package algs24;

import stdlib.StdIn;

import stdlib.StdOut;

/**

* The PtrHeap class is the priorityQ class from Question 2.4.24.

* It represents a priority queue of generic keys.

*

* It supports the usual insert and delete-the-maximum

* 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 Section 2.4 of

* Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne.

*/

public class PtrHeap> {

@SuppressWarnings("unchecked")

/** Create an empty priority queue */

public PtrHeap() {

}

/** Is the priority queue empty? */

public boolean isEmpty() { return true; }

/** Is the priority queue full? */

public boolean isFull() { return true; }

/** Return the number of items on the priority queue. */

public int size() { return 0; }

/**

* Return the largest key on the priority queue.

* Throw an exception if the priority queue is empty.

*/

public K max() {return null;

}

/** Add a new key to the priority queue. */

public void insert(K x) { return;

}

/**

* Delete and return the largest key on the priority queue.

* Throw an exception if the priority queue is empty.

*/

public K delMax() {return null;

}

private void showHeap() {

// a method to print out the heap

// useful for debugging

}

public static void main(String[] args) {

PtrHeap pq = new PtrHeap<>();

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)");

}

}