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Merging Cells

USACO · 2024 · January · platinum-2

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prefix-sums · two-pointers

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Merging Cells: prefix sums walkthrough

Merging Cells: use the linked editorial?s prefix sums, two pointers idea on the published sample, then verify the displayed output.

Published input3 1 1 1 4 3 1 1 1modelAlgorithm ideaStore cumulative aggregates so a range can be answered from two prefix values instead of rescanning its elements.task resultExpected output0 500000004 500000004 666666672 0 166666668 166666668
  1. 1

    Accumulate

    Build the running total or count across the input order.
  2. 2

    Query

    Subtract the prefix before a range from the prefix at its end.
  3. 3

    Finish

    Apply the task?s boundary adjustment and compare with the sample result.
  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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