Submission #1183549

#	Time	Username	Problem	Language	Result	Execution time	Memory
1183549		PagodePaiva	Thousands Islands (IOI22_islands)	C++20	9.10 / 100	19 ms	5188 KiB

islands

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

using namespace std;

const int N = 1010;
const int M = 200010;
vector <pair <int, int>> g[N];
int mark[M];
int mark_ver[N];
bool res = false;

void dfs(int v, int p, int idx){
    mark_ver[v] = 1;
    mark[idx] = 1;
    int cnt = 0;
    for(auto [x, i] : g[v]){
        if(mark[i])
            continue;
        cnt++;
        if(cnt > 1){
            res = true;
            return;
        }
    }
    for(auto [x, i] : g[v]){
        if(mark[i])
            continue;
        dfs(x, v, i);
    }
    return;
}

std::variant<bool, std::vector<int>> find_journey(
    int N, int M, std::vector<int> U, std::vector<int> V) {
    for(int i = 0;i < M;i++){
        g[U[i]].push_back({V[i], i/2});

    }  
    vector <int> ans = {};
    if(g[0].size() >= 2){
        return ans;
    }
    dfs(0, 0, M-1);
    if(res) return ans;
    return res;
}

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