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CodeChef_admin's blog

By CodeChef_admin, 3 years ago, In English

Hi There!

I am so glad to announce that after a brief gap, SnackDown, CodeChef's global annual programming contest, is back this year!

The pandemic created a big gap, but we are glad that we could make it happen now. The announcement went yesterday, and today I am messaging to invite your registrations for SnackDown 2021. Yes, the registrations are open and will end on October 19th.

There is one important change this year, w.r.t SnackDown — SnackDown 2021 will be an individual-participant contest and not a team competition.

Why this change? With the current restrictions of maintaining social distancing, we deemed it imprudent to conduct the contest in a team setup. While we feel that team collaboration makes SnackDown a unique event, we believe it’s safer not to risk the health and safety of our participants. We will revert to team-based competition in the next iteration of SnackDown.

A few important details, I want you to note:

Registrations are open now and will be closed on October 19th.

  • The first Online Qualifier Round will be from Oct 15th till the 19th.
  • Online Qualifier Round 1A will be held between 21st — 23rd October, and,
  • Online Qualifier Round 1B will be held between 29th to 31st October.
  • Online Pre-elimination will be on 21st November, and,
  • Online Elimination will be on 5th December.
  • The Online Finale is scheduled to be held on 9th January 2022.

Register Here

SnackDown 2021 champion gets to take home a hefty cash prize of $10000 and a Gold Trophy. The first and second runner-ups will be awarded $7500 and $5000 respectively and trophies of the respective rank. There are many more prizes and cash awards for many other ranks and categories as well.

  • 4th to 25th Prize — $ 500
  • Top Indian Performer — $ 2000
  • Second Best Indian Performer — $ 1000
  • 3rd to 10th rank Indians — $ 250
  • Top School Student — $ 500
  • Second Best School Student — $ 250
  • Top Female Performer — $ 500
  • Second Best Female Performer — $ 250
  • Top School Student (Indian) — $ 250
  • Top Female Performer (Indian) — $ 250

`* Atleast two problems must be solved to claim these prizes.

Apart from these prizes, you can also become the official CodeChef SnackDown Representative for your school/college/company, and earn rewards/merchandise. We have separate categories for our Global Reps and Indian Reps. Details are given on the Referral page of the website.

Apply to become a SnackDown Representative here

We have also created two Practice Contests for you — one with Beginner level problems and one with advanced level problems.

Practice Contest — Beginner

Practice Contest — Advanced

In addition, top CodeChef experts will take live sessions as part of a SnackDown 2021 preparatory series, on our YouTube channel.

To say that we’re elated to bring back SnackDown this year would be an understatement. We’re sure you share the emotion with us. No matter who you are, where you are, if you’re a coder at heart, you will code your heart out, this SnackDown.

Reminder: October has already started, which means SnackDown 2021 is going to be here soon. Register now if you haven't already: https://bit.ly/3FkNynr, the qualifiers will begin on October 15th.

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3 years ago, # |
  Vote: I like it -58 Vote: I do not like it
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3 years ago, # |
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    3 years ago, # ^ |
      Vote: I like it +16 Vote: I do not like it

    I was hoping for a rick-roll, I am disappointed.

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3 years ago, # |
  Vote: I like it +244 Vote: I do not like it

There is one important change this year, w.r.t SnackDown — SnackDown 2021 will be an individual-participant contest and not a team competition.

I personally feel that, taking into account valid concerns about health, at least teams of 1-2 should be allowed (if teams aren't made necessary). It's not hard to compete while on a Zoom/GMeet call (my ICPC team did that for both prelims and regionals and it's not too big of an inconvenience in my experience, and with lesser people in the team, it would be even less of an issue).

IMO, the main reason why Snackdown has been popular in the past was that it was one of very few team competitions for competitive programming on a large scale (apart from ICPC, and perhaps Hash Code, however, that is not competitive programming), and it doesn't have as big a barrier to entry as ICPC (in terms of getting your university to approve you as participants). Also, teams of 2 people make more sense for majority of team contests in my opinion.

If that's taken away, then there's nothing separating this contest from a usual Code Jam or Hackercup round apart from the quality of problems. I believe that even though the participation might "double" or increase by a fraction of $$$\varepsilon$$$ (in terms of "teams", or whatever the metric you guys feel is important and also increases by this measure), it would not have the same appeal for a lot of people. This is an opinion shared by quite a few high-rated people I know, so it probably is a matter of concern. This is not meant to discredit the contest and the problemsetters though.

