Invitation to CodeChef September Mega Cook-Off 2018!



Hello CodeChef Community!
We are excited to invite you to the September Mega Cook-Off 2018 sponsored by ShareChat. This time there are additional incentives to participate in the contest. Top 50 Indian students in the Cook-Off who are participating in the ACM-ICPC 2018 will be eligible for ACM ICPC travel reimbursement.
Not just this! There are more reasons to be excited as ShareChat, our sponsor of September Mega Cook-Off is offering full-time job opportunities for programmers across the globe. More details can be found on the September Cook-Off contest page.

Joining me this time on the problem setting panel are:

  • Problem Setter: jafarbadour (Jafar A Badour), dolabmoon (Max Hsia)

  • Problem Tester: spiral_out (Hussain Kara Fallah)

  • Problem Editorialist: taran_1407 (taran_1407)

  • Statement Verifier: xellos0 (Jakub Safin)

  • Russian Translator: gomelfk (Fedor Korobeinikov)

  • Mandarin Translator: huzecong (Hu Zecong)

  • Vietnamese Translator: (VNOI Team)

  • Hindi Translator: srijand (Srijan Dubey)

  • Bengali Translator:solaimanope (Mohammad Solaiman)

Contest Details:

Time: 23rd September 2018 (2130 hrs) to 24th September 2018 (0000 hrs). (Indian Standard Time — +5:30 GMT) — Check your timezone.

Contest link:

Registration: You just need to have a CodeChef handle to participate. For all those, who are interested and do not have a CodeChef handle, are requested to register in order to participate.

Top 10 performers in Global and Indian category will get CodeChef laddus, with which the winners can claim cool CodeChef goodies. Know more here: (For those who have not yet got their previous winning, please send an email to

Good Luck!
Hope to see you participating!
Happy Programming!


Announcement about top 50 Indians for ACM ICPC?


The problem OTEW from "##MEGA CookOff " had a large number of weak test cases . As I was going through the AC’ed solutions I found many solutions failing in either of the two test cases.

2 1 2 1 2
2 2 1 2 2][2]

The solutions which fail in most of the cases …
Soln 1 , Soln 2, Soln 3, Soln 4, Soln 5, Soln 6, Soln 7, Soln 7, Soln 8, Soln 9, Soln 10.
As it can be clearly seen that many solutions fail on this very small test case (You can’t even call this test case a corner case …XD ) .
So @admin amd @kingofnumbers please look over it … This may result in a huge drop in ratings for many user as it is really painful to get a TLE in a ongoing contest and see such solutions, pass after the contest… :frowning:


Is it rated ??


Yes its rated like all cookoffs so it should me made unrated or else it will be unfair to all users


I am requesting @admin to look into this matter,many people such as me sitting 2hrs for logic with 1 case like this and then see people pass it easily xD!
Many people get Ac and get better rank,what will be the solution of this?
some of top 50 indians get Ac with wrong soln. what will be the soln of reimbursement for this kind of matter??


@admin that’s not fair. I scratched my head for whole contest on problem OTEW, still couldn’t come up with a solution , and there are these wrong solution getting ACed .


Grossly unfair. Even I spent the whole contest time for ONETWO. Along with that, solutions with 3-4 lines of code in Python using Numpy got accepted for DOTIT. What would you do about it?


Making this contest rated is extremely stupid. Here’s what happened to me:
Codechef gives 500 error for the first 2 minutes. Then the problems names (dashboard) load but the problems don’t. Some of them load after 1-2 minutes. I don’t refresh the ones that didn’t load, which was a huge mistake as Codechef believes in not sorting the problems in the order of difficulty. Finally, I decided to try some other problem and refresh the others. I solve the 1st problem.
I try the second problem. I submit a solution, but forget to put a break, so it TLEs. I notice that it will TLE and try to resubmit. I manage to submit it after refreshing the submit page a few times. Then I wait. The submit page doesn’t tell me what happened to my submission, and the status page doesn’t load. I come to know that I got WA after 5 minutes. I tried for 15-20 more minutes and then got 405 error on submit page for 3-4 minutes. After that, thinking that it will be unrated anyway, I slowed down (that’s my mistake, I know).

And to know that there were so many submissions that passed because of wrong testcases. I can’t believe that. I have no idea how you can still make it rated. Hey, but then it’s Codechef. That must be it.


@admin, please have a look here


@vijju123, When will be the editorials of the COOK98 will be updated?


