Submission #736404

#	Time	Username	Problem	Language	Result	Execution time	Memory
736404		puppy	Thousands Islands (IOI22_islands)	C++17	0 / 100	31 ms	4180 KiB

islands

#include "islands.h"

#include <variant>
#include <vector>
#include <utility>
#include <functional>
#include <algorithm>
#include <iostream>
using namespace std;
vector<pair<int, int>> adj[1005];
int ot(int k)
{
    return k % 2 ? (k-1) : (k+1);
}
bool visited[100005]; //간선 방문 체크
bool vsv[1005]; //정점 방문 체크
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 / 2; i++) {
            adj[U[2*i]].push_back(make_pair(V[2*i], i));
        }
        vector<int> vc;
        int _end = -1;
        function<void(int)> dfs = [&](int v)
        {
            vsv[v] = true;
            for (pair<int, int> p:adj[v]) {
                if (visited[p.second]) continue;
                visited[p.second] = true;
                vc.push_back(p.second);
                if (vsv[p.first]) {
                    _end = p.first;
                    return;
                }
                dfs(p.first);
                if (_end != -1) return;
                visited[p.second] = false;
                vc.pop_back();
            }
        };
        dfs(0);
        if (_end == -1) {
            return false;
        }
        vector<int> v1, v2;
        bool flag = false;
        for (int i = 0; i < (int)vc.size(); i++) {
            if (U[2*vc[i]] == _end) flag = true;
            if (flag) v2.push_back(vc[i]);
            else v1.push_back(vc[i]);
        }
        vector<int> ans;
        for (int i:v1) ans.push_back(2*i);
        for (int i:v2) ans.push_back(2*i);
        for (int i:v2) ans.push_back(2*i+1);
        reverse(v2.begin(), v2.end());
        for (int i:v2) ans.push_back(2*i);
        for (int i:v2) ans.push_back(2*i+1);
        reverse(v1.begin(), v1.end());
        for (int i:v1) ans.push_back(2*i);
        return ans;
}

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