Suggestions to minimize any doubt in the legitimacy of your recording:

1. Have an active timer running to make sure no editing was done to the recording
2. At the start of the record open display settings and show that only one monitor is connected, also move the mouse pointer to the edges of the screen
3. Open task manager and show all active processes
4. If possible make your mobile always visible in the background
5. I don't expect (or recommend) you to do this one, exhaust all AI tokens in Gemini, GPT and Claude in the recording before the contest starts.

Another thing, Even if your performance is less than master (Expert performance for example) I think it'll still be enough evidence that you don't cheat because even masters can have Expert performance if they're having a bad day.

I gave up my spot to focus on the IMO.

Also, Tyx2019 will FC IOI using Square Root Decomposition on Cache!

In my blog, I provided clear evidence that you submitted a solution identical to another user, __Midoriya__. Whether or not that account is your alt does not matter — copying another user's solution is still against the rules.

The other points I mentioned were additional evidence suggesting that you may have cheated. If you believe those accusations are incorrect, you can still be banned for copying the solution of another user, __Midoriya__.

I hope MikeMirzayanov and KAN will act quickly, as this Codeforces rule-breaker keeps yapping everywhere.

3 days and still nothing...

Do you deliberately want to get a negative contribution?

i dont know why these cheaters keep trying to defend themselves when anyone with a brain can just look at their submissions and instantly tell this isn't legit...

aufannn will win Gold IOI 2026!

Wouldn't it make perfect sense to automate cheater banning? I think that most people being able to vote would result in a few disasters, but for example allowing only people with rating at least something to vote should do, right? If not voting about banning someone, but even about suggesting these people for a check, I think that if admins would be able to enter a profile of a person and see that for example "95 out of 100 grandmasters voted that this person is a cheater", it would significantly help with cheater detection, right?

In most online games (even in the calm ones, like on chess.com or something) you can report people, maybe cf should have something similar?

Bosnia and Herzegovina team:

• Mirza Bušatlić (BigBadBully) 1st time at IOI, 1 attempt left
• Faruk Demirović (glupan), 3rd time at IOI, 0 attempts left
• Farah Demirović (farica), 1st time at IOI, 0 attempts left
• Adnan Osmić (naneosmic), 2nd time at IOI, 1 attempt left

I definitely didn't comment that for that reason, and I am definitely not commenting on this for this reason.

This is an interactive problem unrelated blog.

Let me bump this once, maybe was simply skipped.

You're using AC_Auto_Machine https://atcoder.jp/contests/abc419/submissions/68567938 25/08/16 with C-style arrays.

Then on 25/11/22 https://atcoder.jp/contests/abc433/submissions/71165721 you used SuffixAutomaton with vectors.

Very AI-ish variable names in https://atcoder.jp/contests/agc077/submissions/74532136 and https://atcoder.jp/contests/abc432/submissions/70983076 (different from your other code's short variable names)

Unnecessary change: https://atcoder.jp/contests/abc432/submissions/70982123 to https://atcoder.jp/contests/abc432/submissions/70983076

1.

int n;
int a[N + 10];

to

int n, a[N + 10];

2.

        double need = avg - mn;
        double over = mx - avg;

to

        int need = avg - mn,over = mx - avg;

If you say you're formatting code, why not add a space after ,?

You're a legit(probably) player in abc428 and before contests. Example: https://atcoder.jp/contests/abc428/submissions/70260203 using your unique Code by zzx.

Then you deleted this unique identifier, and every code of your next contests seems AI.

Being good in offline contests doesn't mean you're a legit player in online contests. If you think using AI for training can improve yourself, just continue; but do not participate contests using AI, violating the platform's rules, bringing unfairness to actual legit players.

I don't know if China's offline contests have strict invigilation but I hope so.

Note: suspicion only.

I think C.

much more than xxx is good, it's a comparison. much than xxx is grammarly incorrect.

and if choose C, it equals to "My son is expecting the holiday much more than we are expecting." Valid comparison.

If choose D, it's comparing "my son expecting holiday" to "we"; which is mismatched.

