32 lines
957 B
Racket
32 lines
957 B
Racket
#lang racket
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(require "scripts/aoc.rkt")
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;; solution for day 2
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(define (password-valid-part1? lmin lmax char password)
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(<= lmin (count (curry char=? char) (string->list password)) lmax))
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(define (password-valid-part2? a b char password)
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(define pwd-chars (string->list password))
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(xor (char=? (string-ref password (sub1 a)) char)
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(char=? (string-ref password (sub1 b)) char)))
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(define (calculate valid-proc input)
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(for/sum ([line (in-list input)])
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(match line
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[(pregexp #px"^([0-9]+)\\-([0-9]+) (.): (.*?)$" (list _ lmin lmax char password))
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(if (valid-proc (string->number lmin) (string->number lmax)
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(string-ref char 0) password) 1 0)]
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[_ (error "failed to parse" line)])))
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(module+ main
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(define input (file->lines "inputs/2"))
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;; part 1
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(answer 2 1 (calculate password-valid-part1? input))
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;; part 2
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(answer 2 2 (calculate password-valid-part2? input))
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(displayln "meow"))
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