Submission #943716

#	Time	Username	Problem	Language	Result	Execution time	Memory
943716		stefanneagu	Cat in a tree (BOI17_catinatree)	C++17	100 / 100	122 ms	26712 KiB

catinatree

#include <bits/stdc++.h>

using namespace std;

const int nmax = 2e5 + 1;

int k, sz[nmax], l[nmax];

vector<vector<int>> adj;

void dfs(int i, int tata) {
  for(auto it : adj[i]) {
    if(it != tata) {
      dfs(it, i);
    }
  }
  int x = 1;
  vector<int> v;
  v.push_back(0); // daca pot sa bag la nodul i?
  for(auto it : adj[i]) {
    if(it != tata) {
      x += sz[it];
      v.push_back(l[it]);
    }
  }
  sort(v.begin(), v.end());
  int ind = 0;
  while(ind < v.size() - 1 && v[ind] + v[ind + 1] < k) {
    ind ++;
    x --;
  }
  l[i] = v[ind] + 1;
  sz[i] = x;
}

int main() {
  int n;
  cin >> n >> k;
  adj.resize(n + 1);
  for(int i = 2; i <= n; i ++) {
    int a;
    cin >> a;
    a ++;
    adj[a].push_back(i);
    adj[i].push_back(a);
  }
  dfs(1, 0);
  cout << sz[1];
  return 0;
}

Compilation message (stderr)

catinatree.cpp: In function 'void dfs(int, int)':
catinatree.cpp:28:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |   while(ind < v.size() - 1 && v[ind] + v[ind + 1] < k) {
      |         ~~~~^~~~~~~~~~~~~~

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