这是个环链表，能够用以解决约瑟夫问题等类似问题，在其他方面也有应用。-it can be used to solve the problems similar to Joesph problem

循环队列，实现循环链表。当走到队尾时，自动回到队头。-Circular queue, linked list implementation. When the team reached the end, the automatic return to the first team.