poj1087最小割

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <climits>
#include <string>
#include <iostream>
#include <map>
#include <cstdlib>
#include <list>
#include <set>
#include <queue>
#include <stack>
using namespace std;
int s;int en;int n;
int m;
struct edge
{
    int to;int val;int next;int op;
}e[1111111];
const int INF=0xfffffff;
int Min(int a,int b)
{
    return a>b?b:a;
}
int len;int head[111111];
int level[111111];
void add(int from,int to,int val)
{
    e[len].val=val;e[len].to=to;e[len].next=head[from];e[len].op=len+1;
    head[from]=len++;
    e[len].val=0;e[len].to=from;e[len].next=head[to];e[len].op=len-1;
    head[to]=len++;
}

bool  bfs()
{
    for(int i=0;i<n+2;i++)
        level[i]=0;
    level[s]=1;
    queue<int > q;
    q.push(s);
    while(!q.empty()){
        int cur=q.front(); q.pop();
        for(int i=head[cur];i!=-1;i=e[i].next){
            if(!e[i].val) continue;
            int cc=e[i].to;
            if(!level[cc]){
                level[cc]=level[cur]+1;
                q.push(cc);
            }
        }
    }
    return level[en];
}

int dfs(int x,int val)
{
    int tem=val;
    if(x==en) return val;
    for(int i=head[x];i!=-1&&tem;i=e[i].next){
        if(!e[i].val) continue;
        int cc=e[i].to;
      //  cout<<cc<<" "<<x<<endl;system("pause");
        if(level[cc]==level[x]+1){
          //  cout<<x<<" "<<cc<<" "<<e[i].val<<endl;
            int t=dfs(cc,Min(tem,e[i].val));
            e[i].val-=t; e[e[i].op].val+=t;
            tem-=t;
        }
    }
    return val-tem;
}

int dinic()
{
    int ans=0;int t;
    while(bfs()){
        while(t=dfs(s,INF)) ans+=t;
    }
    return ans;
}
int main()
{
    while(scanf("%d%d",&n,&m)!=EOF){
        len=0; memset(head,-1,sizeof(head));
        s=0;en=n+1;
        for(int i=1;i<=n;i++){
            int a;int b;
            scanf("%d%d",&a,&b);
            add(s,i,a);add(i,en,b);
        }
        for(int i=0;i<m;i++){
            int a;int b;int c;
            scanf("%d%d%d",&a,&b,&c);
            add(a,b,c);
            add(b,a,c);
        }
        cout<<dinic()<<endl;
    }
    return 0;
}