C语言的链表的一个问题

typedef struct
{
int data;
struct Node *next;



}Node;
typedef Node * LinkList;


LinkList creatLinkList_2()
{
LinkList pRear,pHead,pCur;
int num;

printf("creating pHead...\n");
if( ( pHead = (LinkList)malloc(sizeof(Node)) ) == NULL)
{
printf("failed to allocate memery for pHead");


}
else
{
printf("successfully create pHead!\n");

}
pHead->next = NULL;
pRear = pHead;

while(1)
{
printf("input the number of linklist you want to create:");
printf("(-1 as end )\n");
scanf("%d\n",&num);

if(num == -1)

{
printf("finish creating linklist!");
break;
}

pCur = (LinkList)malloc(sizeof(Node));

pCur->data = num;
pRear->next = pCur;
pRear = pCur;

printf("%n");

}
pRear->next = NULL;

return pHead;



}
void printLinkList(LinkList pHead)
{
LinkList p = pHead;
while(p->next)
{
p = p->next;
printf("your linklist is:%d\n", p->data);

}
}


int main()
{
/* LinkList *L = (LinkList *)malloc(sizeof(LinkList));
create_LinkList(&L,5);
LinkList p = *L;
show_LinkList(p,5);
free(L);*/


LinkList pMyList = creatLinkList_2();
// printf("hehe");
printLinkList(pMyList);

return 0;
}


程序基本没大问题，主要是当输入提示出现后，必须输入2次数字才能进入循环，这是为何，同样，输入2次-1才能退出循环，大家去机子上跑一下如果方便的话，帮我修复一下，我用的是LINUX



printf("请输入数字");
scanf("%d",&num);
while(1)
{
//创建链表
if(num == -1)
退出循环
}

[解决办法]
在每个最后不带\n的printf后面加fflush(stdout);
在每个不想受接收缓冲区旧内容影响的scanf前面加rewind(stdin);
另外请检查scanf的返回值。

[解决办法]

LinkList creatLinkList_2()
{
LinkList pRear,pHead,pCur;
int num, data;

printf("creating pHead...\n");
if ( (pHead = (LinkList)malloc(sizeof(Node))) == NULL)
{
printf("failed to allocate memery for pHead");
return NULL;
}
else
{
printf("successfully create pHead!\n");
}

pHead->next = NULL;
pRear = pHead;


printf("input the number of the node int the linklist you want to create:");
printf("(-1 as end )\n");
scanf("%d\n",&num);
if(num <= -1)
{
printf("finish creating linklist!");
pHead->data = 0;
return pHead;
}
pHead->data = num;

while(num-- >0 )
{
pCur = (LinkList)malloc(sizeof(Node));
if (!pCur) {
pHead->data -= num+1;
break;
}

scanf("%d",&data);

pCur->next = NULL;
pCur->data = data;
pRear->next = pCur;
pRear = pCur;

}
pRear->next = NULL;

return pHead;
}