ArrayProducts

product.py

class Solution:
    def arrayProduct(self, nums):
        #check for edge cases
        if not nums:
          return None
        if len(nums) < 2:
            return 0
        
        #we create an array of 1s, which would be our final output
        res = [1]*len(nums)
        lprod = 1
        rprod = 1
        
        #we update our array res both ways by taking it multiples as we move along
        for i in range(len(nums)):
            res[i] *= lprod 
            lprod *= nums[i] 
            res[~i] *= rprod 
            rprod *= nums[~i]  
        return res
      
# Time O(N), Space O(N)