Submission #1034609

#	Time	Username	Problem	Language	Result	Execution time	Memory
1034609		irmuun	Thousands Islands (IOI22_islands)	C++17	22.75 / 100	68 ms	17556 KiB

islands

#include<bits/stdc++.h>
#include "islands.h"

using namespace std;

#define ll long long
#define pb push_back
#define ff first
#define ss second
#define all(s) s.begin(),s.end()
#define rall(s) s.rbegin(),s.rend()

const int maxn=1e5;

int n,m;
set<pair<int,int>>adj[maxn];
vector<int>ans,r;

bool solve(int x){
    if(adj[x].size()==0) return false;
    if(adj[x].size()==1){
        auto [y,sail]=*adj[x].begin();
        adj[x].erase(adj[x].begin());
        adj[y].erase({x,sail^1});
        ans.pb(sail);
        r.pb(sail);
        return solve(y);
    }
    else{
        auto [y,sail]=*adj[x].begin();
        adj[x].erase(adj[x].begin());
        auto [z,sail2]=*adj[x].begin();
        adj[x].erase(adj[x].begin());
        ans.pb(sail);
        ans.pb(sail^1);
        ans.pb(sail2);
        ans.pb(sail2^1);
        ans.pb(sail^1);
        ans.pb(sail);
        ans.pb(sail2^1);
        ans.pb(sail2);
        return true;
    }
}

variant<bool,vector<int>>find_journey(int N,int M,vector<int>U,vector<int>V){
    //sub3
    n=N,m=M;
    for(int i=0;i<m;i++){
        adj[U[i]].insert({V[i],i});
    }
    if(solve(0)){
        reverse(all(r));
        for(auto x:r){
            ans.pb(x);
        }
        return ans;
    }
    return false;
}

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