Python/sorts/shell_sort.py
matkosoric 7f04e5cd34
contribution guidelines checks (#1787)
* spelling corrections

* review

* improved documentation, removed redundant variables, added testing

* added type hint

* camel case to snake case

* spelling fix

* review

* python --> Python # it is a brand name, not a snake

* explicit cast to int

* spaces in int list

* "!= None" to "is not None"

* Update comb_sort.py

* various spelling corrections in documentation & several variables naming conventions fix

* + char in file name

* import dependency - bug fix

Co-authored-by: John Law <johnlaw.po@gmail.com>
2020-03-04 13:40:28 +01:00

50 lines
1.2 KiB
Python

"""
This is a pure Python implementation of the shell sort algorithm
For doctests run following command:
python -m doctest -v shell_sort.py
or
python3 -m doctest -v shell_sort.py
For manual testing run:
python shell_sort.py
"""
def shell_sort(collection):
"""Pure implementation of shell sort algorithm in Python
:param collection: Some mutable ordered collection with heterogeneous
comparable items inside
:return: the same collection ordered by ascending
>>> shell_sort([0, 5, 3, 2, 2])
[0, 2, 2, 3, 5]
>>> shell_sort([])
[]
>>> shell_sort([-2, -5, -45])
[-45, -5, -2]
"""
# Marcin Ciura's gap sequence
gaps = [701, 301, 132, 57, 23, 10, 4, 1]
for gap in gaps:
i = gap
while i < len(collection):
temp = collection[i]
j = i
while j >= gap and collection[j - gap] > temp:
collection[j] = collection[j - gap]
j -= gap
collection[j] = temp
i += 1
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(shell_sort(unsorted))