Queue的接口结构:

public interface Queue<E> {

    int getSize();
    boolean isEmpty();
    void enqueue(E e);
    E dequeue();
    E getFront();
}

基于最大堆的优先队列的实现,轻松完成入队和出队等基本操作(如果对最大堆的实现不理解请查看前一篇博客):

public class PriorityQueue<E extends Comparable<E>> implements Queue<E> {

    private MaxHeap<E> maxHeap;

    public PriorityQueue(){
        maxHeap = new MaxHeap<>();
    }

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

    @Override
    public boolean isEmpty(){
        return maxHeap.isEmpty();
    }

    @Override
    public E getFront(){
        return maxHeap.findMax();
    }

    @Override
    public void enqueue(E e){
        maxHeap.add(e);
    }

    @Override
    public E dequeue(){
        return maxHeap.extractMax();
    }
}