mod=998244353
by hezihuan @ 2022-10-05 11:21:12
~~我一开始也模成了998244353998244353……~~
by OldDriverTree @ 2022-10-27 21:41:35
无语，我写成了 $10^9+7$，调了十年~~~
by Syrus @ 2023-08-04 10:15:30