之前做这题的时候就觉得那个 $<$ 不对劲（
by CarroT1212 @ 2023-12-28 09:59:41
@[离散小波变换°](/user/68344)
by CarroT1212 @ 2023-12-28 10:07:14
@[CarroT1212](/user/319803) 已经更改。
by chen_zhe @ 2023-12-28 11:50:41