Algorithm challenge week 4 solution

arrayProduct.js

const arrayProduct = nums => {
  if(!Array.isArray(nums)) throw new Error('Invalid input')
  
  let product = 1
  let countOfZeros = 0;
  let productWithoutZeros = 1

  for (let i = 0, j = nums.length - 1; i <= j; i++, j--) {
    if (typeof nums[i] != 'number' || typeof nums[j] != 'number') throw new Error('Invalid input')
    
    if (nums[i] == 0) {
      countOfZeros++
    }

    product *= nums[i]
    productWithoutZeros = nums[i] != 0 ? productWithoutZeros * nums[i] : productWithoutZeros

    if (i != j) {
      if (nums[j] == 0) {
        countOfZeros++
      }

      product *= nums[j]
      productWithoutZeros = nums[j] != 0 ? productWithoutZeros * nums[j] : productWithoutZeros
    }
  }

  return nums.map(num => {
    return countOfZeros > 1 ? 0 : num != 0 ? product / num : productWithoutZeros
  })
}

@meekg33k I missed that edge case. I've now updated the solution.