VS2005调试C程序莫名有关问题，诡异
VS2005调试C程序莫名问题，诡异啊
调试时查看链表head结点的值，提示”无法计算表达式的值，错误的指针“可是我在创建链表的时候命名返回了堆的地址了。
代码如下main.cpp
extern STU_INFO* link_head;
extern TEACHER_INFO* link_head_T;
int main()
{
while(1)
{
printf("1---Log in as Teacher\n");
printf("2---Log in as Student\n");
printf("3---Quit\n");
printf("Please select a number:");
scanf("%d",&iTemp);
if (3 == iTemp)
{
break;
}
else if ((1 == iTemp)||(2==iTemp))
{
iRole = iTemp;
}
else
{
scanf("%s",buffer);
}
if (0 == iErrorcode && ((iRole == 1)||(iRole == 2)))
{
...
if (0 == iErrorCode)
{
if (1 == iRole)
{
get_file_name(iRole,g_sFile_Name);
link_head = create_Stu_Link();
...
infomange.cpp
STU_INFO* link_head;
TEACHER_INFO* link_head_T;
TEACHER_INFO* create_Teacher_Link ()
{
TEACHER_INFO* cur = NULL;//当前节点
TEACHER_INFO* rear = NULL;//尾节点
TEACHER_INFO *head = NULL;
//TEACHER_INFO* p1_prev;
int n = 0;
int iErrorCode = 0;
FILE *fp;
char buffer[STRING_LEN_MAX] = {'\0'};
if (NULL == (fp = fopen(g_sFile_Name_T,"r")))
{
sprintf(buffer,"open file %s failed.",g_sFile_Name);
iErrorCode = OPEN_FILE_ERROR;
printf_error_msg(buffer,iErrorCode);
}
if (0 == iErrorCode)
{
fgets(buffer,STRING_LEN_MAX,fp);
fgets(buffer,STRING_LEN_MAX,fp);//略去第二行
while(!feof(fp))
{
if (NULL == (cur = (TEACHER_INFO*)malloc(sizeof(TEACHER_INFO))))
{
strncpy(buffer,STRING_LEN_MAX-1,"malloc node failed.");
iErrorCode = NULL_POINTER_ERROR;
printf_error_msg(buffer,iErrorCode);
break;
}
if (0 == iErrorCode)
{
memset(cur,0,sizeof(TEACHER_INFO));
fscanf(fp,"%d:%s :%s :\n",&(cur->iID),(cur->sName),(cur->sPassword));
cur->pNext = NULL;
n++;
if(n==1)
{
head = cur;
rear = cur;
}
else
{
rear->pNext = cur;
rear = cur;
}
}
}
sg_iTeacher_Nbr = n;
}
if (fp)
{
fclose(fp);
}
return head;
}
------解决思路----------------------
不要依赖调试器输出复杂数据结构！而要将复杂数据结构的整个内容在处理它的每一步使用一小段代码按自己很容易理解的格式输出，非常有助于调试！或者可以说是“基础设施”：
------解决思路----------------------
不要依赖调试器观察复杂数据结构！
我不喜欢不听话的孩纸。
调试时查看链表head结点的值，提示”无法计算表达式的值，错误的指针“可是我在创建链表的时候命名返回了堆的地址了。
代码如下main.cpp
extern STU_INFO* link_head;
extern TEACHER_INFO* link_head_T;
int main()
{
while(1)
{
printf("1---Log in as Teacher\n");
printf("2---Log in as Student\n");
printf("3---Quit\n");
printf("Please select a number:");
scanf("%d",&iTemp);
if (3 == iTemp)
{
break;
}
else if ((1 == iTemp)||(2==iTemp))
{
iRole = iTemp;
}
else
{
scanf("%s",buffer);
}
if (0 == iErrorcode && ((iRole == 1)||(iRole == 2)))
{
...
if (0 == iErrorCode)
{
if (1 == iRole)
{
get_file_name(iRole,g_sFile_Name);
link_head = create_Stu_Link();
...
infomange.cpp
STU_INFO* link_head;
TEACHER_INFO* link_head_T;
TEACHER_INFO* create_Teacher_Link ()
{
TEACHER_INFO* cur = NULL;//当前节点
TEACHER_INFO* rear = NULL;//尾节点
TEACHER_INFO *head = NULL;
//TEACHER_INFO* p1_prev;
int n = 0;
int iErrorCode = 0;
FILE *fp;
char buffer[STRING_LEN_MAX] = {'\0'};
if (NULL == (fp = fopen(g_sFile_Name_T,"r")))
{
sprintf(buffer,"open file %s failed.",g_sFile_Name);
iErrorCode = OPEN_FILE_ERROR;
printf_error_msg(buffer,iErrorCode);
}
if (0 == iErrorCode)
{
fgets(buffer,STRING_LEN_MAX,fp);
fgets(buffer,STRING_LEN_MAX,fp);//略去第二行
while(!feof(fp))
{
if (NULL == (cur = (TEACHER_INFO*)malloc(sizeof(TEACHER_INFO))))
{
strncpy(buffer,STRING_LEN_MAX-1,"malloc node failed.");
iErrorCode = NULL_POINTER_ERROR;
printf_error_msg(buffer,iErrorCode);
break;
}
if (0 == iErrorCode)
{
memset(cur,0,sizeof(TEACHER_INFO));
fscanf(fp,"%d:%s :%s :\n",&(cur->iID),(cur->sName),(cur->sPassword));
cur->pNext = NULL;
n++;
if(n==1)
{
head = cur;
rear = cur;
}
else
{
rear->pNext = cur;
rear = cur;
}
}
}
sg_iTeacher_Nbr = n;
}
if (fp)
{
fclose(fp);
}
return head;
}
------解决思路----------------------
