Hello codeforces,

It has been brought to my attention that a certain myst-6, the author of today's esteemed div2, spoiled part of the contest to his friends.

This is truly shocking news, and I expect the community to take action against this great injustice.

I don't know what the significance of this number is, or why it's in about 300 submissions to yesterday's problem F which all either got hacked or FSTed... does anyone have any ideas what 855401101 stands for?

279564452 279584685 279589992

what on earth is going on here

See this... How the hell does creating a 1e5 ish sized array 1e4 times pass?? I think he's probably hacked Codeforces or something...

This contest had problems. A,B and C were suboptimal.

A and B were fully-GPT solvable. Paste statement into GPT, solve and done.

My friend got within the first 20 submissions on B with GPT despite submitting a wrong answer on both A and B. I got A and B within 6 minutes without GPT but clearly it could have been even easier with GPT. This can discourage new participants on codeforces from actually trying to solve the problem, when it’s simply easier to paste the problem into GPT and get a quick solve. Problem B was around 600-700 rating difficulty and so anyone below this rating would have experienced a rank increase by just pasting the statement into GPT and submitting. In fact, the problem is worse than this. Since C’s difficulty was around 1465, it was possible to get a 1430 performance from just A and B, so in this contest GPT would get 1430 performance, significantly above the average participant. This shows how codeforces is falling to GPT, and how much harder it is getting to write problems that cannot be easily solved by GPT. This however is a necessity to keep contests interesting for all participants.

The third problem was an interactive. It was a nice problem, however it is misplaced in such a contest. Many participants (myself included) have struggled severely with the interaction, and what is more, on the announcement it did say there would be an interactive problem, but in small, non boldface print. It should be a law for any interactive problem to be mentioned in 48 pt size bold underlined italic text to ensure that it is not missed, and to ensure that this problem is accessible to everyone.

So, I joined today's round with pretty high expectations, because I enjoy trying to speedsolve div3's and 4's However, the problems today were truly awful and rife with issues.

Let's start with Problem A. It's probably the easiest problem ever seen on this site. As soon as the contest began, submissions poured in by the thousands, clogging up the queue. It was chaos. I ended up submitting C and D before even finding out if my B submission was correct.

Speaking of Problem B, it was a nightmare of unclear instructions, leading to a flood of Wrong Answer submissions from thousands of people. "For a better understanding, please check the notes section." Seriously? That’s just pathetic, and so lazy...

Surprisingly, Problem C was decent, but Problem D? An absolute disaster! The weak pretests allowed a flood of grey Python/C# users to fail miserably when my braindead brute-force hack of:

1
?????????????????????????????...
abcdefghijklmnopqrstuvwxyzabc...

caused a whole page of submissions to topple like dominoes. And don’t get me started on the terminology — it's "contiguous subsequence," not "continuous." Google could have corrected you, for crying out loud!

Then there was E. Another nightmare with weak pretests and ridiculous O(nt) solutions passing (and of course, the legendary stils somehow using some kind of black magic to withstand about 300 hacks of a nonsense O(nt) solution, including about twenty from my friend myst-6). Of course, it is even in the contest creation guidelines to ensure that "stupid bruteforce solutions" don't pass, but I guess the rules maybe didn't apply to today's contest? Lord knows.

And just when I thought a good problem came up, one I actually rather enjoyed solving, I get a message straight after the contest from a certain AG-88301 telling me that GitHub Copilot solved this problem with no input from him???? I thought it was common sense to run problem statements through generative AI to make sure they aren't instantly solved, but I guess not for today's problem writers.

And then after all this, we're hit with just about the most standard ternary search question in existence? It's not even funny at this point, it's just embarrassing.

Rant over. I hope those who deserved rating got it. In a perfect world, low-quality contests like this wouldn’t happen, but in our flawed reality, it’s just another day.

Just when I wanted to try and figure out what the whole barrage of hacks was about in the last div3 I discovered this:

samin07 is hacking their own deliberately bogus submissions on their alt account olympiad2027... and it's obvious that samin07 thinks they will get rating points out of hacks, but they won't in a div3!

Seems like a silly way to out yourself as a cheat...

update: yes please keep downvoting me, I've got the third most downvoted comment in all of Codeforces and it's a badge of honour

There have been like hundreds of blogs about people finding blatant cheaters on this site, thought I'd add one...

https://codeforces.me/contest/1926/submission/247357457

at least try to hide it please...