firstly during the contest Cypher september codechef servers were not working properly ( pages not loading , IDE not working , etc)

many guys who had participated in the contest may have experienced the same.

personally this was my third time I have faced this kind of problem on codechef recently.

Apart from this there was a question Danny and the Square Difference in which only the problem setter(cypher101) got an AC

did this mean that all other participants code was wrong , Absolutely not.

Infact problem setters code was wrong which got an AC . yeah that means during contest the question was being judged wrongly which may have affected many users in different ways.

I personally was victim of the situation I submitted the code 4 times yet I got only WA

@admin @vijju plz see into the matter and make sure these kind of mistakes should not repeat in near future : )

#proof setters code was wrong :-

roughly speaking , In the problem we have to find numbers which can be written as a^2 - b^2 . and we know that 3 (2^2-1^2) should be counted among these numbers but in his solution he straight forwardly ignored 3 as he counted numbers greater than 4 (n > 4) which was the main reason of all Wrong answers


yeah i faced the same problem in the contest

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Yeah i think, the only mistake in code is condition of u>4.
it should be of u>=3; and we know every integer of form 4n+2 can not be written as difference of two squares .
we can check this condition also as:
if(u%4!=2) count++;

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I think admin doesn’t care about it : (

cauz no one has replied till now

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Quality control for external unrated contests is tough since they tend to get their own setters and testers. I’d rather have admin focus on more pressing issues than this.

It was external unrated contest.

Yes @aryanc403 it was :slight_smile:

just wanted to address the issue

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