// Not optimized version
	// Time Complexity: O(n)
	 // Space Complexity: O(n)  due to creating a substring
	 private static boolean isPalindrome(String input) {
        int inputLength = input.length();
        String secondHalfOfInput = input.substring(inputLength / 2);
        int secondHalfOfInputLength = secondHalfOfInput.length();
        for(int i = 0; i < inputLength / 2; i++) {
            if(input.charAt(i) != secondHalfOfInput.charAt(secondHalfOfInputLength - (i + 1))) {
                return false;
            }
        }

        return true;
    }
    
  //  optimized version
	// Time Complexity: O(n)
	 // Space Complexity: O(1)  No substring		
    private static boolean isPalindromeOptimised(String input) {
        int left = 0;
        int right = input.length() - 1;
        while (left < right) {
            if (input.charAt(left) != input.charAt(right)) {
                return false;
            }
            left++;
            right--;
        }
        return true;
  }