Greetings, Codeforces!

We, CodeClub IIT Kharagpur bring to you second edition of CodeNite 2025. a competitive programming contest with individual participation to be held on Codeforces, sponsored by Intercollegiate Informatic and Competitive Programming Camp private limited(IICPC India). This contest is OPEN TO ALL, irrespective of college, year of study, or department. The top performers may get referred to top quants partnered with IICPC India. The problemset is aimed to have difficulty of a Codeforces Div. 2 round.

Details are as follows:

• Date: Sunday, 26th October 2025
• Time: 14:00 to 16:00 IST (GMT +5:30)
• Platform: Codeforces

Prizes:

• 1st — 4000 INR
• 2nd — 2500 INR
• 3rd — 1500 INR
• 4th — 1000 INR
• 5th — 1000 INR

Testers: Um_nik, picramide, harshith_04, morphinecode, psp_09, pastimeplays, Mehul_05, Praty_sp, its_magic

Contest Link: Link

Register here if you want to take part and be eligible for the prizes: Google form link

Deadline to register: 2 PM IST, 26th October 2025.

NOTE — Though everyone is encouraged to participate, only Indian college students are eligible for prizes.

See you all on the leaderboard!

A word from our sponsor:

IICPC hosts two flagship annual recruiting events — Quantfest and Codefest — both of which have gained immense reach across India.

The upcoming IICPC Codefest 2026, scheduled for January till April 2026, will be conducted offline. Institutions interested in participating are requested to contact us via their institute faculty or club head at codefest-inquiries@iicpc.com.

For context, over 40 students were recruited by leading quant and software firms through Codefest 2025.

UPD1: The contest duration has been updated to $$$2$$$ hrs.

UPD2: Contest registration has begun. You can click on the contest link and register.

UPD3: Editorial

Thank you so much for participating!

Congratulations to the winners(with tie at posititons $$$2$$$ and $$$5$$$, how did you guys manage this xd):

1. Dominater069
2. sai-17
3. VanshRA
4. jatin123258
5. Ashwanth.K
6. kingmessi

Hi everyone, writing this blog after the recent rollback, getting red back to top of leaderboard as everyone so much desired, and making the overall leaderboard so much better.

If you disliked the announcement/tutorial of Codeforces Round 1033 (Div. 2) and CodeNite 2025 or posted a genuine critique because of problem quality or or because of some other situation which we could've improved, then this blog is not for you, I don't have any hard feelings and understand why you did it.

The dark side

First of all, everyone who cheated in the round, I really reprimand you all and hope you all are fairly retributed for what you all made me go through and the deeds you've done. I especially hope all those who run the back alley solution distribution during the contest are gone for good and that they are especially retributed for their wrongdoings. (I don't think we can stop GPT or that it can suffer "retribution", so not sure what to say about it. Anyways, people who use GPT for wrong are responsible, not GPT itself.)

Secondly, for everyone else who disliked the blog and commented such beautiful hatred for the reason of cheaters on top of leaderboard, thank you for not waiting till the rollback and for making the announcement blog one of the most downvoted blogs in codeforces history. Ain't I so grateful to you all for giving me trauma for like a week of my life, drilling my confidence to the ground by undermining months of my hardwork over a situation I had no control over. And just don't mention the I don't know how many posts over various other platforms like Reddit, Twitter, Linkedin and what not to curse and spread various false information about what has happened(No I don't use these myself, I was told about these by people I know). I never thought people got so much time until I saw/knew about these. Never in my life I imagined I would block codeforces in my brower of choice(using an extension) to distance myself from the hate for quite some days. I don't know what was the rush that people had to blame everything on us, downvote annoucement before the rollback(this part atleast I can understand, you needed somewhere to vent out your rage against the cheaters) or comment their unfiltered opinions everywhere.

And don't mention codeforces platform itself for rubbing salt in my wounds by imposing a $$$1$$$ comment in $$$10$$$ minute penalty on me for the $$$ \lt -100$$$($$$-153$$$) contribution I'm currently at the time of writing this blog. I don't understand who other than announcement blog writers, a.k.a. contest authors, get to $$$ \lt -100$$$ contribution that they are trying to stop through this. If they do stop them, they can atleast lift the penalty for us when we ask as we have to sometimes reply to many comments as author, especially the same day or the next day of the round.