If choose B, "much as we do" isn't logically correct. If you use "as much as we are" it'll be correct.

Note: "much more than we do" is also incorrect. is aligns with are not do.

This site is for CP...

Based on his ties to Epstien, Trump is very relavent to CP

AI generated text too

If I understand correctly and both "systests = pretests" and "Don't worry, if you tle on systests, it will be rejudged." hold, then the only reason to resubmit is because of being afraid of hacks, right? I'd say then that the number of resubmits would be way less if this information would be public (assuming that they are true).

To show that the fact that this is not public really influences results and performances, here are some statistics about all current LGMs — for each of them I've checked in how many rated rounds (during the last 3 years, as I don't know for how long it's been the case) they had at least one submission judged as "skipped":

1. Benq — 0 out of 30
2. VivaciousAubergine — 3 out of 21
3. jiangly — 0 out of 61
4. Kevin114514 — 0 out of 44
5. maroonrk — 0 out of 66
6. strapple — 1 out of 29
7. Radewoosh — 9 out of 48
8. tourist — 2 out of 60
9. turmax — 5 out of 39
10. Um_nik — 0 out of 38
11. qiuzx — 4 out of 30
12. heuristica — 3 out of 14
13. ecnerwala — 5 out of 57
14. jiangbowen — 7 out of 46
15. ksun48 — 4 out of 70
16. Ormlis — 1 out of 57
17. Otomachi_Una — 0 out of 30
18. squareOf105 — 0 out of 8
19. jeroenodb — 0 out of 38
20. BreakPlay — 0 out of 5
21. PEIMUDA — 1 out of 28
22. StarSilk — 1 out of 64
23. maspy — 5 out of 73
24. Szoboszlai10 — 0 out of 12
25. stepanov.aa — 2 out of 12
26. Nachia — 1 out of 42
27. potato167 — 1 out of 73
28. Maksim1744 — 1 out of 29
29. hos.lyric — 5 out of 65
30. Z-301 — 0 out of 13
31. Dominater069 — 1 out of 51
32. Rinne_qwq — 0 out of 5
33. arvindf232 — 0 out of 22
34. crazy_sea — 2 out of 31
35. Elysion — 0 out of 14
36. pigstd — 0 out of 6
37. Kapt — 1 out of 30
38. PCTprobability — 3 out of 22
39. Petr — 3 out of 36
40. xuanxuan001 — 1 out of 53
41. dog_of_Nesraychan — 0 out of 41
42. makrav — 0 out of 44
43. antontrygubO_o — 1 out of 52
44. yuto1115 — 2 out of 54
45. NanYan — 0 out of 14
46. peltorator — 4 out of 39
47. tiger2005 — 1 out of 26
48. SleeplessSouris — 0 out of 19

It varies from not resubmitting at all to resubmitting in more than 20% of rounds. Not sure if I'd call it a skill issue though.

The conclusions seem rather clear (at least for me), but I'm still hoping for some official comment on the matter, as it's hard to simply accept those, for example because of the situation mentioned in UPD.

As a writer & tester, I highly recommend this contest with plenty of data structure problems.

In one of MIDORIYA_'s comments:

As for the variable names, I intentionally make my code more readable sometimes. A lot of juniors and friends use my solutions as references while training, so I prefer leaving the code documented and understandable instead of keeping variables named like puzzles nobody can read.

Changing names like 'cur_sum' to 'current_sum' or 'vals' to 'values' is literally just improving readability. That is not evidence of anything suspicious.

Even I can make a better excuse lol.

It's even faster just to build prefix sums to figure out where each element would go in a flattened array of all the vectors. I built V at the end in the code, but you can probably just use std::ranges as well to avoid another copy (although that's a small part of the runtime). It runs in about 0.9s on my PC, while your optimized solution takes about 1.15s. If you don't build V then my code takes 0.77s.

