### ck98's blog

By ck98, history, 2 months ago, ,

Hey Codeforces!

Greetings from NJACK, the Computer Science Club of IIT Patna,

We feel excited to announce our very first edition of Apeireon , the annual coding fest of the Department of Computer Science and Engineering, IIT Patna. The fest will be packed with a plethora of fun events for all our dear "logicians". Introducing this time, Hacking Challenge, an event that requires you to think about the edge cases for the problems. The event is analogous to the process of hacking where we have to find loopholes in a built system. Here, you will be given a problem and its partially accepted solution (a code which seems to be correct but fails on some of the test cases), and you as ‘the debugger’ have to find an ‘edge’ test case where it fails. The problems have been prepared by eThAnE, MinorMiracle, Redemptioner and ElusiveDream.

1st Prize : 5000 INR

2nd Prize: 3000 INR

3rd Prize: 2000 INR

Ranks/Prizes are considered globally.

Please find the rulebook and registration form links below.

Rulebook: https://bit.ly/2vFDIO3

Registration: https://bit.ly/2QAnXPM

Contest link: https://bit.ly/33N67Oz

For more such fun events do check our facebook page https://www.facebook.com/njack.iitp/

• +62

 » 2 months ago, # |   +23 Very excited to participate in the event. Hope to get the cash prize.
 » 2 months ago, # |   +3 Good Luck to all n Have Fun guys
 » 2 months ago, # |   +26 Reminder : Contest starts in 5 hrs from now.
 » 2 months ago, # |   +16 Reminder : Contest starts in 24 minutes from now.
•  » » 2 months ago, # ^ |   +12 I wish i had seen this 74 minutes before.
 » 2 months ago, # |   0 As you do not response on challenge page, I will ask here. Are you sure that your checker to problem F is correct? I am almost 100% sure that something is wrong with problem.
•  » » 2 months ago, # ^ |   +4 Yes we are sure that problem F is correct .
•  » » » 2 months ago, # ^ |   +6 OK, what is c and n (k <= n^2) in problem H?
•  » » » » 2 months ago, # ^ |   +12 sorry for the typo c is defined in the question And c<=a^2
•  » » » » 2 months ago, # ^ |   +4 The question has been updated . It was a typo , Sorry for the inconvenience .
•  » » » 2 months ago, # ^ |   0 Again on problem F:) Maybe I do not understand something, but do strings a = "ac" and b = "bc" satisfying condition? If yes, which $d$ will work?
•  » » 2 months ago, # ^ |   +12 Your submissions for the question F are correct ! I manually checked them , I copied your hack and submitted from my account and it got accepted . It must be a hackerrank issue. We might remove the question since it is happening with 2-3 more contestants .
•  » » » 2 months ago, # ^ |   0 Ah, okay, that's happens...
•  » » » » 2 months ago, # ^ |   0 We are extremely sorry for the inconvenience !!!!
•  » » » » » 2 months ago, # ^ |   0 Is this the only problem with such strange behavior?
 » 2 months ago, # |   0 Is there any time limit for each task?
•  » » 2 months ago, # ^ |   +1 1 sec only But we have not considered TLE hacks since in all questions the given code wont give TLE.
•  » » » 2 months ago, # ^ |   0 I am not able to get any verdict past 10 mins
•  » » » » 2 months ago, # ^ |   0 Processed means WA as mentioned in instructions.
 » 2 months ago, # | ← Rev. 2 →   +6 Can someone explain what mistake I made in I? I answered 2 2 4, which should work as the code given produces -1 and the area satisfies all the conditions? I feel I'm missing something stupid here :(All in all, it was a pretty decent contest, definitely recommend :)
 » 2 months ago, # | ← Rev. 4 →   0 Seems that the contest is over, let's try to discuss the problems here.For problem F, is test case n = 6, s = (1, 1, 1, 1, 1, 30) correct? (correct answer = 1, code outputs 15) The bishop is unable to move anywhere other than staying in its original position.For problem I, is test case n = 2, s = (2, 4) correct? (correct answer 1 2, code outputs -1). The area is 2 * 4 = 8 which clearly has four distinct divisors.
•  » » 2 months ago, # ^ |   +8 Yes, for F I got AC with something like that I think.
•  » » 2 months ago, # ^ |   0 Also, problem F's statement was changed midway of contest without announcement. Will there be any rejudge regarding the old vs new statement?
•  » » 2 months ago, # ^ | ← Rev. 2 →   0 For F your test is correct, I used 6, (3, 1, 1, 1, 1, 1) with the same logic, and got AC.
•  » » 2 months ago, # ^ |   +1 Your F one was correct. Many people got it correct on that test case , even me. Don't know why it was showing wrong
•  » » 2 months ago, # ^ | ← Rev. 2 →   0 Very weird. My in contest submission https://www.hackerrank.com/contests/hacking-challenge/challenges/mutated-bishop/submissions/code/1322258142 was marked incorrect, but the after contest submission of identical testcase was marked correct https://www.hackerrank.com/contests/hacking-challenge/challenges/mutated-bishop/submissions/code/1322263661. Don't think I make any stupid mistakes of inserting random whitespace or newline, so can't understand what really went wrong?
•  » » » 2 months ago, # ^ |   +13 Seems that problem was not just with removed problem, but with hackerrank at all.
 » 2 months ago, # |   +15 Hey Everyone! So here went our very first online contest, Hacking Challenge v1.0. The event was a huge success, all because of the huge participation. With total 718 registered contestants who turned up for this event, we thank each one of you for your contribution towards making this event a ‘grandeur’ in the very first attempt of our annual coding fest, Apeireon. These are the top three contestants: guptagaurang00 shubhamjainiitb ll9311108110 Congratulations to all the winners for their brilliant performance!!! Fill this( https://bit.ly/2QAnXPM ) form (in case you have missed) to claim your prize money as soon as possible and contact Sameer(9028782395) for futher queries..!
•  » » 2 months ago, # ^ |   +3 Can you clarify the above discrepancies as well (Posted in the other comments)?
•  » » » 2 months ago, # ^ |   +14 Actually, many contestants have submitted the correct hacks, but the custom judge was giving WA verdict even if the script was accurate. We don't know the reason, maybe it's a technical issue from Hackerrank. So finally we decided to remove one question from the contest to minimize the issues during the contest. We are incredibly sorry for the inconvenience:(
•  » » 2 months ago, # ^ |   0 Can you please release some explanations/tutorial for all the problems? Or unlock other's submissions. Thanks.
•  » » » 2 months ago, # ^ |   +3 We have uploaded them !
 » 2 months ago, # |   0 What is the test case for problem Help Me Divide ?
•  » » 2 months ago, # ^ |   +3 Any two numbers with ratio 1e5 a/b = 1e5 to be precise
•  » » 2 months ago, # ^ |   +3 100000 1 As it will give output -1