Monistus

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


int main(){

char c;
ll n;
deque<char> d;

while (cin >> c){
    d.push_back(c);
}

while (!d.empty()){
    if (isdigit(d.front())){
        n = d.front() - '0';
        d.pop_front();
        for (int i = 0; i < n; i++){
            auto it = d.begin() + n - 1;
            d.push_front(*it);
        }
    } else {
        cout << d.front();
        d.pop_front();
    }
}

}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 1, 2

Verdict: ACCEPTED

Test 3

Group: 1, 2

Verdict: ACCEPTED

Test 4

Group: 1, 2

Verdict: ACCEPTED

Test 5

Group: 1, 2

Verdict: ACCEPTED

Test 6

Group: 1, 2

Verdict: ACCEPTED

Test 7

Group: 1, 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 2

Verdict: ACCEPTED

Test 12

Group: 2

Verdict: ACCEPTED

Test 13

Group: 2

Verdict: ACCEPTED

Test 14

Group: 2

Verdict: ACCEPTED