Product of Array Except Self
Medium
Array
Prefix Sum
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 **without using division**.
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.
Time Complexity
O(n)
Space Complexity
O(1)
14
Case 1
Input: [1,2,3,4]
Expected: [24,12,8,6]
Case 2
Input: [-1,1,0,-3,3]
Expected: [0,0,9,0,0]
Case 3
Input: [2,3]
Expected: [3,2]