Monistus

input/code.cpp: In function 'std::string duplicate(std::string)':
input/code.cpp:8:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 |     while (index < str.size())
      |            ~~~~~~^~~~~~~~~~~~

#include <iostream>

using namespace std;

string duplicate(string str)
{
    long long index = 0;
    while (index < str.size())
    {
        if (isdigit(str[index]))
        {
            int numberLetter = str[index] - 48;
            string first_part = "";
            if (index > 0)
            {
                first_part = str.substr(0, index);
            }
            string second_part = str.substr(index + 1, str.length() - 1 - index);
            string dup_part = str.substr(index + 1, numberLetter);
            str = first_part + dup_part + second_part;
            index = 0;
        }
        else
        {
            index++;
        }
    }
    return str;
}

int main()
{
    string word;
    cin >> word;
    cout << duplicate(word);
    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: TIME LIMIT EXCEEDED

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