Submission #938910

#	Time	Username	Problem	Language	Result	Execution time	Memory
938910		vjudge1	Bosses (BOI16_bosses)	C++17	100 / 100	392 ms	848 KiB

bosses

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

const int INF = 1e9;
const int MAXN = 5e3;

int N;
vector<int> children[MAXN + 5];
int vis[MAXN + 5];
queue<int> BFS;

int bfs(int start) {
  while (!BFS.empty()) BFS.pop();
  memset(vis, -1, sizeof vis);

  BFS.push(start);
  vis[start] = 1;
  while (!BFS.empty()) {
    int cur = BFS.front(); BFS.pop();
    for (auto next: children[cur]) {
      if (vis[next] != -1) continue;
      vis[next] = vis[cur] + 1;
      BFS.push(next);
    }
  }

  int ans = 0;
  for (int i = 0; i < N; i++) {
    if (vis[i] == -1) return INF;
    ans += vis[i];
  }
  return ans;
}

int main() {
  ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
  cin >> N;
  for (int i = 0; i < N; i++) {
    int sz; cin >> sz;
    while (sz--) {
      int u; cin >> u; u--;
      children[u].push_back(i);
    }
  }
  int ans = INF;
  for (int i = 0; i < N; i++) ans = min(ans, bfs(i));
  cout << ans << endl;
  return 0;
}

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