removing duplicate implementation

Palindromes/Palindromes.playground/Contents.swift

@@ -1,49 +1,7 @@
 //: Playground - noun: a place where people can play
 
-// last checked with Xcode 9.0b4
-#if swift(>=4.0)
-print("Hello, Swift 4!")
-#endif
-
 import Foundation
 
-/**
- Validate that a string is a plaindrome
- - parameter str: The string to validate
- - returns: `true` if string is plaindrome, `false` if string is not
- */
-func isPalindrome(_ str: String) -> Bool {
-    let strippedString = str.replacingOccurrences(of: "\\W", with: "", options: .regularExpression, range: nil)
-    let length = strippedString.characters.count
-
-    if length > 1 {
-        return palindrome(strippedString.lowercased(), left: 0, right: length - 1)
-    }
-    return false
-}
-
-/**
- Compares a strings left side character against right side character following
- - parameter str: The string to compare characters of
- - parameter left: Index of left side to compare, must be less than or equal to right
- - parameter right: Index of right side to compare, must be greater than or equal to left
- - returns: `true` if left side and right side have all been compared and they all match, `false` if a left and right aren't equal
- */
-private func palindrome(_ str: String, left: Int, right: Int) -> Bool {
-    if left >= right {
-        return true
-    }
-
-    let lhs = str[str.index(str.startIndex, offsetBy: left)]
-    let rhs = str[str.index(str.startIndex, offsetBy: right)]
-
-    if lhs != rhs {
-        return false
-    }
-
-    return palindrome(str, left: left + 1, right: right - 1)
-}
-
 //true
 isPalindrome("A man, a plan, a canal, Panama!")
 isPalindrome("abbcbba")