Monistus

// https://cses.fi/484/task/B
 
#include <iostream>
using namespace std;
#define ll long long
 
int main() {
    string word;
    cin >> word;
    string word_array[word.size()];
 
    for (int i = word.size() - 1; i >= 0; i--)
    {
        char a = word[i];
 
        if (isalpha(a)) {
            word_array[i] = a;
        } else {
            word_array[i] = "";
            int number = int(a) - 48;
 
            for (int j = 1; j <= number; j++)
            {   
                word_array[i] += word_array[i+j];
            }
            
        }
    }
 
    for (string::size_type i = 0; i < word.size(); i++)
    {
        cout << word_array[i];    
    }
 
    
    
    
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 1, 2

Verdict: ACCEPTED

Test 3

Group: 1, 2

Verdict: WRONG ANSWER

Test 4

Group: 1, 2

Verdict: ACCEPTED

Test 5

Group: 1, 2

Verdict: WRONG ANSWER

Test 6

Group: 1, 2

Verdict: WRONG ANSWER

Test 7

Group: 1, 2

Verdict: WRONG ANSWER

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: WRONG ANSWER

Test 10

Group: 2

Verdict: WRONG ANSWER

Test 11

Group: 2

Verdict: ACCEPTED

Test 12

Group: 2

Verdict: ACCEPTED

Test 13

Group: 2

Verdict: ACCEPTED

Test 14

Group: 2

Verdict: ACCEPTED