Nickolas's blog

By Nickolas, 8 months ago, translation, In English,

The contest is over; I hope you've enjoyed it :-) Editorial is here.


The fifth April Fools Day Contest will take place on Friday March 31st. This is a joke competition in which solving the problem is often easier than figuring out what the actual task is. Thanks to kit1980 and Codeforces team for their help in preparing problems!

In this round you'll be given 7 weird problems and 2 hours to solve them. The contest will use ACM ICPC rules (no hacks, the standings are decided by the number of solved problems and penalty time earned on them), and it will be unrated. You can submit solutions in any language allowed by Codeforces. To get an idea of what the contest will look like, you can check out the contests of the past years: 2012, 2013, 2014, 2016.

Be warned, to enjoy competing in this round you'll need a sense of humor compatible with mine! Good luck, and have fun!

Announcement of April Fools Contest 2017
 
 
 
 
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8 months ago, # |
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Any plans for another Surprise Language Round?

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    8 months ago, # ^ |
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    Not for another Surprise Language Round by me, not in the next few months — I already have too many contests to prepare :-) But VK Cup Wildcard 1 next week is usually an Surprise Language Round, and there is a mirror for non-VK Cup participants.

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8 months ago, # |
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I sincerely hope they dont announce it to be a rated round after it has ended as a April fool's prank xD

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    8 months ago, # ^ |
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    yea it is good idea. some participant try slowly or not with "heart". but in my opinion rate is not important for programmer.

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      8 months ago, # ^ |
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      Yeah, contribution is the most important. That's for sure.

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8 months ago, # |
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I think my sense of humor is compatible with yours. I hope I will win again this year :)

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8 months ago, # |
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"April" fools on "March" 31st. Good.

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    8 months ago, # ^ |
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    The contest will be hosted on March 31 to ensure us that they won't switch it into a rated one making use of "April fools".

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    8 months ago, # ^ |
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    It is on April 1st (right at midnight, even) in my timezone. So I can say this is a true April Fools contest.

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8 months ago, # |
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Would "it will be unrated" be an April fool :D

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8 months ago, # |
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It overlaps with Catalyst Coding Contest :(

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    8 months ago, # ^ |
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    These days it's pretty much impossible to schedule a contest on or near weekend without it overlapping with something. I, for one, would love to have April Fools contest on the actual April 1st :-)

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      8 months ago, # ^ |
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      Round on March 31st sounds fishy maybe because round can become rated on April 1st. :P

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    8 months ago, # ^ |
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    If you don't like it, your sense of humor is simply incompatible with my

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8 months ago, # |
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I want my rate to be changed to 3600 as an april fool!

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8 months ago, # |
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After round #407 it seems like April fools' joke is the only way for me to get into div1...

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The contest should be not be a RATED one because it's for fun only.............And I wish after the contest is over everyone's rating gets doubled for sometime XD

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8 months ago, # |
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There was no fun in 2015..

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8 months ago, # |
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Hope the problems will not be fools XD

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8 months ago, # |
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is there a contest really ?(:funny,,maybe it is just a joke.

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    8 months ago, # ^ |
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    People have tried that kind of joke in 2015 when I didn't do the real contest. Personally I prefer more elaborate jokes :-)

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      8 months ago, # ^ |
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      i think you commented almost the same comment last year too! XD i prefer new jokes! ;P !

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        8 months ago, # ^ |
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        The jokes (as in tasks) will be new, but this comment is serious, and I still feel the same way about announcing non-existent contests as I felt a year or two ago :-)

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...

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8 months ago, # |
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Happy Fool is coming up :-D :-D

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8 months ago, # |
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"Is unrated" Are you sure it is not an april fool prank :p

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Keeping all jokes aside we should thank Nickolas who took time and effort and made this contest! This is my first April fool's contest and I wish I get to see amazing questions! :)

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8 months ago, # |
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Тут была картинка, показалась смешной, и не мне одному. Ну, не зашла у "зарубежников", бывает.

Всем удачи

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8 months ago, # |
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I hope this contest will be as crazy as last year's.

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Waited a year to participate in this unique contest and it overlaps with my office timing. Anyways, I will try to participate it in the middle or will just try to solve the problems after the contest.

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I hope, it will be fun more than a contest. Stress free contest :D :D Wish, everyone will enjoy and will not become fool. :p

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why unrated ?:(

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Damn!! no problem statement.. !! you had me.

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It is giving "rejected on test 1" in problem F. Crunching Numbers Just for You. What does that mean ?

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    8 months ago, # ^ |
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    Just wanted to ask the same thing

    Edit: "Results unsatisfactory, try harder"

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Will the contest be un-(unrated) because of the issue in G? :D

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8 months ago, # |
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I am become brute force, destroyer of problems.

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How look happiness

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8 months ago, # |
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What are you supposed to do in F?

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    8 months ago, # ^ |
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    You must consume more than 1 seconds

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    8 months ago, # ^ |
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    Spend more than one second for each test.

