mirror of
https://github.com/TheAlgorithms/Python.git
synced 2025-02-26 02:48:40 +00:00
61 lines
1.6 KiB
Python
61 lines
1.6 KiB
Python
from math import ceil , sqrt
|
|
from __future__ import annotations
|
|
|
|
def primeproduct(n : int, x : list = []):
|
|
'''
|
|
>>> primeproduct(868)
|
|
[2, 2, 7, 31]
|
|
>>> primeproduct(9039423423423743)
|
|
[2, 2, 7, 31, 719, 12572216166097]
|
|
>>> primeproduct(0.02)
|
|
[]
|
|
'''
|
|
if n < 1:
|
|
return []
|
|
|
|
if n > 1:
|
|
if len(x)>=1 and x[-1] % n == 0: # check in already factorised
|
|
x.append(x[-1])
|
|
n = n // x[-1]
|
|
|
|
else:
|
|
sq = ceil(sqrt(n))
|
|
flag = 0
|
|
|
|
if x != []:
|
|
for i in range(x[-1] , sq+1, 2):
|
|
if n % i == 0:
|
|
n = n // i
|
|
x.append(i)
|
|
flag = 1
|
|
break
|
|
|
|
|
|
else:
|
|
# Handle factor 2 separately
|
|
while n % 2 ==0: # only 2 is even prime
|
|
n = n // 2
|
|
x.append(2)
|
|
|
|
# Start loop from 3 and increment by 2
|
|
for i in range(3 , sq+1, 2): # skip even numbers
|
|
if n % i == 0:
|
|
n = n // i
|
|
x.append(i)
|
|
flag = 1
|
|
break
|
|
|
|
if not flag:
|
|
x.append(n)
|
|
n = 1
|
|
|
|
return primeproduct(n,x)
|
|
|
|
return x
|
|
|
|
# faster than https://github.com/sourabhkv/Python/blob/master/maths/prime_factors.py approx 2x
|
|
if __name__ == "__main__":
|
|
import doctest
|
|
|
|
doctest.testmod()
|