erdos's blog

By erdos, history, 4 weeks ago, In English,

CodeChef October Mega-Cook Off 2018 starts in ~48h, (sunday 21 11:00 PET).

You will have 2.5h to solve 5 puzzles. My last contest was April Cook-off, ussually I only set one contest per year, so this year I broke the curse!

The character of the contest is Chef Ada, she is the most intuitive girl I have ever met. Sometimes she can solve a problem before I finish telling the statement!

Hope you enjoy the problems. See you in the ranklist!

Upd. This time there will be also statements in spanish. Spanish is a complex language, let's hope I didn't miss any accent mark:)

Contest log:

  • 11:08 many WAs in PUMPWAT. maddythakker takes the lead in div2.

  • 11:13 megabidoof ACed PUMPWAT, even tester had a couple of WAs in this problem

  • 11:24 kingofnumbers frightened me, numbers of equal height in the tests of PUMPWAT? false alarm, only the sample had a repeated element. Actually in the original version there was hills with equal height, but I decided to made the problem easier, and forgot to fix sample input.

  • 11:30 I just noticed zemen is in div2! with two div1 problems solved, he could be first in div1 in this moment.

  • 11:49 user:AlexDmitriev solved PWRTREE, he is still first

  • 12:00 zemen finally solved PWRTREE in div2

  • 12:31 KrK and uwi solving only two problems in a cc contest after 90 minutes? that is not often seen

  • 12:45 AlexDmitriev solved ADASHOP, IMHO it took him too much time, there are no submissions for ADAFARM yet.

  • 12:56 The blue coder (3 stars) zemen :) got perfect score in div2, wondering if he could get perfect score in div1.

  • 13:22 hatter from belarus solved ADASHOP skipping PWRTREE, that was an wise decision, I think PWRTREE is harder. Now he is 4th in div2.

  • 13:27 ADAFARM has only one submission, and unfortunately it is RE (sorry Golovanov399)

  • 13:35 Congrats to the winners!

Div 1.

  1. AlexDmitriev

  2. isaf27

  3. nuip

Div 2.

  1. zemen

  2. andrey_efremov

  3. Januzaj497

 
 
 
 
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4 weeks ago, # |
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Is there pasta or pizza?

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    4 weeks ago, # ^ |
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    There’s spaghetti.

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    4 weeks ago, # ^ |
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    There will be 5 delicious dishes (puzzles), and for dessert the editorials and some bonus problems.

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4 weeks ago, # |
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Hopefully "mega" won't bring the servers down, like the last time :)

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4 weeks ago, # |
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what does "MEGA" means this time?

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4 weeks ago, # |
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Auto comment: topic has been updated by erdos (previous revision, new revision, compare).

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3 weeks ago, # |
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Thanks for the PWRTREE task. I really loved it!

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    3 weeks ago, # ^ |
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    Without any spoilers (I'm still planning to upsolve it :) ), does one need to know some facts about tournament graphs or some fancy stuff to solve the power tree task?

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      3 weeks ago, # ^ |
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      No. It has completely elementary solution.

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        3 weeks ago, # ^ |
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        Here is my solution:

        Solution
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3 weeks ago, # |
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What was the intended solution for BINIM2?

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3 weeks ago, # |
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Editorial for some of the problems in my blog: https://aleigorithms.wordpress.com/2018/10/19/874/

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3 weeks ago, # |
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What is your solution to ADASHOP if you think that it is easier than PWRTREE?

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    3 weeks ago, # ^ |
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    the problem can be reduced to the case when the bishop is on the first column, then is just to find the pattern and count the number of cells of a given color in a triangle. Maybe ADASHOP is longer to code, but PWRTREE required more creativity.

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      3 weeks ago, # ^ |
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      As for me, ADASHOP was both harder to come up with and to implement. Certainly, PWRTREE required an idea, but it was rather straightforward: it's logical that you need to create PT(n) from something smaller, and 2 PT(n — 1)s is natural candidate given the size of PT(n) is 2^n. ADASHOP, on the other hand, required some case analysis and understanding some unusual structure (btw, I actually am not sure why my solution works fine for r = 1, I thought to special case it, but it passed bruteforce)

      Of course, problem difficulty is subjective, just my two cents.

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3 weeks ago, # |
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What is the general difference between a regular cook-off and a mega one?