Product of Array Except Self

arrayprefix sum

Problem Statement

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

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 <= 10 ^5

-30 <= nums[i] <= 30

The input is generated such that answer[i] 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.)

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicPrefix Sum