循环对联实现,
//1.创建空的循环队列,为结构体在堆区分配空间
//2.判断队列是否为空
//3.判断队列是否为满
//4.入队，操作rear
//5.出对，操作front(Circular couplet implementation,
//1. creates an empty loop queue that allocates space for the structure in the heap area
//2. determines whether the queue is empty
The //3. determines whether the queue is full
The //4. team, rear
//5. out, operation front)