mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-30 16:31:08 +00:00
bc8df6de31
* [pre-commit.ci] pre-commit autoupdate updates: - [github.com/astral-sh/ruff-pre-commit: v0.2.2 → v0.3.2](https://github.com/astral-sh/ruff-pre-commit/compare/v0.2.2...v0.3.2) - [github.com/pre-commit/mirrors-mypy: v1.8.0 → v1.9.0](https://github.com/pre-commit/mirrors-mypy/compare/v1.8.0...v1.9.0) * [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>
62 lines
1.8 KiB
Python
62 lines
1.8 KiB
Python
"""
|
|
Slowsort is a sorting algorithm. It is of humorous nature and not useful.
|
|
It's based on the principle of multiply and surrender,
|
|
a tongue-in-cheek joke of divide and conquer.
|
|
It was published in 1986 by Andrei Broder and Jorge Stolfi
|
|
in their paper Pessimal Algorithms and Simplexity Analysis
|
|
(a parody of optimal algorithms and complexity analysis).
|
|
|
|
Source: https://en.wikipedia.org/wiki/Slowsort
|
|
"""
|
|
|
|
from __future__ import annotations
|
|
|
|
|
|
def slowsort(sequence: list, start: int | None = None, end: int | None = None) -> None:
|
|
"""
|
|
Sorts sequence[start..end] (both inclusive) in-place.
|
|
start defaults to 0 if not given.
|
|
end defaults to len(sequence) - 1 if not given.
|
|
It returns None.
|
|
>>> seq = [1, 6, 2, 5, 3, 4, 4, 5]; slowsort(seq); seq
|
|
[1, 2, 3, 4, 4, 5, 5, 6]
|
|
>>> seq = []; slowsort(seq); seq
|
|
[]
|
|
>>> seq = [2]; slowsort(seq); seq
|
|
[2]
|
|
>>> seq = [1, 2, 3, 4]; slowsort(seq); seq
|
|
[1, 2, 3, 4]
|
|
>>> seq = [4, 3, 2, 1]; slowsort(seq); seq
|
|
[1, 2, 3, 4]
|
|
>>> seq = [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]; slowsort(seq, 2, 7); seq
|
|
[9, 8, 2, 3, 4, 5, 6, 7, 1, 0]
|
|
>>> seq = [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]; slowsort(seq, end = 4); seq
|
|
[5, 6, 7, 8, 9, 4, 3, 2, 1, 0]
|
|
>>> seq = [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]; slowsort(seq, start = 5); seq
|
|
[9, 8, 7, 6, 5, 0, 1, 2, 3, 4]
|
|
"""
|
|
if start is None:
|
|
start = 0
|
|
|
|
if end is None:
|
|
end = len(sequence) - 1
|
|
|
|
if start >= end:
|
|
return
|
|
|
|
mid = (start + end) // 2
|
|
|
|
slowsort(sequence, start, mid)
|
|
slowsort(sequence, mid + 1, end)
|
|
|
|
if sequence[end] < sequence[mid]:
|
|
sequence[end], sequence[mid] = sequence[mid], sequence[end]
|
|
|
|
slowsort(sequence, start, end - 1)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
from doctest import testmod
|
|
|
|
testmod()
|