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    8 months ago, # ^ |
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    Make your code take more than 1 second (try harder!)

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    8 months ago, # ^ |
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    I guess, that get time consumed > 1s.

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    8 months ago, # ^ |
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    Make your program run long enough (I think > 1 second)

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    8 months ago, # ^ |
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    In Vietnamese we have a term for it "Chạy quá nhanh" (program runs too fast).

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      8 months ago, # ^ |
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      I don't get it. Why customer would request your program to run slow?

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        8 months ago, # ^ |
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        The words "Crunching Numbers" is an Idiom in English, I think it is "fake hard work"

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          8 months ago, # ^ |
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          Got it. Thanks.

          It's seem that I'm not as humorous as the problem setter tonight.

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          8 months ago, # ^ |
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          Reminded me with the Windows troubleshooter, it works for few seconds then tell you "Windows could not solve the problem automatically"

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        8 months ago, # ^ |
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        Imagine you are in a website, if your program runs too fast you may not even notice the website did something, so it may be better usability to delay the results a little to make the illusion that your program did something.

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        8 months ago, # ^ |
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        I heard websites that search for airfare tickets (like the problem) do intentionally make search results slow; that way people think they are doing their very best to search the cheapest, best fares.

        I also heard that they could do the job quickly, so I assumed that means they just slept for a few seconds before displaying the results. Which my submissions did, several times. Apparently you need to work, not just sleep.

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    8 months ago, # ^ |
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    Time run > 1 second

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    8 months ago, # ^ |
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    I tried to make the program run slower, but failed :p

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      8 months ago, # ^ |
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      If you were using Java, Thread.sleep will just make your program idle and will not take up any time on the CPU. Thus, your program's calculated runtime will still be small although the real time was low. You may get an "idleness limit exceeded" from the system because your program may be idle for too long if you slept for too much.

      Instead, loop until System.currentTimeMillis() is large enough so you know your program has been running for over a second.

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Ok I'm stupid. How to solve A? ;-;

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    8 months ago, # ^ |
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    Joke numbers in OEIS

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    8 months ago, # ^ |
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    You aren't stupid its ok: https://oeis.org/A006753

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    8 months ago, # ^ |
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    google the title of the problem

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    8 months ago, # ^ |
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    Search "joke" on OEIS website.

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    8 months ago, # ^ |
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    After submit many times, (about 40), I got the result for 1, 2, 3 is 4, 22, 27. Search that on OEIS, you can find a sequence called Smith (or joke numbers): https://oeis.org/A006753.

    I guess search joke numbers in google is much faster! :(

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    8 months ago, # ^ |
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    Bruteforce the first few values: 4,22,27... then search for a sequence in OEIS that starts with them :D

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      8 months ago, # ^ |
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      Many people solved it with first attempt, without bruteforcing. Can you explain this? :)

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      8 months ago, # ^ |
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      You can search "_,_,27 joke" instead of brute-forcing :)

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        8 months ago, # ^ |
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        "*Insert legend 27 joke used more than the internet* — 9GAG"

        "27 Times The "Hamilton" Fandom Had Jokes — BuzzFeed"

        "The single best joke told by every president, from Obama to Washington"

        Other search results are about equally helpful. How about no.

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          8 months ago, # ^ |
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          I should make my comment clearer :). You should search it on OEIS. The "_" is called wild card and it can replace any number.

          Capture.JPG

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    8 months ago, # ^ |
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    Basically there exists a sequence of numbers called joke numbers. you can go to this link to learn the sequence : https://oeis.org/search?q=number+joke&language=english&go=Search

    Now for the problem all we had to do was to print the nth number of the sequence where n is the given input.

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    8 months ago, # ^ |
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    I also want to know

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8 months ago, # |
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Explain me A, please.

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how do you solve A?

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8 months ago, # |
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Are the problems related to the chinese culture?

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    8 months ago, # ^ |
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    Er...I'm a Chinese but I did not find something about it (but I only solved a few questions...)Maybe.....QwQ

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      8 months ago, # ^ |
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      It was a joke, mainly because in top 20 there are like 17 chinese people.

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8 months ago, # |
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I wrote Bogosort for F but unfortunately it worked too fast.

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How to solve E? I solved with bruteforce but some people got AC with only one try.....

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    8 months ago, # ^ |
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    The three gates are and, or, xor. Enumerate which corresponds to which :-)

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So many rejections tonight...

It hurts :(

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How to solve E? I did all according to scheme, but it didn't work, so I just guessed all the tests. And how to solve B?

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    8 months ago, # ^ |
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    swap(or, xor)

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    8 months ago, # ^ |
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    binary search

    Spoiler
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    8 months ago, # ^ |
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    For B, count number of holes in hexadecimal representation. It comes from popular problem where you have to count number of holes in decimal.

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    8 months ago, # ^ |
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    Interchange xor and or operations

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    8 months ago, # ^ |
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    Check all variants of and, or , xor in scheme.

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How to solve E ?

