两个有序单向链表的合并

void And(linkP A, linkP B)
{
    linkP p = A->next;
    linkP q = B->next;
    free(B);// 释放头指针；
    linkP r = A;
    while(p && q)
    {
        if (p->data <= q->data)
        {
            r->next = p;
            r = p;
            p = p->next;
        }
        else
        {
            r->next = q;
            r = q;
            q = q->next;
        }
    }
    if (p == NULL) p = q;
    r->next = p;

}