aoc2022/2.rkt

#lang curly-fn racket

(require "scripts/aoc.rkt")

;; solution for day 2

(define (part1 input)
  (for/sum ([line (in-list input)])
    (+ 1 (second line)
       (~> (- (second line) 2 (first line))
           (modulo 3)
           (* 3)))))

(define (part2 input)
  (for/sum ([line (in-list input)])
    (+ (* (second line) 3)
       (~> (+ (second line) (first line) 2)
           (modulo 3)
           (add1)))))

(define (parse fname)
  (for/list ([line (in-list (file->lines fname))])
    (map #{hash-ref (hash "A" 0 "B" 1 "C" 2 "X" 0 "Y" 1 "Z" 2) %}
         (string-split line " "))))

(module+ main
  (define input (parse "inputs/2"))
  (answer 2 1 (time (part1 input)))
  (answer 2 2 (time (part2 input)))
  (displayln "meow"))