关于链表的问题，高手请指教！！！！

[wenqiguo]

先上源码：
#include <stdio.h>
#include <malloc.h>
#define LEN sizeof(struct people)
struct people
{int num;
char name[20];
struct people *next;
};
int n;
struct people *creat(void)//建立链表
{struct people *head;
struct people *p1,*p2;
n=0;
p1=p2=(struct people*)malloc(LEN);//开辟一个新单元
scanf("%d%s",&p1->num,&p1->name);
head=NULL;
while(p1->num!=0)
{n=n+1;
if(n==1) head=p1;
else p2->next=p1;
p2=p1;
p1=(struct people*)malloc(LEN);
scanf("%d%s",&p1->num,&p1->name);
}
p2->next=NULL;
return(head);
}
struct people *del(struct people *head,int num)//删除结点
{struct people *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;
n=n-1;
}
end:
return(head);}
void main()
{
struct people *head1,*head2,*p;
int num;
printf("输入链表a:\n");
head1=creat();
printf("输入链表b:\n");
head2=creat();
loop:for(;head1->num==head2->num;head2=head2->next)
{
num=head1->num;
head1=del(head1,num);
}
if(head1->num!=head2->num)
{
head1=head1->next;
goto loop;
}
printf("处理后的a链表为:\n");//编译能通过，运行到这时就出现程序终止？？？
p=head1;
if(head1!=NULL)
do
{
printf("%d %s\n",p->num,p->name);
p=p->next;
}
while(p!=NULL);
}

[guojianxun17953]

友情帮顶

[wenqiguo]

没人知道吗

[swl82560397pq]

scanf("%d%s",&p1->num,&p1->name);改成p1->name.

[swl82560397pq]

另外最好别用goto语句把！

[wenqiguo]

改了后也不对啊！数据都输不进！！

[wenqiguo]

[Quote=引用 3 楼 swl82560397pq 的回复:]
scanf("%d%s",&p1->num,&p1->name);改成p1->name.
[/Quote]改了后也不对，数据都输不进了

[hrlhrl0]

head搞错了吧

[东大坡居士]

while(p1->num!=0)
{n=n+1;
if(n==1) head=p1;
else p2->next=p1;
p2=p1;
p1=(struct people*)malloc(LEN);
scanf("%d%s",&p1->num,&p1->name);
}
p2->next=NULL;
return(head);
}

//这块你新建的时候错了,每次申请完一个结点,都将head=p1,最后head都指向最后节点了,当然就什么也不能输出了

[东大坡居士]

可以在这个while之前,在p1 malloc之后,将p1赋给head,另外,
scanf("%d%s",&p1->num,&p1->name); 这个也应该是错了,要改成
scanf("%d%s",&p1->num,p1->name);

[jernymy]

加了个保护，不过输入数据是可以的，只是运行不知道楼主的意思。

#include <stdio.h> 
#include <malloc.h> 

#define LEN sizeof(struct people) 

struct people 
{
	int num; 
	char name[20]; 
	struct people *next; 
}; 

int n; 
struct people *creat(void)//建立链表 
{
	struct people *head; 
	struct people *p1,*p2; 
	n=0; 
	p1=p2=(struct people*)malloc(LEN);//开辟一个新单元 
	scanf("%d%s",&p1->num,&p1->name); 
	head=NULL; 
	while(p1->num!=0) 
	{
		n=n+1; 
		if(n==1)
			head=p1; 
		else
			p2->next=p1; 
		p2=p1; 
		p1=(struct people*)malloc(LEN); 
		scanf("%d%s",&p1->num,&p1->name); 
	} 
	p2->next=NULL; 
	return(head); 
} 

struct people *del(struct people *head,int num)//删除结点 
{
	struct people *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; 
		n=n-1; 
	} 
	end: 
	return(head);
} 

void main() 
{ 
	struct people *head1,*head2,*p; 
	int num; 

	printf("输入链表a:\n"); 
	head1=creat(); 
	printf("输入链表b:\n"); 
	head2=creat(); 
	loop:
	if (NULL == head1)
	{
		printf("head1 check finished\n");
		return ;
	}
	for (;head1->num==head2->num;head2=head2->next) 
	{ 
		num=head1->num; 
		head1=del(head1,num); 
	} 
	if( head1->num!=head2->num) 
	{ 
	head1=head1->next; 
		goto loop; 
	} 
	printf("处理后的a链表为:\n");//编译能通过，运行到这时就出现程序终止？？？ 
	p=head1; 
	if(head1!=NULL) 
	do 
	{ 
		printf("%d %s\n",p->num,p->name); 
		p=p->next; 
	} while (p!=NULL); 
} 

[show_bill]

好多错误啊，而且程序结构不好，goto没有必要， 对链表操作的时候条件指针是否为空都没有判断,
在建立链表时head并没有赋值

[东大坡居士]

不好意思,看错了~~~抱歉~~~

[woodwoods]

最好还是不用goto语句

[woaipanit]

struct people *del(struct people *head,int num)//删除结点
{struct people *p1,*p2;
if(head==NULL)
{printf("\nlist null!\n");return head;}
p1=p2=head;
while(p2)
{
if(p2->num==num){if(p2->next!=NULL){p1->next=p2->next};
else
p1->next=NULL;
return head;}
else {p2=p1->next;}
}
}

[wenqiguo]

就循环那有问题！！
这是我自己改正后的源码：（但还是有错，请高手指教）
#include <stdio.h>
#include <malloc.h>
#define LEN sizeof(struct people)
struct people
{int num;
char name[20];
struct people *next;
};
int n;
struct people *creat(void)//建立链表
{struct people *head;
struct people *p1,*p2;
n=0;
p1=p2=(struct people*)malloc(LEN);//开辟一个新单元
scanf("%d%s",&p1->num,&p1->name);
head=NULL;
while(p1->num!=0)
{n=n+1;
if(n==1) head=p1;
else p2->next=p1;
p2=p1;
p1=(struct people*)malloc(LEN);
scanf("%d%s",&p1->num,&p1->name);
}
p2->next=NULL;
return(head);
}
struct people *del(struct people *head,int num)//删除结点
{struct people *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;
n=n-1;
}
end:
return(head);}
void main()
{
struct people *head1,*head2,*head3,*p;
int num;
printf("输入链表a:\n");
head1=creat();
printf("输入链表b:\n");
head2=creat();
loop:for(;head1->num==head2->num,head2!=NULL;head2=head2->next)//这里有错！！！！！！，请高手只出
{
num=head1->num;
head3=del(head1,num);
}
if(head1->num!=head2->num&&head1!=NULL)
{
head1=head1->next;
goto loop;
}
printf("处理后的a链表为:\n");
p=head3;
if(head3!=NULL)
do
{
printf("%d %s\n",p->num,p->name);
p=p->next;
}
while(p!=NULL);
}

[苍蝇①号]

ls都说了
jf

[wenqiguo]

[Quote=引用 15 楼 cangyingzhijia 的回复:]
ls都说了
jf
[/Quote]不对

[renzhewh]

loop:for(;head1->num==head2->num,head2!=NULL;head2=head2->next)//这里有错！！！！！！，我没运行程序，感觉判断条件中的逗号运算符有错，应改成&&。

另外 如楼上scanf("%d%s",&p1->num,&p1->name);
&p1->name 应把 & 去掉