一个程序引发的电脑内存问题

#include<stdio.h>
#include<malloc.h>
#define NULL 0
#define LEN sizeof(struct student)
void print(struct student *head);
struct student
{
long num;
float score;
struct student *next;
};
int n; /*n为全局变量*/
struct student *creat(void) /*定义函数，此函数带回一个指向链表头的指针*/
{
struct student *head;
struct student *p1,*p2;
n=0;
p1=p2=(struct student *)malloc(LEN);/*开辟一个新单元*/
scanf("%ld,%f",&p1->num,&p1->score);
head=NULL;
while(p1->num!=0)
{
n=n+1;
if(n==1)
head=p1;
else
p2->next=p1;
p2=p1;
p1=(struct student *)malloc(LEN);
scanf("%ld,%f",&p1->num,&p1->score);
}
p2->next=NULL;
return(head);
}
void main()
{
struct student *head;
head=creat();
print(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 %5.1f\n",p->num,p->score);
p=p->next;
}while(p!=NULL);
}
为何运行的时候 内存都占满了 求大神详解