atcoder_official's blog

AtCoder Beginner Contest 322 Announcement
By atcoder_official, history, 7 months ago, In English

We will hold AtCoder Beginner Contest 322.

We are looking forward to your participation!

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7 months ago, # |
  Vote: I like it +27 Vote: I do not like it

Note to self: Solve in this order A-B-D-E-C

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    7 months ago, # ^ |
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    why?

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    7 months ago, # ^ |
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    Why? I get an Accepted verdict with just around 10 lines of code for problem C? Today's C problem seems quite straightforward.

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      7 months ago, # ^ |
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      Yes, you are right. Today's D problem is very hard!

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    7 months ago, # ^ |
    ← Rev. 2   Vote: I like it 0 Vote: I do not like it

    But, in fact, I will solve in this order: A-C-B-D-E

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      7 months ago, # ^ |
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      Because I think C is easier than B

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      7 months ago, # ^ |
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      Am I weird for wanting to solve it in the order A-C-B-F-E-D?

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    7 months ago, # ^ |
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    C is quite easy today, even easier than B qwq.

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      7 months ago, # ^ |
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      I solved B way faster than C.I found C to be hard.

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    7 months ago, # ^ |
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    this time C was easy as hell

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7 months ago, # |
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I'm looking forward to seeing the problems of the contest! Atcoder has problems which are very interesting and useful for learning.

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7 months ago, # |
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Yeah, looking forward to getting a positive delta:D

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7 months ago, # |
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why 7 problems instead of 8?

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    7 months ago, # ^ |
      Vote: I like it +2 Vote: I do not like it

    It changed from ABC319. See the post archive.

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7 months ago, # |
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I hope my performance can get 2100+.

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7 months ago, # |
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Good luck with all the questions!

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7 months ago, # |
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Good luck everyone ^^

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

Posting this with no context

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7 months ago, # |
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D,E are so much difficult :(

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7 months ago, # |
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Writers of D and E I am coming to your house

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    7 months ago, # ^ |
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    E was easy,D was difficult,problem like F is also present in codeforces edu section.

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      7 months ago, # ^ |
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      I kinda disagree D is easy but the implementation part is too much for an ABC-D problem and E is kinda of no brainer as well and the implementation also a bit too much

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7 months ago, # |
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I guess today's test was a confidence booster

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7 months ago, # |
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How can we solve E using DP ? what's the state and transition

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    7 months ago, # ^ |
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    States were index and parameters. you can see my submission for ref.

    Code
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    7 months ago, # ^ |
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    it's pretty easy it's knapsack type of dp where either you pick a plan or no but since you have atmost 5 parameters where you can add the A[I][J] you can hardcode those states and you will have a dp[N][6][6][6][6][6] and transition you have two options skip or add the a[i][0] to the first parameters a[i][1] ... to a[i][K] but you should be careful since we need to be atleast P you don't have to keep adding while it's above P so you can do this trick of max(a[i][0] + Par1 , P) where Par1 is the first parameter etc... Or you can use map as as DP array to store all the 6^5 possible states instead of hard coding them.

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7 months ago, # |
  Vote: I like it -9 Vote: I do not like it

What is the purpose for setting the problem D? It uses almost no algorithm!

E and F is both easier than D in coding, and D takes me more time.I don't think problems like D is good.

And also, F is an original problem in Luogu.

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    7 months ago, # ^ |
      Vote: I like it +28 Vote: I do not like it

    The purpose is to test your implementation skills and speed. These kinds of problems often require you to compose your code correctly into functions in order to save time spent writing code in the contest. I think they are good to have on occasion, but maybe better in contests that are a little longer.

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      7 months ago, # ^ |
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      True, but it is quite hard to write. Sad.

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    7 months ago, # ^ |
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    Which problem in Luogu is F?