#include <bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int N = 1e6;
const int Q = 1e8;
vector<int> V[N];
int cum[N + 1], x[Q], y[Q];
int ord[Q];
signed main() {
  for (int i = 0; i < Q; i++) {
    x[i] = rng() % N;
    y[i] = rng();
    cum[x[i]]++;
  }
  int a = 0;
  for (int i = 0; i < N; i++) {
    a += cum[i];
    cum[i] = a - cum[i];
  }
  for (int i = 0; i < Q; i++) {
    ord[cum[x[i]]++] = y[i];
  }
  for (int i = 0; i < N; i++) {
    int s = i ? cum[i - 1] : 0;
    V[i] = vector<int>{&ord[s], &ord[cum[i]]};
  }
}

I will let you know tommorrow.

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I think someone in codeforce adminstration have a very bad habit of procrastination.

I like data structures.

As a tester, I also highly recommend this contest with plenty of data structures.

wx03 and aufannn will win IOI 2026!

The correct option is B. more than we are.

Here is why:

When making a comparison, the auxiliary verb in the second part of the sentence needs to match the verb tense used in the first part.

Your sentence: "My son is expecting..." uses the present continuous tense, so the matching verb for "we" is are ("...more than we are").

If you wanted to use option A, you would need to change the first part of the sentence to the simple present tense:

"My son expects the holiday much more than we do."

orz bitset

what are you saying? please say in english

375830571 Claim about being KOI silver is probably lie.

Just make a graph on this and do BFS with checking that the day/night properties hold for visited cells. Why wont this work?

While the subject of your concern may indeed affect chances winning macbooks, I think you're missing a more important problem, which also affects your chances for material prizes.

NanYan in your LGM list is very likely a cheater. User with similar nickname who scored high places in rounds was banned on AtCoder.

XVIII is a cheater who scored even higher places and even won one Div 1. He also scored 3rd in Spectral::Cup 2026 Round 1 (Codeforces Round 1094, Div. 1 + Div. 2), and despite numerous blogs calling him out, according to this admin's comment https://mirror.codeforces.com/blog/entry/153179?#comment-1362536, they contacted him to give instructions to receive a prize for 3rd place.

Good news is that XVIII is banned now. Bad news is that he was only banned after about a month after he reached LGM, and after he could've received the material prize, and there are other LGM cheaters who are not banned.

Thank you for explaining. I'm just who wants a fair competition environment, and if you did not cheat, continue improving yourself and make greater progress. You're already a red coder, one of the strongest coders in Codeforces.

Thanks for 5 skipped contests!

Your code indicates potential AI-usage behavior.

https://mirror.codeforces.com/contest/2229/submission/375803503 -> What's the function of abss? Every red C++ coder knows abs function which is more robust than your manually-implemented version.

Also in your practice (https://mirror.codeforces.com/contest/163/submission/375225747) you used floor instead of writing one yourself.

In your practice https://mirror.codeforces.com/contest/679/submission/375291831: write segtree not in a struct; using C-style arrays.

In your contest https://mirror.codeforces.com/contest/2229/submission/375847377: write lichao tree (a variation of segtree) in a struct; using C++-style vectors.

Also many of your codes have AI-ish behavior (AI-favored variable names), but I'm not listing them.

Your AtCoder account (https://clist.by/account/MCYYDS/resource/atcoder.jp/) is also banned.

Note: This is just a suspicion.

why nobody downvote me?

Ok, this is gonna be good.

So, 3 things:

1. You are a ragebaiter.

2. You have no shame.

3. You are incredibly stupid.

I'm 99 percent sure at least 2 out of these 3 are true, though i do not know which.

Anybody who attended more than 2 contests would immediately understand that you are not a legitimate competitor.

It's actually so sad that even your comment is LLM generated, but fuck me for arguing with a literal bot I guess.

Thanks for all your efforts for keeping the site clean, Headquarters. Although it's becoming incredibly apparent said efforts are just not enough...

