poikniok's blog

By poikniok, 7 years ago, In English

So when I woke up this morning I saw that Codechef removed 2 of the 7 problems that were in the monthly long contest, link, because they were “found to be available online”. I wanted to make this post to protest this decision, as I feel like this sets a bad precedent, and does not have many benefits in my opinion.

My issue lies with the fact that part of reason I compete in long contest is so that when I do indeed solve a problem, I enjoy being able to look at other solutions after the contest is over, and learning from them. Removing problems makes this impossible I believe, and is also simply discouraging.

In addition I feel like the Codechef writers should spend 10 minutes Googling around before putting problem in. If they can not find anything in 10 minutes than I would say even if the problem can indeed be found somewhere, say on Chinese blog with code written in assembly, that it is nontrivial enough to find that it is okay to include the problem.

Having problems included for 3 days, letting people solve them and spent a lot of time thinking about them, and then removing them, makes for a bad contest in my opinion. As somebody who solved the problems without finding solutions online I would have been perfectly happy if they kept the problems, the fact that other people may have solved them by Googling does not upset me at all, particularly since in my opinion Googling is always a part of Codechef long contests, as at the very least for approximation problems and the like one can frequently find academic papers on the topic.

Anyway just wanted to make my opinion known, I don’t suppose the Codechef people likely care what I think, but maybe if people agree with me then they can change their policy for future.

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7 years ago, # |
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Edit: We will add those problems in the practice section. And add them in the contest only after the contest ends to avoid any confusion and also allow people to see other people's solution made during the contest. Sorry once again

I work with CodeChef, and we do care.

We sincerely apologise for what happened. We take a lot of care in the testing process. However, at times slippages happen. The process is human.

Your opinion matters and every opinion matters. We agree that removing problem was not a good idea. We will add them back and disable submissions and remove them from contributing to the rank list. We certainly cannot undo your effort. We hope that this address some of your concerns.

And we will try and ensure that the testing process is more full proof.

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7 years ago, # |
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the question they just added is copied from here which is again copied from here which is copied from a problem in POI (i cant find the link).

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    7 years ago, # ^ |
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    7 years ago, # ^ |
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    in problem MFREQ, the occurrences should be consecutive so it's different.

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      7 years ago, # ^ |
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      i dont think so as i submitted the same thing i did in the other questions and got AC

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        7 years ago, # ^ |
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        There are other solutions also. I got an AC with a solution which is no where near to these both problems.

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        7 years ago, # ^ |
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        as deva2802 said, there are solutions which are not related to (and also can't be used to solve) not-necessarily-consecutive version

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          7 years ago, # ^ |
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          Which don't matter too much now, as everyone can just grab the posted ones ;)

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            7 years ago, # ^ |
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            it is not pretty much obvious how to change the solution to not-necessarily-consecutive to make it fit consecutive version, it might be even easier to solve consecutive version from scratch :)

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          7 years ago, # ^ |
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          deva2802 was talking about the consecutive version, whereas rajat1603 was talking about the not-necessarily-consecutive version.

          Nevertheless, non-intended (and clearly wrong, according to the statement) solutions are getting accepted. The test cases seem to be very weak.

          EDIT: Okay, so exact code from this problem goes not get 100 points. But still gets 40 points and passes most files. (we should avoid discussing this further in this thread during the contest, though)

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            7 years ago, # ^ |
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            actually rajat1603 meant he got AC after he made small changes I checked his submission and it is actually correct, not that the testcases are weak

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              7 years ago, # ^ |
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              i didn't make any changes , also sometimes solution might exist for nonconsecutive case but not for consecutive case like {1 , 1 , 1 , 1 , 2 , 2 , 2 , 1} with k = 5.

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                7 years ago, # ^ |
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                if you didn't change anything how did your code answer -1 for this case

                5 1
                1 2 1 2 1
                1 5 3
                

                I meant you made changes to the solution of non-consecutive to make it fit the consecutive version, otherwise you shouldn't get AC

                as you said "solution might exist for nonconsecutive case but not for consecutive case" that means they are not same problem

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                  7 years ago, # ^ |
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                  I guess the testdata is just too weak as my code shouldn't give -1 on your case.

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                  7 years ago, # ^ |
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                  It's -1 for both the consecutive and non case(more than k times). You forgot to add an extra 1 maybe..

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                  7 years ago, # ^ |
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                  Actually, the problem statement wrongly states "more". It should be "more or equal". I commented on the problem too, but received no reply. I just assumed that that was the case by looking at the constraints, and my solution got AC.

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7 years ago, # |
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I work hard for both problems and felt discouraging. They should come up with a solution instead directly removing problems.