栈的实现

该程序定义了链式栈（栈的链式存储结构）的存储结构，并实现了链式栈的基本操作，例如：构造函数、拷贝构造函数和赋值运算符重载函数的实现、析构函数、判空、插入、删除、获取栈顶元素，遍历。

 

#include<iostream>

using namespace std;

typedef int StackElement;

struct Node

{

     Node *next;

     StackElement data;

     Node(StackElement value, Node *link = NULL) :data(value),next(link)

    {}

};

class Stack

{

public:

        Stack() :myTop(NULL)

                     {}

         Stack(const Stack& original)

         {

             myTop = NULL;

             if (!original.empty())

            {

                      myTop = new Node(original.Top());  //复制第一个节点

                     Nodeptr lastPtr = myTop;    //设置指针以遍历整个栈的链表

                     Nodeptr origPtr =original.myTop->next;

             while (origPtr != 0)

             {

                     lastPtr->next = new Node(origPtr->data);

                     lastPtr = lastPtr->next;

                     origPtr = origPtr->next;

              }

         }

    }

    ~Stack()

    {

                   Nodeptr ptr = myTop, nextPtr;//ptr将被释放的节点，nextptr是ptr后继

                  while (ptr!=0)

                   {

                            nextPtr = ptr->next;

                            delete ptr;

                            ptr = nextPtr;

                   }

    }

    Stack& operator=(const Stack&rhs)

    {

            if (this!=&rhs)

            {

                   this->~Stack();//销毁当前的链表

                 if (rhs.empty())  //空栈

                      myTop = NULL;

                  else

                  {

                            myTop = new Node(rhs.Top());   //复制第一个节点

                          Nodeptr lastPtr = myTop;    //设置指针以遍历整个栈的链表

                           Nodeptr rhsPtr = rhs.myTop->next;

                      while (rhsPtr != 0)

                       {

                           lastPtr->next = new Node(rhsPtr->data);

                            lastPtr = lastPtr->next;

                            rhsPtr = rhsPtr->next;

                       }

                 }

            }

    return *this;

    }

    StackElement Top() const

    {

           if (!empty())

          {

                 return (myTop->data);

          }

         else

          {

                cout << "The Stack is empty!" << endl;

          }

    }

    bool empty() const

    {

           return myTop==0;

    }

    void push(const StackElement& value)

    {

          myTop = new Node(value, myTop);

    }

    void Display()

    {

         Nodeptr ptr;

         for (ptr = myTop; ptr != 0; ptr = ptr->next)

         cout << ptr->data <<" ";

         cout << endl;

    }

    void pop()

    {

         if (!empty())

         {

               Nodeptr ptr=myTop;

               myTop = myTop->next;

               delete ptr;

         }

        else

        {

               cout << "Stack is empty" << endl;

        }

    }

private:

   typedef Node* Nodeptr;

   Nodeptr myTop;

};

void main()

{

   Stack s;

   cout<<s.empty()<<endl;

   for (StackElement i = 1; i < 6; ++i)

   {

           s.push(i);

   }

   cout << s.empty() << endl;

   cout << s.Top() << endl;

   s.Display();

   s.pop();

   s.Display();

   Stack s1(s);

   s1.Display();

   Stack s2;

    s2 = s;

    s2.Display();

    system("pause");

}