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a0ab3ce098
Modify the list comprehensions to reduce the number of judgments, the speed has increased by more than 50%.
59 lines
1.6 KiB
Python
59 lines
1.6 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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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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length = len(collection)
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if length <= 1:
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return collection
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else:
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pivot = collection[0]
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# Modify the list comprehensions to reduce the number of judgments, the speed has increased by more than 50%.
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greater = []
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lesser = []
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for element in collection[1:]:
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if element > pivot:
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greater.append(element)
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else:
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lesser.append(element)
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# greater = [element for element in collection[1:] if element > pivot]
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# lesser = [element for element in collection[1:] if element <= pivot]
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return quick_sort(lesser) + [pivot] + quick_sort(greater)
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if __name__ == '__main__':
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try:
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raw_input # Python 2
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except NameError:
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raw_input = input # Python 3
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user_input = raw_input('Enter numbers separated by a comma:\n').strip()
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unsorted = [ int(item) for item in user_input.split(',') ]
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print( quick_sort(unsorted) )
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