Python/sorts/quick_sort.py
2017-04-06 03:55:28 +01:00

55 lines
1.4 KiB
Python

"""
This is a pure python implementation of the quick sort algorithm
For doctests run following command:
python -m doctest -v quick_sort.py
or
python3 -m doctest -v quick_sort.py
For manual testing run:
python quick_sort.py
"""
from __future__ import print_function
def quick_sort(ARRAY):
"""Pure implementation of quick sort algorithm in Python
:param collection: some mutable ordered collection with heterogeneous
comparable items inside
:return: the same collection ordered by ascending
Examples:
>>> quick_sort([0, 5, 3, 2, 2])
[0, 2, 2, 3, 5]
>>> quick_sort([])
[]
>>> quick_sort([-2, -5, -45])
[-45, -5, -2]
"""
ARRAY_LENGTH = len(ARRAY)
if( ARRAY_LENGTH <= 1):
return ARRAY
else:
PIVOT = ARRAY[0]
GREATER = [ element for element in ARRAY[1:] if element > PIVOT ]
LESSER = [ element for element in ARRAY[1:] if element <= PIVOT ]
return quick_sort(LESSER) + [PIVOT] + quick_sort(GREATER)
if __name__ == '__main__':
import sys
# For python 2.x and 3.x compatibility: 3.x has not raw_input builtin
# otherwise 2.x's input builtin function is too "smart"
if sys.version_info.major < 3:
input_function = raw_input
else:
input_function = input
user_input = input_function('Enter numbers separated by a comma:\n')
unsorted = [ int(item) for item in user_input.split(',') ]
print( quick_sort(unsorted) )