链表问题

//=============创建链表
student *create()
{
        student *head1=NULL,*p1,*p2;
        int n=0;
        printf("请输入信息\n");
        p1=p2=(student *)malloc(len);
        printf("请输入学号和成绩:"); scanf("%d %f",&p1->num,&p1->score);
        while(p1->num!=0)
        {
             n++;
             if(n==1) head1=p1;
             else {p2->next=p1;}    p2=p1;
             p1=(student *)malloc(len);
             printf("请输入学号和成绩:"); scanf("%d %f",&p1->num,&p1->score);
        }
        p2->next=NULL;
        return head1;
}

//==============输出链表
void print(student *head1)
{
              student *p1;
              p1=head1;
              if(head1==NULL) printf("无记录\n");
              else{
              printf("有以下记录\n");
              while(p1!=NULL)
              {
                              printf("学号:%d   成绩:%.2f\n",p1->num,p1->score);
                              p1=p1->next;
              }
              }
              system("pause");
}

为什么当输入完第八个节点的信息然后回车 不能继续输入地九个的信息 却直接执行了输出链表函数？？？  求高手指点