// Exercise 1.3.29
package algs13;
import stdlib.*;
import java.util.Iterator;

public class MyQueueCircular<T> implements Iterable<T> {
  private int N; // number of elements on queue
  private Node<T> last; // end of queue

  // helper linked list class
  private static class Node<T> {
    public Node() { }
    public T item;
    public Node<T> next;
  }

  public MyQueueCircular () {}

  public boolean isEmpty () {
    return false;
  }

  public int size () {
    return 0;
  }

  public T peek () {
    return null;
  }

  public void enqueue (T item) {}

  public T dequeue () {
    return null;
  }

  public String toString () {
    return null;
  }

  public Iterator<T> iterator () {
    return new QueueIterator ();
  }

  // an iterator, doesn't implement remove() since it's optional
  private class QueueIterator implements Iterator<T> {
    public boolean hasNext () {
      return false;
    }
    public T next () {
      return null;
    }
    public void remove () {}
  }

  /**
   * A test client.
   */
  public static void main (String[] args) {
    MyQueueCircular<String> q = new MyQueueCircular<> ();
    while (!StdIn.isEmpty ()) {
      String item = StdIn.readString ();
      if (!item.equals ("-")) q.enqueue (item);
      else if (!q.isEmpty ()) StdOut.print (q.dequeue () + " ");
    }
    StdOut.println ("(" + q.size () + " left on queue)");
  }
}