Python/sorts/patience_sort.py
Matthew a4726ca248
[mypy]Correction of all errors in the sorts directory (#4224)
* [mypy] Add/fix type annotations for recursive_insertion_sort(#4085)

* [mypy] Add/fix type annotations for bucket_sort(#4085)

* [mypy] Reworked code for cocktail_shaker_sort so that missing return statement error is resolved(#4085)

* [mypy] Add/fix type annotations for patience_sort(#4085)

* [mypy] Add/fix type annotations for radix_sort(#4085)

Co-authored-by: goodm2 <4qjpngu8mem8cz>
2021-02-23 10:02:30 +01:00

66 lines
1.6 KiB
Python

from bisect import bisect_left
from functools import total_ordering
from heapq import merge
from typing import List
"""
A pure Python implementation of the patience sort algorithm
For more information: https://en.wikipedia.org/wiki/Patience_sorting
This algorithm is based on the card game patience
For doctests run following command:
python3 -m doctest -v patience_sort.py
For manual testing run:
python3 patience_sort.py
"""
@total_ordering
class Stack(list):
def __lt__(self, other):
return self[-1] < other[-1]
def __eq__(self, other):
return self[-1] == other[-1]
def patience_sort(collection: list) -> list:
"""A pure implementation of quick sort algorithm in Python
:param collection: some mutable ordered collection with heterogeneous
comparable items inside
:return: the same collection ordered by ascending
Examples:
>>> patience_sort([1, 9, 5, 21, 17, 6])
[1, 5, 6, 9, 17, 21]
>>> patience_sort([])
[]
>>> patience_sort([-3, -17, -48])
[-48, -17, -3]
"""
stacks: List[Stack] = []
# sort into stacks
for element in collection:
new_stacks = Stack([element])
i = bisect_left(stacks, new_stacks)
if i != len(stacks):
stacks[i].append(element)
else:
stacks.append(new_stacks)
# use a heap-based merge to merge stack efficiently
collection[:] = merge(*[reversed(stack) for stack in stacks])
return collection
if __name__ == "__main__":
user_input = input("Enter numbers separated by a comma:\n").strip()
unsorted = [int(item) for item in user_input.split(",")]
print(patience_sort(unsorted))