Merkkijono

#include <stdio.h>
#include <iostream>
#include <math.h>

using namespace std;
string ToStr( char c ) {
   return string( 1, c );
}
int main()
{
    string ans = "a";
    string abc = "abcdefghijklmnop";
    int n;
    cin >> n;
    for (int i = 1; i < n; i++) {
        string c = string(1,abc.at(i));
        for (int j = 0;ans.at(ans.length()-1) != abc.at(i); j+=2) {
            ans.insert(j,c);
        }
    } 
    /*string c = ToStr(abc.at(0));
    ans.insert(0,c);*/
    cout << ans;
    
    

    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED