qndmx
by Midoria7 @ 2020-10-27 08:53:06
~~只要你愿意写，所有二分都是倍增二分的题~~
by HH_Halo @ 2020-10-27 08:54:44
https://www.luogu.com.cn/problem/P3517
by 嘉然小姐的狗 @ 2020-10-27 19:01:08