package com.xgiovio.esercizi;

import exceptions.EmptyStackException;
import priorityqueue.PriorityQueue;
import priorityqueue.heap.HeapPriorityQueue;
import stack.Stack;

/**
 * Created with MONSTER.
 * User: xgiovio
 * Date: 03/06/2014
 * Time: 13:50
 */
public class PQStack<E> implements Stack<E> {

    private int priority = 0;
    private PriorityQueue<Integer,E> p = new HeapPriorityQueue<Integer, E>();


    @Override
    public void push(E element) {
       priority--;
       p.insert(priority,element);
    }

    @Override
    public E top() throws EmptyStackException {
        return p.min().getValue();
    }

    @Override
    public E pop() throws EmptyStackException {
        return p.removeMin().getValue();
    }

    @Override
    public boolean isEmpty() {
        return (size()== 0);
    }

    @Override
    public int size() {
        return p.size();
    }
}