Hello CodeForces!
I would like to invite you to participate in a testing round for a training contest prepared for an Olympiad camp.
The contest was created to replicate the algorithmic skills and approximate difficulty of last year's Camp 1 end-of-camp contest. The problems have been recreated, with some modifications, especially to the constraints and story.
Since I prepared the contest by myself, I would really appreciate having some testers before it is used in the actual camp.
The testing round will start on September 18, 2026 at 12:00 (UTC+7) and will remain open for three days.
Everyone is welcome to participate!
I would especially appreciate feedback regarding:
- unclear or confusing statements
- weak tests
- unintended solutions
- approximate difficulty of each problem
The contest is intended for students attending their first Olympiad training camp, so the goal here is to get feedback.
If you find anything strange or have any suggestions, please leave a comment or send me your feedback.
If you are a student you may attempt these problems for practice.
Please note that only C++ submissions are allowed. The contest also uses strict output checking, so leading or trailing whitespace is not allowed in the output.
Things I don't like about this:
No $$$t$$$ test cases
I HATE THIS: "leading or trailing whitespace is not allowed", me: literally why, why can't I just print an endline at the end T-T
array input is very weird, why not on a single line
No notes
I'll add more while I solve the problems
Fair. It’s supposed to be a reconstruction of the original contest, and their grader compares output character-by-character, so I kept that behavior too. The array input format is unusual as well, but I’m trying to mirror the original style as closely as possible for the experience.
Just change the checker bro T-T, and also, why is the original contest like this, I think no one ever does this, this doesn't even do anything to the solution, it just makes participants' lives worse while solving this
For camp 1, they use the professor checker which is this and then in camp 2 this year they will finally use CMS.
I do agree that it makes the participants' job much harder. Since now you aren't just debugging the algorithm, you're also debugging the output format. Many students feel this way too, not just you.
You might have to ask the professor why he made the checker this way, it could be for simplicity cause the frontend also looks very barebones.
then use cms or polygon or whatever for camp 1
It's hard to convince those contest authors generally since it's easier to use the same thing. They wouldn't need to learn a new system.
nice contest, especially since you made it yourself, my feedback:
(i == (int)ans.size()-1 ? "" : "\n", in which if the answers are separated by whitespace you can just" \n"[i == (int)ans.size()-1], but the current one is still okIt is actually easy, idk why it is the last year of camp 1 but it is still easy
It is always a pain reading those stories and trying to understand them
extra lines are whitespace
Thanks for your feedback!
I didn't actually author the problems. I modified the problems, I only prepared them on polygon.
The reason I didn't specify extra lines but just whitespace is because extra lines are whitespace.
Camp 1 at least for my centre, teaches basic algorithms and STL so it can't be too hard. Last year, out of 70 students they would select 30 to move on to camp 2. The lowest known qualifying score is around 110-120/600.
If I do write a contest myself the checker would definitely allow whitespace.
?????? So people in the camp can just read this blog and get the problemset?
Well, technically they could, but I think the chance of one of them finding this blog and practicing this exact set is pretty low, especially with finals coming up. It’s mainly to give them a feel for the contest environment. The difficulty is similar to last year’s Camp 1 contest, though I changed some constraints so a few old solutions wouldn’t pass here.
If this is really meant to be an in-camp contest, you have already leaked it. I suppose this is more of a "see how people feels about the problem"?
Yeah, pretty much. The main purpose is to get feedback to see if the statements or anything can be improved. So when it's used it goes smoothly.