Sukat

input/code.cpp: In function 'int main()':
input/code.cpp:29:13: warning: unused variable 'largest_value' [-Wunused-variable]
   29 |         int largest_value = socks[largest_index];
      |             ^~~~~~~~~~~~~

#include <iostream>
#include <vector>
#include <string>
#include <queue>

int socks[26]{0};


int main() {
    std::vector<std::string> operations;
    std::string input;
    std::cin >> input;

    for (char c : input) {
        socks[c-'A']++;
    }

    auto cmp = [](int left, int right) { return socks[left] < socks[right]; };
    std::priority_queue<int, std::vector<int>, decltype(cmp)> queue(cmp);

    for (int i=0; i<26; i++)
        queue.push(i);

    std::string PAIR1 = "";
    std::string PAIR2 = "";

    while (true) {
        int largest_index = queue.top();
        int largest_value = socks[largest_index];
        queue.pop();
        int second_largest_index = queue.top();
        int second_largest_value = socks[second_largest_index];
        queue.pop();

        if (second_largest_value <= 0) break;

        PAIR1 = (char)(largest_index+'A');
        PAIR2 = (char)(second_largest_index+'A');
        operations.push_back(PAIR1+PAIR2);

        socks[largest_index]        -= 1;
        socks[second_largest_index] -= 1;

        queue.push(second_largest_index);
        queue.push(largest_index);
    }

    std::cout << operations.size() << '\n';

    for (std::string& operation : operations) {
        std::cout << operation << '\n';
    }

    return 0;
}


// A-Z == 0-25

/*

ACCEABFFZZZZ

*/

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