data structure --Queue(基于数组的实现)

「爱情、让人受尽委屈。」 2022-09-20 05:55 151阅读 0赞

#include<iostream>
    using namespace std;
    const int maxqueue=10;
    template <class T>
    class ArrayQueue
    {
    public:
    	ArrayQueue();
    	bool empty() const; 
    	bool full() const;
    	int size() const;
    	void append(T &item);
    	void serve();
    	T& retrieve();
    	void clear();
    private:
    	int count;
    	int front,rear;
    	T array[maxqueue];		
    };
    template <class T>
    ArrayQueue<T>::ArrayQueue()
    /*Pre: None
      Post: The Queue is initialized to be empty.*/
    {
    	count=0;
    	front=0;
    	rear=maxqueue-1;
    }
    template <class T>
    bool ArrayQueue<T>::empty() const
    /*Pre: None
      Post: Return true if the Queue is empty,otherwise return false.*/
    {
    	return count==0;
    }
    template <class T>
    bool ArrayQueue<T>::full() const
    /*Pre:None
      Post:If the queue is full,true is returned.Otherwise,false is returned*/
    {
    	return count==10;
    }
    template <class T>
    int ArrayQueue<T>::size() const
    /*Pre:None
      Post:Return the number of entries in the queue.*/
    {
    	return count;
    }
    template <class T>
    void ArrayQueue<T>::append(T &item)
    /*Pre: None
      Post: Item is added to the rear of the Queue if it is not full,otherwise the queue is left unchanged.*/
    {
    	if(count<maxqueue)
        {
        	 count++;
        	 rear=((rear+1)==maxqueue)?0:(rear+1);
    	     array[rear]=item;
        }	  
    }
    template <class T>
    void ArrayQueue<T>::serve()
    /*Pre: None
      Post: The front of the Queue  is removed if the queue is not empty.*/
    {
    	if(count>0)
    	{
    		count--;
    		front=((front+1)==maxqueue)?0:(front+1);
    	}
    }
    template <class T>
    T& ArrayQueue<T>::retrieve()
    /*Pre: None
      Post: The front of the Queue  is returnd if the queue is not empty.*/
    {
    	if(count>0)
    	   return array[front];
    }
    template <class T>
    void ArrayQueue<T>::clear()
    /*Pre: None
      Post: The Queue  is reset to be empty.*/
    {
    	count=0;
    	front=0;
    	rear=maxqueue-1;
    }