Simple script wich try all 4x4 mumbers and get the highest palindrome of it in Swift

palindrome.swift

/*

    Simple script wich try all 4x4 mumbers and get the highest palindrome of it.

    - results: 4x4 numbers (Imac 2013, i5, swift 5.3.2)
      Highest palindrome -> 99000099
      Found in -> 240.52266907691956 seconds

    - results: 4x4 numbers (Macbook air 2020, M1, swift 5.4)
      Highest palindrome -> 99000099
      Found in -> 92.4186509847641 seconds

    - results: 4x4 numbers (Ipad pro 2018, A12X, swift playground)
      Highest palindrome -> 99000099
      Found in -> 160.87225997447968 seconds



*/

import Foundation

/**
    Function to test if a number is palindrome

    - parameter number: (Int) The number to check

    - returns: (Bool) Result if the number is palindrome

    - notes : Cast the int entry to a str to a list wich got reversed and
    the list is joined to a string casted to an int and check if the entry is
    equal to the reversed entry.
*/
func isPalindrome(number: Int) -> Bool {
  return Int(String(String(number).reversed()))! == number
}

let startTime = Date().timeIntervalSinceReferenceDate

var highestPalindrome = 0

for i in 1000...9999 {
  for s in 1000...9999 {
    let r = i*s
    if isPalindrome(number: r) && r > highestPalindrome {
      highestPalindrome = r
    }
  }
}

let endTime = Date().timeIntervalSinceReferenceDate

print("Highest palindrome -> \(highestPalindrome)")
print("Found in -> \(endTime - startTime) seconds")