import java.util.*;

public interface MyPriorityQueue {

    /**
     * Indicates the status of the queue.
     * @return <code>true</code> if the queue is empty.
     */
    public boolean isEmpty();

    /**
     * Returns the current size of the queue
     * @return the current size of the queue
     */
    public int size();

    /**
     * Adds an item to the queue.
     * @param <code>item</code> the item to be added.
     */
    public void add(Comparable item);

    /**
     * Removes the highest priority item from the queue.
     * @return the item of highest priority.
     * @exception NoSuchElementException if the queue is empty.
     */
    public Comparable remove();

    /**
     * Deletes an item from the queue if it was present.
     * @param <code>item</code> the item to be deleted.
     */
    public void delete(Comparable item);

    /**
     * Enumerates the items in the list in their order of priority.
     * @return the enumeration.
     * @exception NoSuchElementException if the <tt>nextElement</tt> method
     *            is called when there is no next element
     */
    // public Enumeration elements();

}