程序五

#include<stdio.h>
#include<alloc.h>

#define NULL 0
#define len sizeof(struct student)

struct date
{
int year,month,day;
};

struct student
{
long num;
char name[20];
char sex;
struct date age;
struct student *next;
};

int n;

struct student *creat(void)
{
 struct student *head;
 struct student *p1,*p2;
 head=NULL;
 n=0;
 p1=p2=(struct student *)malloc(len);
 printf("please input information:/n/n");
 printf("num:");
 scanf("%ld",&p1->num);
 printf("name:");
 scanf("%s",p1->name);
 getchar();
 printf("sex:");
 p1->sex=getchar();
 printf("age:");
 scanf("%d%d%d",&p1->age.year,&p1->age.month,&p1->age.day);
 while(p1->num!=-1)
 {
  n++;
  if(n==1)head=p1;
  else p2->next=p1;
  p2=p1;
  p1=(struct student *)malloc(len);
  printf("num:");
  scanf("%ld",&p1->num);
  printf("name:");
  scanf("%s",p1->name);
  getchar();
  printf("sex:");
  p1->sex=getchar();
  printf("age:");
  scanf("%d%d%d",&p1->age.year,&p1->age.month,&p1->age.day);
 }
 p2->next=NULL;
 return (head);
}

void print(struct student *p)
{
if(p->next!=NULL)
 do
 {
  printf("The result is: num:%ld name:%s sex:%c age:%d %d %d/n",p->num,p->name,p->sex,p->age.year,p->age.month,p->age.day);
  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");
p1=head;
while(num!=p1->num&&p1->next!=NULL&&head!=NULL)
{
p2=p1;
p1=p1->next;
}
if(num==p1->num)
 {
 if(p1==head)head=p1->next;
 else p2->next=p1->next;
 printf("have del./n");
 n--;
 }
else printf("Not found!/n");
return head;
}

void main()
{
struct student *stud;
long num;
clrscr();
stud=creat();
print(stud);
printf("Input a num to del:/n");
scanf("%ld",&num);
stud=del(stud,num);
print(stud);
}