lperovskaya's blog

By lperovskaya, 10 years ago, translation, In English

The warm-up round for Yandex's annual international open championship in competitive programming, Yandex.Algorithm, starts tomorrow, May 16, 2014.

Yandex’s annual programming championship, Yandex.Algorithm, with original rules, international participants and monetary prizes is open to anybody who wishes to participate, regardless of their education, profession or programming style.

You can register for participation and compete for a top prize of about $9,000, with runner up prizes totalling to about $4,500 for second and about $3,000 for third places respectively. Yandex.Algorithm 2014 will consist of six rounds, including a warm-up round on May 16, a qualification round on May 25, three elimination rounds, which will run from June 1 to June 15, and a final round on August 1.

The registration deadline for Yandex.Algorithm 2014 is May 26.

Join Yandex.Algorithm 2014 to try yourself against real-life algorithmic problems, meet new friends and discover new possibilities.

PS: you need to have a full Yandex account to register. To convert your account use the link below

https://passport.yandex.ru/passport?mode=light2full

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10 years ago, # |
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Start time links are broken, as the links contain month=M.

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10 years ago, # |
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Is the contest rated?

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    10 years ago, # ^ |
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    It's not a CodeForces contest at all.

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10 years ago, # |
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In the registration page I saw the word "affiliation". What information I need to provide in this content?

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    10 years ago, # ^ |
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    I think it is the school/college/university/workplace you're in.

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10 years ago, # |
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The contest will take place, here on CodeForces?

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    10 years ago, # ^ |
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    No, Yandex has their own platform. Follow the links.

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10 years ago, # |
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I have two questions for you:

  1. What I need to do with your passport link? I have already registered an Yandex account and when I open your link, I only saw my personal information.

  2. The contest rules said that: "Contestants submit their solutions into the contest system with the help of the software provided. Before submitting a solution, the contestant chooses the compiler that will be used by the contest system, which runs on Linux, to compile the solution." -> What is the required program? Where can I download it?

Thank you.

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    10 years ago, # ^ |
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    1. The passport link is necessary for the owners of light accounts (i.e. authorised using social networks). As soon as you are registered, there is no need to do anything with the passport link.

    2. Rules refer to the contest environment as a provided software. You won't need to download or install anything, just use the online submission form. It should work well on Linux. =)

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10 years ago, # |
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In the Registration form, there is a section which we must fill in ---->>> "Affiliation", I don't know what does it mean, can you help me?

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10 years ago, # |
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As somebody said — some participant join to compete, other — to help with testing the server load. I am going to help with testing the server load at this competition :) At last RCC round help of people like me was invaluable :)

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10 years ago, # |
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Link to the contest for those how is lazy as me

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10 years ago, # |
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Many thanks to all participants! We know and already working on issues of old monitor content and the internal server errors in the beginning and at the very end of the contest. If you faced any other problems, please, report them to the http://feedback.yandex.com/contest/

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10 years ago, # |
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Can someone find the mistake in this code for A? I am puzzled :(

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    10 years ago, # ^ |
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    There are two:

    1) rook can't attack through white king.

    Test: a3 a5 a1. Right answer: normal. Your: check.

    2) black can capture white rook.

    Test a3 b1 a1. Right answer: check. Your: checkmate.

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      10 years ago, # ^ |
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      Thanks a lot, I realize my answer was far from correct and now, I feel stupid :P I guess this problem requires careful implementation, something which I suck at.

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    10 years ago, # ^ |
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    c1 a1 h1

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    10 years ago, # ^ |
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    a5 a1 a8

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10 years ago, # |
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Can I participate in the qualification round If I did not write the warm-up round?

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10 years ago, # |
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how to solve problem E that factorial??

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    10 years ago, # ^ |
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    For k = 0, answer will be the last non-zero digit the number n+1. Let d[n][k] is the answer. Then for n > 3 , d[n][k] = d[4][k].

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    10 years ago, # ^ |
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    Bruteforce in Python, just keep the last 10M digits for chosen reasonable M (feel free to use M = 10). No thinking required.

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      10 years ago, # ^ |
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      Actually M = 3 is enough :P

      PS: I just noticed, you mentioned last 10M digits, you mean the last M digits :D

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        10 years ago, # ^ |
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        Yeah, last M digits. But the more you choose, the more confident you can be.

