Product of Array Except Self
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]
Examples
Example 1
Input: nums = [1,2,3,4]
Output: [24,12,8,6]
Explanation: answer[0] = 2*3*4 = 24, answer[1] = 1*3*4 = 12, answer[2] = 1*2*4 = 8, answer[3] = 1*2*3 = 6.
Example 2
Input: nums = [-1,1,0,-3,3]
Output: [0,0,9,0,0]
Explanation: Because there is a zero in the array at index 2, most products will be 0. answer[2] = (-1)*1*(-3)*3 = 9.
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.
Optimal Complexity
Time
O(n)
Space
O(1)
Practice this problem with an AI interviewer
TechInView conducts a full voice mock interview — the AI asks clarifying questions, evaluates your approach, watches you code, and scores you on 5 dimensions. Just like a real FAANG interview.
Start a free interview