Monistus

#include<iostream>
#include<bits/stdc++.h>
#include<string> 
#include<map>
#include <unordered_map>
using namespace std;

typedef long long ll;
 
constexpr ll M = 1000000007;
constexpr ll P = (1 << 18);
constexpr int INF = 1e9;

string before;

int main() {
	string input; 
	cin >> input;

	bool hasDigits = true;
	while (hasDigits) {
		hasDigits = false;
		for (int i=0; i<(int)input.size(); i++) {
			char ch = input[i];
			int digit = ch - '0'; 

			if (digit > 0 && digit <= 9) {
				hasDigits = true;

				string b4 = input.substr(0, i); 
				before += b4;

				string expanded = input.substr(i+1, digit); 
				string after = input.substr(i+1); 

				input = expanded + after;
				break;
			}
		}
	}

	cout << before + input << endl;

}

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: TIME LIMIT EXCEEDED

Test 10

Group: 2

Verdict: TIME LIMIT EXCEEDED

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