Submission #1287395

#	Time	Username	Problem	Language	Result	Execution time	Memory
1287395		kawhiet	Migrations (IOI25_migrations)	C++20	0 / 100	31 ms	1008 KiB

migrations

#include <bits/stdc++.h>
#include "migrations.h"
using namespace std;

constexpr int mxn = 1e5 + 1;

vector<int> g[mxn];
vector<int> d;
vector<bool> vis;

void dfs(int u) {
  vis[u] = 1;
  for (auto v : g[u]) {
    if (!vis[v]) {
      d[v] = d[u] + 1;
      dfs(v);
    }
  }
}

pair<int, int> get(int N) {
  d.assign(N, 0);
  vis.assign(N, false);
  dfs(0);
  int u = d.size() - 1 - (max_element(d.rbegin(), d.rend()) - d.rbegin());
  d.assign(N, 0);
  vis.assign(N, false);
  dfs(u);
  int v = d.size() - 1 - (max_element(d.rbegin(), d.rend()) - d.rbegin());
  if (u > v) swap(u, v);
  return {u, v};
}

int x = 0, y = 0;

int send_message(int N, int i, int Pi) {
  g[i].push_back(Pi);
  g[Pi].push_back(i);
  if (i == N - 2) {
    auto [u, v] = get(N);
    x = u; y = v;
    return x;
  }
  if (i == N - 1) {
    auto [u, v] = get(N);
    if (u == 9999) {
      return v;
    } else {
      return u;
    }
  }
  return 0;
}

pair<int, int> longest_path(vector<int> S) {
  int N = S.size();
  if (S[N - 1] == S[N - 2]) {
    return {S[N - 2], 9999};
  } else {
    return {S[N - 1], S[N - 2]};
  }
}

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