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-rw-r--r--advent-of-code/2023/10/1.rkt83
1 files changed, 0 insertions, 83 deletions
diff --git a/advent-of-code/2023/10/1.rkt b/advent-of-code/2023/10/1.rkt
deleted file mode 100644
index e4911aa..0000000
--- a/advent-of-code/2023/10/1.rkt
+++ /dev/null
@@ -1,83 +0,0 @@
-#lang racket
-
-(require "../../lib/utils.rkt")
-
-(define lines
- (call-with-input-file "input"
- (λ (fp)
- (get-lines fp))))
-
-(define diagram (list->vector lines))
-(define height (vector-length diagram))
-(define width (string-length (vector-ref diagram 0)))
-(define (char-at x y)
- (string-ref (vector-ref diagram y) x))
-
-(define (find-start)
- (let loop ((x 0) (y 0))
- (if (>= y height)
- #f
- (if (>= x width)
- (loop 0 (+ y 1))
- (if (char=? #\S (char-at x y))
- (cons x y)
- (loop (+ x 1) y))))))
-
-(define start (find-start))
-
-(define (valid-pos? pos)
- (define x (car pos))
- (define y (cdr pos))
- (and (and (>= x 0) (< x width))
- (and (>= y 0) (< y height))))
-
-(define first-pos
- (let ()
- (define up (cons (car start) (- (cdr start) 1)))
- (define down (cons (car start) (+ (cdr start) 1)))
- (define left (cons (- (car start) 1) (cdr start)))
- (define right (cons (+ (car start) 1) (cdr start)))
- (cond ((and (valid-pos? up)
- (member (char-at (car up) (cdr up)) (list #\| #\F #\7)))
- up)
- ((and (valid-pos? down)
- (member (char-at (car down) (cdr down)) (list #\| #\L #\J )))
- down)
- ((and (valid-pos? left)
- (member (char-at (car left) (cdr left)) (list #\- #\F #\L )))
- left)
- ((and (valid-pos? right)
- (member (char-at (car right) (cdr right)) (list #\- #\7 #\J)))
- right))))
-
-(define (next cur recent)
- (define up (cons (car cur) (- (cdr cur) 1)))
- (define down (cons (car cur) (+ (cdr cur) 1)))
- (define left (cons (- (car cur) 1) (cdr cur)))
- (define right (cons (+ (car cur) 1) (cdr cur)))
- (define c (char-at (car cur) (cdr cur)))
- (define possible-pos
- (cond ((char=? c #\|) (list up down))
- ((char=? c #\-) (list left right))
- ((char=? c #\F) (list right down))
- ((char=? c #\L) (list up right))
- ((char=? c #\7) (list left down))
- ((char=? c #\J) (list up left))))
- (let loop ((cur possible-pos))
- (if (not (equal? (car cur) recent))
- (car cur)
- (loop (cdr cur)))))
-
-(define (simulate)
- (let loop ((i 0) (cur first-pos) (recent start))
- (if (equal? cur start)
- i
- (let ()
- (define next-loc (next cur recent))
- (loop (+ i 1) next-loc cur)))))
-
-(define loop-length (simulate))
-
-(if (= 0 (modulo loop-length 2))
- (/ loop-length 2)
- (+ 1 (quotient loop-length 2)))