Python/sorts/odd_even_sort.py

"""
Odd even sort implementation.

https://en.wikipedia.org/wiki/Odd%E2%80%93even_sort
"""


def odd_even_sort(input_list: list) -> list:
    """
    Sort input with odd even sort.

    This algorithm uses the same idea of bubblesort,
    but by first dividing in two phase (odd and even).
    Originally developed for use on parallel processors
    with local interconnections.
    :param collection: mutable ordered sequence of elements
    :return: same collection in ascending order
    Examples:
    >>> odd_even_sort([5 , 4 ,3 ,2 ,1])
    [1, 2, 3, 4, 5]
    >>> odd_even_sort([])
    []
    >>> odd_even_sort([-10 ,-1 ,10 ,2])
    [-10, -1, 2, 10]
    >>> odd_even_sort([1 ,2 ,3 ,4])
    [1, 2, 3, 4]
    """
    is_sorted = False
    while is_sorted is False:  # Until all the indices are traversed keep looping
        is_sorted = True
        for i in range(0, len(input_list) - 1, 2):  # iterating over all even indices
            if input_list[i] > input_list[i + 1]:
                input_list[i], input_list[i + 1] = input_list[i + 1], input_list[i]
                # swapping if elements not in order
                is_sorted = False

        for i in range(1, len(input_list) - 1, 2):  # iterating over all odd indices
            if input_list[i] > input_list[i + 1]:
                input_list[i], input_list[i + 1] = input_list[i + 1], input_list[i]
                # swapping if elements not in order
                is_sorted = False
    return input_list


if __name__ == "__main__":
    print("Enter list to be sorted")
    input_list = [int(x) for x in input().split()]
    # inputing elements of the list in one line
    sorted_list = odd_even_sort(input_list)
    print("The sorted list is")
    print(sorted_list)