c++用双向链表实现模板栈

 

可直接编译运行，其中方法status为形象的显示出栈的结构：

// visual stack , need define "cout<<" 

#include <iostream>
using std::cout;

template<typename T>
struct item
{
    item():value(),last(NULL),next(NULL){}
    item *last,*next;
    T value;
};
template<typename T>
class Stack
{
    public:
        Stack():m_size(0),m_bottom(NULL),m_top(NULL){}
        int size();
        bool push(const T&);
        T pop();
        T top();
        bool empty();
        void status();
    private:
        item<T> *m_bottom,*m_top;
        int m_size;
};


///////////////////
int main()
{
    Stack<int> st;
    for(int i=0;i<10;i++)
    {
        st.push(i);
        st.status();
    }
    cout<<"size="<<st.size()<<"
";
    
    for(    i=0;i<10;i++)
    {
        st.pop();
        st.status();
    }
    if(st.empty())cout<<"empty
";
    cout<<st.top()<<"
";
    return 0;
}


////////////////////////////
template<typename T>
inline int Stack<T>::size(){return m_size;}

template<typename T>
inline bool Stack<T>::empty(){return m_size==0?false:true;}

template<typename T>
inline T Stack<T>::top(){return m_size!=0?m_top->value:T();}

template<typename T>
bool Stack<T>::push(const T& t)
{
    if(m_size==0)
    {
        m_bottom=new item<T>;
        m_bottom->value=t;
        m_top=m_bottom;
    }
    else
    {
        m_top->next=new item<T>;
        m_top->next->value=t;
        m_top->next->last=m_top;
        m_top=m_top->next;
    }
    m_size++;
    return true;
}

template<typename T>
T Stack<T>::pop()
{
    if(m_size==1)
    {
        T t=m_top->value;
        delete m_top;
        m_bottom=m_top=NULL;
        m_size=0;
        return t;
    }
    else if(m_size==0)
    {
        return T();
    }
    else 
    {
        T t=m_top->value;
        m_top=m_top->last;
        delete m_top->next;
        m_top->next=NULL;
        m_size--;
        return t;
    }
    return T();
}

template<typename T>
void Stack<T>::status()
{
    item<T> *p;
    cout<<"栈顶  |
";
    if( m_size==0 )return ;
    else if(m_size<10)
    {
        for(p=m_top;p!=NULL;p=p->last)
        {    
            if(p->last==NULL)cout<<"栈底  |"<<p->value<<"|
";
            else cout<<"      |"<<p->value<<"|
";
        }
    }
    else 
    {
        int i;
        for(p=m_top,i=0;i<4;p=p->last,i++)cout<<"      |"<<p->value<<"|
";
        for(p=m_bottom,i=0;i<4;p=p->next,i++);
        cout<<"      略...
";
        for(;i>=0;i--,p=p->last)
        {
            if(i==0)cout<<"栈底  |"<<p->value<<"|
";
            else cout<<"      |"<<p->value<<"|
";
        }
    }
}