PYTHON - Determine all possible factor combinations for a given number, from a given numeric array

Check this out at GitHub.com https://github.com/falconerandloillc/factors # 1. Sample call #print( factors( 240, [2,3,4,5,6,7,8,9,10,11,12,24] ) ); # 2. The function...

import time

def factors(target, arr):

# Parameters test/fix

if target == None or target == 0 or arr == None or len(arr) < 2:

return None

# Declarer

start = int(round(time.time() * 1000))

global iterations

global combinations

iterations=0

combinations=[]

# Keep only non-zero numbers

arr = [x for x in arr if isinstance(x, float) or isinstance(x, int)]

if len(arr) <= 1:

return None

# Sort

arr.sort()

# Recurse each array element

for j in range(len(arr)):

i = j

r = []

def recurse(v, i):

global iterations, combinations

while i < len(arr) and (v*arr[i-1]) < abs(target):

iterations += 1

r.append(arr[i])

recurse(v*arr[i], i+1)

i += 1

r.pop()

if v == target and len(r) > 1:

combinations.append("".join(str(r)))

return 1

r.append(arr[j])

recurse(arr[j], j+1)

return {

"combinations": combinations

, "count": len(combinations)

, "time": str(int(round(time.time()*1000))-start) + " ms"

, "array": arr

, "target": target

, "iterations": iterations

}