#include<stdio.h>
#include<malloc.h>
struct student
{
    int num;
    struct student *link;
}stud;
  
 creat(int n)
{
    struct student *h,*p;
    int i;
    if((h=(stud *)malloc(sizeof(stud)))==NULL);
    {
        printf("not enough memory!");
        return(0);
    }
    h=NULL;
    for(i=0;i<=n;i++)
    {
         p=h;
         
        if((p=(stud *)malloc(sizeof(stud)))==NULL);

            
            
        {
            printf("内存不足！");
            return(0);
        }
        scanf("%d",&p->num);
        p->link=h;
        h=p;
    }
    }
    void main()
    {
        struct student *h;
        h=(struct student *)creat(4);
    }
   

原来这样，明白了