@[Dzhao](/user/108610) 应该先add后del
by ButterCake @ 2021-02-10 14:06:44
@[youjiajun](/user/110713) az，有什么区别吗qwq
by Dzhao @ 2021-02-10 14:07:59
@[youjiajun](/user/110713) 过了,yjjnb!!!
by Dzhao @ 2021-02-10 14:08:48
所以到底有什么关系呢/yiw
by Dzhao @ 2021-02-10 14:09:16
如果减到 $r<l$，$cnt$ 会为负数
by ButterCake @ 2021-02-10 14:09:17
@[youjiajun](/user/110713) 有道理，yjjnb！
by Dzhao @ 2021-02-10 14:10:17
@[Dzhao](/user/108610) ~~我不是前几天刚错过~~
by ButterCake @ 2021-02-10 14:10:50
@[youjiajun](/user/110713) ~~啊我看你的qzone没看出哪里错了耶好吧是我太菜了~~
by Dzhao @ 2021-02-10 14:12:36