LinkStack

 //Node.h
 template<typename ElemType>
 struct Node
 {
     ElemType data;
     Node<ElemType> *next;
     Node();
     Node(ElemType item,Node<ElemType> * link=NULL);
 };
 template<typename ElemType>
 Node<ElemType>::Node()
 {
     next=NULL;
 }
 template<typename ElemType>
 Node<ElemType>::Node(ElemType item,Node<ElemType> *link)
 {
     data=item;
     next=link;
 }
 //LinkStack.h
 template<typename ElemType>
 class LinkStack
 {
 protected:
     Node<ElemType> *top;
     int count;
 public:
     LinkStack();
     virtual ~LinkStack();
     int Length() const;
     bool Empty() const;
     void Clear();
     void Traverse(void (*visit)(const ElemType &)) const;
     bool Push(const ElemType &e);
     bool Top(ElemType &e) const;
     bool Pop(ElemType &e);
     LinkStack(const LinkStack<ElemType> &copy);
     LinkStack<ElemType> &operator=(const LinkStack<ElemType> &copy);
 };
 template<typename ElemType>
 LinkStack<ElemType>::LinkStack()
 {
     top=NULL;
     count=;
 }
 template<typename ElemType>
 LinkStack<ElemType>::~LinkStack()
 {
     Clear();
 }
 template<typename ElemType>
 int LinkStack<ElemType>::Length() const
 {
     return count;
 }
 template<typename ElemType>
 bool LinkStack<ElemType>::Empty() const
 {
     return top==NULL;
 }
 template<typename ElemType>
 void LinkStack<ElemType>::Clear()
 {
     ElemType tmpElem;
     while(!Empty())
         Pop(tmpElem);
 }
 template<typename ElemType>
 void LinkStack<ElemType>::Traverse(void (*visit)(const ElemType &))const
 {
     Node<ElemType> *tmpPtr;
     LinkStack<ElemType> tmpS;
     for(tmpPtr=top;tmpPtr!=NULL;tmpPtr=tmpPtr->next)
         tmpS.Push(tmpPtr->data);
     for(tmpPtr=tmpS.top;tmpPtr!=NULL;tmpPtr=tmpPtr->next)
         (*visit)(tmpPtr->data);
 }
 template<typename ElemType>
 bool LinkStack<ElemType>::Push(const ElemType &e)
 {
     Node<ElemType> *newTop=new Node<ElemType>(e,top);
     if(newTop==NULL)//内存耗尽
         return false;
     else
     {
         top=newTop;
         count++;
         return true;
     }

 }
 template<typename ElemType>
 bool LinkStack<ElemType>::Top(ElemType &e)const
 {
     if(Empty())
         return false;
     else
     {
         e=top->data;
         return true;
     }

 }
 template<typename ElemType>
 bool LinkStack<ElemType>::Pop(ElemType &e)
 {
     if(Empty())
         return false;
     else
     {
         Node<ElemType> *old_top=top;
         top=old_top->next;
         e=old_top->data;
         count--;
         delete old_top;
         return true;
     }

 }
 template<typename ElemType>
 LinkStack<ElemType>::LinkStack(const LinkStack<ElemType> &copy)
 {
     if(Empty())
     {
         top=NULL;
         count=;
     }
     else
     {
         top=new Node<ElemType>(copy.top->data);
         count=copy.count;
         node<ElemType> *buttomPtr=top;
         for(Node<ElemType> *tmpPtr=copy.top->next;tmPtr!=NULL;tmpPtr=tmpPtr->next)
         {
             buttomPtr->next=new Node<ElemType> (tmpPtr->data);
             buttomPtr=buttomPtr->next;
         }

     }
 }
 template<typename ElemType>
 LinkStack<ElemType> &LinkStack<ElemType>::operator=(const LinkStack<ElemType> &copy)
 {
     if(&copy!=this)
     {
         if(copy.Empty())
         {
             top=NULL;
             count=;
         }
         else
         {
             Clear();
             top=new Node<ElemType>(copy.top->data);
             count=copy.count;
             Node<ElemType> *buttomTop=top;
             for(Node<ElemType> *tmpPtr=copy.top->next;tmpPtr!=NULL;tmpPtr=tmpPtr->next)
             {
                 buttomTop->next=new node<ElemType>(tmpPtr->data);
                 buttomTop=buttomTop->next;
             }

         }
     }

 }