ACM ICPC 2017 Online Round Solutions discussed on maths stackexchange

It took my team the fortune to figure out the solution for 2nd and 3rd problem. Ohh dear maths. And after the contest I came to know the solutions for them were already posted on Maths StackExchange.

Is this fair ?

Link 1 : Expected Value

Link 2 : Standard Deviation

EDIT : One of questions has already been taken down by the user who posted it.


You can find old version of the page here

PS - I don’t see any solution posted there. Was there a solution?


Here is the other page.

Though it was answered after the contest was ended.


this is against code of conduct. And also we will not be able to know who did it and how many teams actually saw solution there and updated their code so to escape plagiarism.admin please see into the matter.


This contest need to be re-conducted because of the following reasons :-

  1. Questions were discussed on MathStackExchange.

  2. There was a problem with the STDDEV code evaluation.

Please look into the matter @admin and there is no way of finding out which teams cheated by looking at the discussion on MathStackExchange so it’s totally unfair for the teams who will not be able to qualify just because of the above mentioned reasons!


This round had lots of errors which created a huge chaos among the participants. This contest was not fairly conducted. These are not some silly errors at this level.

This contest must be reconducted


I agree contest must be re-conducted @admin . Even i was shocked to see so may submissions for the first 3 problems considering the fact that the 2nd and 3rd weren’t that easy. This isn’t a fair contest and totally hampers the spirit of those who don’t cheat and prepare well for the contest throughout the year and then give it. I am not saying everyone who submitted 2nd and 3rd problem cheated but seeing the amount of submissions, it isn’t fair for those who do it neat, even if the 5% of the submitted solutions were done by cheating.


This round had a few errors with both second ( STDDEV ) and third ( COMPRESSION ALGORITHM ) question which hampered the performance of many of the teams.It was really surprising to see that so many teams ( around 1000+ correct submissions for STDDEV and 500+ correct for COMPRESSION ALGO ) were able to solve them so quickly. Maybe, many of them were really good , so they were able to figure out the formulas that would give the correct answer. But, the fact that solutions were discussed for both the problems on an online forum like stack exchange must not be ignored.The contest was not fairly conducted. I agree that the contest must be re-conducted @admin .


I also request @admin to re-conduct the contest. These kinds of thing are not helping the CodeChef’s initiative for increasing the spirit of competitive programming in the country but are killing the same of those who work hard. Re-conducting the contest will be an answer to such people and will send a very strong message for the future.


Yeah, that’s right! The 2nd and 3rd questions weren’t easy. But there were lots of submissions to this problems. Please remove cheated teams, those who copied solutions from other websites. Hoping for the best rank of our team.

I was totally disheartened when i saw so many problems happened during the contest ,though we solved 3 and are hopefully attending onsite round ,but i feel really bad for my seniors who did have a greater knowledge and experience in coding, could not even have a look at the third question since they lost all hopes when they got stuck in the second one due to codechef errors.


I had a conversation with one of my friends in another college. He was highly ecstatic to say that he solved 3 problems without much effort. On asking further, he straight away told me that the math.stackexchange link was posted in the college FB group. Imagine the mass cheating that took place that day.


We solved 2 problems.for 2nd problem we did our best when we got that extra time so they provide and extra time for such issues is technically fine in my aspect ,but cheating was not good and ultimately its the mistake of that candidate who wished to find that answer on google rather than solving by themselves so let it be hats off to such questions _/_ @admin

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Recontest isnt a solution. No one can assure that such things will not happen again. And also for most colleges semesters will be starting soon. So most of us cant manage time for preparing again. I know many deserved candidates didnt get chance but like this there will be just an infinite loop of recontests. I know the contest wasnt fair but again recontest isnt a solution. Maybe the admins of those sites should be cautious in these times and anything related to ongoing contests should be deleted asap.


And for internal errors everyone faced that. Whenever you see something unexpected refer to the comments section. I saw the admins did respond pretty quickly anyone who asked about the verdict they got for their solution.

You know what this can be solved !!! This cheating issue for the preliminary Round can be solved.

How ?

  1. Set questions that are Algorithmic (instead of mathematical) , having long codes and a lot of Test Cases.

Benefits -

1)This type of question wont be answered on any of the online sites like etc withing 3 hours of time.

  1. Even if it is answered, then it would most probably be answered at the end of the contest on these online sites, like at 2:00 hrs of the competition , then those people who are negligent to think will eventually copy the code , as a result will end being caught under plagiarism.

3)Moreover, Having questions with long codes and good edge cases will make the contestants busy to think about solution rather than discussing on the college groups.

You can put the math questions on the regional rounds where there is no internet and no cheating can be done(only one’s knowledge and ability to think will be tested).

Yes, making such questions is tough.

So , things can be done , just don’t ignore the hardwork by saying “Nothing can be done” .


:frowning: Pathetic!! It is very disappointing to see such things happening in such a big contest. My whole team kept on thinking how to solve 2nd problem for 3 hrs without knowing this was happening, I don’t know how will codechef find who all cheated but it would be unethical and highly disappointing if the teams who cheated will move into regionals.

Can someone tell total time mentioned in the result of amritapuri region is in which unit?

I will report it to @admin . Dont worry, teams in past have been disqualified for it, and this will continue to happen.

And how could you possibly identify those teams which found the solution on this link @vijju123 ?