以带头结点的循环列表表示队列，只设一个指针指向队尾元素，不设头指针，编写队列初始化、入队、出队、判空的算法。-To take the lead in circulating the list of nodes that the queue, only to set a pointer to the tail element with no head pointer, write queue is initialized into the team, a team, sub-space algor