Submission #3825956

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Source Code Expand

#include <algorithm>
#include <bitset>
#include <cctype>
#include <chrono>
#include <cmath>
#include <cstdio>
#include <ctime>
#include <deque>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <string>
#include <tuple>
#include <unordered_map>
#include <vector>
using namespace std;

#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

const int INF = 0x3f3f3f3f;
const long long LINF = 0x3f3f3f3f3f3f3f3fLL;
/*----------------------------------------*/

int main() {
  cin.tie(0); ios::sync_with_stdio(false);
  // freopen("input.txt", "r", stdin);

  int t; cin >> t;
  REP(repeat, t) {
    int n; cin >> n;
    vector<vector<int> > a(n, vector<int>(n));
    bool ok = true;
    REP(i, n) REP(j, n) {
      cin >> a[i][j];
      if (i == j && a[i][j] != 0) ok = false;
    }
    REP(i, n) REP(j, n) REP(k, n) {
      if (a[i][j] != -1 && a[i][k] != -1 && a[k][j] != -1) {
        if (a[i][j] > a[i][k] + a[k][j]) ok = false;
      }
    }
    cout << (ok? "YES" : "NO") << '\n';
  }
  return 0;
}

Submission Info

Judge Result