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day 21: more minor prettification for no reason

This commit is contained in:
xenia 2020-12-21 01:55:22 -05:00
parent 79ff63e453
commit 318749e6b3
1 changed files with 7 additions and 8 deletions
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13
21.rkt
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@ -9,21 +9,20 @@
(define (part1 input) (define (part1 input)
(match-define (data lines all-is all-as tainted) input) (match-define (data lines all-is all-as tainted) input)
(define untainted (set-subtract all-is (apply set-union (hash-values tainted)))) (define all-tainted (apply set-union (hash-values tainted)))
(for*/sum ([l (in-list lines)] [i (in-set (line-is l))] #:when (set-member? untainted i))
(for*/sum ([l (in-list lines)] [i (in-set (line-is l))] #:unless (set-member? all-tainted i))
1)) 1))
(define (part2 input) (define (part2 input)
(match-define (data lines all-is all-as tainted) input) (match-define (data lines all-is all-as tainted) input)
(define edges (define G (undirected-graph
(for*/list ([(k v*) (in-hash tainted)] [v (in-set v*)]) (for*/list ([(k v*) (in-hash tainted)] [v (in-set v*)])
(list k v))) (list k v))))
(define G (undirected-graph edges))
(define matching (maximum-bipartite-matching G)) (define matching (maximum-bipartite-matching G))
(string-join (string-join
(for/list ([val (in-list (sort matching #{string<? (first %1) (first %2)}))]) (map second (sort matching string<? #:key first))
(second val))
",")) ","))
;; parse input file ;; parse input file