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Promotion Counting

USACO · 2017 · January · platinum-1

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trees

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Promotion Counting: trees walkthrough

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

Published input5 804289384 846930887 681692778 714636916 957747794 1 1 2 3modelAlgorithm ideaUse the rooted tree structure: each subtree is a self-contained region, and parent/child summaries support the requested query.task resultExpected output2 0 1 0 0
  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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