제출 #1034644

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1034644		Mr_Husanboy	수천개의 섬 (IOI22_islands)	C++17	5 / 100	1129 ms	886900 KiB

islands

#include "islands.h"

#include <variant>
#include <bits/stdc++.h>

using namespace std;

#define ff first
#define ss second
#define all(a) (a).begin(), (a).end()
#define ll long long
const int mod = 1000002022;

vector<int> state, p;
int n, m; 
vector<vector<int>> g;
template<typename T>
int len(T &a){return a.size();}

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());


variant<bool, vector<int>> find_journey(
    int n, int m, std::vector<int> u, std::vector<int> v) {
  vector<vector<int>> g(n);
  for(int i = 0; i < m; i ++) g[u[i]].push_back(i);
  if(len(g[0]) == 0) return false;

  if(n == 2){
    if(len(g[0]) <= 1) return false;
    if(len(g[1]) == 0) return false;
    return vector {g[0][0], g[1][0], g[0][1], g[0][0], g[1][0], g[0][1]};
  } 
  vector<int> ans;
  vector<int> vis(n);
  vector<int> cyc;
  vector<int> par(n);
  auto dfs = [&](auto &dfs, int i)->bool{
    vis[i] = 1;
    int r = 0;
    for(auto j : g[i]){
      if(j % 2) continue;
      int x = v[j];
      par[x] = j;
      if(vis[x]){
        cyc.push_back(j);
        int cur = i;
        while(cur != x){
          cyc.push_back(par[cur]);
          cur = u[par[cur]];
        }
        return true;
      }
      if(dfs(dfs, x)){
        return true;
      }
    }
    return false;
  };

  return dfs(dfs, 0);
}

컴파일 시 표준 에러 (stderr) 메시지

islands.cpp: In instantiation of 'find_journey(int, int, std::vector<int>, std::vector<int>)::<lambda(auto:23&, int)> [with auto:23 = find_journey(int, int, std::vector<int>, std::vector<int>)::<lambda(auto:23&, int)>]':
islands.cpp:61:13:   required from here
islands.cpp:40:9: warning: unused variable 'r' [-Wunused-variable]
   40 |     int r = 0;
      |         ^

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