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I still can't believe I got B :D

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    8 months ago, # ^ |
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    Could you tell me how solve B? Or give any hint.

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      8 months ago, # ^ |
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      You had to count the number of holes (gaps inside the numbers) in hexadecimal representation. (8 has 2 gaps, F has 0 for example)

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horrible problems :3

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Those who couldn't solve any problem, don't get upset! maybe you are not a fool!

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How to solve D?

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I noticed that the statement in C are compile error in INTERCAL. Then what next?

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    8 months ago, # ^ |
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    You should find wrong words in error and join it in the one statement, which will be: "Find xor of the max and last number of the array"

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    8 months ago, # ^ |
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    In each line there is on incorrect word. These words give you the statement

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Oh fuck. I'd only solved E ,for its transposed XOR and OR. Who solved F? i only got a rejection by using sort in STL.

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8 months ago, # |
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This contest has the lowest quality comparing to previous years 4.1 Contest. I doubt there's anyway to solve some problems without looking at others submissions. For example, in problem F, how can I extract enough information from judge's response "try harder"?

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    8 months ago, # ^ |
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    See name of the problem?

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      8 months ago, # ^ |
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      And what does it give? Because I don't get it.

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        8 months ago, # ^ |
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        Crunching Numbers — "What people pretend to do all day at work whilst daydreaming about things that will never happen."

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          8 months ago, # ^ |
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          But it looks like it does not always mean necessarily doing useless work, it may mean doing legitimate math or some calculation.

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WTF??????????????????? using BRAILLE to solve D????????????????????

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    8 months ago, # ^ |
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    WWWWWWWWHHHHHHHHHHAAAAAAAAAAATTTTTTTTTT????????????

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    8 months ago, # ^ |
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    wow, and 64 people solved it. How is it possible? And how are chinese participants connected with it? (28/37 participants from top-37, that solved D, are chinese)

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      8 months ago, # ^ |
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      Are they blind programmers? :D (just joking)

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      8 months ago, # ^ |
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      I think in this case the name "touchy-feely" is an appropriate hint to solve the problem.

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        8 months ago, # ^ |
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        I read statement and title in russian and it was closer to the meaning "sensitive".

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After discussing my solutions with chortos-2 and from this thread, I think we got all solutions. Here is the summary:

A. Joke numbers.

B. Number of holes in hexadecimal notation.

C. Every line is an INTERCAL compile error with a single word changes. Changed words form "FIND XOR OF LARGEST AND LAST ARRAY ELEMENTS".

D. Is the number palindrome in Braille?

E. Swap OR and XOR gates.

F. Make your sort work long enough.

H. Many solutions, one approach to split by digits, get the byte value to digit + 48 with '+', output it with '.' and reduce it back to 0 with '-'.

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    8 months ago, # ^ |
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    It's simplier to switch to another cart position in G with a single ">" instead of writing thousands of "-" to reduce it to 0.

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      8 months ago, # ^ |
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      We don’t need to reduce the value to zero though. The next digit only ever differs from the previous one by at most 9, so each digit needs at most 9 pluses or at most 9 minuses and a single dot.

      If we started each digit from scratch like you propose, we would need at least 48 pluses per digit to get from zero to the ASCII code range for digits.

      Edit: oh, I see eduardische phrased it that way. Yeah, we don’t need to use 48+ minuses to go back to literal zero; but we don’t need to switch cells either. Just use enough pluses or minuses to modify the current value into the value for the next digit.

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All right D is braille......Maybe I'm a fool....I stayed up in my country to take part in this contest....but I may not solve even one problem without other's hint.....(my English is not very good,forgive me)QWQ

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How did you come up with the solution of B?

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    8 months ago, # ^ |
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    The problem statement was somewhat similar to this image which was once went viral on facebook.

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      8 months ago, # ^ |
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      How did the 'hex' come up? Any hints in the Problem? Apart from guesses

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        8 months ago, # ^ |
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        It's not just any kid, it's a programmer's kid! Their parents would teach them the nicer bases as well.

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        'Programmer's kid'.

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      2 :-)

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When can we upsolve?

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For the problem D I even googled the word "touchy-feely" and I thought the problem really related to the other meaning of that word :p.

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The real programmers' kid:

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I must have been born with a fake brain....

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They said this was not a joke. I thought it was joke. I cout << "What the...."; for problem G and I Accepted. After that, WA :'(

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8 months ago, # |
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When we can see another people's submissions? It'll be funny!

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can someone really give me a quick-tip to improve my rating? plz... i wanna defeat my bro in this...

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    8 months ago, # ^ |
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    Upsolve the problems after every single contest and improve dynamic programming by regular practice. You can even become RED with this technique.

    P.S. I don't upsolve as I am a bit lazy.

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8 months ago, # |
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I get it that explaining a joke usually kills it, but maybe we can get at least some little hints? Like "Google" in case of task A? Edit: Nevermind, reading comments here might actually help.

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8 months ago, # |
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Any tutorials ?