atcoder_official's blog

AtCoder Regular Contest 199 (Div. 1) Announcement
By atcoder_official, history, 11 months ago, In English

We will hold AtCoder Regular Contest 199 (Div. 1).

The point values will be 800-800-900-1000.

We are looking forward to your participation!

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

The AGC-ization of ARC is real...

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11 months ago, hide # |
 
Vote: I like it +6 Vote: I do not like it

A wasted me half a round ... Nice problem but it's too alien-like.

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

In problem B I wonder why my solution is wrong.As you can see,first I can find all subsequences that xor up to K using Linear Basis.Also I think that among all subsequences,only 1,3,5,...n-[n is even] or 2,4,6,,...,n-[n is odd] cannot be produce.Otherwise I can make a construction.Why does that result in WA?

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    11 months ago, hide # ^ |
    ← Rev. 3  
    Vote: I like it 0 Vote: I do not like it

    If you find a subset that has a xor sum = K and that subset is 1,3,5... or 0,2,4,6... but there is another subset has a xor sum = K and is not 1,3,5... or 0,2,4,6..., you will get WA. To avoid this, the method in Official Editorial is good.

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

A and B both were very nice.

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11 months ago, hide # |
 
Vote: I like it +4 Vote: I do not like it

ARC Div1 should be renamed as AGC Div2. What do you think?

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

Can you public some of the B's test cases. It's hard to debug.

Edit: OK, debug B is not so that hard. I've got a good method to debug B, If you can pass all $$$K\in[0,1023]$$$ if $$$A=[1,2,4,8,16,32,64,128,256,512]$$$, you can have a high chance to get AC. I don't need test cases any more. Thanks.

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