The bright side

But hey, I won't only show the dark side. A thank you from the bottom of my heart really for everyone who tried to support me, many of you who messaged me personally in codeforces or by other media to appreciate the efforts, who commented positively, who tried to defend me on various platforms, those who really stood up despite being a complete stranger, and those who even just enjoying the contest for what it was. I wasn't able to respond to many of your messages or comments, but I genuinely am grateful to you all. Also, thank you so much to my friends especially who stood for me or helped me cool down. You all really we a great help to boost my morale. It felt so good to see that there is so much positivity still left on the internet, and it isn't just overrun by negativitiy. Also, a special thanks to Educational Codeforces Round 180 (Rated for Div. 2) for existing, as things died down mostly for us after it took place(I personally liked its problems, especially D).

Conclusion

Don't worry, I'm quite over the negativity and stuff, I'm just writing this blog as a final wrap up to the emotional downhill that I went through in much of the past week. This experience did get me to become a stronger person not gonna lie. As I said previously in another blog, I always have loved and would continue to love the problems and I've made and the contest we've created. Hoping that maybe, some future author wouldn't have to face this over something that was out of their control, and that they are appreciated for the effort they've put, and critiqued genuinely for the mistakes that they have made. Hope that people understand that authors are not responsible for everything, that they are there just so to make problems that you all can enjoy, and if you get to learn just a bit more from the problems, it is just a win.

So yeah, hey guys. I'm Dragmon, the "cyan author", the "trash problemsetter", the "author of Codeforces Round 1033 (Div. 2) and CodeNite 2025". So, you might be wondering, who am I to suggest anything to you? Well, I don't know, you clicked on the blog. I have made sections, you can just skip to what you want to read.

Brief History of Me

First of all, I'll give a brief history of myself, because why not? You might not be expecting it, but problem-setting is my passion. I've been setting problems on Physics and Maths during my JEE time. If you are interested, you can find them here in drive. I had ~100 more in brilliant.org, but sadly, the community feature was disabled around July 2021. If you are interested, I can get it exported and share it with you. After coming to IIT Kharagpur, I joined CodeClub and set some problems in the unrated CodeNite that we conduct half yearly, along with amazing peers, some hard, some easy, you can find them here in doc if you are interested.

How can you set a problem?

So, why can an expert(lol no, specialist) like me set problems that are 2600+, you might be wondering? I think it is because of one simple fact: to be a 2600+, you have to master most topics and problems that are 2600+. But to be a problem setter, you can master just some/one topic, and it will work out for you. For me, the topic turned out to be "Graph Theory". I've been fascinated by this topic since I set foot in it, maybe during some Div 1 codechef long challenge in 2019, when the first two problems had graphs/trees, so I basically had no option. Since then, I've really taken it and I do have a publication on the topic of "Line Graphs" link to Springer paper if you are interested. So, hard questions that I come up with typically come from the domain of graph theory, especially line graph, like the problem 2120G - Eulerian Line Graph. I would like to thank the problem setter of problem "LLLGRAPH" gainullinildar, a.k.a. 300iq for the ‘April long challenge 2020 in CodeChef for getting me inspired and pursuing the topic of line graphs(Yeah, I'm thanking him here because I never got another chance).

The thing that I do to come up with problems is just find problems in everything in life — while learning topics, solving problems(general version of problem, combining it with some other concept, array problems now on trees, graphs), etc.. For example, I'm an ardent gamer. I love playing games, especially ones that involve RTS, RPG, or Supercell's name ;). I've come up with problems with their mechanics and stuff. Also, real life is just as good for that stuff of finding problems. One of my problems is even based on screen pattern lock(you can find it in the doc above).

As an example, for the contest that you might’ve not liked Codeforces Round 1033 (Div. 2) and CodeNite 2025, I was the author and setter of 2120A - Square of Rectangles, 2120D - Matrix game, 2120E - Lanes of Cars, 2120F - Superb Graphs, and 2120G - Eulerian Line Graph. 2120A - Square of Rectangles I just came up with randomly, 2120D - Matrix game was based on an interview problem that I got asked about whether we can find a rectangle in every infinitely colored grid, 2120E - Lanes of Cars when my friend was telling me his problem, but I somehow misheard it, 2120F - Superb Graphs when I was studying the topic of conflict-free coloring, and came across the concept of neighborhood diversity and type graphs, 2120G - Eulerian Line Graph when I was studying and research line graphs.

