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Day 05: Better parsing.

This commit is contained in:
Jonathan Chan 2021-12-04 21:44:16 -08:00
parent 9cdb24bfa5
commit bb5718c3ec
1 changed files with 4 additions and 7 deletions
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11
src/05.rkt
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@ -6,10 +6,7 @@
(define lines
(for/list ([line input])
(~> line
(regexp-match #px"(\\d+),(\\d+) -> (\\d+),(\\d+)" _)
rest
(map string->number _))))
(map string->number (regexp-match* #px"(\\d+)" line))))
(define-values (hvs diags)
(partition #{or (= (first %) (third %))
@ -24,10 +21,10 @@
(match hv
[`(,x ,y1 ,x ,y2)
(for ([y (range (min y1 y2) (add1 (max y1 y2)))])
(hash-update! grid (list x y) add1 0))]
(hash-update! grid `(,x ,y) add1 0))]
[`(,x1 ,y ,x2 ,y)
(for ([x (range (min x1 x2) (add1 (max x1 x2)))])
(hash-update! grid (list x y) add1 0))]))
(hash-update! grid `(,x ,y) add1 0))]))
(define part1 (count-crosses grid))
@ -40,7 +37,7 @@
(if (>= y2 y1) (values add1 1) (values sub1 -1)))
(for ([x (range x1 (x-offset x2) x-step)]
[y (range y1 (y-offset y2) y-step)])
(hash-update! grid (list x y) add1 0))]))
(hash-update! grid `(,x ,y) add1 0))]))
(define part2 (count-crosses grid))