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Tree Merging

USACO · 2023 · US Open · gold-3

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trees

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sample trace

Tree Merging: trees walkthrough

Tree Merging: use the linked editorial?s trees idea on the published sample, then verify the displayed output.

Published input1 8 7 5 2 1 4 2 5 1 3 2 8 5 6 2 4 8 5 5 1 6 5modelAlgorithm ideaUse the rooted tree structure: each subtree is a self-contained region, and parent/child summaries support the requested query.task resultExpected output4 2 5 4 8 3 8 7 8
  1. 1

    Root

    Choose the root and record parent, child, and subtree relationships.
  2. 2

    Combine

    Process child subtrees or ancestor paths using the task?s required summary.
  3. 3

    Answer

    Translate the relevant tree region into the requested value or output.
  4. 4

    Verify the sample

    Use the published sample output to check the result of this idea on the displayed input.
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