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* optimize quicksort implementation * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci * Apply suggestions from code review * Update quick_sort.py --------- Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com> Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>
52 lines
1.6 KiB
Python
52 lines
1.6 KiB
Python
"""
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A pure Python implementation of the quick sort algorithm
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For doctests run following command:
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python3 -m doctest -v quick_sort.py
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For manual testing run:
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python3 quick_sort.py
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"""
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from __future__ import annotations
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from random import randrange
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def quick_sort(collection: list) -> list:
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"""A pure Python implementation of quicksort algorithm.
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:param collection: a mutable collection of comparable items
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:return: the same collection ordered in ascending order
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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, 0, -45])
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[-45, -2, 0, 5]
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"""
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# Base case: if the collection has 0 or 1 elements, it is already sorted
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if len(collection) < 2:
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return collection
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# Randomly select a pivot index and remove the pivot element from the collection
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pivot_index = randrange(len(collection))
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pivot = collection.pop(pivot_index)
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# Partition the remaining elements into two groups: lesser or equal, and greater
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lesser = [item for item in collection if item <= pivot]
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greater = [item for item in collection if item > pivot]
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# Recursively sort the lesser and greater groups, and combine with the pivot
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return [*quick_sort(lesser), pivot, *quick_sort(greater)]
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if __name__ == "__main__":
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# Get user input and convert it into a list of integers
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user_input = 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 the result of sorting the user-provided list
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print(quick_sort(unsorted))
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