"""

 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()