palindromestack

class Solution {
  /**
   * Checks for a String represented as a SLList whether this String is a palindrome.
   * This is done by using a stack.
   *
   * An empty String or null should return true.
   *
   * @param list
   *     SLList used to represent a String
   * @return true if the String represented as a SLList is a palindrome, otherwise false
   */
  public static boolean checkPalindrome(SLList list) {
    LibraryStack<Character> stack = new LibraryStack<>();
    if (list == null || list.size() < 2) {
      return true;
    }
    int n = list.size();
    for(int i = 0; i < n/2; i++) {
      stack.push(list.removeFirst());
    }
    if(n % 2 == 1) {
      list.removeFirst();
    }
    for(int i = 0; i < n/2; i++) {
      if(stack.pop() != list.removeFirst()) {
        return false;
      }
    }
    return true;
  }
}

// class Solution {
//   /**
//    * Checks for a String represented as a SLList whether this String is a palindrome.
//    * This is done by using a stack.
//    *
//    * An empty String or null should return true.
//    *
//    * @param list
//    *     SLList used to represent a String
//    * @return true if the String represented as a SLList is a palindrome, otherwise false
//    */
//   public static boolean checkPalindrome(SLList list) {
//     LibraryStack<Character> stack = new LibraryStack<>();
//     if (list == null || list.size() <= 1) {
//       return true;
//     }
//     while(stack.size() != list.size()) {
//       char temp = list.removeFirst();
//       stack.push(temp);
//       if(list.size() == stack.size()+1) {
//         list.removeFirst();
//       }
//     }
//     while(!stack.isEmpty()) {
//       char temp = stack.pop();
//       char temp1 = list.removeFirst();
//       if (temp != temp1) {
//         return false;
//       }
//     }
//     return true;
//   }
// }
//