链表

  #include<stdio.h>
#include<stdlib.h>
#define null 0
typedef struct node
{
  char data;
  struct node *next;

}listnode;
//创建返回头节点的函数；
listnode *creatlist()
{

 listnode *Head=(listnode *)malloc(sizeof(listnode));
 listnode *s,*r=Head;
 char ch;
 printf("请输入jiedian数据:");
  ch=getchar();
  while(ch!='\n')
  { 
  s=(listnode *)malloc(sizeof(listnode));
  s->data=ch;
      r->next=s;
  r=s;
  ch=getchar();
  
  
  }
 r->next=null;