mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-24 05:21:09 +00:00
1f8a21d727
* Tighten up psf/black and flake8
* Fix some tests
* Fix some E741
* Fix some E741
* updating DIRECTORY.md
Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
47 lines
1.4 KiB
Python
47 lines
1.4 KiB
Python
def aliquot_sum(input_num: int) -> int:
|
|
"""
|
|
Finds the aliquot sum of an input integer, where the
|
|
aliquot sum of a number n is defined as the sum of all
|
|
natural numbers less than n that divide n evenly. For
|
|
example, the aliquot sum of 15 is 1 + 3 + 5 = 9. This is
|
|
a simple O(n) implementation.
|
|
@param input_num: a positive integer whose aliquot sum is to be found
|
|
@return: the aliquot sum of input_num, if input_num is positive.
|
|
Otherwise, raise a ValueError
|
|
Wikipedia Explanation: https://en.wikipedia.org/wiki/Aliquot_sum
|
|
|
|
>>> aliquot_sum(15)
|
|
9
|
|
>>> aliquot_sum(6)
|
|
6
|
|
>>> aliquot_sum(-1)
|
|
Traceback (most recent call last):
|
|
...
|
|
ValueError: Input must be positive
|
|
>>> aliquot_sum(0)
|
|
Traceback (most recent call last):
|
|
...
|
|
ValueError: Input must be positive
|
|
>>> aliquot_sum(1.6)
|
|
Traceback (most recent call last):
|
|
...
|
|
ValueError: Input must be an integer
|
|
>>> aliquot_sum(12)
|
|
16
|
|
>>> aliquot_sum(1)
|
|
0
|
|
>>> aliquot_sum(19)
|
|
1
|
|
"""
|
|
if not isinstance(input_num, int):
|
|
raise ValueError("Input must be an integer")
|
|
if input_num <= 0:
|
|
raise ValueError("Input must be positive")
|
|
return sum(divisor for divisor in range(1, input_num) if input_num % divisor == 0)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
import doctest
|
|
|
|
doctest.testmod()
|