不要依赖调试器输出复杂数据结构！而要将复杂数据结构的整个内容在处理它的每一步使用一小段代码按自己很容易理解的格式输出，非常有助于调试！或者可以说是“基础设施”：
//不带表头结点的单向链表
#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include <time.h>
#include <locale.h>
struct NODE {
int data;
struct NODE *next;
} *head,*p,*q,*s,*p1,*p2,*q1,**ta;
int i,k,n,t,m,v,N=10;
int main() {
setlocale(LC_ALL,"chs");
srand(time(NULL));
head=NULL;
printf("创建%d个节点的单链表:",N);//创建N个节点的单链表
p=head;
for (i=0;i<N;i++) {
q=(struct NODE *)malloc(sizeof(struct NODE));
if (NULL==q) exit(1);
q->data=rand()%100;//填写0..99的随机值
q->next=NULL;
if (NULL==p) {
head=q;
p=head;
} else {
p->next=q;
p=q;
}
}
//输出整个单链表
s=head;
while (1) {
if (NULL==s) {
printf("\n");
break;
}
printf("%02d->",s->data);
s=s->next;
}
k=3;
v=5;
printf("将值为%d的结点插入到单链表的第%d个结点前:",v,k);//将值为v的结点插入到单链表的第k个结点前
n=0;
p=head;
while (1) {
if (NULL==p) {
break;
}
n++;
if (k==1) {
q=(struct NODE *)malloc(sizeof(struct NODE));
if (NULL==q) exit(1);
q->data=5;
q->next=head;
head=q;
break;
} else {
if (k-1==n) {
q=(struct NODE *)malloc(sizeof(struct NODE));
if (NULL==q) exit(1);
q->data=5;
q->next=p->next;
p->next=q;
break;
}
}
p=p->next;
}
//输出整个单链表
s=head;
while (1) {
if (NULL==s) {
printf("\n");
break;
}
printf("%02d->",s->data);
s=s->next;
}
k=5;
printf("删除第%d个节点:",k);//删除第k个节点
n=0;
p=head;
while (1) {
if (NULL==p) {
break;
}
n++;
if (k==1) {
q=head;
head=head->next;
free(q);
break;
} else {
if (k-1==n) {
q=p->next;
if (q) {
p->next=q->next;
free(q);
}
break;
}
}
p=p->next;
}
//输出整个单链表
s=head;
while (1) {
if (NULL==s) {
printf("\n");
break;
}
printf("%02d->",s->data);
s=s->next;
}
printf("从小到大排序:");//从小到大排序
for (p=head,p1=NULL;p!=NULL;p1=p,p=p->next) {
for (q=p->next,q1=p;q!=NULL;q1=q,q=q->next) {
if (p->data > q->data) {
//交换data
// printf("swap %02d %02d\n",p->data,q->data);
// t=p->data;p->data=q->data;q->data=t;
//或者
//交换next
// printf("swap %02d %02d\n",p->data,q->data);
if (p==head) {//p是头
if (p->next==q) {//pq挨着
head=q;
p->next=q->next;
q->next=p;
q=p;
p=head;
} else {//pq不挨着
head=q;
p2=p->next;
p->next=q->next;
q->next=p2;
q1->next=p;
q=p;
p=head;
}
} else {//p不是头
if (p->next==q) {//pq挨着
p1->next=q;
p->next=q->next;
q->next=p;
q=p;
p=p1->next;
} else {//pq不挨着
p1->next=q;
p2=p->next;
p->next=q->next;
q->next=p2;
q1->next=p;
q=p;
p=p1->next;
}
}
//输出整个单链表
// s=head;
// while (1) {
// if (NULL==s) {
// printf("\n");
// break;
// }
// printf("%02d->",s->data);
// s=s->next;
// }
// getchar();
}
}
}
//输出整个单链表并计算链表长度n
n=0;
s=head;
while (1) {
if (NULL==s) {
printf("\n");
break;
}
printf("%02d->",s->data);
n++;
s=s->next;
}
printf("将整个链表逆序:");//将整个链表逆序
if (n>=2) {
p=head;
q=p->next;
p->next=NULL;
while (1) {
q1=q->next;
q->next=p;
p=q;
q=q1;
if (NULL==q) break;
}
head=p;
}
//输出整个单链表
s=head;
while (1) {
if (NULL==s) {
printf("\n");
break;
}
printf("%02d->",s->data);
s=s->next;
}
m=4;
n=6;
printf("将单链表中前%d个结点和后%d个结点进行互换:",m,n);//将单链表中前m个结点和后n个结点进行互换,m+n为链表总长
k=0;
p=head;
while (1) {
if (NULL==p) {
break;
}
k++;
if (m==k) {
q=p;
}
s=p;
p=p->next;
}
q1=head;
head=q->next;
s->next=q1;
q->next=NULL;
//输出整个单链表
s=head;
while (1) {
if (NULL==s) {
printf("\n");
break;
}
printf("%02d->",s->data);
s=s->next;
}
//释放所有节点
p=head;
while (1) {
if (NULL==p) {
break;
}
q=p->next;
free(p);
p=q;
}
return 0;
}
//创建10个节点的单链表:08->74->07->23->03->99->31->56->88->16->
//将值为5的结点插入到单链表的第3个结点前:08->74->05->07->23->03->99->31->56->88->16->
//删除第5个节点:08->74->05->07->03->99->31->56->88->16->
//从小到大排序:03->05->07->08->16->31->56->74->88->99->
//将整个链表逆序:99->88->74->56->31->16->08->07->05->03->
//将单链表中前4个结点和后6个结点进行互换:31->16->08->07->05->03->99->88->74->56->
//
------解决思路----------------------
不要依赖调试器观察复杂数据结构！
我不喜欢不听话的孩纸。