Why the task C is appeared on the Div1 contest?

Thank you for the contest!

I like how natural the problems are.

Ojala q podia participar en la ronda, voy a resolver las problemas manana. Buena suerte a todos q van a participar (damn my spanish is rusty). MANIFEST POSITIVE DELTAA

Thanks for the contest!

I especially liked how div1D allowed (encouraged?) this way of solving: pretend that $$$x$$$ can only be up to, say, $$$m = 100$$$, brute force the first move, then try all possible hidden $$$x$$$ and choose the one that maximizes the total loss (it's not hard to see what to do after the first move more or less optimally, in particular how to spend about the theoretically minimal loss in the second move and achieve 0 loss in all upcoming rounds), print the optimal first move and generalize for $$$m = 10^4$$$. This way you don't get to experience this beautiful underlying construction, but it's a reliable strategy of using the computer that I don't see very often

btw the author is cheater

Do u really think getting bronze medal from KHIMO is an honor ? (newbie / pupil can get a bronze from that olympiad)

also if anyone's interested in what KHIMO is, here's the the link to the website :)

what proof you want, just read the top comment of this blog, you just keep asking to prove things which already proven

As a tester, I highly recommend this problemset and BTW

Sniping Cheaters — Episode 2

Well well well, it seems Mr. Cheater Accuser PiggyPump is a cheater himself...

First, let's look at the obviously cheating (and disabled) account PumpyPig. What might his motives be?

levitational

Please take it to the DMs. Cheating allegations can go to the appropriate channels. You can contact a CF admin if you have credible evidence. One would expect a blog to contribute positively, not some 10 message slapfight that improves nobody's day

cheater means a person owning account has cheated at least once in his life on a platform, if it's long then it's left cheating, also even if you not cheater you are liar, that's even worse, so the fact that you stopped cheating because you were forced to doesn't make things any better. Thus you are cheater, but you don't even know it

if u are saying just "prove it" it proves that you dont have any exuces. and u want to be get proved yeah? just install any cf cheater flagger extension and look at your profile.

why so ????

no YOU are everything that's wrong with our society

Observe that in one move the robot can move modulo 3 +1. And now imagine all diagonals to be of 3 colors Red, Green and Blue. Reds = the ones with (r+c)%3 == 0 Green = (r+c)%3 == 1 Blue = (r+c)%3 == 2

Now in these 3 families the robot will ALWAYS move in the pattern (say we started at index with mod 0) R -> G -> B -> R -> G ....

So we basically want to match the rhythm But one critical thing to also observe is that we have to start top down (top right to bottom left) because observe that lets say robot is at a Red diagonal and we are lasering the diagonal which is the next (whose r + c is just greater than this) Red, then it is guaranteed that if our rhythms are matching then we will collide no matter what because in the next step it will go Green (if it decides top move up) and we will also go Green (moving down) and boom collision. If robot moves down then we will corner it eventually.

As a person who hates reading long stories thank you.

1294F is 2k btw

I hobe nadeem qualifies to SCP next year.

make the vector a have like 2 quadrillion numbers which would overflow n being an int

Found this contest easier compared to normal Div2. I don’t know why

how does your submissions justify that you are not a cheater? an unofficial website that everybody uses that people trust more than your source obviously carries more weight and can determine public opinion.

macaquedev also won't show any evidence as stated here, what we know is that you either cheated in any form of: Plagiarism and External Assistance, Code Obfuscation, Multi-Account Abuse for hacks and other purposes, or any use of an LLM stated here. If you didn't cheat then appeal to the CF Cheater Database to remove the flag.

1. They don't just add whoever is reported, the cheater database have a high trust rate, thus is the most objective proof of a cheater.
2. if you don't care about the website that majority of people uses to judge, use your brain to think how else are you going to prove them wrong.
3. whether you cheat or not i dont rly care that much, i don't even see why macaquedev would care about grey cheaters tbh. btw just continue ruining your reputation and continue "cheat"-ing and contribute your rating to everyone in this zero-sum rating game bc

imagine responding subjective sentences with "lie" lol. also sir, there is something called online trolling, i have lost enough braincells talking with you i just troll you. can you not process that every single point in my last comment is subjective. i know you contacted macaquedev and got ignored so badly you gave up lol. ah and yes i can now differentiate you with SwastikPandey_cheater now you showed me how much less $$$IQ$$$ you have compared to him. do you have any proof of me reporting false positives? if not why are you making wild accusations lol. if you are asking how did it become trusted, well because its deserved to be trusted, ofc you will never ever gain that level of trust by the community bc.

