fpvyzv600's blog

Segment Tree problem
By fpvyzv600, 11 years ago, In English

Hi everyone, I'm trying to solve 316E3 - Summer Homework. Despite reading the tutorial link, I could't understand clearly the solution. Could you explain me more detail??

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11 years ago, # |
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The key is the merging step

While merging and , we need to shift the Fibonacci multiplier of the second one by (l2 - r1) to the right , so that we get

Shifting can be done by using identity Fn + m = FnFm - 1 + Fn + 1Fm

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    11 years ago, # ^ |
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    F[n+m+1] = F[n]*F[m-1] + F[n+1]*F[m] ??

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      11 years ago, # ^ |
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      Yes. Proof can be found from matrix exponentiation, or by induction here

      Then make 2 segtree, for maintain (supposed to be seg1) and (supposed to be seg2).

      Sorry if this explanation seems unclear. More detail you can check my submission 7338693

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        11 years ago, # ^ |
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        wow, I've got it. Thanks you very much :)

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