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    10 years ago, # ^ |
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    You can use BigInteger in java.

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10 years ago, # |
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For Problem A I am unable to find any errors with my code. Can anyone please find out the mistake in it?
http://pastebin.com/jB6H3b7W
A small request to Yandex organisers. Kindly provide the test cases or editorials for the problems. Thanks in advance.

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    10 years ago, # ^ |
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    try f2 h2 h5 upd: try f5 h2 h5

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      10 years ago, # ^ |
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      It's showing "Check".
      Also if the just the white king is attacking black king at its current position and not the rook then what should be the answer "Check" or "Strange". I tried it both ways still it's giving wrong answer. Thanks for the test case but I think the code is giving right answer for this.

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        10 years ago, # ^ |
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        No, in this test answer is "Checkmate".

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          10 years ago, # ^ |
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          Thanks for pointing out the test case. I wasn't checking for the piece going off the board. my bad.

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          10 years ago, # ^ |
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          The answer is "Check" for this test case. But it helped me notice the stupid mistake I have been doing. Thanks.

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        10 years ago, # ^ |
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        Queen? King, no? If the kings are mutually attacking, then the position's Strange (it shouldn't be possible within chess rules!), wherever the rook is. The rules in the problem statement are listed in order of priority and make sense to anyone who knows the rules of chess.

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          10 years ago, # ^ |
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          Sorry for the typo there. Yaa got that. Sorry for such a naive question. Thanks.

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      10 years ago, # ^ |
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      try f5 h2 h5

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    10 years ago, # ^ |
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    I'd recommend you never, ever write code like this again. One little mistake while copy-pasting will throw all your work away. If the most primitive concept in the problem is the point, you most probably need a pair<int, int> or a struct with two fields. If you need to copy your code 8 times with small corrections, you most probably should think about looping over a constant array of 8 elements, rather than copy-pasting and adjusting indices by hand. (I'm trying to help, sorry if it sounds offensive.)

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      10 years ago, # ^ |
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      @udalov Thanks for pointing it out. I will take care of it in future.
      Doesn't sound offensive at all. I am open to all kind of suggestions.
      Thanks again.

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      10 years ago, # ^ |
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      While this way eliminates the risk of missing just one element to rewrite, it has other risks. Sometimes, there are problems which do a lot of operations on one 2D array in each direction; this can be solved by rotating/flipping that array and only doing a lot of operations on another array, but you need to pay attention to the order in which you use the elements of that other array; the more complex the operations are, the harder this is, and it gets harder much faster than copy-pasting and naming your 16 variables differently, because it requires heavy thinking about every line of code (and you need to think in indices instead of words). It's easy to be off by 1 in some formula, and these mistakes are harder to find than copy-pasting ones (find and replace).

      If the algorithm's doing something simple multiple times with small variations (or it's not too many times, it's not good to copy-paste. If it's something complex, it's debatable.

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10 years ago, # |
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10 years ago, # |
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Did B really have tests for large integer arithmetic? This seems totally unfair because solutions in Java will be like 3 times shorter than ones in C++, which is probably why such problems are avoided in other contests.

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    10 years ago, # ^ |
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    As a Python lover I can equally say that giving computation intensive problems with short TL is totally unfair, because same solution in C++ is 10 times faster. My point is that every language has its weak sides, even C++.

    I don't see any rule limiting you from developing your own small class for working with BigIngeters. To have it just in case. To be honest this is what I am doing now :)

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      10 years ago, # ^ |
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      @zholnin: Isn't it required in every online contest to start from scratch and to not use any previous code?

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        10 years ago, # ^ |
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        Why do you think so?

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          10 years ago, # ^ |
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          ACM ICPC rules

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            10 years ago, # ^ |
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            But this is not ACM ICPC competition

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        10 years ago, # ^ |
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        Isn't it required in every online contest to start from scratch and to not use any previous code?

        NO, it isn't!

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Can I participate in the qualification round if I didn't participate in the warm-up round?

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can someone explain to problem E on factorial. I see the solution but somewhat unable to get why for N > 4 , we take N = 4

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    10 years ago, # ^ |
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    Solve the small cases by hand and think about it :D

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I am unable to open the yandex links. Does this happen only with me?

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I can't find any working link for the contest, for hours. I guess the qualification round is running now, but I can't find a link for the contest.