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3 years ago, # |
  Vote: I like it +251 Vote: I do not like it

Cool, hope to see interesting problems! I would prefer a 2-person format though. It was unique.

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    2 years ago, # ^ |
      Vote: I like it +11 Vote: I do not like it
    • it was unique after VK cup kicked it out :(.
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3 years ago, # |
Rev. 4   Vote: I like it +60 Vote: I do not like it

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2 years ago, # |
Rev. 2   Vote: I like it +19 Vote: I do not like it

Sorry to say but the give aways in snackdown 2021 qualifier are just too easy, I am disappointed

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    2 years ago, # ^ |
    Rev. 3   Vote: I like it -6 Vote: I do not like it

    Yes and probably in accordance with that, I have noticed that literally all of the good/popular CP people have boycotted the contest altogether. Contestants from India/total contestants is also stable at 93 percent, while it was closer to 80 percent in past years and remains closer to 60 on Hacker Cup/Code Jam, which is reducing the competition's capacity as a "Global Competition".

    I understand that this has probably been done not to demotivate middle schoolers and other pure beginners in programming in general, by giving them basic input/output and parsing problems, but still there's really no point if they aren't going to progress beyond r1 anyways.

    Really hope they pick the level up from round 1.

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      2 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      Where do you get the country percentage statistics? I'm probably missing something trivial, but I can't find how to filter the scoreboard by country.

      As for the real or imaginary boycott, I see that tourist was participating in many codechef contests and this is telling a lot. If even tourist finds the problems interesting enough to participate, then I don't see any big reason to avoid the codechef platform. Well, they do have a misconfigured D compiler with disabled optimizations affecting me personally, but I hope that this issue can be resolved.

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        2 years ago, # ^ |
        Rev. 2   Vote: I like it 0 Vote: I do not like it

        Indian Contestants Ranks Here you go you can see the ranks of everybody from India via this filter ^

        Yes I think it's probably all in my imagination, but still I can't find any of the top 20ish to have solved a problem. Even Errichto who expressed interest in seeing the problems in this very thread, doesn't seem to have to have done any as of now. Idk maybe they've all become admins or something haha

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          2 years ago, # ^ |
            Vote: I like it 0 Vote: I do not like it

          Thanks for the link. Do I understand it correctly that the country selection is not available via the UI and can only be added in the browser address bar? Are there any other interesting filtering options available in the same way?

          I can see that at least tourist and maroonrk are participating in SnackDown 2021. And there's still more than 1 day left for Errichto or anyone else to join. But I agree that only 27334 — 25401 = 1933 non-Indian participants right now is a bit too low.

          For comparison, there were 33853 participants, who managed to solve at least one problem in CodeJam 2021 qualification. And 16675 of them were Indians, which means that there were 17178 non-Indian participants. Though CodeJam is a special thing. It is sometimes featured in the news outlets and is much better known to the general public. Very few people know that Codeforces or Codechef exist.

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      2 years ago, # ^ |
      Rev. 2   Vote: I like it +38 Vote: I do not like it

      I doubt many people are boycotting this contest, it's more likely that people are just ignoring or dismissing it. I don't think I know anyone who would boycott a championship because the problems in the "press the registration button" round are too easy.

      It's also incorrect to say that all good people are ignoring the contest. Just by looking through the ranklists of a few countries I found Maksim, isaf, awoo, kostroma, maroonrk, uwi, acrush, etc. And I'm not cherry picking or anything, I just opened the ranklist and started writing down names I recognized; there was no shortage of them.

      Contestants from India/total contestants is also stable at 93 percent, while it was closer to 80 percent in past years

      The percentage of Indians in Codeforces is also much higher than it was 2 years ago. I think this is just an orthogonal thing and a misleading comparison. It's also natural that a championship organized by an Indian site has a higher percentage of Indians than a competition organized by someone else, I don't think this statistic means anything.

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    2 years ago, # ^ |
      Vote: I like it +4 Vote: I do not like it

    The online qualifier is geared entirely towards beginners, with the aim of getting more people motivated to get into the world of competitive programming through this tournament. The experienced users can just solve one problem and qualify anyway.

