队列课下作业

要求：

• 1 补充课上没有完成的作业
• 2 参考15.3节，用自己完成的队列（链队，循环数组队列）实现模拟票务柜台排队功能
• 3 用JDB或IDEA单步跟踪排队情况，画出队列变化图，包含自己的学号信息
• 4 把代码推送到代码托管平台
• 5 把完成过程写一篇博客：重点是单步跟踪过程和遇到的问题及解决过程
• 6 提交博客链接

补充代码：

public class CircularArrayQueue<T> implements Queue<T>
{
    private final int DEFAULT_CAPACITY = 10000;
    private int front, rear, size;
    private T[] queue;
    //-----------------------------------------------------------------
// Creates an empty queue using the default capacity.
//-----------------------------------------------------------------
    public CircularArrayQueue()
    {
        front = rear = size = 0;
        queue = (T[]) (new Object[DEFAULT_CAPACITY]);
    }
    //-----------------------------------------------------------------
// Adds the specified element to the rear of this queue, expanding
// the capacity of the queue array if necessary.
//-----------------------------------------------------------------
    public void enqueue (T element)
    {
        if (size == queue.length)
            expandCapacity();
        queue[rear] = element;
        rear = (rear+1) % queue.length;
        size++;
    }
    public void expandCapacity()
    {
        T[] larger = (T[])(new Object[queue.length*2]);
        for (int index = 0; index < size; index++)
            larger[index] = queue[(front+index) % queue.length];
        front = 0;
        rear = size;
        queue = larger;
    }

    @Override
    public T dequeue()
    {
        if (size == 0)
            throw new EmptyCollectionException("queue");
        T d = queue[front];
        queue[front] = null;
        front = (front+1)%queue.length;
        size--;
        return d;
    }

    @Override
    public T first() {
        return queue[front];
    }

    @Override
    public boolean isEmpty() {
        boolean course = false;
        if(size ==0){
            course = true;
        }
        return course;
    }

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



    @Override
    public String toString(){
        String result = "";
        int scan = 0;

        while(scan < size)
        {
            if(queue[scan]!=null)
            {
                result += queue[scan].toString()+"
";
            }
            scan++;
        }
        return result;
    }
}

单步跟踪：

队列变化图：