SignOfTheProductOfAnArray.cpp

// Source : https://leetcode.com/problems/sign-of-the-product-of-an-array/
// Author : Hao Chen
// Date   : 2021-04-11

/***************************************************************************************************** 
 *
 * 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
 ******************************************************************************************************/

class Solution {
public:
    int arraySign(vector<int>& nums) {
        int negtive=0;
        for(auto& n : nums) {
            if (n==0) return 0;
            if (n < 0) negtive++;
        }
        return negtive % 2 == 0 ? 1 : -1;
    }
};