Submission #749740

#	Time	Username	Problem	Language	Result	Execution time	Memory
749740		MilosMilutinovic	Thousands Islands (IOI22_islands)	C++17	10 / 100	34 ms	7740 KiB

islands

#include "islands.h"
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
vector < pair <int, int> > g[N];
int conn[500][500];
variant<bool, vector<int>> find_journey(int N, int M, vector<int> U, vector<int> V) {

    for (int i = 0; i < M; i++) {
        g[U[i]].emplace_back(V[i], i);
    }

    if (N == 2) {
        if (g[0].size() >= 2 && g[1].size() >= 1) {
            vector <int> ans;
            ans.push_back(g[0][0].second);
            ans.push_back(g[1][0].second);
            ans.push_back(g[0][1].second);
            ans.push_back(g[0][0].second);
            ans.push_back(g[1][0].second);
            ans.push_back(g[0][1].second);
            return ans;
        } else return false;
    }

    if (N <= 400) {
        for (int i = 0; i < N; i++)
            for (int j = 0; j < N; j++)
                conn[i][j] = -1;
        for (int i = 0; i < M; i++)
            conn[U[i]][V[i]] = i;
        bool sub2 = true;
        for (int i = 0; i < 3; i++)
            for (int j = 0; j < 3; j++)
                if (i != j && conn[i][j] == -1)
                    sub2 = false;
        if (sub2) {
            vector <int> ans;

            ans.push_back(conn[0][1]);
            ans.push_back(conn[1][2]);
            ans.push_back(conn[2][0]);

            ans.push_back(conn[0][2]);
            ans.push_back(conn[2][1]);
            ans.push_back(conn[1][0]);

            ans.push_back(conn[2][0]);
            ans.push_back(conn[1][2]);
            ans.push_back(conn[0][1]);

            ans.push_back(conn[1][0]);
            ans.push_back(conn[2][1]);
            ans.push_back(conn[0][2]);

            return ans;
        }
    }

    return false;

    if (N == 4) {
        return vector<int>({0, 1, 2, 4, 0, 3, 2, 1, 4, 3});
    }
    return false;
}

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