Hello Codeforces!

Ready for a high-intensity ICPC-style battle?

We are excited to announce CodeRed, one of the flagship competitive programming events of Aparoksha, the annual tech fest of the Indian Institute of Information Technology Allahabad.

If team strategy, whiteboard arguments, last-minute hacks, and the sweet sound of Accepted excite you, this contest is for you.

Contest Details

Date: 12 April 2026
Time: 5:00 PM – 8:00 PM (IST)

Contest Link

Kindly use the invitation link below to register for the contest: https://codeforces.me/contestInvitation/baac2882fdbed30238dedbb68160772bfcde6bff

Finals (Offline Round)

Top performing teams from the online round will be invited to the offline finals at IIIT Allahabad.

The finals will be conducted on campus, where selected teams will compete in an intense ICPC-style showdown.

Contest Format

CodeRed follows the classic ICPC-style contest format.

Rules

Team size: 3 participants
Duration: 3 hours
Scoring: ICPC penalty scoring
Machine: One machine per team

The problem set will include a mix of challenges testing:

Speed
Algorithmic insight
Team coordination

Prize Pool

The competition features a total prize pool of ₹56,000, distributed as follows:

Online Prelims Round

1st Place: ₹3,000

2nd Place: ₹2,000

3rd Place: ₹1,000

Finals

1st Place: ₹16,000

2nd Place: ₹13,000

3rd Place: ₹10,000

First Solve Bonus: ₹1,000 for the first team to solve each problem

Note: In case any question remains unsolved, the prize money allocated for that question will be distributed among the top teams.

Registration

Registration Form
https://forms.gle/9hMSD2CsfgJzAEo98

Make sure to register early — slots may be limited.

For doubts and latest updates , join the WhatsApp group — https://chat.whatsapp.com/CABDhcXMXaA041A3HB3v4l?mode=gi_t

We have initiated the verification process. You will shortly receive the guidelines and further details.

Rules and Guidelines

All participants must follow the official contest rules and submission requirements. Teams are strongly advised to review the complete rulebook and ensure their recording setup is properly configured before the contest begins.

Official Rulebook

The detailed contest rules, scoring system, and participation policies are available in the official rulebook:

Rulebook : https://drive.google.com/file/d/1hlEGkx3N_r3f3l6vKtw751-K1vE48YEx/view

OBS Recording Requirement

All teams must follow the proctoring and screen-recording requirements specified by the organizers.

The setup instructions for recording using OBS Studio are provided in the official proctoring guide.

Proctoring Guide: https://docs.google.com/document/d/1zGt7vcU_wF1pA5FhHCbXEFLXoRDosYnavQ_2edKCncw/edit?tab=t.0

To ensure contest integrity, teams must record their contest session using OBS Studio.

To maintain the integrity of the contest, the following rules will be strictly enforced:

Use of AI tools (such as ChatGPT, Copilot, or similar systems) during the contest is strictly prohibited.
Teams must solve all problems independently without external assistance.
Any form of plagiarism, collaboration between teams, or unfair means may lead to disqualification.

In case if all members are not available at one place, all three of them must be connected through any online platform and only one system can be used for typing code. This machine must remain the same throughout the contest duration. Recording of the entire meet has to be uploaded and if multiple machines are found to be used for typing then it will lead to disqualification.

The organizers may perform submission reviews and anti-cheating checks.

Important Notice

All decisions related to qualification for the offline finals, disqualification, rule interpretation, contest administration, and resolution of any discrepancies or disputes will be taken by the organizers, and these decisions will be final and binding.

Team Reference Document Submission

The reference document must be submitted through the official Google Form provided below.
Only one submission per team is allowed.
The document must be uploaded in PDF format only.
The document must not exceed 15 pages.

Form Link — https://docs.google.com/forms/d/e/1FAIpQLSeGndtBveBbPkWSqrmNQok9AzWSG65DvPvNmXdbX1dG6XnbqA/viewform

Post Contest Video Submission Link

Kindly use the link provided below to submit the OBS recording post contest.

https://docs.google.com/forms/d/e/1FAIpQLScKqUzgRWFcefGwldrotsSSuyNwHnuKK6mlekGmk0Oynk8Oaw/viewform

Gather your team.
Sharpen your algorithms.
Prepare for CodeRed.

See you on the scoreboard..

Comments (32)

Write comment?

pranavsingh0111

6 months ago, hide # |

Auto comment: topic has been updated by pranavsingh0111 (previous revision, new revision, compare).

→ Reply

schrodeR

+35

love you

_hmt

6 months ago, hide # ^ |

-6

gay gay!!!

vineetiwari

hi,after registration what are the next steps?

rn_das_2004

We'll mail you the details like contest link and proctoring guidelines on the mail id used for registering on Google Form. After contest, we'll announce top teams who qualified for offline final round.

