import java.util.LinkedList;
import java.util.List;
import java.util.Stack;

public class Palindrome {
  /**
   * Determine if a linked list is a palindrome
   * @param List<Character>
   * @return boolean
   */
  public static boolean isPalindrome(List<Character> list) {
    Stack<Character> letters = new Stack<>();

    // Push the first half of the list onto a stack
    int i = 0;
    for(; i < list.size() / 2; i++) {
      letters.push(list.get(i));
    }

    // if the list is of odd size skip the center letter
    if(list.size() % 2 != 0) {
      i++;
    }

    // verify the end of the list is the opposite of the beginning
    for(; i < list.size(); i++) {
      if(letters.pop() != list.get(i)) {
        return false;
      }
    }

    return true;
  }


  public static void main(String[] args) {

    for(int i = 0; i < args.length; i++) {

      List<Character> palindrome = new LinkedList<>();

      for(int j = 0; j < args[i].length(); j++) {
        palindrome.add(args[i].charAt(j));
      }

      System.out.println("Is " + args[i] + " a palindrome?:\t" + Palindrome.isPalindrome(palindrome));
    }
  }
}