errorgorn's blog

Invitation to TLX Regular Open Contest #30
By errorgorn, 15 months ago, In English

Selamat pagi Codeforces!

We are excited to invite you to TLX Regular Open Contest #30!

Key details:

Many thanks to:

Please register for the contest or else rama_pang will drink all your milk 😋🥛.

UPD: the contest is over!

Congratulations to the top 5:

  1. Benq (perfect score)
  2. maroonrk
  3. hos.lyric
  4. hitonanode
  5. nuip

Congratulations to our first solvers:

Also, congratulations to Phantom_Performer for getting the 400000-th submission!

You can upsolve the problem here. Editorial is available in the upsolve link!

Thank you for participating and see you on the next contest!

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15 months ago, # |
  Vote: I like it +18 Vote: I do not like it

How to register

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    15 months ago, # ^ |
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    You should go to the contest link in TLX and register there. You need to login to register. If you have not made a TLX account before, you can easily make one there.

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15 months ago, # |
  Vote: I like it +48 Vote: I do not like it

TLX Regular Open Contest

Is the TOKI Regular Open Contest being renamed TLX Regular Open Contest?

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    15 months ago, # ^ |
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    Yes! It has been renamed since TROC 29.

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15 months ago, # |
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What's the contest difficulty when compared to a cf round? Div2 ? Div3? Div1?Div1+Div2?Div4?

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    15 months ago, # ^ |
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    It is like an easier version of a Div. 1 + Div. 2 Codeforces round.

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15 months ago, # |
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Friendly reminder that the contest will start in less than 90 minutes!

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    15 months ago, # ^ |
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    Don't forget to drink milk for good luck 😋🥛!

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15 months ago, # |
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Just curious, is there no tester for TROC or are they hidden?

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15 months ago, # |
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F: https://codeforces.com/gym/103447/problem/H

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15 months ago, # |
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E: dynamic connectivity is dead

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15 months ago, # |
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How to solve E without LCA and segment trees?

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    15 months ago, # ^ |
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    I used Zobrist Hashing code

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    15 months ago, # ^ |
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    It is possible solve it deterministically only using DSU.

    For the second part of the problem where we need to mark roads on a path from $$$A_i$$$ to $$$B_i$$$, we will merge vertices $$$u$$$ and $$$v$$$ if edge $$$(u,v)$$$ is marked on the DSU. When we add a new father from $$$A_i$$$ to $$$B_i$$$, we need to mark all unmarked paths from $$$A_i$$$ to $$$B_i$$$. This can be done quickly using DSU if in each DSU component, we store the highest vertex. This way we can quickly to the highest unmarked edge.

    code: https://tlx.toki.id/problems/troc-30/E/submissions/1289709

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      15 months ago, # ^ |
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      I wrote MST for the initial graph, and then deleted edges that were not necessary. I ran dfs on MST, lets say I am at a node ND and K is a son of ND, then look at a subtree starting with K, if in this subtree there is no node that needs to pass ND on it's way to it's "interesting" node then you can delete ND-K edge.

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15 months ago, # |
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Lucky me :)

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