求解！！！链表，究竟是哪里出错
#include<stdio.h>#include<malloc.h>
#define NULL 0
#define LEN sizeof(struct student)
struct student
{
long num;
float score;
struct student *next;
};
int n;
struct student *creat(void)
{
struct student *head;
struct student *p1,*p2;
n=0;
p1=p2=(struct student *)malloc(LEN);
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);
}
出现的错误提示：--------------------Configuration: 6.c - Win32 Debug--------------------
Linking...
LIBCD.lib(crt0.obj) : error LNK2001: unresolved external symbol _main
Debug/6.c.exe : fatal error LNK1120: 1 unresolved externals
