循环单链表-查找元素

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

LinkList listTailInsert(LinkList &L)
{
	ElemType x;
	LNode *s,*r;
	L = (LinkList)malloc(sizeof(LNode));
	r = L;
	scanf("%d",&x);
	while(x!=9999)
	{
		s = (LNode*)malloc(sizeof(LNode));
		s->data = x;
		r->next = s;
		r = s;
		scanf("%d",&x);
	}
	r->next = L;
	return L;
}

//查找第i位结点元素
LNode *findElem(LinkList &L,int i)
{
	int j=0;
	LNode *p = L;
	while(j<i && p)
	{
		p = p->next;
		++j;
	}
	if(j==i && p)
		return p;
	else
		return NULL;
}

void printList(LinkList L)
{
	LNode *p = L->next;
	while(p!=L)
	{
		printf("%d ",p->data);
		p = p->next;
	}
	printf("\n");
}

void main()
{
	LinkList L;
	LNode *s;
	ElemType x;
	listTailInsert(L);
	printList(L);
	s = findElem(L,2);
	printf("第二位元素:%d\n",s->data);
}