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