Sukat

input/code.cpp: In function 'int main()':
input/code.cpp:25:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |         if (i + half < socks.size() && a != b) {
      |             ~~~~~~~~~^~~~~~~~~~~~~~

#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
using namespace std;

string socks = "";
vector<pair<char, char>> ans;

int main() {
    cin >> socks;

    sort(socks.begin(), socks.end());

    int half = socks.size()/2 + (socks.size() % 2);
    //cout << half << endl;
    for (int i=0; i<half; i++){
        char a = socks[i], b = socks[i + half];

        // if (a == socks[lo-1] && b == socks[hi+1]) {
        //     hi--;
        //     continue;
        // }

        if (i + half < socks.size() && a != b) {
            ans.push_back({a, b});
        } 
    }

    cout << ans.size() << endl;
    for (auto pair : ans) {
        cout << pair.first << pair.second << endl;
    }
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 1, 2, 3

Verdict: ACCEPTED

Test 3

Group: 1, 2, 3

Verdict: ACCEPTED

Test 4

Group: 1, 2, 3

Verdict: ACCEPTED

Test 5

Group: 1, 2, 3

Verdict: ACCEPTED

Test 6

Group: 1, 2, 3

Verdict: ACCEPTED

Test 7

Group: 1, 2, 3

Verdict: ACCEPTED

Test 8

Group: 2, 3

Verdict: ACCEPTED

Test 9

Group: 2, 3

Verdict: ACCEPTED

Test 10

Group: 2, 3

Verdict: ACCEPTED

Test 11

Group: 2, 3

Verdict: ACCEPTED

Test 12

Group: 2, 3

Verdict: ACCEPTED

Test 13

Group: 2, 3

Verdict: ACCEPTED

Test 14

Group: 2, 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED

Test 16

Group: 3

Verdict: ACCEPTED

Test 17

Group: 3

Verdict: ACCEPTED

Test 18

Group: 3

Verdict: ACCEPTED

Test 19

Group: 3

Verdict: ACCEPTED

Test 20

Group: 3

Verdict: ACCEPTED

Test 21

Group: 3

Verdict: ACCEPTED