自己写双链表

<pre name="code" class="cpp">#include<iostream>using namespace std;typedef struct student{int data;struct student *pre;struct student*next;}Dlist;Dlist *Crt_dlist(){Dlist *head,*p,*next;int x,cycle = 1;head  = new Dlist;p = head;while(cycle){cout<<"请输入"<<endl;cin>>x;if(x != 0 ){next=new Dlist;next->data =x;next->pre =p;p->next = next;p = next;}else{cycle =0;}}head =head->next;head->pre =NULL;p->next =  NULL;return head;}void Insert_dlist(Dlist *L,int e){Dlist *p=L,*ptemp;ptemp =new Dlist;ptemp->data = e;while(ptemp->data >p->data&&p->next!=NULL)p=p->next;if(ptemp->data<=p->data){//at the head if(p==L){ptemp->next = L;L->pre =ptemp;ptemp->pre = NULL;L = ptemp;}else{//in the middleptemp->next=p;p->pre->next =ptemp;ptemp->pre = p->pre;p->pre = ptemp;}}else{//at the tailp->next = ptemp;ptemp->next = NULL;ptemp->pre =  p;}return ;}void Travert_dlist(Dlist *L){while(L!= NULL){cout<<L->data<<"-";L = L->next;}}void Del_dlist(Dlist *L,int e){Dlist *p;p=L;while(p->data!=e&&p->next!= NULL)p = p->next;if(p->data==e){if(p == L){//the positon of e is head;L = L->next;L->pre = NULL;delete p;}else if(p->next ==NULL){//at the tailp->pre->next =NULL;delete p;}else{//in the middlep->next->pre = p->pre;p->pre->next =p->next;}}}int Locat_e_dlist(Dlist *L,int e){int j=1;Dlist *p = L;while(p->data != e && p->next != NULL){p = p->next;j++;}if(p->data == e){if(p == L){return 1;}else{return j;}}else{cout << "不存在该数" << endl;return 65535;}}int Get_len_dlist(Dlist *L){int len=1;while(L!= NULL){len++;L = L->next;}return len;}void Sort_dlist(Dlist *L){Dlist *p,*pnext,*ptemp;int data;for(p = L;p->next != NULL;p = p->next){ptemp = p;for(pnext =p->next;pnext != NULL;pnext = pnext->next){if(p->data < pnext->data){ptemp = pnext;}}if(ptemp != p){data = p->data;p->data = ptemp->data;ptemp->data =data;}}}void main(){Dlist *head;int x;head =Crt_dlist();Travert_dlist(head);cout<<"*******************"<<endl;Insert_dlist(head,10);cout<<"*******************"<<endl;Travert_dlist(head);cout << "请输入删除那个数？";cin >> x;Del_dlist(head,x);cout<<"*******************"<<endl;Travert_dlist(head);cout << "请输入要定位的数";cin >> x;Locat_e_dlist(head,x);cout<<"*******************"<<endl;cout << Locat_e_dlist(head,x);cout<<"*******************"<<endl;cout << "the length of the dlist:"<<Get_len_dlist(head)<<endl;cout<<"*******************"<<endl;Sort_dlist(head);cout << "after select sort:" <<endl;Travert_dlist(head);}