#include<iostream>
using namespace std;
template <class T>
class Stack
{
    private:
        int top;
        int MaxTop;
        T * stack;
    public:
        Stack(int Max=10);
        ~Stack(){delete []stack;}
        bool Empty()const{return top==-1;}
        bool Full();
        T Top();
        void ClearStack();
        Stack<T>&Push(const T & x);
        Stack<T>&Pop(T & x );
};
template<class T>
Stack<T>::Stack(int Max)
{
    MaxTop=Max-1;
    stack=new T[Max];
    top=-1;
}
template<class T>
void Stack<T>::ClearStack()
{
    top=-1;
}
template<class T>
bool Stack<T>::Full()
{
    if(top==MaxTop)
        return true;
    else
        return false;
}
template<class T>
T Stack<T>::Top()
{
    if(top==-1)
        cout<<"栈空！"<<endl;
    else
        return stack[top];
}
template<class T>
Stack<T>&Stack<T>::Push(const T & x)
{
    if(Full())
        cout<<"栈满！"<<endl;
    top++;
    stack[top]=x;
    return *this;
}
template<class T>
Stack<T>&Stack<T>::Pop(T &x)
{
    if(top==-1)
        cout<<"栈空！"<<endl;
    x=stack[top];
    top--;
    return *this;
}
int main()
{
    Stack<char> s;
    char ch,c;
    ch=getchar();
    while(ch!=EOF)
    {
         while(ch!=EOF && ch!='\n')
        {
             switch(ch)
             {
                  case '#':s.Pop(c);
                     break;
                  case '@':s.ClearStack();
                    break;
                  default :s.Push(ch);
                    break;
             }
             ch=getchar();
        }
        s.ClearStack();
        if(ch!=EOF)
           ch=getchar();                       
    }
    return 0;
}

    上述程序为什么不能实现操作？