Greetings, Codeforces Community!

We, the Programming and Algorithms Group, are excited to invite you to our upcoming event, Insomnia 2026! This event is proudly sponsored by IMC.

Format

Insomnia 2026 is an ICPC style team contest where you would be given 10-15 problems in the span of 4 hours, for teams of at most 3 members.

• Date & Time: Sunday, March 22, 2025, at 17:00 IST
• Mode: Hybrid (Online+Offline)
• Platform: Codeforces
• Registration Link
• Eligibility: Teams of 1-3 Members and Participants may use their own computer (No 1PC per team rule)
• Prizes: Total Prize Pool: 2L INR

Contest Link — https://mirror.codeforces.com/contestInvitation/4dbe34f649efdf387e5ea871d742fb461a3c242d

Please make a team on codeforces with same name as registered on unstop to be eligible for prizes.

The contest will be conducted in a hybrid format. Students from the following institutes are required to participate in offline mode:

• Indian Institute of Information Technology Hyderabad (IIITH)
• Indian Institute of Technology (BHU) Varanasi (IIT BHU)
• Indian Institute of Technology Bombay (IITB)
• Indian Institute of Technology Delhi (IITD)
• Indian Institute of Technology Guwahati (IITG)
• Indian Institute of Technology Kanpur (IITK)
• Indian Institute of Technology Madras (IITM)
• Indian Institute of Technology Roorkee (IITR)

Only teams comprising of Indian Undergraduate or Postgraduate students are eligible for prizes, but everyone is welcome to participate. It is compulsory to register on Unstop to be eligible for prizes.

Sponsors

This event would not have been possible without the generous support of our sponsor.

• IMC: IMC is a global trading firm powered by a cutting-edge research environment and a world-class technology backbone. Since 1989, we’ve been a stabilizing force in financial markets, providing essential liquidity upon which market participants depend. Across our offices in the US, Europe, Asia Pacific, and India, our talented quant researchers, engineers, traders, and business operations professionals are united by our uniquely collaborative, high-performance culture, and our commitment to giving back.

Organizing Team

• The problems have been set by shorya1835, ho-oh, friedel, wakanda-forever, tridipta2806, Dragokj03, Prady, raichu_, Forge, and Krishbansal333.
• Thanks to our dear testers: __baozii__, Kira_1234, cry, Proof_by_QED, wuhudsm,nik_exists, Jrke, Mewtwo, Coding............, HackerGupta069, dord, SomilP, blue_phoenixx, twistedumar, penguinsAreCool, krish273, psyduck06 and raghavb_007.
• Thanks to aastik231205, Darsh_Jain, sigma273, ainesh_d, and MADSAM123321 for their help in preparing the contest.

Upd — Editorial is out!!!

Upd 2 — Here are the results after careful verification of all entries

We will reach out to the winners soon to distribute the prizes and Also, Note that all decisions taken are final and binding.

This is the latest announcement

There seems to be quite bad limits set in problem A of the recent contest such that a brute force approach is passing using one set of operations but getting TLE using another set of operations both giving same Big O complexity. The two submissions are :-

Here is the submission getting TLE and here is the one getting Accepted.

Literally the only difference is that in one code there is an extra division in place of many multiplications in the TLE submission. Look I know integer division is slow but still either both of them should pass or both should fail.

Hello guys, I just realised how much of a difference putting const in a global variable can make. I was doing CSES problem Coin combinations II. I was getting tle on the problem for quite a while. Just for trying i changed the global mod value's datatype from long long to const long long. My code which was giving tle on 1s got executed in 0.2s due to that 1 change.

Here's my Old submission and here's the New one.