intrusiv's blog

By intrusiv, history, 3 months ago, In English

Hi Codeforces,

Time goes by, and so should we. And it seems that the time has come for this year. So, it's a great time to reflect on and appreciate the standout problem sets that made this year memorable. What specific problem stands out to you as the highlight of your year?

PS: For the problems included in some of the most upvoted comments, I think I will host a poll to truly get the best problem of the year (so problems should be from a contest pertaining to this year). Applications (meaning comments taken in consideration) for this will naturally close at the end of the year after we've had time to see all of them.

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3 months ago, # |
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For me it is Milica And String

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    3 months ago, # ^ |
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    Note that "1 A" and "3 A" are also correct one-operation solutions.

    This problem statement update makes the problem 100 times easier.

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I've mentioned this before, but CF round 887 contains some of my favorite problems of the year. ABC are all great, B in particular is one of the best constructives I've seen (at least for problems of that level). This round also holds a special place in my heart, as my first ever div1 contest ;)

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1889B - Doremy's Connecting Plan Interestingly enough when I solved it I didn't really feel anything but only when I was discussing it with my friend this problem somehow touched my heart

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https://codeforces.com/blog/entry/122360 Can anyone help me to solve the above question

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Mine is definitely to become max since …

Spoiler
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In order of difficulty:

Comments
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    3 months ago, # ^ |
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    in Game of Stacks , idea is to remove the cycles since their removal will not affect the result.

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      3 months ago, # ^ |
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      I mean, the idea is quite intuitive after you come up with it, but it's hard to believe something so simple just works.

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        3 months ago, # ^ |
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        Agreed , I also find the idea quite neat and beatiful. I think it is a good candidate for the problem of the year.

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My most favourite is for sure 1844G - Tree Weights. The problem itself is natural, and the solution is cute!

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For me it is Tourism from JOI Spring Camp :3

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Serval and Brain Power by Serval (February)

M-tree by RDDCCD (March)

Tenzing and Tree by ??? (June)

Imbalanced Arrays by synths (July)

Candy Party (Easy) by Error_Yuan (September)

Turtle and GCD by skye__ (October)

Bonus! Aranara Game (easy) by oursaco (March)

Spoilers!!!

As always, thanks to all problemsetters who wrote problems this year :). Thank you for writing problems!

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https://codeforces.com/problemset/problem/1863/H

Loved the Pinley round in general, especially Goldberg Machine 3. Thanks Endagorion!

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3 months ago, # |
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This is a good shortest path problem: 1860E - Fast Travel Text Editor

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As a beginner , this problem 1872E - Data Structures Fan was one of the best competitive programming problems I've ever seen, its simple idea really blowing my mind

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koxia and number theory

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For me its of course

https://codeforces.com/contest/1875/problem/E (Jellyfish and Math)

Just look at the difference between number of people who solved D and E

What I like about this problem is the reduction to shortest path in graph and the construction was also pretty ingenious among other things, definitely the best problem I have seen so far

PS : Also this round was also my first CF round

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1804F — Approximate Diameter

1835C — Twin Clusters

1863G — Swaps

1876E — Ball-Stackable

AGC064D — Red and Blue Chips

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3 months ago, # |
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1860D - Balanced String , this is the problem that took me to the candidate master !!

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1830E — Bully Sort

(totally unbiased opinion :clown:)

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Probably sorted by difficulty:

Spoiler
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    2 months ago, # ^ |
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    Hint for subtask 7 of the last problem
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