View difference between Paste ID: kUWKbwWm and

-
+/**
  * Write a description of class Deque here.
  *
  * @author (your name)
  * @version (a version number or a date)
  */
 
 import java.util.NoSuchElementException;
 
 public class Deque<E> implements Queue<E>
 {
     private static class LLNode<E>
     {
         private E data;
         private LLNode<E> next;
         private LLNode<E> previous;
 
         public LLNode(E data, LLNode<E> next, LLNode<E> previous)
         {
             this.data = data;
             this.next = next;
             this.previous = previous;
         }
     }
 
 
     private LLNode<E> head, tail;
     private int size;
 
     public boolean isEmpty()
     {
         return head == null;
     }
 
 
     public void enqueueFront(E newData)
     {
         if (isEmpty()) {
             head = tail = new LLNode<E>(newData, null, null);
 
 
         } else {
             tail.next = new LLNode<E>(newData, null, null);
             tail = tail.next;
         }
 
         size++;
     }
 
     public void enqueueBack(E newData)
     {
         if (isEmpty()) {
             head = tail = new LLNode<E>(newData, null, null);
         } else {
             tail.previous = new LLNode<E>(newData, null, null);
             tail = rail.previous;
         }
 
         size++;
     }
 
     public E dequeueFront()
     {
         if (!isEmpty()) {
             E temp = head.data;
             head = head.next;
             size--;
 
             if (size == 0)
                 tail = null;
 
             return temp;
         } else {
             throw new NoSuchElementException();
         }
     }
 
     public E dequeueBack()
     {
         if (!isEmpty()) {
             E temp = head.data;
             head = head.previous;
             size--;
 
             if (size == 0)
                 tail = null;
 
             return temp;
         } else {
             throw new NoSuchElementException();
         }
     }
 
     public E peekFront()
     {
         if (!isEmpty())
             return head.data;
         else
             throw new NoSuchElementException();
     }
 
     public E peekBack()
     {
         if (!isEmpty())
             return tail.data;
         else
             throw new NoSuchElementException();
     }
 
     public String toString()
     {
         String s = "LLQueue (size = " + size + "), containing (front to back): ";
         LLNode<E> temp = head;
         while (temp != null) {
             s += temp.data + " ";
             temp = temp.next;
         }
         return s;
     }
 }