#include "stdio.h"
#include "malloc.h"
#define LEN sezeof(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);
}

报错信息：

 warning C4013: 'sezeof' undefined; assuming extern returning int
: error C2143: syntax error : missing ')' before 'type'
: error C2143: syntax error : missing ')' before 'type'

求指点下   谢谢了

这么明晃晃提示信息你是看不见呢还是看不懂呢？你需要改进的是学习方法。
#defineLEN sezeof(struct student)  这句应该是:
#defineLEN sizeof(struct student)

同意楼上。
仔细一点啊，楼主，这种错误，编译后也给了你明确提示：
warning C4013: 'sezeof' undefined; assuming extern returning int

明晃晃
……

呵呵   偶错了

lihai

你的没有main（）函数。同样运行不了