Auto comment: topic has been translated by 74TrAkToR (original revision, translated revision, compare)

OK, then maybe make the round unrated if the entire community is unhappy with it?

it's alright

thanks for everything you and others do (preparing problems, testing etc)

"You guys put in a lot of effort" shouldn't be the reason this round is rated.

пацаны не извиняются

Now this is all history!

to change problem A at the very last moment

How did you manage to find that some problem was in 1986 Olympiad and at the same time forgot to put pretest of H in oeis?

so please distinguish the effort and the end.please unr this trash round.

guys, downvote this instead of the round announcement. That way the right person's contribution gets decreased. There is no way an experienced coordinator misses 2 (3?) googlable problems, a wrong model solution and accepts tasks like D. he just doesnt care about the quality of his rounds

Where is the apology to marzipan for -142 contributions and a successful top 1 since the end?

it's should be unrated, untested A, wrong G, copypasted H, not enough?

add genshin to statements next time so ppl wont blame ur problems

We asked problem H from other authors and, unfortunately, it turned out to be known.

That is, you know that H is known, and still use it in the round?

I could be happier if it was unrated ...

It is okay knowing you tried your best , Happy New Year !

Poorly written statements, googleable last problem, wrong author solution of the pre-last problem, how could this round stay rated?

Almost everyone is unhappy with it, and I think it must to be unrated.

Dude, you don't just post a blog saying what difficult you've met and all is over. You ARE actually ignoring what you've made to us, and do nothing but saying you're sorry? If it is, then we are way TOO forgiving.

???

So make this round unrated!

You made lots of bad contests even if you tried your best. Isn't that one reason you should STOP coordinating contests instead of continuing coordinating contests?

Problem G was my authorship and there was an error in the author’s solution.

Did anyone submit a correct solution to G, only to have it marked as WA? Are you going to retest G? This seems like it alone would be a reason to make the round unrated, unless you claim that it didn't affect many people...

You think the problems are math. Understand, I don’t like mathematics, but I can solve the problems that are offered to me. There may be other reasons, we have testers for this and they give us all the necessary advice.

I think it's disingenuous to frame crititicism of your other rounds as "not liking math". There are a bunch of authors and coordinators who love putting math problems and they don't get nearly the same ammount of criticism as you do.

Was there no tester on problem G? Is having a second solution not required to hold a problem anymore? I think you should go through some training from other coordinators and learn how to prepare a round before doing any more, given the history of your rounds.

I believe that we will see the history again in the near future.

I'm sure that these tasks is not easy job, but please unr this round. Everyone will enjoy happy year.

Ok let me believe you are caring about your rounds and you tried hard (yeah actually too much hard) for them and other bul***it stuff you said.
CAN YOU EXPLAIN WHY ARE YOU DELETING COMMENTS THAT CRITICIZE YOU TOO??? link

Bro played the victim card. This is all history Lmaoo

Why is he still a coordinator? — Firstly NP problem in round 846, now a mistake in author's solution and plagiarism in one single round

Apology accepted!, now make it unrated? I guess?

unrate pls

What a convincing blog "this is all history".
world war 1, world war 2, covid19 virus & ... is all history too so lets forget them dear people!!!

I wish i could also say Happy New Year but it is not happy until this is rated

Maybe you made lots of efforts. Maybe you do not want such incident happen. But all above can not be the reasons that this round will still be rated.

Imagine how bad history would be if worst round with incorrect problem would be rated.

Crocodile tears!? Is it you?

I'm sorry about the -ve contribution

chill out

I could mash a better contest in a week without knowing solutions for my problems.

chill out

https://mirror.codeforces.com/contest/1916/submission/239626221 Weak system tests as well, this solution is hackable. Make this round unrated. Edit: Sorry guys, it's alright. I missed something.

The last sentence sounds pretty dumb... What do u mean by you "put a lot of effort into it"? Does it seems like a good excuse to pardon your muff?

