I'm working on algorithm that finds all the factors of a number from its prime factors. Here's my code up to this point
def is_prime(x):
return all(x % i for i in range(2, x))
def next_prime(x):
return min([a for a in range(x+1, 2*x) if is_prime(a)])
def numFactors(n):
factors = {1, n}
primeFactors = dict()
s = n
while s != 1:
# print(s)
pr = 2
while s % pr != 0:
pr = next_prime(pr)
if pr in primeFactors.keys():
primeFactors[pr] += 1
else:
primeFactors[pr] = 1
factors.add(pr)
factors.add(int(s/pr))
s = int(s/pr)
This code gives me a dictionary with all the prime factors and their exponent. So, for example, 120 gives {2: 3, 3: 1, 5: 1}
What I'm trying to do get every factor like such: (2^1 * 3^0 * 5^0), (2^2 * 3^0 * 5^0)...
which is more or less an odometer like this
(0 0 0)
(1 0 0)
(2 0 0)
(3 0 0)
(0 1 0)
(1 1 0)
(2 1 0)
...
How do I achieve this from the primeFactors values? I can't seem to put together the right loop combination, especially since each column has a different max int.
You can try itertools.product
from itertools import product
d = {2: 3, 3: 1, 5: 1}
keys = d.keys()
possibilies = ['*'.join([f'{j[0]}^{j[1]}' for j in zip(keys, i)]) for i in product(*[range(v+1) for v in d.values()])]
print(possibilies)
['2^0*3^0*5^0',
'2^0*3^0*5^1',
'2^0*3^1*5^0',
'2^0*3^1*5^1',
'2^1*3^0*5^0',
'2^1*3^0*5^1',
'2^1*3^1*5^0',
'2^1*3^1*5^1',
'2^2*3^0*5^0',
'2^2*3^0*5^1',
'2^2*3^1*5^0',
'2^2*3^1*5^1',
'2^3*3^0*5^0',
'2^3*3^0*5^1',
'2^3*3^1*5^0',
'2^3*3^1*5^1']