LeetCode： Maximum Product of Three Numbers

Question

Given an integer array nums, find three numbers whose product is maximum and return the maximum product.

Example 1:

Input: nums = [1,2,3]

Output: 6

Example 2:

Input: [1,2,3,4]

Output: 24

Example 3:

Input: nums = [-1,-2,-3]

Output: -6

Solution

def maximum_product(nums)
  # two possilbe scenaros for maximum product: could be all positive
  # 1. 3 maximum numbers are all positive
  # 2. 2 negative number(smallest) * 1 positive number(largest)

  # take 2 smallest numbers
  min_nums = nums.min(2)
  # take 3 largest numbers
  max_nums = nums.max(3)
  # result is to compare which scenaro has maximum product
  [max_nums[0] * max_nums[1] * max_nums[2], max_nums[0] * min_nums[0] * min_nums[1]].max
end