Will the round be rated or not??

I just hate the problem B, I came up with the idea using half an hour but still don't know why. And C-E for me is just fine, but others i just don't know why. Also, as a Chinese programer, participating this contest until this moment without sleep, expecting gaining some joy from it, but it came out to be an upset result, just feelng painful. Hope next contest could be better.

https://mirror.codeforces.com/contest/1916/submission/239633251 this solution is hackable maybe !

I love googleforces

Why is it rated?

Everyone is unhappy with round(sry, everyone except few people that googled H), and u say this is all history. U guys litteraly took people's 2 hours. Make round unrated cuz its crap.

Everyone is unhappy with round(sry, everyone except few people that googled H), and u say this is all history. U guys litteraly took people's 2 hours. Make round unrated cuz its crap.

This test can hack solutions that received an AC verdict for problem A on system tests that uses int rather than long long. The system tests are weak.

1 4 1 293 879 1253 2023

In problem B , b shouldn't be <=1e9 , because if b can be 1e9 then x will not be <=1e9.

I have sent a clarification for this issue : "How b could be 10^9 with the fact that b is the largest divisor and not equal to 10^9 and x must be less than or equal 10^9?"

And the answer was : "Read the problem statement".

Now enjoy this submission : https://mirror.codeforces.com/contest/1916/submission/239725756.

And try to be clear next time.

"Now this is all history."

Bro pulled a "I'm sorry, but fuck you everyone"

Ходи оглядывайся

why rated if some people couldnt hack and that's an obvious disadvantage?

Someone won't be a setter in 2024, as i can see

To follow up on many of the comments above, I wanted to summarize what I view as some preparation errors in the round and to give constructive feedback to coordinators in the hope that we can avoid similar errors in the future.

In my opinion, the original post (quote below) mischaracterizes why rounds you've coordinated have been viewed unfavorably:

You think the problems are math. Understand, I don’t like mathematics, but I can solve the problems that are offered to me. There may be other reasons, we have testers for this and they give us all the necessary advice.

I believe that (aside perhaps from the arguments against D), the criticism of your rounds is motivated not by the topics of the problems but by mistakes in preparation and problem selection. The coordinator is ultimately responsible for ensuring that problems are prepared well, low-quality tasks are rejected, and rounds are reasonably balanced. (As an example from another round you coordinated, CF round 907 F was not suitable for its position and belonged around the D2D range.) For this round in particular, there were several significant errors, most of which were relatively simple and will hopefully be easy enough to avoid in the future.

Below, I discuss my criticism of the problems in roughly decreasing order of significance.

H: By far the most major error imo; this problem should have been rejected immediately for being too well-known. The biggest problem is that the hardest steps can be bypassed immediately by Googling; this page is easy to find and gives a formula that is relatively straightforward to implement (at least, once you're willing to assume division by zero modulo 998244353 won't be a problem). Perhaps this problem might have been suitable for an offline contest, but it doesn't fit well on Codeforces, especially not at position H.

G: The error in the judge solution here is confusing to me. Was there not a tester solution, or did the tester's solution have the same bug? The obvious fix here is to hold strictly to the requirement that there should be multiple independent tester solutions (and these solutions should be rerun when limits are changed to ensure correctness).

A: Pretests excluded int vs long long. Of course, there's a school of thought that suggests pretests should be weak and allowing such hacks is a good thing, but at this point the majority of the community seems to prefer strong pretests, and in general it's assumed at this point that int vs long long is always included in pretests. Indeed, the Codeforces problem preparation rules specify that a test against integer overflow should always be included in pretests. This was probably an oversight that could have been avoided by preparing this problem further in advance rather than switching to a new task at the last minute.

F: Another problem that's much too easy to Google. Searching "partition biconnected graph into two connected subgraphs" got me to a StackOverflow comment about st-numbering, and googling st-numbering gave me a free solution.

