思路启发：
https://www.zhihu.com/question/55505229
https://www.joinquant.com/algorithm/index/edit?algorithmId=1ee1d35a52a4151a1ec580d21934f15b&f=
posted on 2017-03-21 08:43 樊四郎 阅读(121) 评论(0) 编辑 收藏 举报
