Submission #628577

#	Time	Username	Problem	Language	Result	Execution time	Memory
628577		c28dnv9q3	Thousands Islands (IOI22_islands)	C++17	9.10 / 100	31 ms	5580 KiB

islands

#include "islands.h"

#include <variant>
#include <vector>
#include <map>
#include <queue>
using namespace std;

vector<int> U, V;
int N, M;
vector<vector<int>> adj;

bool path_exists(int target) {
  vector<bool> vis(N);
  queue<int> q;
  q.push(0);
  vis[0] = true;
  while (!q.empty()) {
    int x = q.front(); q.pop();
    if (x == target) return true;
    for (auto c : adj[x]) {
      if (!vis[V[c]]) {
        vis[V[c]] = true;
        q.push(V[c]);
      }
    }
  }

  return false;
}

variant<bool, vector<int>> find_journey(
    int N, int M, vector<int> U, vector<int> V) {
  ::U = U;
  ::V = V;
  ::N = N;
  ::M = M;
  adj.resize(N);
  for (int i = 0; i < M; i++)
    adj[U[i]].push_back(i);
  if (adj[0].size() >= 2)
    return true;
  
  for (int i = 0; i < N; i++) {
    if (adj[i].size() >= 3 && path_exists(i)) 
      return true;
  }
  return false;
}

• Subtask 1: 0 / 5
• Subtask 2: 1.75 / 5
• Subtask 3: 7.35 / 21
• Subtask 4: 0 / 24
• Subtask 5: 0 / 45