Submission #528828

#	Time	Username	Problem	Language	Result	Execution time	Memory
528828		Alex_tz307	Cat in a tree (BOI17_catinatree)	C++17	100 / 100	133 ms	16268 KiB

catinatree

#include <bits/stdc++.h>
#define INF 0x3f3f3f3f

using namespace std;

const int kN = 2e5;
vector<int> g[kN];
int mark[kN];

void dfs(int u, int d) {
  if (d <= mark[u]) {
    return;
  }
  mark[u] = d;
  for (int v : g[u]) {
    dfs(v, d - 1);
  }
}

void testCase() {
  int n, d;
  cin >> n >> d;
  vector<int> dep(n);
  vector<pair<int, int>> nodes(n, {0, 0});
  for (int v = 1; v < n; ++v) {
    int u;
    cin >> u;
    g[u].emplace_back(v);
    g[v].emplace_back(u);
    dep[v] = dep[u] + 1;
    nodes[v] = {dep[v], v};
  }
  sort(nodes.begin(), nodes.end(), greater<pair<int, int>>());
  int ans = 0;
  for (auto it : nodes) {
    if (mark[it.second] == 0) {
      ans += 1;
      dfs(it.second, d);
    }
  }
  cout << ans << '\n';
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  int tests = 1;
  for (int tc = 0; tc < tests; ++tc) {
    testCase();
  }
  return 0;
}

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