LeetCode——Product of Array Except Self

Description：

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.)

public class Solution {
    public int[] productExceptSelf(int[] nums) {

        int[] res = new int[nums.length];
        res[nums.length - 1] = 1;
        for(int i=res.length-2; i>=0; i--) {
            res[i] = nums[i+1] * res[i+1];
        }

        int l = 1;
        for(int i=0; i<nums.length; i++) {
            res[i] *= l;
            l *= nums[i];
        }

        return res;
    }
}