链表——逆置

给定程序中，函数fun的功能是将带头结点的单向链表逆置，即若原链表中从头至尾结点数据与依次为2、4、6、8、10，逆置后，从头至尾结点数据依次为10、8、6、4、2。 
请在程序的下画线处填入正确的内容并将下画线删除，使程序得出正确的结果。 
试题程序。

#define N 5
typedef struct node
{
    int data;
    struct node *next;
} NODE;
void fun(NODE *h)
{
    NODE *p, *q, *r;

    p = h-> 1 ;
    if (p == 2 )
        return;
    q = p->next;
    p->next = NULL;
    while (q)
    {
        r = q->next; q->next = p;
        p = q; q = 3 );   
    }
    h->next = p;
}
NODE *creatlist(int a[ ])
{
    NODE *h, *p, *q; int i;
    h = (NODE *)malloc(sizeof(NODE));
    h->next = NULL;
    for (i = 0; i < N; i++)
    {
        q = (NODE *)malloc(sizeof(NODE));
        q->data = a[i];
        p->next = q;
        p = q;
    }
    
}
 return h;
}
void outlist(NODE *h)
{
    NODE *p;
    p = h->next;
    if (p == NULL)
        printf("The list is NULL!
");
    else
    {
        printf("
Head ");
        do
        {
            printf("->%d", p->data);
            p = p->next;
        }
        while (p != NULL);
        printf("->End
");
        
    }
    
}
main( )
{
    NODE *head;
    int a[N] = {2, 4, 6, 8, 10};
    head = creatlist(a);
    printf("
The original list:
");
    outlist(head);
    fun(head);
    printf("
The list after inverting :
");
    outlist(head);
}

答案：

你的答案 (正确)

1  next

2  NULL

3  r