约瑟夫环问题 以7个人为例，用链表实现，每个人都有自己的密码，当他出列时，以他的密码作为下一个的个数，例这七个人的密码分别是3，1，7，2，4，8，4。第一个执行的个数是20 -Joseph Central to 7 personal problems as an example, use list realize that everyone has their own password, when he was out of time, with his password