用双链表实现的踢人问题，一群人按顺序排成一圈，从第一个人开始每隔M人踢出一个人，如此循环，求已知最后n个被踢出的，求M-used to achieve the double chain gangs, a group of people formed a circle on the order, started from the first one out of every M-1, so the cycle, known for the last n throwaway, for M