Merkkijono

#include <bits/stdc++.h>
using namespace std;

string solution(char current_char, int n) {
	if (n == 0) {
		return string(1, current_char);
	}

	return solution(current_char + 1, n -1 ) + string(1, current_char) + solution(current_char + 1, n-1);
}

int main() {
	int n;
	cin >> n;

	cout << solution('a', n) << '\n';

	return 0;
}

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: WRONG ANSWER