线性筛：https://blog.csdn.net/calculate23/article/details/89513721

球&盒子：https://blog.csdn.net/qwb492859377/article/details/50654627

https://www.cnblogs.com/flashhu/p/9480669.html

https://www.cnblogs.com/Tian-Xing-Sakura/p/13557676.html