Monistus

#include <iostream>
#include <string>
#include <vector>

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(NULL);

    std::string s;
    std::cin >> s;

    std::vector<char> result(s.begin(), s.end());

    size_t i = 0;
    while (i < result.size()) {
        if (isdigit(result[i])) {
            int length = result[i] - '0';
            std::vector<char> temp(result.begin() + i + 1, result.begin() + i + 1 + length);
            result.erase(result.begin() + i);
            result.insert(result.begin() + i, temp.begin(), temp.end());
	}else{   
	  i++;}
    }
    

    for (char c : result) {
        std::cout << c;
    }
    return 0;
}

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: TIME LIMIT EXCEEDED

Test 12

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 14

Group: 2

Verdict: TIME LIMIT EXCEEDED