1822.Sign of the Product of an Array
===

###### tags: `Easy`,`Array`,`Math`

[1822. Sign of the Product of an Array](https://leetcode.com/problems/sign-of-the-product-of-an-array/)

### 題目描述

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)`.

### 範例

**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

### 解答
#### Python

class Solution:
    def arraySign(self, nums: List[int]) -> int:
        return 1 if reduce(lambda x, y: x * y, nums) > 0 else -1 if reduce(lambda x, y: x * y, nums) < 0 else 0

> [name=Ron Chen][time=Tue, May 2, 2023]

#### Javascript

function arraySign(nums) {
  let count = 0;
  for (const num of nums) {
    if (num === 0) return 0;
    if (num < 0) count++;
  }

  if (count % 2 === 0) return 1;
  return -1;
}

> [name=Marsgoat][time=Tue, May 2, 2023]

#### C#

public int ArraySign(int[] nums) {
    return nums.Aggregate(1, (dot, num) => dot * ((num >> 31) - ((-num) >> 31)));
}

> [name=Jim][time=Wed, May 3, 2023]
### Reference

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