SignOfTheProductOfAnArray.ts

// Source : https://leetcode.com/problems/sign-of-the-product-of-an-array/
// Author : squxq
// Date   : 2023-09-21

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

/** Function Definition: arraySign
// number[] -> number
// produces the sign of the product of all values in the given array

// Stub:
function arraySign(nums: number[]): number {
    return 0
}

// Tests:
arraySign([-1,-2,-3,-4,3,2,1]) -> 1
arraySign([1,5,0,2,-3]) -> 0
arraySign([-1,1,-1,1,-1]) -> -1
arraySign([1,28,-91,-62,-36,-1,-84,-90,-92,61,6,-58,-60,2,51,-15,-18,-81,87,84,100,-84,-13,-87,-33,72,-72,-59,-79,28,-69,-97,-93,17,67,11,-12,19,5,42,-85,71,-77,-82,26,-58,-51,-14,63,-85,-86,66,47,57,-86,-25,-75,59,-17,-71,89,-78,-42,30,39,61,-96,-30,-29,-92,-90,69,20,65,32,92,44,-71,-18,87,-86,23,-96,-21,-49,-96,-98,35,-11,-1,81,-48,68,5,75,57,-30,-7,32,86,-29,-86,-61,45,-31,-93,-26,-9,86,57,-52,75,68,-58,14,27,-94,47,-38,-44,75,-83,21,-83,43,62,74,97,78,43,54,28,64,-19,-89,88,68,18,-96,-83,-25,-71,88,-84,-24,-61,72,-90,-56,29,46,56,51,16,66,-2,65,-95,16,51,42,61,99,89,-93,59,-99,69,26,-61,21,41,40,-4,-49,3,-96,57,65,72,-41,-77,-4,61,71,-88,21,-95,38,64,92,0,-63]) -> 0

// Template:
function arraySign(nums: number[]): number {
    (... nums)
}
*/

export function arraySign(nums: number[]): number {
  return nums.reduce((acc, crr) => {
    return (acc *= Math.sign(crr));
  }, 1);
}