Leetcode: Product of Array Except Self

Question

Given an array of n integers where n > 1, nums, return an array output such that output[i] is equal to the product of all the elements of nums except nums[i].

Solve it without division and in O(n).

For example, given [1,2,3,4], return [24,12,8,6].

Follow up:
Could you solve it with constant space complexity? (Note: The output array does not count as extra space for the purpose of space complexity analysis.)

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Solution

Get idea from here, here2

class Solution(object):
    def productExceptSelf(self, nums):
        """
        :type nums: List[int]
        :rtype: List[int]
        """

        res = [0]*len(nums)
        n = 1
        for ind,elem in enumerate(nums):
            res[ind] = n
            n *= elem

        n = 1
        for ind in range(len(nums)-1,-1,-1):
            res[ind] *= n
            n *= nums[ind]

        return res