Product of Array Except Self

Problem

Given integer array nums, return an array answer where answer[i] is the product of all elements of nums except nums[i]. You must solve it in O(n) without using division. Example: [1,2,3,4] → [24,12,8,6] because answer[0]=2×3×4=24, answer[1]=1×3×4=12, etc.

Constraints

• ›2 ≤ nums.length ≤ 10⁵
• ›-30 ≤ nums[i] ≤ 30
• ›No division allowed. O(n) time, O(1) extra space