Python/sorts/pigeon_sort.py
Christian Clauss cecf43d648
Pyupgrade to Python 3.9 ()
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Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
2021-09-07 13:37:03 +02:00

61 lines
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Python

"""
This is an implementation of Pigeon Hole Sort.
For doctests run following command:
python3 -m doctest -v pigeon_sort.py
or
python -m doctest -v pigeon_sort.py
For manual testing run:
python pigeon_sort.py
"""
from __future__ import annotations
def pigeon_sort(array: list[int]) -> list[int]:
"""
Implementation of pigeon hole sort algorithm
:param array: Collection of comparable items
:return: Collection sorted in ascending order
>>> pigeon_sort([0, 5, 3, 2, 2])
[0, 2, 2, 3, 5]
>>> pigeon_sort([])
[]
>>> pigeon_sort([-2, -5, -45])
[-45, -5, -2]
"""
if len(array) == 0:
return array
_min, _max = min(array), max(array)
# Compute the variables
holes_range = _max - _min + 1
holes, holes_repeat = [0] * holes_range, [0] * holes_range
# Make the sorting.
for i in array:
index = i - _min
holes[index] = i
holes_repeat[index] += 1
# Makes the array back by replacing the numbers.
index = 0
for i in range(holes_range):
while holes_repeat[i] > 0:
array[index] = holes[i]
index += 1
holes_repeat[i] -= 1
# Returns the sorted array.
return array
if __name__ == "__main__":
import doctest
doctest.testmod()
user_input = input("Enter numbers separated by comma:\n")
unsorted = [int(x) for x in user_input.split(",")]
print(pigeon_sort(unsorted))