ACM ICPC IIT KGP online round goof-up. We are sorry

3 min read

Dear CodeCheffers,

As the time nears the declaration of the selected list of teams for the onsite, we think we must own up the mistake and issue an apology. We understand that there were some problems with the online round for ACM ICPC 2013 IIT KGP regionals. For those who missed it:

  • Despite a few days of frantic optimising and working hard, we still experienced some issues during the last few minutes of the contest. This was due to heavy load on our database server which was unexpected given that we had fixed all such issues long back and had not experienced anything like this in any recent contest. There were multiple complaints of people not being able to access the site towards the end of the contest.
  • The problem statement of the problem EDITLIST was slightly ambiguous and to make matters worse, at 49th minute into the contest, we answered to a query in a haste making a comment that changed the problem specification and made the problem much easier to solve, but led to getting WA for many who tried to solve it in this way. Quite a few of you were not affected by it and were able to still get the solution accepted. Well done. For others, this led to a lot of frustration.

For the first issue, we investigated and found out that it was caused due to an un-optimised query that fetches you all the submissions of a particular problem in the practice section! We are in the process of fixing it, but we thought we should at least tell you what the reason is while the fix happens. To make up for it, we had extended the contest by another 10 minutes. We also eliminated all penalties for those who were affected by the slowness and ended up submitting the same solution multiple times.

The second issue impacted users much more. And we realised that we had goofed up, only after the contest. At this stage, we sat down and evaluated all the options to salvage the situation. We knew that we could not be fair to everyone from that point. No matter what we did from there, there would be one section who would be affected by this mistake of ours. Considering every possible scenario (including a re-contest), here’s what we decided to do:

Change the test data such that the solutions which solved the problem without sorting the output list also passes. This essentially also meant that the problem no longer required a DP solution to pass and became easier than what it was intended to be. We rejudged all the solutions which had not passed during the contest for this problem with the new test data, leaving aside those that had passed. This resulted in more teams now solving the problem.

Some of you are bound to feel (especially those who wasted a lot of time on this problem) that this isn’t fair. We know it, but there is not much that we can do about it. We screwed up, and we’re really sorry. Here are the other options and an explanation of why we took this approach:

  • Do nothing – Everyone had access to the same problem statement and the same comment, right or wrong. Many teams were able to solve it based on that. So why not do nothing about it and ignore the mistake. We almost did this, but then we felt it was just not right. There were also teams who read the comment made by us and kept trying to solve this seemingly new version of the problem without any success. And we had guided them towards this. So it was important for us to correct our mistake and acknowledge their effort at the very least.
  • A re-contest – Those affected have called for this, and though this may seem to be a fair solution, it is not and there are many factors that makes it almost impossible for us to do so. The execution of each contest (including this one) involves just about as many man hours of work on the problem setter’s / testers end as the number of man hours extended by the participants when the contest runs. And then finding the right schedule for all the people to participate is also not trivial. A re-contest would also waste the time of so many more people. And most importantly, it will be unfair to those teams who have already done very well in this contest and deserve to be there onsite.
  • Re-judge EDITLIST, altering the test data to accept both solutions – This is what we did. As mentioned earlier, it was not fair to everyone. It was specially unfair on those who spent more time in solving the DP version of the problem and not the new easier version. And also to those who got stuck at solving this one problem. But it did allow us to be fair to those who got misguided by our comment and acknowledge their effort.

While we acknowledge that we have goofed up and we regret it beyond what we can put across, we also think, that not being stuck on a problem, you are unable to solve, is among the many things that can propel your team to be a good ICPC team. A team of three wasting all their time on a single problem can cause a lot of frustration, but then that should not warrant wasting the time of so many other teams that have done well and also learnt to deal with such situations and got more efficient.

Some people will undoubtably feel like we should’ve taken one of the other approaches listed above. We’re sorry, we cannot do that. Don’t hate us. We know we have goofed up. And we did try our best to be as fair as we possibly can in the given circumstances. We wanted a good fair contest as much as you all did. We did receive some positive feedback on the problems being good as well. We have also published the editorials for the problems. We did try to do as much as we can.

For those who will not be able to make it to the onsites due to this mistake of ours, we sincerely apologise. We know, nothing can make up for it. But there is only so much we can do. Please do not get demotivated and do not give up. Please practice hard for next year. We will be around to help you all in your preparations. We assure you, that we will be extra careful next time around. We are sorry.

Anup

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53 Replies to “ACM ICPC IIT KGP online round goof-up. We are…”

  1. ” A team of three wasting all their time on a single problem ” , Just Think … If one can’t get a solution for a single simple question .. how they move to next question?

    “practice hard for next year.” , So what about Final Years ..?

  2. ” A team of three wasting all their time on a single problem ” , Just Think … If one can’t get a solution for a single simple question .. how they move to next question?

    “practice hard for next year.” , So what about Final Years ..?

