public static List<int> countingSort(List<int> arr)
    {
        // Initialize a frequency List<int> with 100 elements, all set to 0
        List<int> result = new List<int>(new int[100]);
        
        // Iterate through the input list and count the occurrences
        foreach (int num in arr)
        {
            result[num]++;
        }
        
        // Return the frequency list
        return result;
    }