https://blog.csdn.net/Flaze_/article/details/52204900
http://www.cnblogs.com/oyking/archive/2013/08/02/3232872.html
https://www.cnblogs.com/xzyxzy/p/9186759.html
https://blog.csdn.net/Aiphis/article/details/49486601
https://blog.csdn.net/As_A_Kid/article/details/80177070
将代码
https://blog.csdn.net/stevensonson/article/details/81748438
题目
https://blog.csdn.net/u013632138/article/details/52384290
https://www.luogu.org/problemnew/show/P3804
https://blog.csdn.net/di4covery/article/category/6966152