27 lines
689 B
Racket
27 lines
689 B
Racket
#lang curly-fn racket
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(require "scripts/aoc.rkt")
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;; solution for day 3
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(define (char->prio chr)
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(- (char->integer chr) (if (char-upper-case? chr) 38 96)))
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(define (part1 input)
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(for/sum ([line (in-list input)])
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(define-values [left right] (split-at line (/ (length line) 2)))
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(~> (set-intersect left right) (set-first) (char->prio))))
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(define (part2 input)
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(for/sum ([group (in-slice 3 input)])
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(~> (apply set-intersect group) (set-first) (char->prio))))
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(define (parse fname)
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(map string->list (file->lines fname)))
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(module+ main
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(define input (parse "inputs/3"))
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(answer 3 1 (time (part1 input)))
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(answer 3 2 (time (part2 input)))
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(displayln "meow"))
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