1 files changed, 0 insertions, 38 deletions
diff --git a/2021/day-12/day-12.rkt b/2021/day-12/day-12.rkt
deleted file mode 100644
index 18ed86f..0000000
--- a/2021/day-12/day-12.rkt
+++ /dev/null
@@ -1,38 +0,0 @@
-#lang racket
-(require "../../jj-aoc.rkt"
-         threading)
-
-(define path-pairs
-  (for/list ([l (in-lines (open-day 12 2021))])
-    (match (string-split l "-")
-      [(list start end) (cons start end)])))
-
-(define edges-hash (make-hash))
-
-(for ([pair (in-list path-pairs)])
-  (match-define (cons start end) pair)
-  (hash-update! edges-hash start (curry cons end) '())
-  (hash-update! edges-hash end (curry cons start) '()))
-
-;; part 1
-(define (backtracking-disallowed? next prevs)
-  (and (equal? (string-downcase next) next) (member next prevs)))
-
-(define (look-for-next-cave [path-list '("start")] #:only-one-visit? [visit-used-up? #t])
-  (define current-cave (car path-list))
-  (cond
-    [(equal? current-cave "end") (list path-list)]
-    [else
-     (~>> (for/list ([next-path (in-list (hash-ref edges-hash current-cave null))]
-                     #:when (and (not (equal? next-path "start"))
-                                 (not (and (backtracking-disallowed? next-path path-list)
-                                           visit-used-up?))))
-            (look-for-next-cave
-             (cons next-path path-list)
-             #:only-one-visit? (or (backtracking-disallowed? next-path path-list) visit-used-up?)))
-          (apply append))]))
-
-(~> (look-for-next-cave) length time)
-
-;; part 2
-(~> (look-for-next-cave #:only-one-visit? #f) length time)