Today I participated in Codeforces Round 819 (Div. 1 + Div. 2) and Grimoire of Code Annual Contest 2022. At first glance, this was really a nice contest, and even though some problems were a bit too technical, they did contain some certain ideas (and as to whether these ideas were cool and beautiful, I guess there's no accounting for taste). However, the tests in the harder problems weren't strong enough. For example,

• I easily uphacked nikgaevoy's solution 171150224 of 1726F - Опоздать на работу (отправка решений запрещена), where he printed negative numbers on tests as little as with $$$n=2$$$; (btw, congrats nikgaevoy on becoming an IGM!)

• heno239 uphacked turmax's solution 171126442 of 1726G - Некая волшебная вечеринка with also a tiny test; (btw, congrats turmax on becoming an LGM!)

Nevertheless, I screencast the solving process (with my struggling to solve 1726F - Опоздать на работу (отправка решений запрещена)) and explanation of problems A–F, and I am now uploading it to YouTube, the video should appear here in several hours. Please leave your feedback (and other cases of high- or low-quality testing in this contest) in the comments!

UPD: While I was sleeping, two news have happened:

1. The video uploaded successfully.

2. The round became unrated because of the problem F, from which I suffered a lot during the contest. (By the way, the suffering had nothing to do with the quality of the tests in this problem or with this issue, I just made stupid bugs). You may read this and this blog to get to know the incident.