    The problems will of course get harder and more interesting in further rounds :)

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2 years ago, # |
  Vote: I like it +6 Vote: I do not like it

I'm unable to register for Snackdown.

This is the series of steps which is taking me into an undending loop.

  1. I'm logged in successfully.
  2. Try to submit a problem. (say https://www.codechef.com/SNCKQL21/submit/LUCKYNUM)
  3. It says "To make a submission you will have to register for this contest. For contest registration, please visit the contest page.".
  4. Cool. I go and try to register in the contest page itself. (i.e https://snackdown.codechef.com/registration/)
  5. I click on "Please login here".
  6. It then takes me to the already logged in site, codechef.com. :)

Anyone facing this issue? Incognito/clearing local data/cookies didn't work.

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2 years ago, # |
  Vote: I like it +71 Vote: I do not like it

Hi, I tried to participate in the qualifiers using Haskell and faced some issues, which I'll try to list below. CodeChef claims that a lot of languages are supported, but many do not seem viable at the moment.

  1. No TL multiplier
    I understand that Haskell is rarely used so a TL multiplier may not have been considered before. Haskell's performance is usually comparable to or slower than Java (which has a 2x multiplier), so I request Haskell be a given a multiplier of at least 2x.

  2. Gigantic input
    I don't understand why this was done. This only serves to hurt slower languages. Do we really need $$$10^6$$$ ints in one input? Do we really need 3 strings of length $$$10^6$$$?

  3. Old compiler
    CodeChef has GHC 8.0.1, which was released in May 2016 >5 years ago. In contrast, for C++ it offers GCC 9.1, released May 2019. From what I can see, most languages have outdated compilers, only C++ seems to have gotten special attention.

I hope some of these points can be addressed, to make usage of different languages more feasible for Snackdown, and on CodeChef in general.

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    2 years ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    Gigantic input

    I'm not familiar with Haskell, but being a user of some elements of the functional programming style in the other non-pure programming languages allowed me to understand the logic of your solution for the MAXDISTKT problem. It also helps to benchmark the code with the max constraints input. For MAXDISTKT the worst input would be something like:

    Ruby generator for testcase1 (T=10^5, N=10)
    Ruby generator for testcase2 (T=5, N=2*10^5)

    Benchmarking your code with GHC 8.0.1 shows that it's very fast for the testcase1 and would easily pass with the 1s limit. But the testcase2 is ~15 times slower, so I strongly doubt that even a 2x time limit multiplier would help you to get an AC verdict. As a quick and dirty test, removing "sort" from your code makes the testcase2 very fast too, so sorting is the only real bottleneck in your submission.

    It doesn't look like the gigantic input is a problem by itself. More like you are trying to sort a big linked list, which appears to be a poor choice of a data structure for this particular problem. I think that a better question is whether more efficient data structures are available in the CodeChef's Haskell setup. The following comment in an old blog implies that the Codeforces Haskell setup is not perfect either, while AtCoder is doing a somewhat better job.

    No TL multiplier

    Time limit multipliers are not used by Codeforces and AtCoder. Which online judge platforms already implement a time limit multiplier for Haskell and how large is it there?

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      2 years ago, # ^ |
      Rev. 2   Vote: I like it +6 Vote: I do not like it

      There is a TL multiplier on hackerearth and it is 3X for haskell.

      Why downvotes?

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      2 years ago, # ^ |
        Vote: I like it +11 Vote: I do not like it

      Gigantic input

      I'm not sure what your point is here. Yes, sort is the bottleneck in my solution. And yes, there are alternate faster ways to do it, with a little more code.
      Maybe I wasn't very clear in my initial comment. It's about the size of the data, not the byte size of the input file. I'm saying that being asked to solve for $$$10^6$$$ ints in 1 sec is overkill. The problem wouldn't be affected if sum of $$$N$$$ was limited, for example, to $$$2 \cdot 10^5$$$, and the solution would likely have passed (it runs in 0.7s locally).

      No TL multiplier

      Looks like it's 3x on HackerEarth (thanks forcdc) with an even older compiler, and 2.5x on Hackerrank.
      I'm not aware of many platforms with multipliers, but I think it's a nice feature when it's there.