Problem source? </s>

If You can get the roots:

1) Just* divide your original $$$P(x)$$$ by $$$(x-x_{root})$$$: $$$P(x)=(x-x_{root})*Q(x)$$$, repeat getting roots and factoring for $$$Q(x)$$$

$$$*$$$ Terms and conditions apply if the root is approximate (You've mentioned calculator)

2) If $$$x_{root}$$$ is a repeated factor of $$$P(x)$$$, then it will be a factor of $$$P'(x)$$$, more formally: if $$$P(x)=(x-x_{root})^2*Q(x)$$$, then $$$P'(x)=2(x-x_{root})*Q(x)+(x-x_{root})^2*Q'(x)=(x-x_{root})(2Q(x)+(x-x_{root})Q'(x))$$$

Similar for higher multiplicities/higher order derivatives of $$$P(x)$$$

aufannn and wx03 will win Gold IOI 2026!

How can you prove that you "competing in ICPC-style contests like the ECPC where I achieved good standings"?

UPD: A friend of mine told me that "btats said he participated in the past years in the ecpc and somethings and got high ranks , he can't prove that as that's his first year in the uni so he didn't participate in anything yet , acpc teens he just participated one time and didn't qualify or got any ranks , same for eoi he participated only one time and didn't make any rank he is just using that as an excuse to say he is a pro but that's not true at all". If you cannot provide real evidence, then it only makes your claims look false.

Actually I can answer these question.

When I first started learning information competition, one of my teachers told me that the abs function in C++ would encounter errors when passed a variable of type long long. Therefore, I developed the habit of defining my own abs function. I often name this function abss, which you should be able to find in my other codes.

I have recently been learning to use vectors, because in my previous understanding, defining non-global arrays is unsafe, and vectors can address this issue.

In Round 1100, the Li Chao's Line Segment Tree I used for Problem G appeared in a mock competition that morning (my time zone is UTC+8). I used it when revising this problem after the competition, saved it, and made it one of my data structure templates. If you know classmates who participated in the same mock competition as me, you can ask them about it. I recall that Codeforces allows preparing some templates before a competition. If this violates the rules, I apologize here and apply for withdrawing my scoring for this round.

Regarding the ban from AtCoder, my understanding is that it was an accident. After the competition, I inquired with my friend about AtCoder's appeal channel and lodged an appeal. However, the response I received only stated that I had violated the community rules, without specifying which rule I had specifically violated. To this day, I still don't know which rule I broke.

Your skepticism is indeed reasonable. It does seem like my growth rate suggests cheating, but I have been studying information competition for 4 years. If you have any other questions or find any violations of Codeforces community rules, please let me know. Thank you

010-Miras.N-2027 , 010-Miras.N-2027 and 010-Miras.N-2027 are obviously cheaters.

My son is expecting much more than we do

B sounds more natural to me, since the first part is "My son is expecting" and not "My son expects" (in which case I'd say A).

I agree that B is definitely correct.

To give a similar example that perhaps better illustrates the mechanic, consider the sentence "I like to do Codeforces, AtCoder, and to do ICPC." This clearly violates parallelism (it is both objectively incorrect and sounds wrong), as "AtCoder" is a noun and "to do ICPC" is an infinitive verb. Either "I like to do Codeforces, to do AtCoder, and to do ICPC" or "I like to do Codeforces, AtCoder, and ICPC" would be proper sentences, as the former is of the form "I like {infinitive, infinitive, infinitive}" and the latter is of the form "I like to do {noun, noun, noun}," both of which satisfy parallelism (the latter is more natural in my opinion since it's more concise, but both are fine).

The example in the blog uses the particle "than," which similarly mandates parallelism. The sentence "my son is expecting the holiday much more than we do" is of the form "my son {present progressive verb} much more than {present indicative verb}," which is incorrect. The sentences "my son is expecting the holiday much more than we are" or "my son expects the holiday much more than we do" are both correct, as the former uses only present progressive verbs, and the latter uses only present indicative verbs.

1952D - Are You a Procrastinator?

Bro to be honest the paragraph you wrote me here is also AI-generated!Also the — sign from AI.

If you are using AI , then don't use in on contest , if not then just do your work , you have to be loyal bro!

What an amazing blog! we want more like these. Whomever I share it with, loved it.

However could you also explain the reason/proof behind the nim-sum being 0 is same as empty game state?

