可以说数论，数学就包含了DP
by _Rainlzy @ 2019-08-19 16:56:26
让管理员加一下
by _Rainlzy @ 2019-08-19 16:56:41
[这里](https://www.luogu.org/discuss/show/122762)
by zhy137036 @ 2019-08-19 16:57:47