高手请帮我看看，我的链表到了 insert（）和destroy（）函数数据就不对，
程序代码：/* Note:Your choice is C IDE */
#include "stdio.h"
#include "stdlib.h"
#include "conio.h"
#include "alloc.h"
#include "dos.h"
#define NULL 0
#define LEN sizeof(struct student)
struct student/* 定义结点结构类型 */
{
int num;
char name[9];/* 用于存放姓名 */
struct student *next;/* 用于指向下一个结点（后继结点） */
};
struct student *create() /*建立链表*/
{
struct student *pHead=NULL;
struct student *pEnd=pHead,*pS=NULL;
int num;
clrscr();
while (1)
{
printf("Please input student\'s number,0 return: ");
scanf("%d",&num);
if (num<1)
{
return(pHead);/*如果小余1返回*/
}
pS=(struct student*)malloc(LEN); /*申请新结点空间*/
pS->num=num;
printf("\nPlease input student\'s name: ");
scanf("%s",pS->name);
pS->next=NULL;
if (pHead==NULL) /*如果链表为空，新结点为表头*/
{
pHead=pS;
}
else
{
pEnd->next=pS;
}
pEnd=pS;
}
}
void showlist(struct student *pHead) /*输出链表所有数据*/
{
clrscr();
while (1)
{
if(pHead==NULL) /*为空输出：The end*/
{
printf("The end");
getch();
break;
}
printf("Student\'s number is: %d student\'s name is: %s\n",pHead->num,pHead->name);
pHead=pHead->next;
}
}
struct student *search(struct student *pHead,int num)
{
struct student *pS=pHead;
while (1)
{
if(pS->num==num||pS==NULL)
{
return(pS);
}
pS=pS->next;
}
}
int insert(struct student *pHead)
{
struct student *pS=NULL,*pSN=NULL;
int num;
char name[9];
showlist(pHead);
printf("\n请输入要在其后插入的学号。");
scanf("%d",&num);
pS=search(pHead,num);
if(pS==NULL)
{
printf("\nCoundn't search this student.");
getchar();
}
else
{
pSN=(struct student*)malloc(LEN); /*申请新结点空间*/
printf("Please input student\'s number: ");
scanf("%d",pSN->num);
printf("\nPlease input student\'s name: ");
scanf("%s",pSN->name);
pSN->next=pS->next;
pS->next=pSN;
return(1);
}
return(0);
}
void destroy(struct student *pHead)
{
struct student * pS=pHead;
while (pHead!=NULL)
{
pS=pHead;
pHead=pHead->next;
free(pS);
}
}
int main()
{
char chl;/* 存放选项*/
char blank[]=" ";/*用来格式控制*/
struct student *pHead,*pS;
int num;
while (1)
{
clrscr();
printf("\n\n\n\n\n\n");/*用天格式控制*/
printf("%s 1 Create new list.\n",blank);
printf("%s 2 Show list.\n",blank);
printf("%s 3 search record.\n",blank);
printf("%s 4 Insert record.\n",blank);
printf("%s 5 Delete record.\n",blank);
printf("%s 6 Destroy list.\n",blank);
printf("%s 0 Exit.\n\n",blank);
printf("%s Please enter 0-6: ",blank);
chl=getch();
switch (chl)
{
case '1':pHead=create();
chl='q';break;/* 以head 为表头创建一个链表 */
case '2':showlist(pHead);/* 遍历以 head 为表头的链表 */
break;
case '3':clrscr();
printf("Please input the student\'s number: ");/*查找指定学号的记录*/
scanf("%d",&num);
pS=search(pHead,num);
if(pS==NULL)
{
printf("\nCoundn't search this student.");
}
else
{
printf("\nStudent\'s number is: %d student\'s name is: %s\n",pS->num,pS->name);
}
getch();
break;
case '4':insert(pHead);
break;
case '5':printf("You input 5!\n");getch();
break;
case '6':destroy(pHead);
break;
case '0':destroy(pHead);
exit(1);
default :printf("Please input 0-5!\n");getch();
}
}
} 选择4 插入数据不对，删除链表也有错，高手帮我看看。
谢谢楼上的