diff options
Diffstat (limited to 'racket/aoc2023/day-02/day-02-parser.rkt')
-rw-r--r-- | racket/aoc2023/day-02/day-02-parser.rkt | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/racket/aoc2023/day-02/day-02-parser.rkt b/racket/aoc2023/day-02/day-02-parser.rkt new file mode 100644 index 0000000..76cc24f --- /dev/null +++ b/racket/aoc2023/day-02/day-02-parser.rkt @@ -0,0 +1,55 @@ +#lang racket + +(require racket/hash + advent-of-code + data/applicative + data/either + data/monad + megaparsack + megaparsack/text + threading) + +(struct game (id r g b)) + +(define cube/p + (do [n <- integer/p] + space/p + [c <- (or/p (string/p "red") + (string/p "blue") + (string/p "green"))] + (pure (cons c n)))) + +(define draw/p + (do [xs <- (many/p cube/p #:min 1 #:max 3 #:sep (string/p ", "))] + (pure (apply hash (flatten xs))))) + +(define all-draws/p + (do (string/p "Game ") + [id <- integer/p] + (string/p ": ") + [all-draws <- (many/p draw/p #:min 1 #:sep (string/p "; "))] + (define maxima + (foldl (curry hash-union #:combine max) + (hash "red" 0 "green" 0 "blue" 0) + all-draws)) + (pure (game id + (hash-ref maxima "red") + (hash-ref maxima "green") + (hash-ref maxima "blue"))))) + +(define game-maxima + (~>> (open-aoc-input (find-session) 2023 2) + port->lines + (map (λ~>> (parse-string all-draws/p) + from-either)))) + +;; part 1 +(for/sum ([m (in-list game-maxima)] + #:unless (or (> (game-r m) 12) + (> (game-g m) 13) + (> (game-b m) 14))) + (game-id m)) + +;; part 2 +(for/sum ([m (in-list game-maxima)]) + (* (game-r m) (game-g m) (game-b m))) |