shell.py

from typing import List, Union


def shell_sort(arr: List[Union[int, float]]) -> None:
    """
    Sorts a list in ascending order using the shell sort algorithm.

    Shell Sort is an optimization over insertion sort that compares elements separated by a gap
    and gradually reduces this gap until it's 1, resulting in a final pass of insertion sort.

    Args:
        arr (List[Union[int, float]]): The list of numbers (integers or floats) to be sorted.

    Returns:
        None: The function sorts the list in place and does not return a value.

    Example:
        >>> nums = [1, 34, 21, 1, 5, 3, 54, 9]
        >>> shell_sort(nums)
        >>> print(nums)
        [1, 1, 3, 5, 9, 21, 34, 54]
    """

    n = len(arr)

    gap = n // 2

    while gap > 0:
        for i in range(gap, n):
            temp = arr[i]
            j = i

            while j >= gap and arr[j - gap] > temp:
                arr[j] = arr[j - gap]
                j -= gap

            arr[j] = temp

        gap //= 2


# Test arrays
array_one = [1, 34, 21, 1, 5, 3, 54, 9]
array_two = [4.5, 3.7, 1.6, 0.4, 23.87]

# Sort arrays
shell_sort(array_two)
shell_sort(array_one)

# Print sorted arrays
print(array_one)
print(array_two)