  3. ” A team of three wasting all their time on a single problem ” , Just Think … If one can’t get a solution for a single simple question .. how they move to next question?

    “practice hard for next year.” , So what about Final Years ..?

  4. ” A team of three wasting all their time on a single problem ” , Just Think … If one can’t get a solution for a single simple question .. how they move to next question?

    “practice hard for next year.” , So what about Final Years ..?

  5. ” A team of three wasting all their time on a single problem ” , Just Think … If one can’t get a solution for a single simple question .. how they move to next question?

    “practice hard for next year.” , So what about Final Years ..?

  6. seriously guys, it leads to lots of frustration when you are not able to solve one of the easiest questions around, and well 4th years won’t be able to participate in the event due to well… never expected this big a good up from you guys, no apologies can make up for it, especially for the fourth years around….

          1. I would not agree if you say the teams who did well would suffer.. why will they suffer?? If they are good enough, they will surely perform good in the re-contest also, the only teams which will suffer are the ones who got selected luckily because other good teams failed due to the issues.

          2. Teams which have performed well will anyway perform well in the next contest. What about those teams who screwed up everything because of technical snag !
            We all are humans and mistakes happen. And if some mistake happen. We must try to rectify it. You guys must put in extra efforts to rectify your mistake and host a re-contest. It will be fair to all.

            Thanks

          3. Please please please re-conduct the contest. It will surely be fair to all and the deserved ones will be selected. Please understand

      1. but teams should not solve problems looking at comments, the problem statement should be enough for any problem. Moreover the question was so straighforward that anyone who has solved an Edit Distance Problem directly think upon this, without seeking help from comments

  7. I am from one of the lower NIT’s. I am in final year of my B.Tech degree. From past 2 years I was not able to solve more than one problem. Now this time I solved 2 problems.

    While everyone was getting confused for EDITLIST problem, I realized it quickly that its more or less EDITDISTANCE problem. I coded up a DP solution for that and got AC.
    Even after the contest I checked my rankings and found out that our team is ahead of every one in my whole college(even after a penalty). I was happy that this time I would surely reach the onsite round.

    Now due to your rejudging, one team got ahead of me by 17 seconds. They participated last year in the onsite too. I didn’t get a chance and now I would never get a chance. They would be going again too.

    You are telling that a re-contest would waste man hours of problem setter/tester and ” it will be unfair to those teams who have already done very well in this contest and deserve to be there onsite.”

    If you conduct the contest again , the people who deserve to be in onsite round would surely go ahead.
    But what about me??

    One suggestion : Increase the number of seats for onsite round @IITKgp. Accomodate atleast top 3 teams from each college(if possible)
    Best of luck from my side !!!!!

    1. @f872da583582b59b46e7531fdab86984:disqus: This is indeed very sad. We will try and request for an increase in the number of teams. But having 3 teams from every college may not be possible at all. There are physical constraints here. We truly regret this. We will try to increase a few slots but we cannot promise on that as of now.

  8. it’s acm-icpc u r talking about, not a goofy contest where

    making mistake is normal, I personally don’t mind about such
    things in these contest but for icpc it was a dead end nightmare.

    I agree with many people asking for recontest and that’s bcoz. if u blew
    something u have to pay for it not others.

    1. If it was the question of only us paying up, we would be glad to take it up. Also there are other teams who will also need to pay up for this. And then there are other factors and constraints that make it impossible to do so.

      1. No other teams won’t have to. If they did it first time they would again. This was just one of many rounds for them. I’m pretty sure they can take this once more.

  9. Well that’s true …ICPC is a “team contest” and the other “teams” acted smarter and didn’t waste all the time on EDITLISR and hence they do deserve to go further to next level. Only thing is that I learned something from this experience … and that’s what I will suggest all other teams to do instead of just getting angry at codechef…. I am also affected by this mistake of codechef and can’t make it to onsite .. 🙁 but nevertheless … best of luck & congratulations to those who made it …

    1. It is not about acting smart..The competition is about solving problems which you expect are correct…If u are a contestant of such a huge competition and you are not able to submit such an easy problem knowing that your code is correctly, it plays on your mind during the contest…

      1. Contest is not only about solving problems… it also judges your time management skills… had you even looked at the SUBSTR problem you would realize that it is damn too easy and atleast involve one of the team member to solve that problem … while the others still “debugging” the EDITLIST problem …

  10. With codechef setting such high standards we didn’t expected this in such an important contest…..It has never happened in a cook-off….This has always been a problem with ICPC online contest in India…Happened on Hackerrank (Amritapuri) and again at codechef….This is highly unprofessional from such a huge tech giant…

  11. Another solution possible is to alter the rules for selection of top team from every college ( which currently is counting to 105 and still impossible to accomodate in 60 seats ) and selecting the top teams from the rank list .
    else it will become impossible to accomodate second ranked team from iiit hyderabad which will be another goofy thing to commit

    1. How does this help to those who got affected? And what about those who still do not get selected?

      The slots are very less compared to the number of teams that appeared and hence solving even 2 problems does not guarantee and place at the on sites.

