Submission #223870

#	Time	Username	Problem	Language	Result	Execution time	Memory
223870		Bruteforceman	Cat in a tree (BOI17_catinatree)	C++11	51 / 100	1098 ms	15212 KiB

catinatree

#include <bits/stdc++.h>
using namespace std;
using pii = pair <int, int>;
const int maxn = 2e5 + 10;
vector <int> g[maxn];
int dep[maxn];
bool done[maxn];

void flood(int x, int par, int dist) {
  if(dist == 0) return ;
  done[x] = true;
  for(auto i : g[x]) {
    if(i != par) {
      flood(i, x, dist - 1);
    }
  }
}
void dfs(int x, int par) {
  for(auto i : g[x]) {
    if(i != par) {
      dep[i] = 1 + dep[x];
      dfs(i, x);
    }
  }
}

int main() {
  ios_base :: sync_with_stdio (false);
  cin.tie(0);
  int n, D;
  cin >> n >> D;
  for(int i = 1; i < n; i++) {
    int x;
    cin >> x;
    g[x].emplace_back(i);
    g[i].emplace_back(x);
  }
  dfs(0, -1);
  vector <pii> v;
  for(int i = 0; i < n; i++) {
    v.emplace_back(dep[i], i);
  }
  sort(v.begin(), v.end(), greater <pii> ());
  
  int ans = 0;
  for(auto i : v) {
    if(done[i.second]) continue;
    flood(i.second, -1, D);
    ++ans;
  }
  cout << ans << endl;
  return 0;
}

• Subtask 1: 11 / 11
• Subtask 2: 40 / 40
• Subtask 3: 0 / 49