Maybe this applies to other regions too, I'm not sure. But in the last two weeks, CodeForces has stopped loading for me without a VPN.

I live in Crimea. But everything was always fine before.

Has anyone else encountered this?

When will the rating rollback bug that caused performance to decrease in recent contests be fixed?

My rank has improved, but my performance has decreased.

The last problem was sent 2 minutes before the end of the competition! It was solved by only 2 teams in the world. turmax, fastmath, LeoPro

Also congratulations to all the other teams for their efforts and hard work!

C. DIY (ICPC2024-2025)

Let's say we can choose 4 points to make a rectangle. Let the numbers defining the coordinates be arranged in ascending order: a, b, c, d.

Then I have a question. Is there any INTUITIVE proof that it is advantageous to take exactly

xmin = a

ymin = b

xmax = c

ymax = d ?

And not, for example, as I thought at the very beginning

xmin = a

ymin = b

xmax = d

ymax = c.

I have already done the MATHEMATICAL proof, but now I need the INTUITIVE proof.

https://mirror.codeforces.com/profile/ewtferwgfvr

https://mirror.codeforces.com/contest/2128/submission/331119770

"AI assistant" in his comments, and he is holding top200. And there are at least 10-15 people like him in the top 300, damn

https://mirror.codeforces.com/contest/2033/problem/C

I tried to solve this problem and didn't come up with anything good, except a huge non-working solution. I looked at Editorial — I still didn't understand. I went to ask ChatGPT — I still didn't understand, it was written too briefly. I spent 5 hours and only came to an "intuitive" understanding, where I agree with the facts because I can't find a counterexample, but not because it has been proven that the opposite does not exist.

Please help me prove this greedy. I can't come to terms with it until I fully understand it :(

I've been facing a problem for half a year now, which probably few people have, but if anyone has, I would like to get some information about it.

Many people are now making a mistake in learning — if they don't understand the solution to a problem and go to look at Editorial, they barely delve into it, but simply rewrite the code and send the solution. I have the exact opposite problem. If I don't understand something, I start digging into it until I understand it 100%. I mean REALLY 100%. As long as I'm faced with the question "why does this work?" I won't send the task and won't be able to do other things in my life. It looks like an addiction. And probably the biggest problem here is that sometimes it comes to axioms that simply exist and it is simply impossible to dig deeper into why this is so. In this case, I still continue to ask the question "why is it so and not otherwise", it can come to philosophy, and I will just sit for 5 hours trying to understand this, turn to DeepSeek, turn to my teachers. And so on until the "moment of insight" comes. When something clicks in your head, and the epiphany "SO THIS IS WHY IT WORKS" begins.

I consider this a problem because one simple task can get you stuck for a day, or even several.

The contest ended almost half a year ago