程序代码：

#include<stdio.h>
struct lk
{
char name[20];
int age;
char sex;
struct lk*next;
};
typedef struct lk lkk;
void print(lkk*head)
   {
    if(head==0)
     {
      printf("no data\n");
      getch();
      exit(0);
      }
    while(head!=0)
    {
     printf("%s\t%d\t%c\n",head->name,head->age,head->sex);
     head=head->next;
     }
     }
lkk*creat(int n)
{
lkk*head,*p,*q;
int i,j;
p=(lkk*)malloc(sizeof(lkk));
if(p==0)
{
   printf("error\n");
   getch();
   exit(0);
   }
   head=p;
   printf("input the 1 stdunt date\n");
   do
   {
   printf("name:");
   scanf("%s",p->name);
   i=strlen(p->name);
   if(i>19)
    printf("too long\n");
   }while(i>19);
   do
   {
   fflush(stdin);
   printf("age:");
   scanf("%d",&p->age);
   if(p->age<0)
    printf("error\n");
    }while(p->age<0);
    do
    {
   printf("sex: b for boy g for gile\n");
   while(getchar()!='\n')
   ;
    scanf("%c",&p->sex);
   if(p->sex!='b'&&p->sex!='g')
    printf("input error\n");
   }while(p->sex!='b'&&p->sex!='g');
   p->next=0;
   for(j=1;j<n;j++)
   {
    if(n==1)
      break;
    q=(lkk*)malloc(sizeof(lkk));
    if(q==0)
    {
     printf("error error\n");
     getch();
     exit(0);
     }
     p->next=q;
     printf("input the %d stdunt date\n",j+1);
    do
   {
   printf("name:");
   scanf("%s",q->name);
   i=strlen(q->name);
   if(i>19)
    printf("too long\n");
   }while(i>19);
   do
   {
   printf("age:");
   scanf("%d",&q->age);
   if(q->age<0)
    printf("error\n");
   }while(q->age<0);
    do
    {
    getchar();
   printf("sex: b for boy g for gile\n");
   scanf("%c",&q->sex);
   if(q->sex!='b'&&q->sex!='g')
    printf("input error\n");
   }while(q->sex!='b'&&q->sex!='g');
   q->next=0;
   p=q;
   }
   return(head);
   }
  main()
  {
  lkk*head;
  int i;
  printf("input numbers\n");
  scanf("%d",&i);
  head=creat(i);
  print(head);
  getch();
  }