向各位求助，关于链表的问题
#include<stdio.h>#include<stdlib.h>
#define LEN sizeof(struct student)
struct student
{
long num;
float score;
struct student *next;
};
int n;
struct student *creat()
{
struct student *head;
struct student *p1,*p2;
n=0;
p1=p2=(struct student*)malloc(LEN);
scanf("%ld,%f",&p1->num,&p2->score);
head=NULL;
while (p1->num!=0)
{
n=n+1;
if(n==1)head=p1;
else p2->next=p1;////////
p2=p1;//////////////////问题（1）想不通程序怎么通过p2对该链表进行扩增的
p1=(struct student *)malloc(LEN);
scanf("%ld,%f",&p1->num,&p1->score);
}
p1->next=NULL;
return (head);
}
void print(struct student *head)
{
struct student *p;
printf("\nNow,These %d records are :\n",n);
p=head;
if(head!=NULL)
do
{
printf("%ld %5.1lf\n",p->num,p->score);
p=p->next;
}while(p!=NULL);
}
void main()
{
struct student *head;
head=creat();
print(head);
}
这是谭老先生编的书上的程序，不过我有一个问题！问题在上面了，请各位多多帮助！
