单链表——The headless singly linked list

 

#include <stdio.h>
#include <stdlib.h>
#include "list.h"

int main()
{
 int i;
 DATA x;
 LIST head = NULL;
 head = ListCreate();
 if(NULL == head)
 {
  return 1;
 }
 for(i = 0;i < 6; i++)
 {
  x = i + 3;
 // ListInsertHead(head,&x); 
  ListInsertTail(head,&x);
 }
 x = 5;
 PtrNode p = ListFind(head,&x);
 if(p == NULL)
 {
  printf("not find value!\n");
 }
 else
 {
  printf("data = %d\n",p->data);
 }
 ListDelete(head,&x);
 ListDisplay(head);
 ListDistroy(head);
 return 0;
}

#ifndef _LIST_H__
#define _LIST_H__

struct node;
typedef int DATA;
typedef struct node * LIST;
typedef struct node * PtrNode;
typedef struct node * Position;

LIST ListCreate();
int ListIsEmpty(LIST);
int ListMakeEmpty(LIST);
int ListIsLast(LIST,Position);
int ListInsert(LIST,Position,const DATA *);
int ListInsertHead(LIST,const DATA *);
int ListInsertTail(LIST,const DATA *);
PtrNode ListFind(LIST,const DATA *);
PtrNode ListFindPrev(LIST,const DATA *);
int ListDelete(LIST,const DATA *);
void ListDisplay(LIST);
void ListDistroy(LIST);

 

struct node{
 DATA data;
 struct node * next;  
};
#endif

 

#include <stdio.h>
#include <stdlib.h>
#include "list.h"

LIST ListCreate()
{
 PtrNode head = malloc(sizeof(*head));
 if(head == NULL)
 {
  return NULL;
 }
 ListMakeEmpty(head);
 return head;
}

int ListIsEmpty(LIST l)
{
 return l->next == NULL; 
}
int ListMakeEmpty(LIST l)
{
 l->next = NULL; 
}
int ListIsLast(LIST l,Position p)
{
 return p->next == NULL;  
}
int ListInsert(LIST l,Position prev,const DATA * data)
{
 PtrNode cur = malloc(sizeof(*cur));
 if(cur == NULL)
 {
  return 2; 
 }
 cur->data = *data;
 cur->next = prev->next;
 prev->next = cur;

 return 0;
}
int ListInsertHead(LIST l,const DATA * data)
{
 return ListInsert(l,l,data);
}
int ListInsertTail(LIST l,const DATA * data)
{
 Position tail = l;
 for(;tail->next != NULL;tail = tail->next);
  return ListInsert(l,tail,data);
}
PtrNode ListFind(LIST l, const DATA *data)
{
 PtrNode p = l->next;
 for(;p != NULL && p->data != *data;p = p->next);
  return p;
}
PtrNode ListFindPrev(LIST l,const DATA *data)
{
 PtrNode p = l;
 for(;p->next != NULL && p->next->data!=*data;p=p->next);
 return p;
}
int ListDelete(LIST l,const DATA *data)
{ 
 Position prev = ListFindPrev(l,data);
 if(!ListIsLast(l,prev))
 {
  Position q = prev->next;
  prev->next = q->next;
  free(q);
  return 0;
 }
 return -1; 
}

void ListDisplay(LIST l)
{
 Position p = l->next;
 while(p != NULL)
 {
  printf("%d ", p->data);
  p = p->next;
 }
 putchar('\n');
}
void ListDistroy(LIST l)
{
 Position p = l->next;
 Position q;

 while(p != NULL)
 {
  q = p;
  p = p->next;

  free(q);
 }
 free(l);
}