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      7 months ago, # ^ |
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      P2572

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        7 months ago, # ^ |
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        thx, going to get double experiences now :)

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          7 months ago, # ^ |
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          In fact it is not the same one. Problem F is part of it:)

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7 months ago, # |
  Vote: I like it +5 Vote: I do not like it

fucking dirty D

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7 months ago, # |
  Vote: I like it +9 Vote: I do not like it

Is there a way to do F other than lazy bashing? Also D is the most awful implementation I have had the misfortune of solving

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7 months ago, # |
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D is a good problem , but i dont like it. hope never see some as it again

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7 months ago, # |
← Rev. 2   Vote: I like it -6 Vote: I do not like it

what trash D and typical F......

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7 months ago, # |
  Vote: I like it +14 Vote: I do not like it

D is fkin implementation

E is fkin DP

F is fkin segtree template

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

Problem F is so typical, it is even an exist problem.

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7 months ago, # |
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Is there some elegant less code solution for D? Otherwise the problem is just implementation hell.

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7 months ago, # |
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Sometimes you have to do some tedious works. D is just a reflection of life which is very educational.

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7 months ago, # |
  Vote: I like it -18 Vote: I do not like it

what's wrong with this round????? boring as shit.

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7 months ago, # |
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Can anyone explain how (if possible) I can improve my method to work for D. Basically, I'm tiling in a checkerboard manner, with the observation that if a polyomino is even, the black and white squares will match, so polarity can either be Odd Odd Even or Even Even Even. Then I check if it's possible to match up to equate. This fails on sample 3 and 3 other random cases. I refuse to believe that there's a non-brute force method, so can someone improve my code to AC? Thanks.

Here is a link to my submission:

https://atcoder.jp/contests/abc322/submissions/46104612

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7 months ago, # |
  Vote: I like it -27 Vote: I do not like it

trash D

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7 months ago, # |
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First time for me to write a 11-level nested for-loop in a contest!

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7 months ago, # |
  Vote: I like it -15 Vote: I do not like it

Implementation of D insulted my implementation skill or is it trash itself ?

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7 months ago, # |
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The D and E are not very good,they don't have many thinking difficulty, but need a lot of code

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7 months ago, # |
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Why this contest felt like till C, there's nothing, and then the difficulty jumps sudden?

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7 months ago, # |
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C is easy,true

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7 months ago, # |
  Vote: I like it -18 Vote: I do not like it

Immediately after looking at D, I didn't want to solve it.

After looking at evima's video editorial, I just want to think that the task never existed in all history.

Like seriously what is this abomination

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7 months ago, # |
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Is there someone who can help me? I'm having trouble with this code not working in E.

My E code

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7 months ago, # |
← Rev. 2   Vote: I like it 0 Vote: I do not like it

F is an old problem (it is a easy version of SCOI2010 序列操作(SC, Sichuan, is a province of China)).

I think E is better, the trick is not very very easy to think of.

D is hard to write.

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7 months ago, # |
← Rev. 2   Vote: I like it +6 Vote: I do not like it

Tests for problem D are a bit weak. For example, this submission is wrong because if all three pieces overlap at the same place, it will be judged as correct. The following test can hack it.

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upd: There is another problem with the code, I have no idea how it could possibly have passed. Hack:

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    7 months ago, # ^ |
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    Lol, the irony that this guy wrote the alternate solution in official editorial 🤣

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    7 months ago, # ^ |
      Vote: I like it +10 Vote: I do not like it

    The given polyominoes are connected. In other words, the squares that make up a polyomino can be reached from each other by following only the squares up, down, left, and right.

    It seems that the first polyomino of the second hack violates the constraints.

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7 months ago, # |
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:v D is a big problem when implementing, E is DP tricky

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7 months ago, # |
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Some people cheat in problem F. Like this submission, it is nearly the same as the first article in the luogu tutorial.

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7 months ago, # |
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C is easier than usual,D is harder than usual

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6 months ago, # |
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Hello, in problem D editorial, there's proposition of using binary operation : https://atcoder.jp/contests/abc322/editorial/7311. To be honest, I didn't understand it at all. Can someone explain it further. Thank you,

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