Tanzim_bn's blog

Problem of the Year 2024
By Tanzim_bn, history, 6 hours ago, In English

As 2024 nears its end, let’s share the problems we enjoyed the most this year so far! Drop the problem name, link and what made it special (optional).

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5 hours ago, # |
  Vote: I like it +10 Vote: I do not like it

2044F - Easy Demon Problem Quite an interesting problem, looked really hard but had an easy mathematical solution (Do give it a try if you haven't).

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    4 hours ago, # ^ |
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    Would you mind giving some hints about it?

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      3 hours ago, # ^ |
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      Think about how you could decompose the query that you have been given into parts that you can correlate with the orignal input.

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      48 minutes ago, # ^ |
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      Try factoring

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    74 minutes ago, # ^ |
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    Indeed, this is one of the best questions I came across this year.

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5 hours ago, # |
  Vote: I like it +15 Vote: I do not like it

1933E. Xor-Grid Problem It demonstrates the magical nature of XOR operations, completing the missing rows and columns in an array.

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5 hours ago, # |
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1919D — 01 Tree Everything fits so nicely together!

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4 hours ago, # |
  Vote: I like it +4 Vote: I do not like it

1878F - Vasilije Loves Number Theory

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4 hours ago, # |
  Vote: I like it +7 Vote: I do not like it

2029C - New Rating Although dp is easier to think here, the bin search solution is really satisfying.

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3 hours ago, # |
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1843E — Tracking Segments binary search on the prefix sum!

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

https://mirror.codeforces.com/contest/1931/problem/F It was such a nice thing to use cycle detection in a statement like this.

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

Universal Cup 3.11 O - New School Term

I enjoyed being trolled by this problem. The final observation is so natural, yet so invisible. As far as I know, some LGMs were also trolled.

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    26 minutes ago, # ^ |
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    Can you share the observation? My idea is a bit ugly.

    Spoiler
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      25 minutes ago, # ^ |
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      Spoiler
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2 hours ago, # |
← Rev. 2   Vote: I like it +4 Vote: I do not like it

1977D - XORificator never seen this trick before and thought it was unsolvable before seeing the tutorial

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110 minutes ago, # |
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https://mirror.codeforces.com/problemset/problem/2042/E

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110 minutes ago, # |
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ARC171E — Rookhopper's Tour

The setting feels very chaotic to me initially, but after thinking it though, it turns out there exist an elegant way to analysis the problem model very simply to make it solvable. It's just... astonishing!

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58 minutes ago, # |
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https://mirror.codeforces.com/contest/1991/problem/H

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43 minutes ago, # |
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D. YEET!

Not because I'm the author , but because the non-randomized solution is really satisfying and cool !

For Problems I solved , hmm

B. Shohag Loves Strings is cool.

D. Harder Problem is indeed a nice "harder" trolling problem .

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38 minutes ago, # |
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https://mirror.codeforces.com/contest/321/problem/C

My 1st and only centroid decomposition AC

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29 minutes ago, # |
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I don't know about best problem, but worst problem of the year is definitely problem C in APIO, the problem sucks A LOT

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