C Foundation--The construction of doubly linked list

#include <stdio.h>#include"link.h"voidprint_item (link p) {printf ("%d\n", p->item);}intMainvoid) {link head, tail, p; //struct node *head;Link_init (&head, &tail);//head = NULLP= Make_node (3); Link_insert (&head, &tail, p);//Head Insertion Methodp = Make_node (5); Link_insert (&head, &tail, p);//Head Insertion Methodp = Make_node (1); Link_insert (&head, &tail, p);//Head Insertion Methodp = Make_node (8); Link_insert (&head, &tail, p);//Head Insertion MethodLink_travel_head (&head, Print_item);//traversing the Print List numeric fieldsprintf"***************\n"); Link_travel_tail (&tail, Print_item);//traversing the Print List numeric fieldsprintf"***************\n"); P= Link_search (&head,1); if(P! =NULL) {Link_delete (&head, &tail, p);    Free_node (P); } link_travel_tail (&tail, Print_item);//traversing the Print List numeric fieldsLink_destory (&head, &tail); return 0;}

#ifndef _link_h_#define_link_h_typedefstructNode *link;structNode {intitem;        Link next; //struct node *next; successorLink pre;//struct node *pre; precursor};voidLink_init (link *head, link *tail); link Make_node (intitem);voidLink_insert (link *head, link *tail, link p); Link link_search (Link*head,intkey);voidLink_delete (link *head, link *tail, link p);voidfree_node (link p);voidLink_modfie (link p,intkey);voidLink_destory (link *head, link *tail);voidLink_travel_head (Link *head,void(*vist) (link));voidLink_travel_tail (Link *tail,void(*vist) (link));#endif

#include <stdio.h>#include<stdlib.h>#include"link.h"voidLink_init (link *head, link *tail)//struct Node **head = &head{    //head = NULL;*head = *tail =NULL;} Link Make_node (intItem) {    //link p = (link *) malloc (sizeof (struct node));Link p = (link)malloc(sizeof(*p)); P->item = Item;//(*p). Itme = Item;P->next = NULL;//#define NULL (void *) 0P->pre = NULL;//#define NULL (void *) 0    returnp;}voidLink_insert (link *head, link *tail, link p)//Head Insertion Method{link q; if(*head = =NULL) {        *head =p; *tail =p; return; } P->next = *Head; (*head)->pre =p; *head =p;} Link link_search (link*head,intkey)    {link p;  for(p = *head; p! = NULL; p = p->next)if(P->item = =key)returnp; returnNULL;}voidLink_delete (link *head, link *tail, link q)    {link p; if(q = = *head) {        *head = q->Next; (*head)->pre =NULL; return; }    if(q = = *tail) {        *tail = q->Pre; (*tail)->next =NULL; return; } q->pre->next = q->Next; Q->next->pre = q->pre;}voidfree_node (link p) { Free(P);}voidLink_modfie (link p,intkey) {P->item =key;}voidLink_destory (link *head, link *tail) {Link P= *Head, q;  while(P! =NULL) {Q= p->Next;  Free(P); P=Q; }    *head = NULL; *tail =NULL;}voidLink_travel_head (Link *head,void(*vist) (link))    {link p;  for(p = *head; p! = NULL; p = p->next) vist (p);}voidLink_travel_tail (Link *tail,void(*vist) (link))    {link p;  for(p = *tail; p! = NULL; p = p->pre) vist (p);}

C Foundation--The construction of doubly linked list