data structure--Stack(基于数组实现)

傷城~ 2022-09-20 05:55 195阅读 0赞

#include<iostream>
    using namespace std;
    const int maxstack=10;
    template <class T>
    class ArrayStack
    {
    public:
    		ArrayStack();
    		T& top();
    		void pop();
    		void push(T&);
    		bool IsEmpty()  const;
    		bool full() const;
    		void clear();
    		int size() const;
    private:
    	    int current;
    		T array[maxstack];		
    };
    template <class T>
    ArrayStack<T>::ArrayStack()
    /*Pre: None
      Post: The stack is initialized to be empty.*/
    {	  
    	current=-1;
    }
    template <class T>
    void ArrayStack<T>::push(T &item)
    /*Pre:None
      Post:If the stack is not full,item is added to the top of the ArrayStack. Else,the stack is left unchanged.*/
    {
    	if(current<maxstack-1)
    	   array[++current]=item;	
    }
    template <class T>
    void ArrayStack<T>::pop()
    /*Pre:None
      Post:If the stack is not empty,the top of the ArrayStack is removed. Else,the stack is left unchanged.*/
    {
    	if(!IsEmpty())
    	   current--;
    }
    template <class T>
    T& ArrayStack<T>::top()
    /*Pre:None
      Post:If the stack is not empty,the top of the ArrayStack is returned.*/
    {
         if(!IsEmpty())
    	   return array[current];	 
    }
    template <class T>
    bool ArrayStack<T>::IsEmpty() const
    /*Pre:None
      Post:If the stack is empty,true is returned.Otherwise,false is returned*/
    {	  	
       if(current==-1)
          return 1;
       else 
        return 0;
    }
    template <class T>
    bool ArrayStack<T>::full() const
    /*Pre:None
      Post:If the stack is full,true is returned.Otherwise,false is returned*/
    {
    	return current==9;
    }
    template <class T>
    int ArrayStack<T>::size() const
    /*Pre:None
      Post:Return the number of entries in the stack.*/
    {
    	return (current+1);
    }
    template <class T>
    void ArrayStack<T>::clear()
    /*Pre:None
      Post:Reset the stack to be empty*/
    {
    	current=-1;
    }