Submission #3825527

---

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) {
      if (i == j) continue;
      int ans = INF;
      vector<bool> used(n, false);
      used[i] = true;
      priority_queue<pair<int, int>> que;
      REP(k, n) if (k != i && k != j && a[i][k] != -1) {
        que.push(make_pair(a[i][k], k));
        used[k] = true;
      }
      while (!que.empty()) {
        auto aut = que.top(); que.pop();
        if (aut.second == j) {
          ans = aut.first;
          break;
        }
        REP(k, n) if (!used[k] && a[aut.second][k] != -1) {
          que.push(make_pair(aut.first + a[aut.second][k], k));
          used[k] = true;
        }
      }
      if (a[i][j] > ans) {
        ok = false;
        break;
      }
    }
    cout << (ok? "YES" : "NO") << '\n';
  }
  return 0;
}

Submission Info

Judge Result