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

Example 1:
Input: [1,2,3]
Output: 6
Example 2:
Input: [1,2,3,4]
Output: 24
Note:
The length of the given array will be in range [3,104] and all elements are in the range [-1000, 1000].
Multiplication of any three numbers in the input won't exceed the range of 32-bit signed integer.

func maximumProduct(_ nums: [Int]) -> Int {
    if nums.count < 3 {
        return 0
    }
    var nums = nums.sorted()
    let num1 = nums[nums.count - 1]
    let num2 = nums[nums.count - 2]
    let num3 = nums[nums.count - 3]
    let num4 = nums[1]
    let num5 = nums[0]
    let max1 = num1 * num2 * num3
    let max2 = num1 * num4 * num5
    return max(max1, max2)
}