238. Product of Array Except Self

238. Product of Array Except Self

Medium

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Given an integer array nums, return an array answer such that answer[i] is equal to the product of all the elements of nums except nums[i].

The product of any prefix or suffix of nums is guaranteed to fit in a 32-bit integer.

You must write an algorithm that runs in O(n) time and without using the division operation.

Example 1:

Input: nums = [1,2,3,4]
Output: [24,12,8,6]

Example 2:

Input: nums = [-1,1,0,-3,3]
Output: [0,0,9,0,0]

Constraints:

• 2 <= nums.length <= 105
• -30 <= nums[i] <= 30
• The product of any prefix or suffix of nums is guaranteed to fit in a 32-bit integer.

Follow up: Can you solve the problem in O(1) extra space complexity? (The output array does not count as extra space for space complexity analysis.)

Accepted

1,088,769

Submissions

1,708,477

class Solution:
    def productExceptSelf(self, nums: List[int]) -> List[int]:
        t1=[1]+list(accumulate(nums,mul))[:-1]
        t2=list(accumulate(nums[::-1],mul))[::-1][1:]+[1]
        return [x*y for x,y in zip(t1,t2)]

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