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.)

public class ProductOfArrayExceptSelf {
    public int[] productExceptSelf(int[] nums) {
        if(nums==null || nums.length<2){
return nums;
}
int[] res = new int[nums.length];
int prod = 1;
//find the products from left
for(int i=0;i<nums.length; i++){
res[i]= prod;
prod*=nums[i];
}
//find the products from right
prod = 1;
for(int i=nums.length-1; i>=0;i--){
res[i]*=prod;
prod*=nums[i];
}
return res;
    }
}