      1. should solving three problems guarantee our selection?
        our team has a rank under 20, but still we worry for our selection just because of college preference criteria. We stand second in a college with large participation (IIIT Allahabad). Please do look into our matter.

      2. You are saying ” what about those who still do not get selected?” :O …Since ULTIMATE JUSTICE will be RE-CONDUCT which you are saying is IMPOSSIBLE. I am just suggesting a way to give justice to some more teams thats it.This will surely “help” those who were top from there college and even close to top 60s “before your rejudge” and after rejudge were thrown down the second team of college who submitted brute force ( before the admin’s comment :'( or without even seeing admin’s comment… )
        In process of giving justice to those who got affected by your comment by rejudging , you in a way are doing injustice to those who were put down the ranklist from 1st position in the college because of your rejudge . Is this fair to them . Surely not. In order to acknowledge the affected teams efforts you are ignoring and putting down other teams efforts :/ ……And yes the scenario and situation was same for every team …Please Conctact the Kharagpur and ask them to increase the slots at least for top 2 teams as it was done by Amritapuri Onsite contest.
        *Or you can iterate from the top rank and select top 2 teams from every college till the slots are not full (thus no need for doubling the slots) .
        As this was the last chance for many of the teams who were damn serious for ACM-ICPC . TRY TO ACKNOWLEDGE THEIR EFFORTS TOO :/

  12. Our team couldn’t make it to the onsite. After not being able to solve the easiest problem there is, we were really demotivated. All of us took on solving the EDITLIST problem. But even then, I agree, apart from errors from your side, it does teach us an important lesson too. We have a lot to learn. We should’ve left that problem and went on ahead.We lack confidence and frankly experience.
    It still is a terrible mistake but well, nothing can be done about it than moving on.

    Thank you for being so honest 🙂

  13. Reconducting the contest would have been the best move i feel.
    Ofcourse it would require great efforts from your side but that would have brought even greater appreciation to codechef that you guys in order to keep it fair to everyone are even ready to put more efforts again.
    And now you can see everyone is blaming codechef only for your move.
    Because the happiness that we got after thinking we are selected and that too a day before the festival turned out to be nothing more than a heartbreaker the very next day of festival.
    Please think about this.
    And ofcourse your move brought loads of happiness to those whose “any kind” of solution got accepted and they are selected now. Although they should not be blamed.

    1. From an effort standpoint, conducting a re-contest is no big thing. There are other practical implications to it that have been discussed, debated and only then presented. It was considered but does not seem viable at this point.

  14. Would you please fire the admin who replied wrongly to the query and yes, you say “you worked hard on setting the problems and organizing everything” . Are you kidding me? Had you read EDITLIST once you would’ve asked what about the order of final list? Also, JACKPOT had the same initial para written twice. Don’t you get that it is a time bound contest? Where the heck is the hard work? I bet you didn’t even read the statements before publishing. YOU DON’T MAKE IT ONSITES UNLESS YOU SOLVE ALL OF THEM. SO YES!!!!!! ALL OF THE TEAM LOOKED AT THE EDITLIST. WE DID ALL THE REST OF THEM BUT COULDN’T EVEN SUBMIT BECAUSE OF YOUR AWESOME SERVERS. JUST SO YOU KNOW I WAS IN 4th YEAR AND YOU JUST RUINED WHAT I HAD BEEN PREPARING FOR SINCE YEAR-1.

  15. PLEASE EVERYONE WHO THINKS IT WAS UNFAIR AND THAT THE MISTAKE WAS UNACCEPTABLE REPORT CODECHEF AT manager@acmicpc.org .Please take the time to do this. How the heck can we GO FOR GOLD if it is like this. YOU DON’T GO FOR GOLD UNLESS YOU SOLVE ALL THE PROBLEMS IN THE QUALIFICATION ROUND. Especially the easiest one. so yes, we(all in final year) were stuck at it. we really would’ve solved it had the admin not commented that order was insignificant. it was the very next thing on our mind but well, he had to comment.

    1. NSG Yes , you are rite . Sent a Complaint to manager@acmicpc.org regarding this Issue. as codechef itself accepts its their fault . then why should we suffer .

      and the answer for 4th years ” As we said, there is nothing that we can do about them. ”

      what a great answer isn’t it?

  16. I hope you can consider using HackerRank. The Amrita regionals was so smmooth except the first 5 mins. Please try to consider or hosting it again in their platform. Please. We don’t have any more chances 🙁 – final year

  17. Other than “Rejudge EDITLIST”, 1 more thing you can do is to increase the seats from every college by 1 (i.e. 2 teams from every college) for onsite contest. As this will be helpful for many teams like mine who are from final year and do not want to loose the chance for onsite contest just bcz of a Mistake from your’s side.

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