E: A 1s time limit seems unnecessarily tight to me. In a problem like this where many contestants will use lazy segment trees and sets to achieve solutions of the desired n log n complexity, the time limit should be raised so as to be insensitive to the constant factor (accidentally accepting some n log^2 n solutions doesn't seem like the end of the world to me). I think 3s would have been more suitable.

The last few comments below are less significant; one is a matter of taste and the other is a minor clarification to a statement. Neither meaningfully harmed my experience in the round.

D: In general I don't like problems where the easiest solution path is to write a brute force and notice a pattern on small cases. This is a matter of personal taste, and I don't think this problem is objectively bad (I would not have complained about it if there weren't many other issues with the round).

B: The statement could have been made more clear by explicitly stating that a and b are the two largest divisors of x other than x itself.

As a result of these issues, and particularly because both of the problems relevant to my rating level (F and H) were largely tests of Googling ability, I had a negative experience in the round (despite gaining rating). Below, I suggest some specific ways to avoid these issues in the future:

1. Spend a few minutes on Google trying to find solutions to proposed problems. If a major component of the solution can be found online easily, the problem should be rejected (this applies to both F and H; I found helpful results for both of them within my first two Google searches).
2. Set a deadline to prepare and finalize all problems several days before the competition, and do not make major changes to the problems after that time. Afterwards, do a final runthrough to make sure authors' and testers' solutions agree, pretest preparation rules are followed, etc. (This likely would have prevented the issues with A and G. My understanding is that many rounds with other coordinators have also changed problems at the last minute, so this suggestion applies to everyone, not just to you.)
3. Set generous time limits when contestants are likely to submit solutions similar to the intended one with slightly higher constant factors. This would have avoided using a tight time limit for E, and might also have prevented some FSTs in your previous rounds.

Obviously, these guidelines are not sufficient to guarantee perfect contests, but I believe that following them would have prevented a lot of the negativity surrounding this round and several past rounds you've coordinated.

In any case, thanks to the authors/coordinators for their efforts organizing the round. Obviously, the contest was not as successful as the community hoped it would be, but the organizers still undoubtedly put many hours into devising and preparing the problems, and hopefully everyone involved can build from this experience in order to propose more successful competitions in the future. (Also, I should emphasize that the contest was not a total failure: I quite enjoyed C, for example, and aside from the preparation issues noted above, A, B, and E were pretty good for their positions.)

Finally, an appeal to the other critics of the round: let's stop downvoting/flaming the authors, please. Most of the setters were preparing this as their first Codeforces round, and as a result mistakes are inevitable (preparing a round is obviously an incredible amount of work and nobody is going to get it exactly right on the first try without outside support). Rather than blaming the authors, we should thank them for their effort; then, we should better organize round coordination so that these errors are caught prior to the start of the round.

Definetely the most controversial contest of the year.

Don't bother to apologize. Just quit.

Almost 4000 downvotes and still isn’t unrated? Seriously?

It means there is a bug in the standard solution of problem G, right? Is it fixed now?

The problem is not to unrate or not. If we just simply unrate rounds and rounds, and doing "You are wrong. Here's why" to keep on rating rounds and rounds, we will just be like using mosquito swatters, showing dissatisfied attitude only when we participate in a round and after that.

To be honest, I personally don't want this round to get unrated (as my high rating increase), but I have no objection to unrating it because this is not my real programming level at all. But it reflects, that, you are just casually picking problems, casually preparing problems, casually immersed in your own feeling about how good this problem will be appreciated after contest. As a result, the topped participants on the list (but more than the top, the situation can be seen all over the list) are casually selected.

