一个双向移动的scroll，响应左右移动的消息，并且能够显示坐标-A two-way movement of the scroll, move left and right response to the message, and can display coordinates

这是一个Josephus问题的C++代码,用双向链表实现,很好(This is a c + + code, Josephus problem with two-way linked list implementation, is very good)