Defend for the round

Now, if you are thinking "well, where is the defend for the round Codeforces Round 1033 (Div. 2) and CodeNite 2025?". Well, as is said in One Piece, you can't hate the ship you made, even if the whole world is against it, so I love my problems and would continue to. Also, as I like to say, trying to change a person’s opinions just leads to a void function, that can't return anything to you or the said person. So, please be your own judge. An exact match for the problem by my fellow co-author harshith_04 being found on the last day leading to the round being a div. 2 instead of div.1 + div. 2, when searched by our coordinator, was really unfortunate, and I won’t blame anyone for it. Believe us, we were wayy more hurt by that news than anyone of you even think you were. (Though it seems that you’ll would’ve hated it even more if it was a div.1+div.2 from the comments, blog and messages you’ve sent me, which yes I’ve read them all. It’s funny how people can be damned to hell for the "heinous crime" of setting a “trash” round and being an Indian.)

Issue of cheating

As for the issue of cheating, I just completely agree with Um_nik's blog. I don't care if people cheat or use AI. I came to this platform to enjoy solving problems with a time constraint, not to boast my rating or show it to a company. And I'm not setting problems that I don't like just to satisfy the criteria of it not being able to be solved by AI (Some people are saying that we authors leaked the problems ourselves lol. Do people really think we’re that stupid to sell off our own problems?).

And to the people who are accusing my co-author harshith_04, I just don’t get what a person cheating or not cheating says about the quality of problems they prepare, least of all one that happened in 2023. For all I care, he is just an amazing, cheerful, and helpful senior who loves Competitive Programming. (Maybe you don’t respect me now, aye? Feel free not to lol, I ain’t going as shallow to just judge a person by one incident, which I’m not sure is true and neither do I care if it is).

Conclusion

As for this blog, feel free to like it or dislike it, idk, not like my contribution is gonna get affected much after my announcement blog for Codeforces Round 1033 (Div. 2) and CodeNite 2025. But, in any case, I'm happy if this blog helped maybe even one of the experts/cyan coders are to set problems, I'll also like to thank all the problemsetters as it is only because of them that the platform is still running. Don't worry, I don't have much plans for rated problemsetting in the future :). I think I have my job done! Thank you for participating in this with me, I guess :)) (Did you even read the whole blog lol?).

Namaste Codeforces!

We, CodeClub, the Computer Science and Engineering Department Club of IIT Kharagpur, are glad to invite you to participate in our landmark 25th CodeNite — Codeforces Round 1033 (Div. 2) and CodeNite 2025, which will take place on Jun/21/2025 17:35 (Moscow time).

You will be given 7 problems and 2 hours to solve them. This round will be rated for participants whose rating is below 2100. Participants with higher rating can participate unofficially.

The problems are prepared by Dragmon and the amazing former CodeClub President harshith_04. Special thanks to picramide for his support throughout the process and for his help in preparing the problems.

We would like to thank everyone who made this round possible:

• SSerxhs for schzmooth coordination.
• Alexdat2000 for Russian translation.
• picramide, morphinecode, and anubhavdhar for providing some problems that couldn't make it to the round.
• Um_nik, turmax, ugly2333, le0n, EvenImage, StarSilk, physics0523, fallleaves01, tiger2005, tarjen, IceKnight1093, Serval, Dominater069, satyam343, djm03178, huansir, sai-17, anubhavdhar, weirdflexbutok, Proelectro444, Little_Sheep_Yawn, shstyle., Theresa_Apocalypse, PaperCloud, Nanani, shorya1835, fr200110217102, chromate00, vivan_01, envariant, isosceles, pastimeplays, chrisrex, ssp2004, psp_09, XiaoXia, Newtech66, Me_as_coder for testing and providing useful feedback.
• KAN for the initial review of the problems and overall coordination.
• MikeMirzayanov for the amazing Codeforces and Polygon platforms.
• You for participating.

We really hope that you like the problems. Shubhakamana tatha vijaya!

UPD1: Unfortunately, today we found out that one of the harder problems was an exact match to an earlier published problem. Therefore, we have decided to only hold the Div. 2 round. We hope for your understanding. It will now have 6 or 7 problems, and you will be given 2 hours to solve them. We hope for your understanding. The scoring distribution will be announced soon.

UPD2: There will be 7 problems in the round and you will be given 2 hours to solve them.

UPD3: Editorial.

Score Distribution: $$$500-750-1250-1750-2500-3000-4000$$$