单链表的创建：SIGSEGV segmentation fault wenti如何解决

Question

用*Init_LNode()函数创建新单链表时,（r->next=p; ）这行出现SIGSEGV segmentation fault 问题。并不觉得哪里非法占用内存啊

struct LNode{
int data;
struct LNode *next;
}*head;

struct LNode *Init_LNode()
{
struct LNode *head=NULL,*r=NULL,*p=NULL;
int data;

r=head;
printf("Input 数组数:");
scanf("%d",&data);
while(data!=0){
p=(struct LNode*)malloc(sizeof(struct LNode));
if(!p)exit(0);
p->data=data;
**r->next=p; **

r=p;
scanf("%d",&data);
}
r->next=NULL;
return head;
}

Answer 1

http://blog.chinaunix.net/uid-24347760-id-1989555.html