mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-10-06 05:39:30 +00:00
7f04e5cd34
* 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>
59 lines
1.5 KiB
Python
59 lines
1.5 KiB
Python
"""
|
|
This is a pure Python implementation of the heap sort algorithm.
|
|
|
|
For doctests run following command:
|
|
python -m doctest -v heap_sort.py
|
|
or
|
|
python3 -m doctest -v heap_sort.py
|
|
|
|
For manual testing run:
|
|
python heap_sort.py
|
|
"""
|
|
|
|
|
|
def heapify(unsorted, index, heap_size):
|
|
largest = index
|
|
left_index = 2 * index + 1
|
|
right_index = 2 * index + 2
|
|
if left_index < heap_size and unsorted[left_index] > unsorted[largest]:
|
|
largest = left_index
|
|
|
|
if right_index < heap_size and unsorted[right_index] > unsorted[largest]:
|
|
largest = right_index
|
|
|
|
if largest != index:
|
|
unsorted[largest], unsorted[index] = unsorted[index], unsorted[largest]
|
|
heapify(unsorted, largest, heap_size)
|
|
|
|
|
|
def heap_sort(unsorted):
|
|
"""
|
|
Pure implementation of the heap sort algorithm in Python
|
|
:param collection: some mutable ordered collection with heterogeneous
|
|
comparable items inside
|
|
:return: the same collection ordered by ascending
|
|
|
|
Examples:
|
|
>>> heap_sort([0, 5, 3, 2, 2])
|
|
[0, 2, 2, 3, 5]
|
|
|
|
>>> heap_sort([])
|
|
[]
|
|
|
|
>>> heap_sort([-2, -5, -45])
|
|
[-45, -5, -2]
|
|
"""
|
|
n = len(unsorted)
|
|
for i in range(n // 2 - 1, -1, -1):
|
|
heapify(unsorted, i, n)
|
|
for i in range(n - 1, 0, -1):
|
|
unsorted[0], unsorted[i] = unsorted[i], unsorted[0]
|
|
heapify(unsorted, 0, i)
|
|
return unsorted
|
|
|
|
|
|
if __name__ == "__main__":
|
|
user_input = input("Enter numbers separated by a comma:\n").strip()
|
|
unsorted = [int(item) for item in user_input.split(",")]
|
|
print(heap_sort(unsorted))
|