sol6.cpp

sol6.cpp

#include <iostream>
#include <unordered_set>
#include <utility>

using namespace std;

class Solution {
public:
    vector<pair<int,int>> doubleCheck(vector<int> V) {
        unordered_set<int> H;
        vector<pair<int,int>> K;
        for (auto i : V) H.insert(i);
        for (auto i : V) {
            if (H.contains(2 * i)) {
                K.push_back(make_pair(i, 2*i));
            }
        }
        return K;
    }
};

int main() {
    vector<int> test1 = { 33, 12, 41, 6, 20, 10, 52, 34, 52, 27, 26 };
    Solution solution;
    vector<pair<int,int>> output = solution.doubleCheck(test1);
    for (auto p : output) {
        cout << "("  << p.first << ", " << p.second << ")\n";
    }
}