尾插法构建循环链表，获取循环链表表尾，输出循环链表

#include "stdafx.h"
#include<stdio.h> 
#include<malloc.h> 
#include<stdlib.h>
typedef int type;
typedef struct lnode //定义链表结点的数据结构 
{
    int data;
    struct lnode *next;
}Lnode;
typedef Lnode node;
typedef struct dnode//定义双链表结点的数据结构 
{
    int data;
    struct dnode *lnext;
    struct dnode *rnext;
}Dnode;
           

Dnode *createcirDlink()//尾插法构建循环链表带头结点
{
    int x;
    Dnode *h, *t;
    t = h = (Dnode *)malloc(sizeof(Dnode));
    h->rnext = NULL;

    scanf_s("%d", &x);
    while (x != -1)
    {
        Dnode *s = (Dnode *)malloc(sizeof(Dnode));
        s->data = x;
        s->rnext = h->rnext;
        t->rnext = s;
        s->lnext = t;
        t = s;
        scanf_s("%d", &x);
    }
       t->rnext = h;
       h->lnext = t;
        return h;
}
           

node *createcirlink()//尾插法构建循环链表不带头结点
{
    int x;
    node *h, *t;
    t = h = (node *)malloc(sizeof(node));
    h->next = NULL;

    scanf_s("%d", &x);
    while (x != -1)
    {
        node *s = (node *)malloc(sizeof(node));
        s->data = x;
        s->next = h->next;
        t->next = s;
        t = s;
        scanf_s("%d", &x);
    }
    t->next = h;//尾和head相连
    return h;//带头结点
}
           

node *getcirlinktail(node *h)//获取循环链表表尾
{
    node *p = h->next;
    while (p->next != h)
        p = p->next;
    return p;
}
           

void printcirlink(node *h)//输出循环链表
{
    node *p = h->next;
    while (p != h)
    {
        printf("%d ", p->data);
        p = p->next;
    }
}