在双向循环链表中,在p指针所指向的结点前插入一个指针q所指向的新结点,其修改指针的操作是()。
A. p->prior=q;q->next=p;p->prior->next=q;q->prior=q;
B. p->prior=q;p->prior->next=q;q->next=p;q->prior=p->prior;
C. q->next=p;q->prior=p->prior;p->prior->next=q;p->prior=q;
D. q->prior=p->prior;q->next=p; p->prior=q;p->prior=q;