5 months ago, hide # |

hi team, i didnt recieved any mail for contest link and etc i filled the form 2 days ago and contest is tomorrow and still their is no communication from you side

5 months ago, hide # ^ |

We'll mail the contest link along with guidelines pdf on your registered mail by today evening

All participants who have registered till 10:30pm IST today will receive guidelines and other instructions in their mail by 11:30pm IST. For others we'll update the blog, you can directly refer to instructions from there. The guidelines are nearly same as that of most online team contests.

We have sent mails to everyone. If you have registered before 10:59PM IST and have not received your mails, kindly message on whatsapp group (in blog)

As a problem setter, I guarantee that everyone will solve a non-negative number of problems.

vishwas_16.0

The prizes for online round are 3000, 2000, 1000 INR for 1st,2nd and 3rd position respectively. The blog will be updated shortly. Thank you Happy Coding

Reminder: Registration for CODERED prelims have started. Kindly register for the contest.

mnnit.prakharg

Why delaying the contest?

UP84

For problem E,my solution keeps getting RE , finally it passes after end of contest because constraints given are wrong (M>200000) and yet somehow people keep passing that,problem A was complete disaster ,PATHETIC experience.

Ragnar21

Got MLE on E due to #define int long long

Pathetic experience.

DysfunctionalDegenerate

Your solution was sub-optimal.

Completely agreed with problem setters point here

+12

I sincerely apologize for the inconvenience caused in Problem E. It has come to my attention that the constraints provided during the contest were incorrect, particularly regarding the upper bound on M.

This mismatch may have caused unexpected runtime errors for valid solutions, which I understand is frustrating during a contest.

To address this, I will rejudge all submissions for this problem using the corrected constraints.

Enigma27

My feedback of the round :

Problem J: I misunderstood the problem and was solving for two-tone sequences where both distinct elements should have exactly $$$K$$$ elements. The formula boils down to $$$\sum(C(f_1, k) \cdot C(f_2, k))$$$. This can be solved directly with the identity $$$(\sum A_i)^2 = \sum A_i^2 + 2 \cdot \sum (A_i \cdot A_j)$$$, where $$$A_i = C(f_i, k)$$$. I used this exact identity yesterday, so it felt a bit odd. After re-reading the statement, I started solving the original problem. The idea was good—overall a good 1700–1800 level problem, likely Div2 C-D.

Problem I: Good problem. The main challenge is formulating the solution for easy implementation. I’ve solved many similar problems before; in these cases, fixing the number of distinct characters in the final string works like a charm. I’d rate it around 1500 (Div2 C).

Problem D: Decent problem. $$$n \ge 5$$$ is always possible. For $$$n=3$$$ and $$$n=4$$$, I initially tried a brute-force solution in $$$2^{n \cdot n}$$$ but decided to hard-code instead. During hard-coding, I realized $$$n=4$$$ is also impossible. Rating: 1300 (Div2 B).

Problem E: I was solving Problem A during this time, but after one of my students got AC on E, I checked it out. It was the easiest problem for me. Binary search was obvious, and the grid constraints were lenient enough to just implement a check function. The problem would have been more interesting if the grid was larger (e.g., $$$10^5 \times 10^5$$$) or if the required square should have at-least side $$$K$$$. It could be rated 1400, but it felt a bit too standard/boring. UP84 faced runtime because of wrong constraints on M, which is bad and should have been caught by vaiidator, but yes, I have fucked up before while creating problem in 2024 ICPC prelims with similar issue so I can understand. I hope, you guys will re-test all your problems of finale contest.

Problem A: I started the contest with this. Binary search was the obvious since we needed to minimise the maximum, but I initially tried fixing the maximum element and checking for the other two in $$$O(1)$$$ or $$$O(\log n)$$$ time. I eventually stuck with binary search and reached a solution involving SOS DP and Inclusion-Exclusion. Factorising up to $$$10^{18}$$$ was tricky; I factorised up to $$$10^6$$$ but wasn't sure how to extract the last two primes. I then realised I could find the remaining primes by taking the GCD with existing elements. This was easily the best problem of the contest. Rating: 2100–2200 (Div2 D-E).

Problem G: Standard game theory with a re-rooting technique. I’d rate it around 1900 (Div2 D).

Thank you for the genuine and honest feedback. We do understand that E had some errors which affected the contest for participants. We are extremely sorry for that. We'll make sure that in future contests constraints are correctly tested. Except that, it was a wonderful experience to have such great coders participate in our contest. We are very thankful to everyone for giving your time and effort, it was a great learning experience for us too which will help us design better contests in the future. Happy Coding