Submission #1983001

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;
int main(){
  int n;
  cin>>n;
  for(int i=0;i<n;i++){
    int V,d[33][33],f=0;
    cin>>V;
    for(int i=0;i<V;i++)
      for(int j=0;j<V;j++){
	cin>>d[i][j];
	if(d[i][j]!=0&&i==j)f=1;
      }
    
    
    for(int k=0;k<V;k++)
      for(int i=0;i<V;i++)
	for(int j=0;j<V;j++)
	  if(d[i][j]!=-1||d[i][k]!=-1||d[k][j]!=-1){
	    int t=d[i][j];
	    d[i][j]=min(d[i][j],d[i][k]+d[k][j]);
	    if(t!=d[i][j])f=1;
	  }
    if(f)cout<<"NO"<<endl;
    else cout<<"YES"<<endl;
  }
  
  return 0;
}

Submission Info

Judge Result