Hello, I'm Sanae.
In ufc+8 zone, I watched the entire contest at midnight. Too many cheaters emerged and we were busy banning them. I noticed WA submissions on 2228B - Remilia Plays Soku, 2228C2 - Cirno and Number (Hard Version) and TLE submissions on 2228D - Sanae, Cross and Color, which was intended. Soon after the end of the contest, I released the editorial. The bad news was, the complaints flooded the website and my contribution fell from +91 to -92. After reflecting on the issues, I was anixous and blamed myself. Now, I make an apology to point out the problems to avoid them next time. Sorry, everyone!
- Too many cheaters emerged. Comment 1
- The problems stay in the queue for a very long time bothered contestants.
- B is easy but many contestants misssed the corner case. And C has many corner cases. Comment 1, Comment 2, Comment 3
- The time limit of D is too tight. Comment 1, Comment 2, Comment 3, Comment 4, Comment 5, Comment 6
- Problems are too hard. Comment 1
- The samples are weak. Comment 1, Comment 2
- The contest causes a lot of rage. My heart is broken. (;﹏;) Comment 1, Comment 2, Comment 3
- C>>D Comment 1, Comment 2
- E is AI-solveable. Comment 1
- E takes too much time and F is so easy. Comment 1
There are still problems unmentioned, but they are enough. I take 4 most seriously. Although 2 seconds can be enough for the best solution, some correct solutions are killed, which obey the principle of problem setting. During testing, D was accepted by different solutions and even $$$O(n\log n)$$$ solution can run within 1.1s. Given that, I didn't modify the TL. $If I had set the TL bigger, the contest could reach its expectation.
I'm sorry for the weak sample. The $$$n=2$$$ in B bothering everyone is intended, but I should have put it in samples at CF. But I didn't even realize C has many corner cases. I set $$$a$$$ up to $$$10^{17}$$$ to reduce the diffculty. In the original version, $$$a$$$ could be up to $$$10^{10^5}$$$. Although the corner cases are the necessary parts in the problem, I missed them. Sorry again.
We tried our best to capture the cheaters, and you can point them out on your own. I'm sorry for that. They are easy to find, though.
Indeed, E should have more scores than F, since it takes more time. I have done the wrong evaluation for the difficulty.
I don't want to show CNOI style initially and make the problems easier and easier. I only hoped that problems would be interesting. Some are said to be standard, but I still believe they have the value of thinking. A is easy. B is easy but have corner cases, which is intended. C is not so easy and happens to have many corner cases. TL for D is too tight. Score of E is too low. F is ok but misses the $$$O(n)$$$ solution. I have made so many mistakes even after so much testing. I let contestants down, failing to keep my promise. (T_T)
I will not author problems any longer until I'm mature enough. I'm guilty and carry this regret from then on. I hope my mistakes serve as a lesson. I have let you down. Sorry...
May love persist?