I think problem F is very good, and I would like to share my solution, which seems to be different from the editorial.

One of the main ideas is greedy, i.e., we stop as long as current state satisfies the requirement. The other one is as follows.

For instance, given 19 11 12 13, what should we do with 19? The process wokrs as follows.

19 11 12 13 -> 18 12 12 13 -> 18 11 13 13 -> 18 11 12 14

One can see that, the result is just like we decrease 19 and increase 13, while the total cost is 3.

Then, we go on with

18 11 12 14 -> 17 12 12 14 -> 17 11 13 14

which is again like that we decrease 18 and increase 12, with cost 2.

After one more step we would get

17 11 13 14 -> 16 12 13 14

So, the total process is 19 11 12 13 -> 16 12 13 14, with cost = 3 + 2 + 1 = 6.

We continue this and will get 16 12 13 14 -> 13 13 14 15, with cost = 3 + 2 + 1 = 6, and totally 6 + 6 = 12.

Finally, we have 13 13 14 15 -> 12 14 14 15 -> 12 13 15 15 -> 12 13 14 16.

Note that in fact, we can directly get 19 11 12 13 -> 13 13 14 15 with some simple calculation, which saves the time complexity.

By enumerating the array from right to left and implement the above method, the problem can be solved.

Europe, Switzerland, ETH Zürich, Ctrl+Alt+DelETHe: VesselinMarkovich, jumpmelon, and Tudy006

Today is not April 1st

France:

• Raphaël Pons (raphaelp) — 3rd time at IOI, 1 attempt left
• Hao-Yuan Jiao (kaltspielerhy) — 1st time at IOI, 1 attempt left
• Daniil Jarykaou (dssfsuper2) — 1st time at IOI, 1 attempt left
• Joachim Bienvenüe (jbn8) — 1st time at IOI, 1 attempt left

whatever you say man

good way of thinking

No problem! I also got a contest of mine here: https://mirror.codeforces.com/blog/entry/150018

You should have added "For each index $$$i$$$ you can choose to add $$$a_i$$$ to $$$c$$$ or $$$b_i$$$ to $$$c$$$", right?

Edit: Ohh, sorry, it was at the bottom of the problem, I didn't see it, please move it up to the main section, I thought it was some random story and didn't read it :)

Looks like he is a big fan of Donald Trump.

Good Question Dude

it is also funny that how you are defending your stupidity. how fast are you to be able to solve C in 9 seconds and then in one 1 minute you solved D in last div2.

WTF https://mirror.codeforces.com/contest/2229/submission/375836893 is that bruh

Get better at problem solving!

Just get better in problem solving in general

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?

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might you not mind sharing the contest link

can you give a link to the problem?

it's on my teacher'OJ ,so if u dont have a valid account , u cant access this

sorry!

He got rolled back

One thing that I have noticed in general is, when the idea you are thinking has a very bad implementation, that might not be the intended solution, because most questions have intended solutions based on 1 or 2 ideas. If you feel your way of thinking is clean enough, that is when you implement the solution

bro is cheater. How I didn't notice it from the beginning. I thought you were above of this habit.

Can you add the macedonian OI problems(found on mendo.mk), and the Croatian TSTs (the ones labeled Izborne Pripreme on QOJ)

I number of fireworks

|B|*3^|A'|

why is 3 here for estimate for A' for not-optimized algorithm?

System MikeMirzayanov I received a coincidence warning for my submission 375835571 on problem 2229F, with submissions 375817492 and 375828452.

I would like to clarify that I do not know these two users and I did not share my code with them, nor did I receive or copy code from them during the contest. I also did not use any public online IDE or paste service that could have exposed my code.

My solution was written independently. The idea and implementation for this problem are relatively simple and standard, so I believe similar code structure may naturally appear among independent submissions. In particular, the main logic does not rely on any unusual trick or custom implementation that would indicate copying.

I understand that unintentional leakage is also considered a violation, so I am providing this clarification here. If needed, I am willing to provide any additional details about my solution process.

