import java.util.LinkedList;
import java.util.ListIterator;

/** LinkedListQueue.java -- Probably the simplest way to implement a queue,
 *  because we don't have to worry about growing array sizes and circularity.
 */
public class LinkedListQueue implements QueueInterface
{
  LinkedList list;

  public LinkedListQueue()
  {
    list = new LinkedList();
  }

  public void enqueue(Object o)
  {
    list.add(o);
  }

  public Object dequeue()
  {
    return list.remove(0);
  }

  public Object peek()
  {
    return list.get(0);
  }

  public int size()
  {
    return list.size();
  }

  public String toString()
  {
    StringBuilder build = new StringBuilder();
    ListIterator iterator = list.listIterator(0);
    while(iterator.hasNext())
      build.append("\t" + iterator.next() + "\n");
    return build.toString();
  }
}