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    2 years ago, # ^ |
      Vote: I like it +6 Vote: I do not like it

    Old Compiler

    CodeChef is notorius for using old compilers for lesser known languages. :(

    CodeChef has Python 3.6 which was released in December 2016 and official support for Python 3.6 will end on 23 December this year.

    Hope @CodeChef_admin takes some action.

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2 years ago, # |
Rev. 2   Vote: I like it +188 Vote: I do not like it

CodeChef_admin Something about PyPy2 and PyPy3 is fundamentally broken on codechef. I keep getting TLE even though my program in no way TLEs. Like just look at this!  For this problem alone I needed to submit the same exact code 8 times just to not get TLE. Only on my 8th attempt is the time correctly reported as 0.09 s.

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    2 years ago, # ^ |
      Vote: I like it +22 Vote: I do not like it

    :(

    PYPY, PYPY3, and NODEJS used to have this issue, but we thought it was mostly resolved a few months back. But evidently not. We'll look into this again now.

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    2 years ago, # ^ |
      Vote: I like it +77 Vote: I do not like it

    Time to play the game of: Did I actually TLE or was I just unlucky?

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2 years ago, # |
  Vote: I like it +3 Vote: I do not like it

The judge system is brutal. Please tell me at least the failed test number...

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2 years ago, # |
  Vote: I like it +14 Vote: I do not like it

Again the submission of equal beauty increases...means somewhere solution is leaked :(

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2 years ago, # |
  Vote: I like it +9 Vote: I do not like it

It's honestly so annoying watching the number of submissions increase drastically. It's quite obvious it's cheating but I'm sure the admins don't even care.

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    2 years ago, # ^ |
      Vote: I like it -13 Vote: I do not like it

    Joke is on you for joining a codechef contest lmfao.

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      2 years ago, # ^ |
        Vote: I like it +10 Vote: I do not like it

      Bruhh.

      I was thinking the cheating won't be as much as regular codechef rounds because it's unrated but I was soo wrong!

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    2 years ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    what's the point if they aren't gonna go beyond the prelims anyways :)

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      2 years ago, # ^ |
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      And what 's the point if more qualified people are unable to qualify for the prelims

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    2 years ago, # ^ |
      Vote: I like it +31 Vote: I do not like it

    It's depressing to see cheating, but at the same time I don't think it is at all fair to say that the admins don't care. Frankly, I think you're severely underestimating the amount of work needed to combat cheating.

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      2 years ago, # ^ |
      Rev. 2   Vote: I like it +6 Vote: I do not like it

      I can't remember the last codechef round they made any efforts to remove cheaters, even if it's just a few, ofc you can't remove them all.

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      2 years ago, # ^ |
        Vote: I like it +1 Vote: I do not like it

      Removing cheaters might be a pain but I don't get why contests are not of shorter length than being a long 2-3 days or 3 hours. They should be maximum of 2 hours (atleast when it's an online round). I guess that is what's the true meaning of "Competitive Programming". I appreciate Leetcode for contests although it 'might' not be a competitive programming site but it has a maximum of 1:30 hrs of contest length which is good. I guess we should all just downvote this Codechef's blog.

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2 years ago, # |
  Vote: I like it +8 Vote: I do not like it

Why couldn't it have been a point based qualification ,like codejam or fbhc? Right Now the current system is just messed up and encourages cheating.

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    2 years ago, # ^ |
      Vote: I like it +37 Vote: I do not like it

    Any system encourages cheating

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      2 years ago, # ^ |
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      Truer words were never spoken.

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      2 years ago, # ^ |
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      True, but some systems encourage or let's say 'permit' cheating more than other systems. Like I still don't get why rounds 1A and 1B are two day rounds rather than 2-3 hours.

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        2 years ago, # ^ |
          Vote: I like it 0 Vote: I do not like it

        Because we want some newbies to solve some problems and be a part of the huge event. Pre-Elim and further contests will be short and time will matter.

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      2 years ago, # ^ |
      Rev. 2   Vote: I like it +13 Vote: I do not like it

      Man, stop using this to comfort yourself. You're the admin of codechef and you guys can do better!

      Other CP sites at least remove cheaters(even if it isn't all) at the end but you guys just don't give a fuck.

