[Update] May 09 — I've received an apology email from CodeChef and my rating has been restored. Hope they improve their procedures for handling such cases in the future.

I participated Codechef Starters 184 last Wednesday. Did pretty well, solved 5 problems with Python, and ranked 17. The live rating graph showing my new rating to be 2018, which is +72 from the contest.

Five days after the contest, I received an email: CodeChef — You have been caught for plagiarism in START184. The email said, "Let us know within 1 day if you think you are being wrongly penalized," or my rating would be dropped by 275 points as a penalty.

Of course I didn't cheat in the contest. The email didn't mention which problem or which submission got marked as plagiarism, so I just carefully read CodeChef Code Of Conduct and Plagiarism FAQs attached in it, making sure I didn't break any rules.

Honestly, I wasn't even that mad at this time. Maybe just some unlucky guy had a really similar code to mine since the solutions to the first few problems are really short (like less than 20 lines in Python). So I replied to the email to ask for an appeal to the plagiarism accusation.

Two days passed, and I still hadn't received any reply. My profile already showed the rating drop, marked as "Cheating in START184B". I just got more impatient and decided to wrote another email asking for a reply.

This time, they replied instantly (in 7 minutes!) And here is what I got:

"don't lie and honestly agree what you did" — This really pissed me off.

Here is the original problem, and here are our source codes:

• My source code
• Their source code

The source code attached (written in Go) are definetely not "every line being same". We indeed share the same idea in solution, however, this is exactly the solution used in official editorial! Since the solution is simple enough, even the sample solution in the editorial looks identical to ours.

I carefully explained why the two codes are "similar", including the editorial's solution and two other contestants' solution, pointing out that anyone using this approach will write code that looks like this.

An hour later, I got another reply — just one line:

It definetely shouldn't be seen as cheating if you're just using a different languages. Still, I gave them a detailed answer about why I use multiple languages. I even included my submission history on Codeforces and AtCoder, and emphasized multiple times that switching languages has nothing to do with cheating or plagiarism.

Then five minutes later, another one-liner reply:

Absolutely ridiculous — what’s the problem with debugging a loop in 4 minutes? So I explained what was wrong in the WA version, what the fix should be, and how just a few small test cases would’ve revealed the issue. I also explained that it was really not that hard to implement the loop.

Finally, they replied:

The cheater mark has been removed. However, I still received a -76 rating change, which should have been a +72, and I have no idea how this was calculated.

To be honest, the thing that pissed me off the most wasn’t even the false accusation. It was how Team CodeChef responded to my emails.

I mean, I understand the importance of punishing plagiarism. But if you’re going to accuse me, asking me to reply in 24 hours, then ignore my email for two days, and when I follow up, the first reply is literally: "don’t lie and honestly agree what you did" — how is that even acceptable?

I don’t understand how a platform like CodeChef could be like this. And even after I carefully explained everything, they just kept asking more and more irrelevant questions that shouldn’t even be criteria for deciding plagiarism. Besides the first email, every email was just rude, dismissive, and unprofessional. The whole time, it felt like they already decided I was guilty. They weren’t interested in my explanation — they just wanted me to shut up and take the punishment.

By the way, not only was my rating dropped, but the other person that was accused of "plagiarism", just got their account deleted. Looks like they just stayed quiet and accepted it. Unfortunate.

If you're interested in the full email responses, here is the screenshot.

Thank you for reading such a long complaint blog.