C++ 数据结构 双链表(模板类)

#ifndef DLIST_H_INCLUDED
#define DLIST_H_INCLUDED

#include<iostream>
using namespace std;

template<class Type>
class DList;

template<class Type>
class ListNode
{
    friend class DList<Type>;
public:
    ListNode():data(Type()),next(NULL),prior(NULL)
    {}
    ListNode(Type d,ListNode<Type> *n = NULL,ListNode<Type> *m = NULL):data(d),next(n),prior(m)
    {}
    ~ListNode()
    {}
public:
    void SetData(Type d)
    {data = d;}
    void GetData()const
    {return data;}
private:
    Type data;
    ListNode<Type> *next;
    ListNode<Type> *prior;
};

template<class Type>
class DList
{
public:
    DList()
    {
        first = last = BuyNode();
    }
    ~DList()
    {
        DList<Type>::destroy();
    }
public:
	void push_back(const Type &x);
	void push_front(const Type &x);
	void show_list()const;
	void pop_back();
	void pop_front();
	void insert_val(const Type &x);
	void delete_val(const Type &x);
	bool find(const Type &x);
	Type length();
	void clear();
	void destroy();                        //摧毁该顺序表
	void reserv();                         //反转
	void sort();
protected:
    ListNode<Type>* BuyNode(Type x = Type())
	{
        ListNode<Type> *p = new ListNode<Type>(x);
        return p;
	}
private:
    ListNode<Type> *first;
	ListNode<Type> *last;
};


template<class Type>
void DList<Type>::push_back(const Type &x)
{
    ListNode<Type> *s = BuyNode(x);
    last->next = s;
    s->prior = last;
    last = s;
    first->data++;
}

template<class Type>
void DList<Type>::push_front(const Type &x)
{
    ListNode<Type> *s = BuyNode(x);
    if(first == last)
    {
        s->prior = first;
        first->next = s;
        last = s;
    }
    else
    {
        first->next->prior = s;
        s->prior = first;
        s->next = first->next;
        first->next = s;
    }
    first->data++;
}

template<class Type>
void DList<Type>::show_list()const
{
    ListNode<Type> *p = first->next;
    while(p != NULL)
    {
        cout<<p->data<<" ";
        p = p->next;
    }
    cout<<endl;
}

template<class Type>
void DList<Type>::pop_back()
{
    if(first->data == 0)
        return;
    ListNode<Type> *p = first;
    while(p->next != last)
        p = p->next;
    ListNode<Type> *q = p->next;
    p->next = NULL;
    last = p;
    delete q;
    first->data--;
}

template<class Type>
void DList<Type>::pop_front()
{
    if(first->data <= 1)
        pop_back();
    else
    {
        ListNode<Type> *p = first->next;
        p->next->prior = first;
        first = p->next->prior;
        first->next = p->next;
        p = NULL;
        delete p;
        first->data--;
    }
}

template<class Type>
void DList<Type>::insert_val(const Type &x)
{
    ListNode<Type> *s =  BuyNode(x);
    ListNode<Type> *p =  first->next;
    if(p->data > s->data)
    {
        push_front(s->data);
    }
    else if(last->data < s->data)
    {
        push_back(s->data);
    }
    else
        {
            while(p != NULL)
           {
                if(p->next->data>x)
                {
                    p->next->prior = s;
                    s->prior = p;
                    s->next = p->next;
                    p->next = s;
                    first->data++;
                    return;
                }
                p=p->next;
            }
        }
}

template<class Type>
void DList<Type>::delete_val(const Type &x)
{
    ListNode<Type> *p = first;
    while (p->next != NULL && p->next->data != x)
        p = p->next;
    if (p->next == NULL)							//未找到即返回
    {
        cout<<"未找到该值"<<endl;
        return;
    }
    ListNode<Type> *q = p->next;
    if (q == last)
        pop_back();
    else
    {
        q->next->prior = p;
        p->next = q->next;
    }
    delete q;
    first->data--;
}

template<class Type>
bool DList<Type>::find(const Type &x)
{
    ListNode<Type> *p = first->next;
    while(p != NULL && p->data != x)
        p = p->next;
    if(p == NULL)
        {cout<<"未找到该值"<<endl;
        return false;}
    else
        {cout<<"存在该值"<<endl;
        return true;}
}

template<class Type>
Type DList<Type>::length()
{
    cout<<"length = "<<first->data<<endl;
}

template<class Type>
void DList<Type>::clear()
{
    while(first->data >0)
        pop_front();
}

template<class Type>
void DList<Type>::destroy()//摧毁该顺序表
{
    clear();
    first = last = NULL;
    delete first;
}

template<class Type>
void DList<Type>::reserv() //反转
{
    ListNode<Type> *p = first->next;
    ListNode<Type> *curr = p->next;
    ListNode<Type> *tmp = NULL;

    first->next->next = NULL;
    while (curr)   //将直接后继指向当前指针的next
    {
        tmp = curr->next;
        curr->next = p;
        p = curr;
        curr = tmp;
    }
    first->next = p;
}

template<class Type>
void DList<Type>::sort()
{
    ListNode<Type> *s = first->next;
    while (s->next)
    {
        ListNode<Type> *p = s;
        while(p->next)
        {
             if(s->data > p->next->data)
                {
                    Type tmp = s->data;
                    s->data = p->next->data;
                    p->next->data = tmp;
                }
                p = p->next;
        }
        s = s->next;
    }
}

#endif // DLIST_H_INCLUDED

<pre name="code" class="cpp">#include"DList.h"

int main()
{
    DList<int> mylist;
	int select = 1;
	int Item;
	int pos;
	while(select)
	{
		cout<<"**************************************"<<endl;
		cout<<"* [1] push_back       [2] push_front *"<<endl;
		cout<<"* [3] show_list       [0] quit_system*"<<endl;
		cout<<"* [4] pop_back        [5] pop_front  *"<<endl;
		cout<<"* [6] insert_val      [7] delete_val *"<<endl;
		cout<<"* [8] find            [9] length     *"<<endl;
		cout<<"* [10]clear           [11]destroy    *"<<endl;
		cout<<"* [12]reserv          [13]sort       *"<<endl;
		cout<<"**************************************"<<endl;
		cout<<"请选择:>";
		cin>>select;
		switch(select)
        {
        case 1:
			cout<<"请输入要插入的值(-1结束):>";
			while(cin>>Item, Item!=-1)
			{
				mylist.push_back(Item);
			}
			break;
		case 2:
			cout<<"请输入要插入的值(-1结束):>";
			while(cin>>Item, Item!=-1)
			{
				mylist.push_front(Item);
			}
			break;
		case 3:
			mylist.show_list();
			break;
        case 4:
            mylist.pop_back();
            break;
        case 5:
            mylist.pop_front();
            break;
        case 6:
            cout<<"请输入要插入的值:>";
            cin>>Item;
            mylist.insert_val(Item);
            break;
		case 7:
			cout<<"请输入要删除的值:>";
			cin>>Item;
			mylist.delete_val(Item);
			break;
		case 8:
			cout<<"请输入要查找的值:>";
			cin>>Item;
			mylist.find(Item);
			break;
        case 9:
            mylist.length();
            break;
        case 10:
            mylist.clear();
            break;
        case 11:
            mylist.destroy();
            break;
        case 12:
            mylist.reserv();
            break;
        case 13:
            mylist.sort();
            break;
		default:
			break;
        }
    }
}