Submission #657175

#	Time	Username	Problem	Language	Result	Execution time	Memory
657175		quocnguyen1012	Bosses (BOI16_bosses)	C++14	100 / 100	626 ms	664 KiB

bosses

#include "bits/stdc++.h"

using namespace std;

int main() {
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  if (fopen("input.txt", "r")) freopen("input.txt", "r", stdin);
  int n; cin >> n;
  vector<vector<int>> adj(n + 5);
  for (int i = 1; i <= n; ++i) {
    int k; cin >> k;
    while (k--) {
      int v; cin >> v;
     // adj[i].emplace_back(v);
      adj[v].emplace_back(i);
    }
  }
  vector<int> d(n + 5, -1);
  int ans = INT_MAX;
  for (int r = 1; r <= n; ++r) {
    queue<int> Q;
    fill(d.begin(), d.end(), -1);
    int tot = 0;
    for (d[r] = 1, Q.push(r); !Q.empty(); ) {
      int u = Q.front(); Q.pop();
      for (int v : adj[u]) {
        if (d[v] == -1) {
          d[v] = d[u] + 1;
          Q.push(v);
        }
      }
    }
    bool bad = false;
    for (int i = 1; i <= n; ++i) {
      tot += d[i];
      if (d[i] == -1) bad = true;
    }
    if (not bad)
      ans = min(ans, tot);
  }
  cout << ans;
}

Compilation message (stderr)

bosses.cpp: In function 'int main()':
bosses.cpp:7:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    7 |   if (fopen("input.txt", "r")) freopen("input.txt", "r", stdin);
      |                                ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 45 / 45
• Subtask 3: 33 / 33