Python/sorts/quick_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

52 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 quick_sort.py
or
python3 -m doctest -v quick_sort.py
For manual testing run:
python quick_sort.py
"""
def quick_sort(collection):
"""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:
>>> quick_sort([0, 5, 3, 2, 2])
[0, 2, 2, 3, 5]
>>> quick_sort([])
[]
>>> quick_sort([-2, -5, -45])
[-45, -5, -2]
"""
length = len(collection)
if length <= 1:
return collection
else:
# Use the last element as the first pivot
pivot = collection.pop()
# Put elements greater than pivot in greater list
# Put elements lesser than pivot in lesser list
greater, lesser = [], []
for element in collection:
if element > pivot:
greater.append(element)
else:
lesser.append(element)
return quick_sort(lesser) + [pivot] + quick_sort(greater)
if __name__ == "__main__":
user_input = input("Enter numbers separated by a comma:\n").strip()
unsorted = [int(item) for item in user_input.split(",")]
print(quick_sort(unsorted))