模板实现双向链表

/************************************

          WZ ASUST   2016

        模板实现双向链表

************************************/

#include"sts.h"
template <class T>
struct node
{
public:node(const T &d):next(NULL),prve(NULL),data(d){}
T data;
node<T> *next;
node<T> *prve;
};
template <class T>
class dlist
{
private: node<T>* head;node<T>* tail;
public:
       dlist():head(NULL),tail(NULL){};
       ~dlist(){node<T>*cur=head;while(cur){node<T>*del=cur;cur=cur->next;delete del;}}
     void print(){node<T>*cur=head;while(cur){cout<<cur->data<< " ";cur=cur->next;}cout<<"ok"<<endl;}
    // void  dlist(const dlist<T>&dl){}//while not error
dlist & operator=(const dlist <T> & dl)
{
if(this!=&dl)
  {
   head=dl.head;
   tail=dl.tail;
   node<T>*dlcur=dl.head;
   node<T>*cur=dlcur;
//  cout<<head->data<<endl;
int xx=length()-1;
 while(xx--)
   {
  // cout<<"wzzx"<<xx<<endl;
    dlcur=dlcur->next;
     dlcur=cur;
    cur=cur->next;
  //cout<<cur->data<<endl;
   }

  }

}
int length()
{
int ret=0;
if(head)
{
 node<T>*cur=head;
while(cur)
{
ret++;
 cur=cur->next;
}

return ret;
}
else return 0;
}

void pushback(const T &d)
{
if(head==NULL)
 {
  head=new node<T>(d);
  tail=head;
 }
else
 {
   tail->next=new node<T>(d);
   tail->next->prve=tail;
   tail=tail->next;
 }
}
T popback()
{
if(head==NULL)
 {
   return 0;
 }
else
 {
   return tail->data;
 
 }

}
void pushfront(const T &d)
{
if(head==NULL)
 {
  head=new node<T>(d);
  tail=head;
 }
else
 {
   head->prve=new node<T>(d);
   head->prve->next=head;
   head=head->prve;
 }
}
T popfront()
{
if(head==NULL)
 {
   return 0;
 }
else
 {
   return head->data;
 
 }

}
void insert(int x, const T d)
{
if(x<0||x<length())
 {x=x-1;
  node<T> *add=new node<T>(d);
   node<T> *cur=head;
  if(head)
     {
      while(x--)
       {cur=cur->next;}
        add->prve=cur;        add->next=cur->next;
        cur->next=add;
     }
  }
}
void reverse()
{
 int len=length();
 node<T> *tmp=NULL;
if(head)
  {
    node<T>* cur = head;
    node<T>*   p = head;  
   while(len--)
   {
     p = p->next;
    tmp=cur->next;
   cur->next=cur->prve;
   cur->prve=tmp;
     cur=p;    
   }
   p=head;
 head=tail;
  tail=p;
  }
 
}

};
 void test()
{
dlist<int> int_dlist;
cout<<"** 1 : ***************"<<endl;
 int_dlist.pushback(11);
 int_dlist.pushback(22);
 int_dlist.pushback(33);
 int_dlist.pushback(44);
 int_dlist.print();
cout<<"*** 2 :**************"<<endl;
 
 int_dlist.pushfront(55);
 int_dlist.pushfront(66);
 int_dlist.pushfront(77);
 int_dlist.print();
cout<<"*** 3 :**************"<<endl;
  cout<<int_dlist.popfront()<<endl;
  cout<<int_dlist.popback()<<endl;
cout<<"*** 4 :**************"<<endl;

}
int main()
{
dlist<int> int_dlist;
cout<<"** 5 : ***************"<<endl;
 int_dlist.pushback(11);
 int_dlist.pushback(22);
int_dlist.pushback(11);
 int_dlist.pushback(22);
 int_dlist.print();
dlist<int> int_dlist2;
int_dlist2=int_dlist;
 int_dlist.print();
cout<<"** 6 : ***************"<<endl;
cout<<int_dlist.length()<<endl;
cout<<"** 7 : ***************"<<endl;
int_dlist.reverse();
int_dlist.print();
cout<<"** 8 : ***************"<<endl;
int_dlist.insert(3,99);

int_dlist.print();

 return 0;
}