package algs24;

import stdlib.StdIn;
import stdlib.StdOut;

/**
 * The {@code PMytrHeap} class is the priorityQ class from Question 2.4.24. It
 * represents a priority queue of generic keys.
 * 
 * It supports the usual <em>insert</em> and <em>delete-the-maximum</em>
 * operations, along with methods for peeking at the maximum key, testing if the
 * priority queue is empty, and iterating through the keys. For additional
 * documentation, see <a href="http://algs4.cs.princeton.edu/24pq">Section
 * 2.4</a> of <i>Algorithms, 4th Edition</i> by Robert Sedgewick and Kevin
 * Wayne.
 */

public class MyPtrHeap<K extends Comparable<? super K>> {

  /** Create an empty priority queue */
  public MyPtrHeap () {
    // TODO
  }

  /** Is the priority queue empty? */
  public boolean isEmpty () {
    // TODO
    return true;
  }

  /** Return the number of items on the priority queue. */
  public int size () {
    // TODO
    return 0;
  }

  /**
   * Return the largest key on the priority queue. Throw an exception if the
   * priority queue is empty.
   */
  public K max () {
    // TODO
    return null;
  }

  /** Add a new key to the priority queue. */
  public void insert (K x) {
    // TODO
    return;
  }

  /**
   * Delete and return the largest key on the priority queue. Throw an
   * exception if the priority queue is empty.
   */
  public K delMax () {
    // TODO
    return null;
  }

  private void showHeap () {
    // a method to print out the heap
    // useful for debugging
  }

  public static void main (String[] args) {
    MyPtrHeap<String> pq = new MyPtrHeap<> ();
    StdIn.fromString ("10 20 30 40 50 - - - 05 25 35 - - - 70 80 05 - - - - ");
    while (!StdIn.isEmpty ()) {
      StdOut.print ("pq:  ");
      pq.showHeap ();
      String item = StdIn.readString ();
      if (item.equals ("-")) StdOut.println ("max: " + pq.delMax ());
      else pq.insert (item);
    }
    StdOut.println ("(" + pq.size () + " left on pq)");

  }

}