Reversort and Reversort engineering are fully, Moons and Umbrellas and Cheating detection are partly solved.
Here are my submissions.
In the first problem I made two errors, because didn't think about two scenarios. I was able to fix them, so the 3rd submission passed both test sets. Which I think is not bad considering that the round took time between 3am and 5:30am in local time. ¯\(◉‿◉)/¯
Second problem: 2 of 3 test sets are solved.
That means 46 points of 100 which was enough for position 2715th. Here are my submissions.
I was able to solve the first problem. Time, math, equation system combined with technical issues like too large numbers. Here is my solution. This is 30 points, for position 1811th.
First problem is solved, 25 points, 3603rd position. Here.