atcoder_official's blog

AtCoder Regular Contest 198 (Div. 2) Announcement
By atcoder_official, history, 17 months ago, In English

We will hold AtCoder Regular Contest 198 (Div. 2).

The point values will be 300-500-700-700-900.

We are looking forward to your participation!

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Comments Comments (17)
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17 months ago, hide # |
 
Vote: I like it 0 Vote: I do not like it

What is the idea behind D? I was thinking of some dsu-based approach, but couldn't fit in the TL.

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17 months ago, hide # |
 
Vote: I like it 0 Vote: I do not like it

B is cancer for me

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17 months ago, hide # |
 
Vote: I like it -24 Vote: I do not like it

Instead of stronger cloudflare AtCoder need stronger sample cases!

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    17 months ago, hide # ^ |
     
    Vote: I like it +8 Vote: I do not like it

    Part of the difficulty in these problems (specially in B and C) is to create corner cases in order to break your solution ideas, with stronger samples it would just be a guessing game until it passes the samples.

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17 months ago, hide # |
 
Vote: I like it +8 Vote: I do not like it

D is very easy for its position

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17 months ago, hide # |
 
Vote: I like it -35 Vote: I do not like it

shit B, easy D

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17 months ago, hide # |
 
Vote: I like it +26 Vote: I do not like it

Supposedly the constraints in problem E were set to cut $$$O(2^N N^2)$$$ solutions. I used a similar idea to online convolution, but with OR convolution instead. It passed in $$$4.5$$$ s :).

My submission

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17 months ago, hide # |
 
Vote: I like it 0 Vote: I do not like it

In editorial of D I find

A naive implementation of this takes $$$O(NM)$$$ time; we speed it up.

But I can't find the definition of $$$M$$$ in the Problem or Editorial. Can you fix it or I'm wrong?

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

C was awesome, kudos to the setters

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

for B, this pattern works too. I used this 2101......2101101.....1012020.....200......0

Submission

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    17 months ago, hide # ^ |
     
    Vote: I like it +3 Vote: I do not like it

    I can't understand this hate for B.... I mean it was decent, no?

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    17 months ago, hide # ^ |
     
    Vote: I like it -10 Vote: I do not like it

    I couldn't even understand the English statement of B. I interpreted it as there are $$$A_i$$$ numbers that is no less than $$$\min(A_{i-1},A_{i+1})$$$, no more than $$$\max(A_{i-1},A_{i+1})$$$ and less than $$$A_i$$$. Unluckily, the sequece in the sample also fits this condition. It wasn't until I changed language to Japanese that I understood the problem.

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      17 months ago, hide # ^ |
       
      Vote: I like it 0 Vote: I do not like it

      I can feel for you. I also couldn't understand at first glance and when asked about it in clarification, they cleared it to me and I understood it

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