恭恭敬敬的放上代码  ：)
标题只是用来勾引大牛的~

#include<iostream>
#include<cstring>
#include<cstdio>
#include<vector>
#include<queue>
#define INF 0x3f3f3f3f
using namespace std;

const int N=20010;
const int M=200010;
int n,m,s,t,ect=-1;
int cur[N],flo[M<<1],dis[N];
struct E {int u,v;} _ei[M<<1];
vector<int> ei[N];

void E_Add(int u,int v,int c){
    _ei[++ect].u=u,_ei[ect].v=v,ei[u].push_back(ect);
    flo[ect]=c;
    _ei[++ect].u=v,_ei[ect].v=u,ei[v].push_back(ect);	  
  return;		
}

void Clear(){
    memset(flo,0,sizeof(flo));
    memset(cur,0,sizeof(cur));
	memset(dis,INF,sizeof(dis));
	memset(_ei,0,sizeof(_ei)),ect=-1;
	for(int i=1;i<=N;i++) ei[i].clear();	
  return;	
}
bool Dc_Bfs(){
    queue<int> qi;
	qi.push(s),dis[s]=0;
	while(!qi.empty()){
	    int p=qi.front(); qi.pop();
		for(int i=0;i<ei[p].size();i++){
		    int k=ei[p][i],v=_ei[k].v;
			if (dis[v]==INF&&flo[k]){
			   qi.push(v);
			   dis[v]=dis[p]+1;	
			}	
		}	
	}	
  return dis[t]==INF?0:1;	
}

int Dc_Dfs(int p,int low){
    if (p==t) return low;
	for(int i=cur[p];i<ei[p].size();i++){
	    int k=ei[p][i],v=_ei[k].v,flow;
	    if (dis[v]==dis[p]+1&&flo[k]&&(flow=Dc_Dfs(v,min(low,flo[k])))){
	        cur[p]=i;
			flo[k]-=flow;
			flo[k^1]+=flow;
			return flow;     	
	    } 
	}	
  return 0;	
}

int main(){
    while(~scanf("%d%d",&n,&m)){		
        s=0,t=n+1;
        Clear();
	    for(int i=1;i<=n;i++){
	       int c1,c2;
	       cin>>c1>>c2;
	       E_Add(s,i,c1),E_Add(i,t,c2);	
	    }	
	    for(int i=1;i<=m;i++){
	       int u,v,c;
	       cin>>u>>v>>c;
	       E_Add(u,v,c),E_Add(v,u,c);	
	    }
	    int ans=0,d;
	    while(Dc_Bfs()){
	       while(d=Dc_Dfs(s,INF)) ans+=d;
	       memset(cur,0,sizeof(cur)),memset(dis,INF,sizeof(dis));	   	
        }        
	    printf("%d\n",ans);
    }
  return 0;	
}

用的是DINIC算法，然而惨败而归...