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* pre-commit: Upgrade psf/black for stable style 2023 Updating https://github.com/psf/black ... updating 22.12.0 -> 23.1.0 for their `2023 stable style`. * https://github.com/psf/black/blob/main/CHANGES.md#2310 > This is the first [psf/black] release of 2023, and following our stability policy, it comes with a number of improvements to our stable style… Also, add https://github.com/tox-dev/pyproject-fmt and https://github.com/abravalheri/validate-pyproject to pre-commit. I only modified `.pre-commit-config.yaml` and all other files were modified by pre-commit.ci and psf/black. * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci --------- Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
66 lines
1.8 KiB
Python
66 lines
1.8 KiB
Python
"""
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This function implements the shell sort algorithm
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which is slightly faster than its pure implementation.
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This shell sort is implemented using a gap, which
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shrinks by a certain factor each iteration. In this
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implementation, the gap is initially set to the
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length of the collection. The gap is then reduced by
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a certain factor (1.3) each iteration.
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For each iteration, the algorithm compares elements
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that are a certain number of positions apart
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(determined by the gap). If the element at the higher
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position is greater than the element at the lower
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position, the two elements are swapped. The process
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is repeated until the gap is equal to 1.
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The reason this is more efficient is that it reduces
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the number of comparisons that need to be made. By
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using a smaller gap, the list is sorted more quickly.
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"""
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def shell_sort(collection: list) -> list:
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"""Implementation of shell 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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>>> shell_sort([3, 2, 1])
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[1, 2, 3]
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>>> shell_sort([])
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[]
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>>> shell_sort([1])
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[1]
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"""
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# Choose an initial gap value
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gap = len(collection)
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# Set the gap value to be decreased by a factor of 1.3
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# after each iteration
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shrink = 1.3
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# Continue sorting until the gap is 1
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while gap > 1:
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# Decrease the gap value
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gap = int(gap / shrink)
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# Sort the elements using insertion sort
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for i in range(gap, len(collection)):
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temp = collection[i]
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j = i
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while j >= gap and collection[j - gap] > temp:
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collection[j] = collection[j - gap]
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j -= gap
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collection[j] = temp
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return collection
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if __name__ == "__main__":
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import doctest
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doctest.testmod()
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