diff options
Diffstat (limited to 'aoc2023-racket/day-08/day-08.rkt')
-rw-r--r-- | aoc2023-racket/day-08/day-08.rkt | 36 |
1 files changed, 0 insertions, 36 deletions
diff --git a/aoc2023-racket/day-08/day-08.rkt b/aoc2023-racket/day-08/day-08.rkt deleted file mode 100644 index 06daafa..0000000 --- a/aoc2023-racket/day-08/day-08.rkt +++ /dev/null @@ -1,36 +0,0 @@ -#lang racket - -(require advent-of-code - threading) - -(struct exits (left right) #:transparent) - -(match-define (list raw-directions raw-maze) - (~> (fetch-aoc-input (find-session) 2023 8 #:cache #true) (string-split "\n\n"))) - -(define directions (string->list raw-directions)) - -(define maze - (for/hash ([line (in-list (string-split raw-maze "\n"))]) - (match (regexp-match #rx"(...) = \\((...), (...)\\)" line) - [(list _ name left right) (values name (exits left right))]))) - -(define (to-next-node start end dirs maze) - (for/fold ([current start] - [acc 0] - #:result acc) - ([dir (in-cycle dirs)]) - #:break (string-suffix? current end) - (define node (hash-ref maze current)) - (case dir - [(#\L) (values (exits-left node) (add1 acc))] - [(#\R) (values (exits-right node) (add1 acc))]))) - -;; part 1 -(to-next-node "AAA" "ZZZ" directions maze) - -;; part 2 -(for/lists (ns #:result (apply lcm ns)) - ([start (in-list (hash-keys maze))] - #:when (string-suffix? start "A")) - (to-next-node start "Z" directions maze)) |