Submission #256870

#	Time	Username	Problem	Language	Result	Execution time	Memory
256870		Nightlight	Bosses (BOI16_bosses)	C++14	100 / 100	997 ms	908 KiB

bosses

#include <bits/stdc++.h>
#define pii pair<int, int>
using namespace std;

int N, K;
vector<int> adj[5005];
bool ok[5005];
int topo[5005], par[5005], pos[5005];
int p;
long long sz[5005];
long long ans = LLONG_MAX;

void solve(int rt) {
  p = N - 1;
  queue<pii> q;
  memset(ok, 0, sizeof(ok));
  ok[rt] = 1;
  for(int v : adj[rt]) q.emplace(v, rt);
  topo[N] = rt;
  par[rt] = 0;
  int u;
  while(!q.empty()) {
    u = q.front().first;
    if(ok[u] == 0) {
      ok[u] = 1;
      topo[p] = u, pos[u] = p;
      par[u] = q.front().second;
      for(int v : adj[u]) {
        q.emplace(v, u);
      }
      p--;
    }
    q.pop();
  }
  if(p) return;
  memset(sz, 0, sizeof(sz));
  long long res = 0;
//  cout << rt << ":\n";
  for(int i = 1; i <= N; i++) {
    u = topo[i];
//    cout << u << " " << par[u] << "\n";
    sz[u]++;
    res += sz[u];
    sz[par[u]] += sz[u];
  }
  ans = min(ans, res);
}

int main() {
  ios_base::sync_with_stdio(0);
  cin >> N;
  int u;
  for(int i = 1; i <= N; i++) {
    cin >> K;
    while(K--) {
      cin >> u;
      adj[u].emplace_back(i);
    }
  }
  for(int i = 1; i <= N; i++) solve(i);
  cout << ans << "\n";
  cin >> N;
}

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