LeetCode 238: Product of Array Except itself

Constant space solution that counting zeros:

class Solution {
    public int[] productExceptSelf(int[] nums) {
        int[] result = new int[nums.length];
        int zeros = 0;
        int multi = 1;
        
        for (int num : nums) {
            if (num == 0) {
                zeros++;
            } else {
                multi *= num;
            }
            
            if (zeros > 1) {
                return result;
            }
        }
        
        for (int i = 0; i < nums.length; i++) {
            if (zeros > 0 && nums[i] != 0) {
                continue;
            }
            
            result[i] = nums[i] == 0 ? multi : multi / nums[i];
        }
        return result;
    }
}

 

Nice Solution:

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