Submission #1983056

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;

#define int long long
#define pb push_back 
#define pf push_front 
#define mp make_pair
#define fr first
#define sc second
#define Rep(i, n) for ( int i = 0 ; i < (n); i++ )
#define All(v) v.begin(), v.end()

typedef pair<int, int> Pii; typedef pair<int, Pii> Pip;
const int INF = 1107110711071107;

signed main() {
  int t;
  cin >> t;
  Rep(i, t) {
    int n;
    cin >> n;

    int d[n][n];
    int t[n][n];
    Rep(i, n) Rep(j, n) {
      cin >> d[i][j];
      if ( d[i][j] == -1 ) d[i][j] = INF;
      t[i][j] = d[i][j];
    }

    Rep(i, n) Rep(j, n) Rep(k, n) {
      t[j][k] = min(t[j][k], t[j][i] + t[i][k]);
    }

    bool flag = true;
    Rep(i, n) {
      Rep(j, n) {
      if ( d[i][j] != t[i][j] || d[j][j] != 0 ) flag = false;
      }
    }
    /*
    Rep(i, n) {
      Rep(j, n) {
	cout << t[i][j];
      }
      cout << endl;
      }*/
    
    if ( flag ) cout << "YES" << endl;
    else cout << "NO" << endl;
  }
}

Submission Info

Judge Result