Reader warning - My views are biased by the fact that yesterday I was in good mood and left contest after 20 min. And hence didn’t allow CC to spoil it further. And I don’t know how I will react after online regionals.
Msg for @admin -
Thank you. You made me realize that this forum is not that bad, by showing me how much the worst situation can be. @admin be like - “We are stopping that bad situation. So Its ok to see occasional 504, 503, 502, 500, 404, etc. What more you want.”

Msg for all those who are unhappy with unpleasant experience -

If you are demanding an unrated contest due to all sort of server errors -
The way they are silent and no announcement, rating updated. It is least likely to happen. If this demand is also accepted then in that case also damage is already done.
If you want an apology statement from @admin, then read this blog after Sept., Oct. Cook-Off and online regionals. Still not satisfied read 2nd point here.

If you are demanding an unrated contest because of proving that you are not a bot again and again -
Sadly this is the best option they have found due to API hackathon else situation will be worst.

If you are demanding the prize for Top 75 in Oct. Cook-Off -
I started codechef after last years ACM ICPC regionals online round. But as told but my seniors and CF comments. What happened yesterday is just a trailer of what will happen in regionals which are scheduled after a month. Maybe more worst can happen in Oct. Cook-Off, so they are ignoring these comments.

If this does not happens again, then you should be surprised and appreciate codechef. Don’t blame them for this. They have already achieved a reputation for Sept, Oct. Cook-Off, Regionals online round. And If they can come above those things, then they deserve appreciation.

If you are demanding an unrated contest due to weak test cases -
Surely its an issue they will try that this does not happen in future. I don’t think that test cases were made weak intentionally.

I forgive them for weak test cases. I will be surprised and will appreciate them if glitches do not happen in Oct. Cook-Off and online regionals.
Let us accept the fact - “CodeChef has limited resources, and they are working hard to give us best out of what they have.”

So let us stop blaming them and focus for a contest which is scheduled after a month. And participate again in Oct. Cook-Off so that you have two unpleasant experiences and you don’t get annoyed due to servers in the online round. Hence the name Mega Cook-Off - “Experience server glitches before facing them in the Online round.”


I didn’t participate in many CodeChef events recently. Is that “Hold right there Sparky!!” something that has been added short time ago? It basically killed half of the contest functionality for me, because the captcha to pass was quickly getting more and more challenging and time-consuming.

It was also horribly annoying and upsetting experience.


Now I can say that it was my huge mistake to decide about taking part in the contest yesterday.

It wasn’t great experience :slight_smile:

But while for me it was just about not having fun when I expected to have a lot of fun, and it didn’t matter for anything except of my mood for the evening - I feel really sorry for people who’ll have to take part in official ICPC competitions under such conditions.

I know all those stories about Indian preliminaries - but I was hoping that it is more about ancient times… And it is frustrating to see that contest platform still can’t be made to work properly even in 2018.


I am so done with CodeChef. I won’t comment much about the platform conditions during the contest as many people have elaborately explained the situation but the thing is after you have realized that the contest was nothing more than a disaster, Why make it rated just because you have to award reimbursements ? Either make a separate contest to reward the reimbursements in a fair contest and just pretend as if this contest never happened or just give the 50 lucky people their reimbursements and make the contest unrated. I see no reason why this contest was made rated. I am already worried about what’s going to happen in the Online ICPC Qualifiers as the number of participants then would be nowhere close to what was yesterday.


Making this contest unrated would be the best possible solution, considering all the server crashes, “hold right there sparky :)” and really weak test cases for the problem OETW !!

Although my wrong solution for OETW got accepted, it’s not fair for the other participants. Rejudging the solutions also won’t work as people may argue that they could have corrected their submission if they had received a WA during contest. As many of the wrong submissions which passed were very close to getting it correct!

@vijju123 @admin by when can we expect an official statement over this issue! It would be better to make this contest unrated for everyone!


The editorials for first five problems has been posted, while editorial for last problem will be posted soon, as I am working on it.


yeah @admin plz look into this matter

same thing happened to me I spent two hours for covering each and every test case and lastly wasn’t able to submit my soln


thank god this means that I was not the only one struggling to get past this problem XD. Also if you could update the ratings and provide us with the solution it will be helpful. I was thinking of count of sum of distinct subarrays for this problem was that a correct approach?


Even I thought that test cases are weak but after very long time after contest… I was waiting for editorial to raise this issue…
I think this question should be removed from cook off… Cuz it won’t be fair to rejudge solutions… and even if we make it unrated then what about travel reimbursement ?
So according to my opinion just remove the question…