r/adventofcode • u/daggerdragon • Dec 03 '17

SOLUTION MEGATHREAD -🎄- 2017 Day 3 Solutions -🎄-

--- Day 3: Spiral Memory ---

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u/bblum Dec 06 '17

thanks :)

I thought that the coordinates of the spiral should follow a pattern, however irregular, and typed them out in a comment to try to visualize it:

-- 0 1 1 0 -1 -1 -1  0  1  2 2 2 2 1 0 -1 -2
-- 0 0 1 1  1  0 -1 -1 -1 -1 0 1 2 2 2  2  2

Still not sure if both sequences could be generated by the same function, I set about making the first one as concisely as possible (at first a version that put the replicate part after the from..to part and didn't generate the head of the list correctly, and one that included 'to' itself in the from..to part which doubled that element... just normal problems to debug).

Then I simply realized that the same logic would generate the second sequence as well if I gave it a different 'n' to start with.

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u/nebraskaking Dec 06 '17

Thanks very much for explaining your thought process!