diff options
Diffstat (limited to '2021/day-15/day-15.rkt')
| -rw-r--r-- | 2021/day-15/day-15.rkt | 48 |
1 files changed, 14 insertions, 34 deletions
diff --git a/2021/day-15/day-15.rkt b/2021/day-15/day-15.rkt index e9101a6..5e61c55 100644 --- a/2021/day-15/day-15.rkt +++ b/2021/day-15/day-15.rkt @@ -6,33 +6,23 @@ (struct Point (x y) #:transparent) (define data - (for/fold ([cells (hash)]) - ([row (in-lines (open-day 15 2021))] - [x (in-naturals)]) - (for/fold ([cells cells]) - ([n (in-string row)] - [y (in-naturals)]) - (hash-set cells - (Point x y) - (~> n string string->number))))) + (for/fold ([cells (hash)]) ([row (in-lines (open-day 15 2021))] [x (in-naturals)]) + (for/fold ([cells cells]) ([n (in-string row)] [y (in-naturals)]) + (hash-set cells (Point x y) (~> n string string->number))))) (define x-max (~>> data hash-keys (map Point-x) (apply max))) (define y-max (~>> data hash-keys (map Point-y) (apply max))) (define (neighbors pt d) (match-define (Point x y) pt) - (~>> (list (Point (add1 x) y) - (Point (sub1 x) y) - (Point x (add1 y)) - (Point x (sub1 y))) + (~>> (list (Point (add1 x) y) (Point (sub1 x) y) (Point x (add1 y)) (Point x (sub1 y))) (filter (curry hash-has-key? d)))) (define (grid-graph d) - (weighted-graph/directed - (for*/list ([coord (in-list (hash-keys d))] - [neighbor (in-list (neighbors coord d))] - [weight (in-value (hash-ref d neighbor))]) - (list weight coord neighbor)))) + (weighted-graph/directed (for*/list ([coord (in-list (hash-keys d))] + [neighbor (in-list (neighbors coord d))] + [weight (in-value (hash-ref d neighbor))]) + (list weight coord neighbor)))) ;; part 1 (define (find-path-weight d) @@ -42,28 +32,18 @@ (define ym (~>> d hash-keys (map Point-y) (apply max))) (hash-ref node-distances (Point xm ym)))) -(~> data - find-path-weight - time) +(~> data find-path-weight time) ;; part 2 -(define nine-cycle - (in-cycle (inclusive-range 1 9))) +(define nine-cycle (in-cycle (inclusive-range 1 9))) (define (expand-data data) - (for/fold ([cells (hash)]) - ([coord (in-list (hash-keys data))]) + (for/fold ([cells (hash)]) ([coord (in-list (hash-keys data))]) (match-define (Point x y) coord) (for*/fold ([cells cells]) - ([n (in-range 5)] - [m (in-range 5)] - [val (in-value (hash-ref data coord))]) + ([n (in-range 5)] [m (in-range 5)] [val (in-value (hash-ref data coord))]) (hash-set cells - (Point (+ x (* n (add1 x-max))) - (+ y (* m (add1 y-max)))) + (Point (+ x (* n (add1 x-max))) (+ y (* m (add1 y-max)))) (sequence-ref nine-cycle (+ val n m -1)))))) -(~> data - expand-data - find-path-weight - time)
\ No newline at end of file +(~> data expand-data find-path-weight time) |