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        2 years ago, # ^ |
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        Nothing can be done. If you say anything against the cheaters, the whole Indian community will attack you (downvote you) and will say the simple sentence," you cannot blame the whole community". My one simple question if 99% of the cheaters are Indian then who should we blame for? You guys made CP desperate for the students and this hasn't remained a fun anymore. It's like a serious study and a CSE student should /must /obviously learn cp. You guys made this happening promoting lame channels on youtube...Man, do cheating on real time interview and show your talent.

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        2 years ago, # ^ |
          Vote: I like it +15 Vote: I do not like it

        You're the admin of codechef

        I'm not sure of what Um_nik exactly does but I fail to see why cheating prevention and problemsetting should be the responsibility of the same person. "The admin" doesn't mean anything.

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          2 years ago, # ^ |
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          Um_nik has nothing to do when the masters and candidate masters sell the solutions of problems for money. Codeforces has many blogs about this.

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        2 years ago, # ^ |
          Vote: I like it +9 Vote: I do not like it

        We are trying. It is not as simple as you think. I, for example, have no idea how to do this. So I have to trust that people in the CodeChef backend team will do their job.

        I'm not responsible for fighting cheaters, so all I can say is that this issue is constantly discussed, and people are working on improving plagiarism check and on taking down YouTube videos.

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    2 years ago, # ^ |
      Vote: I like it +5 Vote: I do not like it

    Always Has Been, CodeChef making Long moves.

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2 years ago, # |
  Vote: I like it +52 Vote: I do not like it

Once again a complete joke. I said it after the qualifiers: remove the cheats or they’ll do it again. It would be very simple to remove cheats — they don’t even hide it. Hope the admin does something this time.

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2 years ago, # |
  Vote: I like it +19 Vote: I do not like it

Bad bad...you can even do a simple google search and you can see many people are sharing the idea / solution of a problem. Please do a plagiarism check after the contest ends.

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2 years ago, # |
Rev. 2   Vote: I like it +32 Vote: I do not like it

Another notorious coincidence brought to you by CodeChef! What an absolute joke of a contest...

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2 years ago, # |
  Vote: I like it +24 Vote: I do not like it

1000+ people seem to have magically come up with the solution to the 2nd hardest problem in the last hour of the contest.

Hope there is a plagiarism check.

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    2 years ago, # ^ |
      Vote: I like it +8 Vote: I do not like it

    At this point, they don't even try to hide that they cheated. Just look at the submissions made in the last hour.

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      2 years ago, # ^ |
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      They never did. I observed this in the qualifiers here

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2 years ago, # |
  Vote: I like it +41 Vote: I do not like it

I am just gonna boycott codechef from here on and would also persuade all my friends to do so.

How to ruin a contest 101 :

  1. Make it 2 days long

  2. Make it just point based scoring system

  3. (which would happen) Dont do plag check even when there are thousand of cheaters.

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    2 years ago, # ^ |
      Vote: I like it +1 Vote: I do not like it

    Codechef doesn't have plag check really?

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    2 years ago, # ^ |
      Vote: I like it +20 Vote: I do not like it

    They have made Long Challenge unrated for the same reason.
    So why are they conducting long challenges again for qualification, is this a joke or what!!

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    2 years ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    i too have the same opinion . i think we can make codechef realise this by not participating in the next round.so i would like to request everyone out there whoever are qualifying for next round plz dont participate to stop this right here.

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      2 years ago, # ^ |
        Vote: I like it +37 Vote: I do not like it

      Yes, let's make it viable for the cheaters to actually get to the finals, that will show them!

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      2 years ago, # ^ |
        Vote: I like it +17 Vote: I do not like it

      a very bad idea, these retards cheat just for the sake of improving their shitty resume, so you'll just be supporting them further

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2 years ago, # |
  Vote: I like it +20 Vote: I do not like it

Codechef is evolving.

Spoiler
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2 years ago, # |
  Vote: I like it +39 Vote: I do not like it

Btw, did anyone else notice the rise in ACs of Q5 from 1200 to 2600 in the last 40min? XD

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2 years ago, # |
  Vote: I like it +16 Vote: I do not like it

When you weren't able to solve enough problems, there are two options: - Leave it - Cheat

I think that P(cheated in this contest given not cheated before) (conditional probability) increased drastically increased in this contest.

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2 years ago, # |
  Vote: I like it 0 Vote: I do not like it

Wow E's AC number doubled in the last hour and I am out of the top 1500.