Submission #1261533

#	Time	Username	Problem	Language	Result	Execution time	Memory
1261533		avighna	Migrations (IOI25_migrations)	C++20	30 / 100	834 ms	1316 KiB

migrations

#include <bits/stdc++.h>

std::vector<std::vector<int>> adj;
int prev_max_idx = 0;

int send_message(int N, int i, int Pi) {
  if (adj.empty()) {
    adj.resize(N);
  }
  adj[i].push_back(Pi);
  adj[Pi].push_back(i);
  std::vector<int> d(N);
  auto dfs = [&](auto &&self, int u, int p) -> void {
    for (int &i : adj[u]) {
      if (i != p) {
        d[i] = d[u] + 1;
        self(self, i, u);
      }
    }
  };
  dfs(dfs, 0, -1);
  int it = std::max_element(d.begin(), d.end()) - d.begin();
  if (d[it] > d[prev_max_idx]) {
    prev_max_idx = it;
  } else if (d[it] == d[prev_max_idx]) {
    it = prev_max_idx;
  }
  if (i < N - 9) {
    return 0;
  }
  if (i == it) {
    return 4;
  }
  int ans = it;
  for (int j = N - 9; j < i; ++j) {
    ans /= 3;
  }
  return ans % 3 + 1;
}

std::pair<int, int> longest_path(std::vector<int> S) {
  const int n = S.size();
  for (int i = 1; i <= 9; ++i) {
    if (S[n - i] == 4) {
      return {0, n - i};
    }
  }
  int ans = 0;
  for (int pow = 1, i = 9; i >= 1; --i, pow *= 3) {
    ans += (S[n - i] - 1) * pow;
  }
  return {0, ans};
}

• Subtask 0: 0 / 0
• Subtask 1: 30 / 30
• Subtask 2: 0 / 70