Merkkijono

#include<iostream>
#include<cmath>
#include<vector>

using namespace std; 
 char d[16]={'a','b','c','d','e','f','g','h','i','j','k','l',
 'm','n','o','p'};

int main(){
    int n;
    cin>>n;
    int s= pow(2, n)-1;
    char ans[s];
    
    for(int i=0; i<n; i++){
        for(int j=pow(2,i)-1;j<=pow(2,n)-1;j+=pow(2,i+1)){
            ans[j]=d[n-i-1];
            
        
        }
    }
    for(auto l: ans)
        cout<<l;
    
}

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