Sukat

input/code.cpp: In function 'int main()':
input/code.cpp:53:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |     for (int k=0;k<result.size();k+=2)
      |                  ~^~~~~~~~~~~~~~

#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second

pair<int, char> a[26];
int counter=0;
vector<char> result;
string s;

int main() {
    for(int i=0;i<26;++i) {
        a[i].S='A'+i;
    }
    cin >> s;
    for (char i : s) {
        a[i-'A'].F++;
    }
    sort(a, a+26); 
    reverse(a, a+26);
    int i=0, j=1;
    while (j < 26) {

        if (a[j].F > a[i].F) {
            counter += a[i].F;
            for(int k=0;k<a[i].F;++k) {
                result.push_back(a[i].S);
                result.push_back(a[j].S);
            }
            a[j].F -= a[i].F;
            a[i].F = 0;
            i = j;
            j++;
            continue;
        }

        counter+=a[j].F;
        for(int k=0;k<a[j].F;++k) {
            result.push_back(a[i].S);
            result.push_back(a[j].S);
        }
        a[i].F-=a[j].F;
        a[j].F=0;
        if (!a[i].F) {
            i = j+1;
            j = j+2;
        }
        else {
            j++;
        }
    }
    cout << counter << endl;
    for (int k=0;k<result.size();k+=2)
        cout << result[k] << result[k+1] << 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: WRONG ANSWER

Test 14

Group: 2, 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: WRONG ANSWER

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: WRONG ANSWER

Test 21

Group: 3

Verdict: ACCEPTED