居然真的是
by X_o_r @ 2017-04-28 18:59:06
其实，这道题老师讲过，上课没听？还是忘了？（.......）
by 杨赛滨 @ 2017-04-28 21:45:11
裸的卡特兰数……
by Lokawa @ 2017-04-29 16:58:55
题解请去题解区，谢谢。
by Thecats @ 2017-06-13 17:05:13
哇塞，好厉害哦
~~早知道了~~
by Ape_epA @ 2017-09-14 20:54:16
您tql
~~早知道了~~
by Apro1066 @ 2019-02-03 17:15:18