mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-12-24 12:10:16 +00:00
0591968947
* * optimization aliquot_sum
* fix bug in average_median
* fixup! Format Python code with psf/black push
* Update maths/average_median.py
* updating DIRECTORY.md
Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
49 lines
1.4 KiB
Python
49 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 // 2 + 1) if input_num % divisor == 0
|
|
)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
import doctest
|
|
|
|
doctest.testmod()
|