mirror of
https://github.com/TheAlgorithms/Python.git
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Orji PatriciaandChristian Clauss
d502013438
* sorts: make comb sort generic for comparable items * tests: cover comb sort incomparable inputs * Update sorts/comb_sort.py * Apply suggestion from @cclauss * Apply suggestion from @cclauss --------- Co-authored-by: Christian Clauss <cclauss@me.com>
81 lines
2.4 KiB
Python
81 lines
2.4 KiB
Python
"""
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This is pure Python implementation of comb sort algorithm.
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Comb sort is a relatively simple sorting algorithm originally designed by Wlodzimierz
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Dobosiewicz in 1980. It was rediscovered by Stephen Lacey and Richard Box in 1991.
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Comb sort improves on bubble sort algorithm.
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In bubble sort, distance (or gap) between two compared elements is always one.
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Comb sort improvement is that gap can be much more than 1, in order to prevent slowing
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down by small values at the end of a list.
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More info on: https://en.wikipedia.org/wiki/Comb_sort
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For doctests run following command:
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python -m doctest -v comb_sort.py
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or
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python3 -m doctest -v comb_sort.py
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For manual testing run:
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python comb_sort.py
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"""
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from typing import Any, Protocol
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class Comparable(Protocol):
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def __lt__(self, other: Any, /) -> bool: ...
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def comb_sort[T: Comparable](data: list[T]) -> list[T]:
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"""Pure implementation of comb sort algorithm in Python
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:param data: mutable collection with comparable items
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:return: the same collection in ascending order
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Examples:
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>>> comb_sort([0, 5, 3, 2, 2])
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[0, 2, 2, 3, 5]
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>>> comb_sort([])
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[]
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>>> comb_sort([99, 45, -7, 8, 2, 0, -15, 3])
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[-15, -7, 0, 2, 3, 8, 45, 99]
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>>> comb_sort([2, 0, 3, 4, 5, 6, 1])
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[0, 1, 2, 3, 4, 5, 6]
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>>> comb_sort(["c", "a", "b"])
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['a', 'b', 'c']
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>>> comb_sort([2.5, -1, 0.0])
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[-1, 0.0, 2.5]
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>>> comb_sort([1, "a"])
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Traceback (most recent call last):
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...
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TypeError: '<' not supported between instances of 'str' and 'int'
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"""
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shrink_factor = 1.3
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gap = len(data)
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completed = False
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while not completed:
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# Update the gap value for a next comb. The gap is never allowed to drop
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# below 1: a gap of 0 compares each element with itself, so no swap can
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# ever happen and the loop would exit while the data is still unsorted.
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gap = max(int(gap / shrink_factor), 1)
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if gap == 1:
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completed = True
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index = 0
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while index + gap < len(data):
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if data[index + gap] < data[index]:
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# Swap values
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data[index], data[index + gap] = data[index + gap], data[index]
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completed = False
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index += 1
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return data
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if __name__ == "__main__":
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import doctest
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doctest.testmod()
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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(comb_sort(unsorted))
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