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optimize quicksort implementation (#11196)

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* optimize quicksort implementation

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* Update quick_sort.py

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Tushar Pamnani 2023-12-20 07:29:51 +05:30 committed by GitHub
parent b46fc1de04
commit 7b9f82cc44
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1 changed files with 13 additions and 10 deletions
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sorts/quick_sort.py
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@ -13,10 +13,10 @@ from random import randrange
def quick_sort(collection: list) -> list: def quick_sort(collection: list) -> list:
"""A pure Python implementation of quick sort algorithm """A pure Python implementation of quicksort algorithm.
:param collection: a mutable collection of comparable items :param collection: a mutable collection of comparable items
:return: the same collection ordered by ascending :return: the same collection ordered in ascending order
Examples: Examples:
>>> quick_sort([0, 5, 3, 2, 2]) >>> quick_sort([0, 5, 3, 2, 2])
@ -26,23 +26,26 @@ def quick_sort(collection: list) -> list:
>>> quick_sort([-2, 5, 0, -45]) >>> quick_sort([-2, 5, 0, -45])
[-45, -2, 0, 5] [-45, -2, 0, 5]
""" """
# Base case: if the collection has 0 or 1 elements, it is already sorted
if len(collection) < 2: if len(collection) < 2:
return collection return collection
pivot_index = randrange(len(collection)) # Use random element as pivot
pivot = collection[pivot_index]
greater: list[int] = [] # All elements greater than pivot
lesser: list[int] = [] # All elements less than or equal to pivot
for element in collection[:pivot_index]: # Randomly select a pivot index and remove the pivot element from the collection
(greater if element > pivot else lesser).append(element) pivot_index = randrange(len(collection))
pivot = collection.pop(pivot_index)
for element in collection[pivot_index + 1 :]: # Partition the remaining elements into two groups: lesser or equal, and greater
(greater if element > pivot else lesser).append(element) lesser = [item for item in collection if item <= pivot]
greater = [item for item in collection if item > pivot]
# Recursively sort the lesser and greater groups, and combine with the pivot
return [*quick_sort(lesser), pivot, *quick_sort(greater)] return [*quick_sort(lesser), pivot, *quick_sort(greater)]
if __name__ == "__main__": if __name__ == "__main__":
# Get user input and convert it into a list of integers
user_input = input("Enter numbers separated by a comma:\n").strip() user_input = input("Enter numbers separated by a comma:\n").strip()
unsorted = [int(item) for item in user_input.split(",")] unsorted = [int(item) for item in user_input.split(",")]
# Print the result of sorting the user-provided list
print(quick_sort(unsorted)) print(quick_sort(unsorted))