I have given more than 10 problems before (I estimate that 2500 people in all solved at least one of them) on some website and I can give some suggestions about it. At the first stage you were in fact giving shit problems. You saw a conclusion somewhere, or you discussed a lot of situations, and then just used it as your own problem. However, when you some time came up with a better problem, you will understand the feeling of what a problem recognized good is based on and whether an approach is interesting. Motivated by this, you will produce much better problems (it also requires something like inspiration and your ability to make hackive datas before contest). You can rate your own problems with quality (but better not difficulty, I have never predicted my problem as hard as what contestants felt when facing it). Thus there will be a cooperation between problemsetters and testers, which will help each other if it goes into a beneficial cycle ———— help when rating problem difficulty in thinking of a solution and implementing, and even worse, if your problem is an NP-Hard or something like that.

So I'm wondering, if all your problemsetters are at the first stage, giving just shit and average-leveled problems, and none of the testers have ever taken notice of it? Or as a coordinator, are you simplying ignoring all the feedbacks and believing you have the sharpest eye in the world? I want to know your time spent on solving problems D, E, F, G, H1 and H2 and I wonder if you really have the ability to solve all the problems without referring to the editorials, and even rate the problem as where it will be put? Come on bro, from several past experiences, I think you should learn. Don't just be an ostrich which sticks its head to the sand and avoid meeting problems and leave your butt to be wiped by Mike! And if your coordination are so perfect, why do you insist on changing A before the contest? Have you ever distinguished what would be the main problem not checked and may happen during contest?

btw, I am very confused why there is such a long queueueueueue for even div 1+2 contests in codeforces. Are coordinators' efforts wasted in shit & non-original & not-even-cared-by-problemsetters problems like yesterday? Yes, I use this word to stress, not only you, but also the problemsetters, don't care about the feedbacks and even have no face-to-face communication with others. Have you experienced writing a 20KB generator and stay up late to modify the datas? Have you experienced the joy after an entire contest when seeing different solutions from backstage pass (or not) exactly as intended? And, you, as a coordinator, should always remember, with great power, comes great responsibility. If you don't care, he doesn't care, now it will be us contestants caring about our rating.

If this comment is deleted due to violation to some rule, I will definitely not make a second comment on this issue. Good Luck, 74TrAkToR.

So,why this contest is still rated? Wrong G,copied H. I also think D is boring. Do you think brute force is interesting? I spent much time to think about maths. Some people even passed H1&H2 just by OEIS. It's really unfair because some people can't cheat themselves,but the others can. And people who cheated themselves got higher rating instead. And this problem is also well-known in university students. I can't believe all the testers didn't notice this problem. So,how did H pass?

So,why this contest is still rated? Because you are 74TrAkToR? I heard of this contest before,everyone who knew something about it told me not to participate in the contest. I myself also had been f**ked by you before. I realize your contest isn't worth to trust now.

My biggest mistake is not to trust my friends but to believe you wouldn't f**k us any more. And you? You don't have any mistakes because you are 74TrAkToR. You messed up a lot of time before,and you messed up again at the end of 2023.

So why did this round rated?

Please, learn from other coordinators about how to coordinate a round well. And, things like changing problems can be done much earlier, don't delay it to the last moment. This is not history. If you don't make any changes, the history will only repeat itself.

Since testers have already indicated some problems in feedback, why are you ignoring these issues as coordinator? I don't think this is a round "put a lot of effort". And this round is not your first trash round, you never seem to take it seriously.

It's RATED??? What a big joke!

You are wrong,here is why.

What is history ? It was just yesterday! I couldn't even solve your last moment problem A.

It's okay bro, mistakes make us better !

FH are all original questions, which is not good

It shoud be unrated. I feel like I wasted a lot of time because of this round. And...... where is Tutorial ??? This is a bad ending of 2023.

1916F - Group Division

Why is hack gets Unexpected verdict

Is there something wrong with the std ?

Good morning. Is it still rated? :D How can I change my voting???

You are wrong. Here's why.

You did mistakes and wasted our time ,ok, maybe we will forgive you for wasting our time , but why this round still rated ! Why we should pay for your mistakes!!