本身没错 但是就是在运行的时候不行...谁能告诉我为什么?
我把这个程序都传上来 你们看下  是关于动态链表的建立,输出,删除,插入的
#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);
}
void print(struct student *head)
{struct student *p;
printf("\nthese %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);
}
struct student *del(struct student *head,long num)
{struct student *p1,*p2;
if(head==null)
{printf("\nlist null!\n");goto end;}
p1=head;
while(num!=p1->num&&p1->next!=null)
  {p2=p1;p1=p1->next;}
if(num==p1->num)
  {if(p1==head)head=p1->next;
   else p2->next=p1->next;
   printf("delete:%ld\n",num);
   n=n-1;
  }
else printf("%ld not beeb found!\n",num);
return(head);
end:return null;
}
struct student *insert(struct student *head,struct student *stu)
{struct student *p0,*p1,*p2;
p1=head;
p0=stu;
if(head==null)
  {head=p0;p0->next=null;}
else
   {while((p0->num>p1->num)&&(p1->next!=null))
     {p2=p1;
      p1=p1->next;}
      if(p0->num<=p1->num)
        {if(head==p1)head=p0;
          else p2->next=p0;
            p0->next=p1;}
       else
           { p1->next=p0;p0->next=null;}
    }
n=n+1;
return(head);
}     
main()
{struct student *head,*stu;
long del_num;
printf("input records:\n");
head=creat();
print(head);
printf("\ninput the deleted number:");
scanf("%ld",&del_num);
while(del_num!=0)
  {head=del(head,del_num);
   print(head);
   printf("\ninput the deleted number:");
   scanf("%ld",&del_num);
  }
printf("\ninput the inserted record:");
stu=(struct student *)malloc(len);
scanf("%ld,%f",&stu->num,&stu->score);
while(stu->num!=0)
   {head=insert(head,stu);
    print(head);
    printf("\ninput the record:");
     stu=(struct student *)malloc(len);
     scanf("%ld,%f",&stu->num,&stu->score);
}
}

 
											





 
	    