Submission #1261526

#	Time	Username	Problem	Language	Result	Execution time	Memory
1261526		avighna	Migrations (IOI25_migrations)	C++20	23 / 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 - 2) {
    return 0;
  }
  if (i == it) {
    return 101;
  }
  if (i == N - 2) {
    return it % 100 + 1;
  }
  if (i == N - 1) {
    return it / 100 + 1;
  }
  return -1; // we should never reach this
}

std::pair<int, int> longest_path(std::vector<int> S) {
  const int n = S.size();
  if (S[n - 1] == 101) {
    return {0, n - 1};
  }
  if (S[n - 2] == 101) {
    return {0, n - 2};
  }
  return {0, (S[n - 1] - 1) * 100 + S[n - 2] - 1};
}

• Subtask 0: 0 / 0
• Subtask 1: 23 / 30
• Subtask 2: 0 / 70