# Poj Solution 3259

```http://poj.org/problem?id=3259

//* @author: ccQ.SuperSupper
import java.io.*;
import java.util.*;
class edge{
int s,t,l;
public void set(int _s,int _t,int _l){
this.s = _s;
this.t = _t;
this.l = _l;
}
}
public class Main {
static int M = 6000,N = 500+20,Inf = 1000000000+10;
static edge e[] =  new edge[M];
static void start(){
for(int i=0;i< M;++i)
e[i] = new edge();
}

static boolean Bellman_Ford(int n,int m,int d[],int s,edge e[]){
int i,j;
boolean flag;
for(i=0;i<=n;++i) d[i] = Inf;
d[s] = 0;
for(i=0;i<=n;++i){
flag = false;
for(j=0;j< m;++j){
if(d[e[j].t]>d[e[j].s]+e[j].l){
d[e[j].t] = d[e[j].s]+e[j].l;
flag = true;
}
}
if(!flag) break;
}
for(i=0;i< m;++i)
if(d[e[i].t]>d[e[i].s]+e[i].l) return false;
return true;
}

public static void main(String[]args) throws Exception{
int d[] = new int[N];
int n,m,w,i,s,t,l,top,F;
start();

F = Get_Num(cin);
while(F--!=0){
top = 0;
n = Get_Num(cin);
m = Get_Num(cin);
w = Get_Num(cin);
for(i=0;i< m;++i){
s = Get_Num(cin);
t = Get_Num(cin);
l = Get_Num(cin);

e[top++].set(s, t, l);
e[top++].set(t, s, l);
}
for(i=0;i< w;++i){
s = Get_Num(cin);
t = Get_Num(cin);
l = Get_Num(cin);
e[top++].set(s, t, -l);
}
for(i=1;i<=n;++i){
e[top++].set(0,i,0);
}
if(Bellman_Ford(n,top,d,0,e))
System.out.println("NO");
else System.out.println("YES");
}

}
static int Get_Num(StreamTokenizer cin)throws Exception{
cin.nextToken();
return (int)cin.nval;
}
}

```
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