제출 #968555

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
968555		AdamGS	Thousands Islands (IOI22_islands)	C++17	3.50 / 100	34 ms	12920 KiB

islands

#include "islands.h"
#include<bits/stdc++.h>
using namespace std;
#define rep(a, b) for(int a = 0; a < (b); ++a)
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
const int LIM=2e5+7;
vector<pair<int,int>>V[LIM];
vector<int>cykl;
int odw[LIM], czy[LIM];
int DFS(int x) {
  odw[x]=1;
  for(auto i : V[x]) if(odw[i.st]) {
    czy[i.nd]=1;
    cykl.pb(i.nd);
    return i.st;
  }
  for(auto i : V[x]) {
    if(!odw[i.st]) {
      int p=DFS(i.st);
      if(p==-1) continue;
      if(p>=0) cykl.pb(i.nd);
      if(p==x) p=-2;
      return p;
    }
  }
  return -1;
}
variant<bool,vector<int>>find_journey(int n, int m, vector<int>X, vector<int>Y) {
  rep(i, m) V[X[i]].pb({Y[i], i});
  if(DFS(0)==-1) return false;
  rep(i, n) V[i].clear();
  for(auto i : cykl) swap(X[i], Y[i]);
  rep(i, m) if(!czy[i]) V[X[i]].pb({Y[i], i});
  if(DFS(0)==-1) return false;
  return true;
}

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