"""

Name: quicksort - Quicksort for arrays of unsorted integers

Description: quicksort applies the Quicksort using static or randomised pivot element selection on an unsorted array of integers.

Author: Eugen Sawin <sawine@me73.com>

"""

def main():

    args = parse_arguments()

    array = [int(e.strip()) for e in args.array.split(',')]

    random = args.r

    print quicksort(array, random)

from random import randrange

def quicksort(array, random=False):

    if len(array) < 2:

        return array    

    if random:

        p = randrange(len(array))

        pivot = array[p]

        array[p] = array[-1]

        array[-1] = pivot

    else:

        pivot = array[-1]

    left, right = partition(array, pivot)

    left = quicksort(left, random)

    right = quicksort(right, random)

    print left + [pivot] + right

    return left + [pivot] + right

def partition(array, pivot):

    left = []

    right = []

    for e in array[:-1]:

        if e < pivot:

            left.append(e)

        else:

            right.append(e)

    return left, right

from argparse import ArgumentParser

def parse_arguments():

    parser = ArgumentParser(description='Applies Quicksort on an unsorted array of integers.')

    parser.add_argument('array', help='comma-separated values')

    parser.add_argument('-r', action='store_true', help='randomised pivot selection')

    return parser.parse_args()

if __name__ == "__main__":

    main()