先在D盘下创建一个 记事本   qq.txt   输入几个数字，随便几个都行，  最后一个的时候打一个空格  ，保存好，
运行程序，看看输出结果中是不是最后一个  数字重复了！


#include"stdio.h"
#include"malloc.h"
#include"stdlib.h"
#define SIZE sizeof(snode)
typedef struct student
{
    int num;
    struct student *next;
    struct student *prior;
}snode;
snode *create1();
void print(snode *head);                 
void main(void)
{

    snode *head1;
        printf("\n链表为：\n");
    head1=create1();
        printf("\n链表为：\n");
   

    print(head1);
   

}
snode *create1()
{
    snode *head,*r,*s;
    FILE *fp;
    int num1;
    head=(snode *)malloc(sizeof(SIZE));
    head->next=head->prior=NULL;
    r=head;
    fp=fopen("D:\\qq.txt","r");
    while(!feof(fp))
    {
        fscanf(fp,"%d",&num1);                        
        s=(snode *)malloc(sizeof(SIZE));
        s->num=num1;s->next=NULL;s->prior=r;
        r->next=s;
        r=s;
    }
    return head;
}

void print(snode *head)
{
    snode *p;
    p=head->next;  
     while(p!=NULL)                          
    {                              
        printf("%6d",p->num);         
        p=p->next;
    }
}