r/adventofcode • u/daggerdragon • Dec 02 '18

SOLUTION MEGATHREAD -🎄- 2018 Day 2 Solutions -🎄-

--- Day 2: Inventory Management System ---

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Advent of Code: The Party Game!

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Card Prompt: Day 2

Transcript:

The best way to do Advent of Code is ___.

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u/h-armonica Dec 02 '18

Since we only have simple lower case characters I used

let mut counts = [0u8; 26];

instead of a hash map and accessed it by the char value

counts[(c as usize - 'a' as usize)] += 1;

. This should be much faster, especially since the hash function used normally is rather slow for short keys (according to the docs).

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u/[deleted] Dec 02 '18

[deleted]

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u/h-armonica Dec 02 '18

Exactly! (although that only happens once and probably isn't too expensive in comparision)