Problem statement confusion (2019 Feb Gold)

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In the problem Painting the Barn, the sample test cases produce the following (truncated) grid (number in the cell represents the number of coats of paint applied):

Now, we can paint regions (2,7)\rarr (8,7) and (8,2)\rarr (8,6) to give a total of 33 cells with 2 coats of paint. However, the answer states 26.

What is the mistake in my diagram or notation?

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Anyone?

[SansPapyrus683]

The coordinates they give you aren’t cell-wise- they’re point-wise.

For example, for the first rectangle, 1 1 and 4 4, the diagram you provided provides a 4 x 4 painted region, while it’s actually only a 3 x 3 painted region.

(disorienting, i know)

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Thanks a lot! Kept banging my head for 3 hours on the sample tests.
How silly of me, smh…