Sign of the Product of an Array

 Sign of the Product of an Array

There is a function signFunc(x) that returns:

• 1 if x is positive.
• -1 if x is negative.
• 0 if x is equal to 0.

You are given an integer array nums. Let product be the product of all values in the array nums.

Return signFunc(product).

 

Example 1:

Input: nums = [-1,-2,-3,-4,3,2,1]
Output: 1
Explanation: The product of all values in the array is 144, and signFunc(144) = 1

Example 2:

Input: nums = [1,5,0,2,-3]
Output: 0
Explanation: The product of all values in the array is 0, and signFunc(0) = 0

Example 3:

Input: nums = [-1,1,-1,1,-1]
Output: -1
Explanation: The product of all values in the array is -1, and signFunc(-1) = -1

 

Constraints:

• 1 <= nums.length <= 1000
• -100 <= nums[i] <= 100

Solution 1:

class Solution {
    public int arraySign(int[] nums) {
        int sign = 1;
        for(int num:nums){
            if(num == 0){
                return 0;
            }
            if(num < 0){
                sign *= -1;
            }
        }
        return sign;
    }
}

Solution 2:

class Solution {
    public int arraySign(int[] nums) {
        int countNeg = 0;
        for(int num:nums){
            if(num == 0){
                return 0;
            }
            if(num < 0){
                countNeg++;
            }
        }
        return countNeg % 2 == 0 ? 1 : -1;
    }
}

TC: O(n) SC: O(1)