Learn to generate random tests and write code carefully and clearly (avoid overflow, MLE, RTE, corner cases). It’s less critical in online contests since you can resubmit, but in offline contests it’s essential if you’re starting CP. (I used AI to fix it because my English is bad)

can i know test and why this wrong ?

no bro look at your ai commented codes

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orz

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I mean, when looking at your code and style, it looks quite suspicious. You write code so quickly, much more quickly than I believe is possible. You solve A, B, and C1 REALLY quickly. However, this can definitely happen, as those are the easy problems in the contest. But then, you submit for problem I with a not-so-short code in 6 minutes? Most of your submissions just do not make sense from a human standpoint. They are way too quick.

Actually, you only use Kotlin. Why are you saying you use mutiple languages?

Regarding TLE,

As far as I understand, a submission is judged as TLE if it gets the TLE verdict twice in a row during the system tests. You can best observe this in the system tests in Edu-style rounds, when some hacks cause many submissions to fail with TLE. In system tests in such contests, you'll observe a small set of submissions get requeued periodically, and they all get TLE eventually (so you'll see a burst of submissions getting TLE in the status page). I assume this is done to save submissions whose running time is close to the limits.

My opinion: Regardless of the existence of run-twice system in the system tests, the rejudge in this case shouldn't have happened. Submitting a slow solution that's close to the limit is itself a risky move, and you shouldn't complain if it becomes TLE eventually. This is true even for problems where pretests = systests.

.

Problem F has weak testcases. I submitted an incorrect code to get AC. The incorrect code I used involved continuous geometry.

Example --> 1 6 2 2 3 5 6 6

Ans should be 5, i submitted two codes, one of which gives 4 as ans. Both got AC.

because on Codeforces, the pretests are equal the same as the system tests.

That is not true, they are usually same as pretest on Div. 2+ for problems A to D, but in Div. 3/4/Edu, people can spam simple TLE or edge-case hacks to gain a lot of successful hacks with little risk. So you should also be careful of Codeforces' contests too.

please add ONI, national olympiad in informatics romania https://sepi.ro

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+1

can mods ban him please?

this account has been posting this type of shit constantly and its harming the platforms younger audience

The thing is, sometimes, you cannot bring real evidence at all. That would require some sort of screen recording.

I saw your message that you got silver in KOI. I, myself, participated in KOI and got gold this and last year. I am very skeptical of your submissions based on this.

If you have years of experience, I doubt you would submit without checking pretests tbh. But that doesn't show anything anyway.

Time can actually be a good indicator of cheating. The fact is, you have participated in one contest, and your submissions are very suspicious. You move around problems and submit to problems very quickly when it seems like you are working on another problem, looking at past submissions.

No one can bring real evidence, and it is impossible to make sure everyone doesn't cheat. There are tens of thousands of participants in every contest. However, the Codeforces team must decide based on the evidence they have. And looking at your submissions, it doesn't look good.

I do not have a problem with AI translation. Those are from other comments. Although I will say it looks like you are copy-pasting comments to AI and telling it to dispute them and basically say, "I am not cheating." Not an accusation, just that it LOOKS like it.

It seems pretty clear, and I think everyone can see it for themselves. You cannot change my opinion at all, so I would not recommend trying to dispute my claims.

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Please add context, I thought you were posting a blog about a random problem on Codeforces, but I looked again and saw that you made the problem

Dear Codeforces Team,

I received this warning — Your solution 375813225 for the problem 2229D significantly coincides.

The solution was written independently by me during the contest. The approach is fairly standard binary search, so similarities with other submissions may occur naturally. Please review it again.

thanks

ahaha yes sorry, i made the question. i was experimenting with polygon and uploading my question on codeforces, and writing tutorial for it. i didn't mean for this to be public

Stress-test your code. Do not entirely trust pretests/samples

Good, though I prefer GeoGuessr.

You won't understand the feeling of ACing the pretest (which had exactly one test — the sample test), passing the stress test (without realizing that the brute-force code was wrong), and then getting 2/100 on the system tests (passing only 1 out of 50 test cases — the only one you passed was the pretest).

It is kinda funny ngl.

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