Bruh you brick div2cs and make gpt alt accounts talking about some "philosophy" I can assure you the downvotes you get isnt the cheater (you) deep state trying to silence you

If you’re using AI for A just quit cp bro

Woah, what is this “Wegmans Food Markets” company? I think I will check it out as a result of their sponsorship of this competition.

nahh

Hope roll back comes and you get 1397 -> 1399!

Bruh I don't care that 50 reds and a few chatgpt pro owners are getting cool tshirts I just want my +delta

Zindagi means life, right? I think I heard it in Persian

you can search linearly on K as well because k is of order sqrt n

fr

I do not say he is CHEATER, but still suspicious, because I did not see he is cheating with my eyes. Let's listen to others.

I heard that if you use your full umamusume powers to mysteriously AK a contest in 20 minutes you get a secret rank called "disabled" which is lower than gray

I know u're cheater but i can't prove it yet...

good blog...commenting for reach

efishel please upload the editorial ;)

Sooner or later, it will be 'Alice' if Alice wins and 'Almost Alice' if Alice loses, making sure Alice's name appears no matter what.

there is modern trends now. men just get no respect. bob deserve justice!

As a writer, I keep forgetting that the last 'C' in CCAPC stands for 'Competition' rather than 'Contest'.

Ahanab bro is down so bad even mambo called him racist... [:wilted_rose:]

Yeah total waste of time

see my submission before yapping mf.

btw here are your accounts, fractal73 attractors AttractorsTheory open90 SwastikPandey_cheater i wonder why 3 of them are banned, 4 including fresh_tangerines

and lets not forget that when id fresh_tangerines became pupil, then u asked for its password to bricked_ and then you cheated on this id for next 4 rounds to get your main account a bit of more rating.

while my accnts are swarya i didnt knew rules so i cheated then i did most fucking dumb thing which was defending, after that i left it and created fresh_tangerines here i did that on 1 ques then gave it to bricked_ who u manipulated to get accnt to cheat a bit more., since then or u can say since 1.5 years im doing a fresh start unlike u.

Great contest!

aura

as tester and former participant, pilliamw puts a lot of effort into making these problems, therefore you should participate

Yes Jon, you are absolutely right!!

1399 factorial? dang big rollback

Insane ragebait attempts

Bro, authors cant make Div. 3 just by "snap". Its hard work, with 3-4 steps, like making original ideas, preparing everything on legendary site polygon.codeforces.com and testing. Preparation often takes 2-3 months minimum.

No, Codeforge is available to anyone who is interested and wants to use its features, regardless of their location.

But it's only for students and not for professionals? The site and the account creation heavily suggest so: You can only create an account as a student or parent, and as a student you are required to select a grade from 5-12. Is parent the "right" option in that case?

Hey hey! Feel free to put grade 12 if you graduate / are a professional. It is the simplest option for now. We will address account types in the future.

i was very sad that leo/need split, but this made my day

sound so serious lol, but i do agree with u

Planned post contest discussion stream here

PumpyPig Noobteric

Oh yeah you use deepseek instead mb

PHSCO MENTIONED !!!

It's over

The Scoreboard Watching is really real. I was someone like that, but I managed to change. It feels less like a competition and more like a challenge now.

When you participate in a contest, don't look at others much. Focus on yourself and do your best.

I think people those are mentioned in this blog post are downvoting me because reality hits harder than anything

makes sense to just disband and conduct from scratch like how we conduct jee, damn at this point icpc is becoming more like neet, only pending thing is some insider faculty not leaking the set to their college team, and I am pretty sure at this rate , it will come to pass too , congrats India

he probably used $$$AI$$$ for more than just the blog

Now there is a need for justice for JonKhan, instead of Bob

No, I am his classfellow and I can assure you JonKhan never used AI during a codeforces round.

He is from a reputable school in the Pakistani CP community and has performed well in on-site contests. JonKhan made it to final round of TST last year and has given medal level performances in many invigilated OI online mirrors.

whether or not he cheated, I don't know, and really it's never been more pointless to discuss specific cf cheaters. but it is admirable that you are sticking up for your friend.

wegmans orz orz orz

im not alleging him of cheating.

this blog was important because he is impersonating to be me to abuse others, so i js awared others through a blog that i and him are different persons.

he have 3 banned ids and he created more to use my identity to abuse others. shouldnt others know about it? so they stop tagging me for his doings!

after you learn how to code in C++, you do not want to write code in python again.

You're right.

