Question

我已经编写了一个队列代码，但我对如何编写一个关于如何填充此队列值的测试用例感到很遗憾。如果有人可以提供帮助，我将不胜感激。

public class Queue {
    private Double[] elements;
    private int back;
    private static final int FRONT = 0;
    public static final int DEFAULT_CAPACITY = 10;
    /** Construct a queue with an ad hoc capacity */
    /** Construct a queue with the default capacity */
    /** put a new object at the end of the queue;
    * follow the model of StackOfIntegers to expand the capacity
    * if the queue is full
    */
    int initCapacity; 

    public Queue()
    {
        initCapacity = DEFAULT_CAPACITY;
        elements = new Double [initCapacity];
    }

    public Queue(int newValue){
        initCapacity = newValue;
        elements = new Double [initCapacity];
    }


    public void enqueue(Double value) {
        if (back == initCapacity){
            initCapacity = initCapacity * 2;
            Double [] elements2 = new Double [initCapacity];
            for (int i =0; i < elements.length; i++){
                elements2[i] = elements[i];
            }
            elements = elements2;
        }
        elements[back]= value;
        back+=1;

    }
    /** Return and remove the front element from the queue ;
    * this method must call the private method shift()
    */
    public Double dequeue() {
        Double temp = elements[FRONT] ;
        shift();
        back = back - 1;
    // we have to temporarily store the current front of the line
        return temp;

    }
    /** Return the element at the front of the queue for inspection */
    public Double peek() {
        return elements[FRONT];
    }
    /** Test whether the queue is empty */
    public boolean isEmpty() {
        return back == FRONT;
    }
    /** Return the number of elements in the queue */
    public int getSize() {
        return back;
    }
    /** shift everything one position to the front and null out the
    old back of the line */
    private void shift() {
        for ( int i = 1; i < back; i++ )
        elements[i-1] = elements[i] ;
        elements[--back] = null ;
    }
    /** A rough-and-ready way to see what is going on in our queue */
    public void dump() {
        System.out.print( "Elements: " ) ;
        for ( int i = 0; i < elements.length; i++ )
        System.out.print( elements[i] + " " ) ;
        System.out.println() ;
        System.out.println( "Back: " + back ) ;
    }
}

到目前为止，我已经写了这个用于填充队列的值，但我怀疑我错了。

public class TestQueueOfDoubles {
    public static void main(String[] args){
        Queue Object = new Queue( 12);
        Queue DefaultObject = new Queue();
        Queue Object2 = new Queue( 14);
        Queue Object3 = new Queue( 9);
        System.out.println(Object.initCapacity);
        System.out.println(DefaultObject.initCapacity);
        System.out.println(Object2.initCapacity);
        System.out.println(Object3.initCapacity);
    }
}

Answer 1

您正在创建多个队列，我猜测这不是您想要的结果。

 //You created your Queue here
 Queue object = new Queue( 12);

现在你要填充。您需要add（）或offer方法您已经实施了入队方法，因此请使用它。

  //Reference Queue you already instanciated and use the enqueue method
  object.enqueue(12);
  object.enqueue(14);
  object.enqueue(9);

现在您拥有一个包含所需值的队列。您可以打印并检查所有值是否都在队列中，如下所示：

for(Double d : object.elements)
  System.out.println(d);

填充队列的值

1 个答案: