Python/sorts/radix_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

53 lines
1.3 KiB
Python

"""
This is a pure Python implementation of the quick sort algorithm
For doctests run following command:
python -m doctest -v radix_sort.py
or
python3 -m doctest -v radix_sort.py
For manual testing run:
python radix_sort.py
"""
from __future__ import annotations
from typing import List
def radix_sort(list_of_ints: List[int]) -> List[int]:
"""
Examples:
>>> radix_sort([0, 5, 3, 2, 2])
[0, 2, 2, 3, 5]
>>> radix_sort(list(range(15))) == sorted(range(15))
True
>>> radix_sort(list(range(14,-1,-1))) == sorted(range(15))
True
>>> radix_sort([1,100,10,1000]) == sorted([1,100,10,1000])
True
"""
RADIX = 10
placement = 1
max_digit = max(list_of_ints)
while placement <= max_digit:
# declare and initialize empty buckets
buckets: List[list] = [list() for _ in range(RADIX)]
# split list_of_ints between the buckets
for i in list_of_ints:
tmp = int((i / placement) % RADIX)
buckets[tmp].append(i)
# put each buckets' contents into list_of_ints
a = 0
for b in range(RADIX):
for i in buckets[b]:
list_of_ints[a] = i
a += 1
# move to next
placement *= RADIX
return list_of_ints
if __name__ == "__main__":
import doctest
doctest.testmod()