Hail Bob

Codeforces hates Bob

In my opinion these problems are hella orz

MattTheNub orz cutsandstone orz sukon orz snowy orz nadya orz scalar orz jdurie orz thehunterjames orz mgoldy orz surajchip2 orz awoo orz Neon orz nickbelov orz headlands orz HRT orz Rutgers CS orz Wegmans orz Mike orz

The diagonal modulus by 3 increases by 1 after every operation.

Nice problems!

Also is it me or getting rating now is getting much harder than before. Like I remember when 1000 or 2000 in Div 2 used to give + in expert or just look at my graph.

How shameless do you have to be? You wrote a terrible post about a useless topic, used AI to generate it, and then had the audacity to upvote it with your own alt accounts.

yt ads spoiling the thing :(

I used that sort of strategy to solve div1B: do BFS over the states (masks of which diagonals the thing can be in) for low N and hope the pattern works out for higher N.

The same template existed in my GitHub repository for more than 6 months: SegmentTree2D Template

we are so doomed sadly

You orz

nifeshe can you add H1 and H2 pls, i guess Axial has already rested

Good luck to you too my friend. I hope i reach specialist in this contest!

What do you mean? I was chatting with thismagic and discussing this topic. I am not cheating.

12 hours study usaco 8 hours codeforces 3 hours sleep 1 hours eating and other

wow! thx for the tool!

I hope I can manage to do the contest, since I have a guitar lesson :(. I’ve already missed classes for the course because I was doing another contest. Good luck, everyone.

I have the same problem. My original account alexenkovova was banned. I created this new account just to try to contact administration or community to find out the reasons.

Probably the reason I got banned is because I used AI, but I dont really know. Actually I used AI quite often to generate boilerplate code for input/output parsing which is allowed by rules. And this is the line I dont cross — only boilerplate, no core logic. But there was one problem where I might crossed this line. Problem A, the easiest problem in the world, I just generated code and moved on, did not even bother to look at it. It was so easy, one loop, one hash-map, thats it, just an exercise for syntax, not really a problem with an algorithm. Anyway, I don't why I got banned, maybe it was the case.

I want to touch another question, which is maybe more important. Why people that are banned can't get even a letter with an explanation and what if it was a mistake, why there is no discussion. Also why permanent ban immediately? Is it an adequate measure? There are probably a lot of people who use AI and they get away with it, some percentage get permament ban, some high rating, no inbetween, no rating penalty, no temporary ban, etc.

Also, what should I do now. Just forget about CF and competitive coding forever. Or do I use this account. But rules permit the use of multiple accounts. So what should I do?

I think this is injustice that AI users get away with it. But it is even worse injustice to ban people without a trial, without a discussion, without an explanation.

What do you think?

next time, try being legit <3

There's an alternate solution to problem B that I think some could find useful. The optimal strategy for Alice is to get as many lower-numbered cards as she can, and the optimal strategy for Bob is to copy Alice's moves (thus, also getting as many lower-numbered cards as she can). The reason why both players desire lower-numbered cards is because that is what changes the k-MEX the most.

Therefore, we can directly simulate how the game would play out. This runs in (I believe) O(n^2), which is slower than the tutorial, but passes all test cases nonetheless.

#include <bits/stdc++.h>
using namespace std;
int kMex(int k, vector<int> numbers, int maxNum){
    for(int i = 0; i<maxNum+1; i++){
        if(count(numbers.begin(), numbers.end(), i) < k){
            return i;
        }
    }
    return maxNum+1;
}
int main(){
    int tests;
    cin>>tests;
    while(tests--){
        int n, k;
        cin>>n>>k;
        int maxNum = 0;
        vector<int> nums(n);
        vector<int> alice;
        vector<int> bob;
        for(int i = 0; i<n; i++){
            cin>>nums[i];
            maxNum = max(maxNum, nums[i]);
        }
        sort(nums.begin(), nums.end());
        for(int i = 0; i<n; i++){
            if (i%2 == 0){
                alice.push_back(nums[i]);
            }
            else if(i%2 == 1){
                bob.push_back(nums[i]);
            }
        }
        if (kMex(k, alice, maxNum) != kMex(k, bob, maxNum)) cout<<"YES"<<endl;
        else cout<<"NO"<<endl;
    }
}

Once a wise man said: "Practice makes perfect".

ig reading catalog blogs before starting will solve majority of your problems.

js open the catalog, skim through it and start reading thats it

catalog https://codeforces.me/catalog

they r not gonna stop bruh, today i saw a guy who was asking mike to unban is 450 rated accnt...

and they thought I was racist

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Wish everyone a good contest!

Auto comment: topic has been updated by KawasakiSakura (previous revision, new revision, compare).