K12教育赛事综合服务平台
聚乐之家官方网站
下载聚乐之家官方App
专注青少年竞赛题库网站
已知：链表结点的next域为直接后继，prev域为直接前驱。
p->next->prev = s; s->prev = p; p->next = s; s->next = p->next;
p->next->prev = s; p->next = s; s->prev = p; s->next = p->next;
s->prev = p; s->next = p->next; p->next = s; p->next->prev = s;
s->next = p->next; p->next->prev = s; s->prev = p; p->next = s;