Brooke

一、題目

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

 

二、程式作法

public class Solution
{
    public int ArraySign(int[] nums)
    {
        int p = 1;
        for (int i = 0; i < nums.Length; i++)
        {
            if (nums[i] == 0) return 0;
            if (nums[i] < 0) p *= -1;
        }
        return p;
    }
}

 

三、思路筆記

略