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-rw-r--r--2021/day-25/day-25.rkt34
1 files changed, 12 insertions, 22 deletions
diff --git a/2021/day-25/day-25.rkt b/2021/day-25/day-25.rkt
index ba18b45..7a3a5ca 100644
--- a/2021/day-25/day-25.rkt
+++ b/2021/day-25/day-25.rkt
@@ -3,43 +3,33 @@
threading)
(define sea-floor
- (for*/hash ([(row i) (in-indexed (in-lines (open-day 25 2021)))]
- [(c j) (in-indexed row)])
+ (for*/hash ([(row i) (in-indexed (in-lines (open-day 25 2021)))] [(c j) (in-indexed row)])
(values (list i j) c)))
(define-values (max-i max-j)
- (~> sea-floor
- hash-keys
- (argmax (λ (coord) (apply + coord)) _)
- (apply values _)))
+ (~> sea-floor hash-keys (argmax (λ (coord) (apply + coord)) _) (apply values _)))
(define (cucumber-movement h c delta-i delta-j)
(define new-hash (hash-copy h))
- (for* ([(coord x) (in-hash h)]
- #:when (eq? x c))
+ (for* ([(coord x) (in-hash h)] #:when (eq? x c))
(match-define (list i j) coord)
(define neighbor (list (+ delta-i i) (+ delta-j j)))
- (define neighbor-or-wrap (if (hash-has-key? h neighbor)
- neighbor
- (list (if (= delta-i 0) i 0)
- (if (= delta-j 0) j 0))))
+ (define neighbor-or-wrap
+ (if (hash-has-key? h neighbor) neighbor (list (if (= delta-i 0) i 0) (if (= delta-j 0) j 0))))
(when (eq? #\. (hash-ref h neighbor-or-wrap))
(hash-set*! new-hash coord #\. neighbor-or-wrap c)))
new-hash)
-(define (eastwards-movement h) (cucumber-movement h #\> 0 1))
+(define (eastwards-movement h)
+ (cucumber-movement h #\> 0 1))
-(define (southwards-movement h) (cucumber-movement h #\v 1 0))
+(define (southwards-movement h)
+ (cucumber-movement h #\v 1 0))
;; part 1
-(for/fold ([f sea-floor]
- [step 0]
- #:result (add1 step))
- ([i (in-naturals 1)])
- (define f* (~> f
- eastwards-movement
- southwards-movement))
+(for/fold ([f sea-floor] [step 0] #:result (add1 step)) ([i (in-naturals 1)])
+ (define f* (~> f eastwards-movement southwards-movement))
#:break (equal? f* f)
(values f* i))
-;; no part 2 -- merry Christmas \ No newline at end of file
+;; no part 2 -- merry Christmas