Product of Array Except Self

MediumArraysPrefix Sum

Solve this the way you would in the interview: out loud, on a timer, with an AI interviewer asking follow-ups while you code. You get a scored report at the end.

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Problem

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.

Examples

Input: nums = [1,2,3,4]
Output: [24,12,8,6]
Input: nums = [-1,1,0,-3,3]
Output: [0,0,9,0,0]

Constraints

  • 2 <= nums.length <= 10^5
  • -30 <= nums[i] <= 30
  • The product of any prefix or suffix of nums is guaranteed to fit in a 32-bit integer.

What the interviewer grades

A correct solution is one of five scores. The report also grades problem understanding (did you clarify inputs and edge cases before coding), problem solving, communication while you work, code quality, and testing. See a sample report, or read up on the pattern in the lessons.