x3fffffff
using namespace std;
struct Node{
    int to;
    int cap;
    int rev;
};
bool used[MAXX];
vector<Node>v[MAXX];
void addedge(int from, int to, int cap){
    v[from].push_back((Node){to,cap,v[to].size()});
    v[to].push_back((Node){from,0,v[from].size()-1});
}
int dfs(int s, int t, int f){
    if(s == t)return f;
    used[s] = true;
    for(int i = 0; i < v[s].size(); i++){
        if(used[v[s][i].to] == true || v[s][i].cap == 0)continue;
        int d = dfs(v[s][i].to, t, min(f,v[s][i].cap));
        if(d > 0){
            v[s][i].cap -= d;
            v[ v[s][i].to ][ v[s][i].rev ].cap += d;
            return d;
        }
    }
    return 0;
}
int max_flow(int s, int t){
    int flow = 0;
    while(1){
        memset(used,false,sizeof(used));
        int f = dfs(s,t,INF);
        //cout << f <<endl;
        if(f == 0)
            return flow;
        flow += f;
    }
}
int main(){
    int n,m;
    while(scanf("%d%d",&m,&n) == 2){
        memset(v,0,sizeof(v));
        for(int i = 0; i < m; i++){
            int from, to, cap;
            scanf("%d%d%d",&from,&to,&cap);
            addedge(from,to,cap);
        }
        cout << max_flow(1,n) << endl;
    }
}

v[i][j].rev是记录这条边的反向边在v[ v[i][j].to ][ v[i][j].rev ]