Product of Array Except Self

Source

• leetcode: Product of Array Except Self

Given an array of n integers where n > 1, nums, return an array output such that output[i]
is equal to the product of all the elements of nums except nums[i].

Solve it without division and in O(n).

For example, given [1,2,3,4], return [24,12,8,6].

Follow up:
Could you solve it with constant space complexity? (Note: The output array does not
count as extra space for the purpose of space complexity analysis.)

Java

public class Solution {
    public int[] productExceptSelf(int[] nums) {
        int[] result = new int[nums.length];
        int left=1;
        for(int i=0; i<nums.length; i++){
            result[i] = left;
            left *= nums[i];
        }

        int right=1;
        for(int i=nums.length-1; i>=0; i--){
            result[i] *= right;
            right *= nums[i];
        }
        return result;
    }
}