Jajceslav's blog

By Jajceslav, 3 months ago, translation, In English

Centroid Decomposition is kinda like Divide & Conquer on arrays (merge sort type divide&connquer) but for trees. Ever thought about it that way? Like HLD is a segment tree but for trees, what do you think? nvm just had a fun thought yesterday, never looked at it from this angle, cool (i attached some imagery)

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3 months ago, # |
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There is more to say, but to begin with. When you need to solve problem on a tree, try solving it on array and then extend your methods to trees. You just showed examples of those extensions, which I use when facing tough problem sometimes.

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    3 months ago, # ^ |
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    True! Very common trick to solve tree probems, esp. query related, trees are dope

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3 months ago, # |
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If I am not wrong then we also have: Fenwick Tree for Arrays = Binary Lifting for Trees

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3 months ago, # |
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BITSET is kinda like BITSET on arrays but for trees

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3 months ago, # |
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Similarly, segment tree is persistent divide and conquer on an array.

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    3 months ago, # ^ |
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    Similarly, persistent segment tree is persistent persistent divide and conquer on an array.

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      3 months ago, # ^ |
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      Similarly, persistent n-dimensional (range sum) segment tree is (persistent divide and conquer on) $$$^{n-1}$$$ persistent persistent divide and conquer on an array.

      Spoiler
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3 months ago, # |
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"Binary Search Tree" is literally "binary search on array, but you store the entire recursion tree".

"Segment tree" is literally "divide and conquer, but you store the entire recursion history".

I wish people teach these kinds of things in classes. This is the definition of knowledge = connect the dots on information.

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3 months ago, # |
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Koreans called this "divide and conquer on tree", before the word centroid decomposition became popular.