#include<stdio.h>
#include<stdlib.h>
typedef int ElemType;
typedef struct LNode{
    ElemType data;
    struct LNode *next;    
}LNode,*LinkList;

//尾插法 
 LinkList List_TailInsert(LinkList &L)
 {
     ElemType x;
     L=(LinkList)malloc(sizeof(LNode));
     LNode *s,*r=L;
     printf("请输入单链表各个节点，以9999结束！\n"); 
     scanf("%d",&x);
     while(x!=9999)
     {
         s=(LNode*)malloc(sizeof(LNode));
         s->data=x;
         r->next=s;
         r=s;
         scanf("%d",&x);
             
     }
     
     r->next=NULL;
     
     return L;
    
  }
   int Length(LinkList L)
 {
     LNode *p=L;
     int count=0;
     while(p->next!=NULL)
     {
         p=p->next;
         count++;
     }
     return count;
     
 }
int Search_k(LinkList list,int k){
    LinkList p=list->next,q=list->next;
    int count=0;
    while(p!=NULL)
    {
        if(count<k)
        {
            count++;
            p=p->next;
        }
        else
        {
            q=q->next;
            p=p->next;
        }
    }
    if(count<k)
    return 0;
    else
    {
            printf("倒数第%d个元素是%d\n",k,q->data);
            return 1;
    }
    
}
 
 
  int main(){
    LinkList L;
    LinkList R,S;//接收输入数据和处理完的B 
    R=List_TailInsert(L);
    int a=Search_k(R,3);
    if(a==1)
        printf("ok");
        else
            printf("error");
        
    

    
}