Yuki726's blog

Help in bitwise OR problem!
By Yuki726, history, 5 years ago, In English

Find a pair in an array with maximum bitwise OR? $$$1 \leq n \leq 1e6, 0 \leq a[i] \leq 1e6$$$

Can anyone help me with the solution or finding a blog somewhere.

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5 years ago, # |
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Maybe we can use SOS DP. Idea ->

We apply SOS DP to find array B, where B[i] represents the maximum masked value present in the given array where (value & i) == i.

Now, We again apply SOS to find array C, where C[i] represents the maximum values of B[i] among all the sub mask of C[i]. now to get maximum or with A[i], we complement it and get the corresponding answer from C[~A[i]].

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    5 years ago, # ^ |
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    Yuki726 I know the explanation is weird. But look at the code below, it's simple. Let me know if it is failing or if I am wrong somewhere. Code

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      5 years ago, # ^ |
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      Same approach has been mentioned in Maxor editorial. So probably your approach is correct (I tested with brute force too). But I am unable to prove it.

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      5 years ago, # ^ |
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      Thanks for the reply. Your code is correct and I was finally able to prove it.

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    5 years ago, # ^ |
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    nvm

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5 years ago, # |
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Check this out ...

problem:- https://www.codechef.com/problems/MAXOR

editorial:- https://discuss.codechef.com/t/maxor-ediorial/15798

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