Submission #857781

#	Time	Username	Problem	Language	Result	Execution time	Memory
857781		qrno	Bosses (BOI16_bosses)	C++17	100 / 100	365 ms	856 KiB

bosses

#include <iostream>
#include <vector>
#include <array>
#include <bitset>
using namespace std;

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

int best = INF;

int N;
array<vector<short>, MAXN> G;
array<short, MAXN> val, q;

signed main() {
  ios::sync_with_stdio(false); cin.tie(nullptr);

  cin >> N;
  for (int i = 0; i < N; i++) {
    int K; cin >> K;
    while (K--) {
      int u; cin >> u; u--;
      G[u].push_back(i);
    }
  }

  for (int i = 0; i < N; i++) {
    int l = 0, r = -1;

    bitset<MAXN> vis;
    q[++r] = i;
    val[i] = 1;
    vis[i] = true;

    int done = 0, sum = 0;
    while (l <= r) {
      auto v = q[l++];
      sum += val[v];
      done++;
      for (auto u : G[v]) {
        if (vis[u]) continue;
        q[++r] = u;
        val[u] = val[v]+1;
        vis[u] = true;
      }
    }
    best = (done < N) ? best : min(best, sum);
  }

  cout << best << '\n';
}

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