Submission #1287251

#	Time	Username	Problem	Language	Result	Execution time	Memory
1287251		kawhiet	Migrations (IOI25_migrations)	C++20	Compilation error	0 ms	0 KiB

migrations

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

vector<int> g[10001];
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());
  return {0, u};
}

int prv;

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);
    prv = v;
    return v;
  } else if (i == N - 1) {
    auto [_, v] = get(N);
    return (prv == v ? 0 : v - prv);
    // auto [u, v] = get(N);
    // if (u != 0) return (d == u ? 0 : u - d);
    // else return (d == v ? 0 : v - d);
  }
  return 0;
}

Compilation message (stderr)

/usr/bin/ld: /tmp/cckeFe7r.o: in function `main':
stub.cpp:(.text.startup+0x230): undefined reference to `longest_path(std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status