adventofcode
/
2020
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Refactored Day 16 again...

This commit is contained in:
Jonathan Chan 2020-12-16 01:33:54 -08:00
parent 309e9769f4
commit c392e6420d
1 changed files with 13 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
src/16.rkt
View File

@ -23,28 +23,26 @@
(define part1
(for*/sum ([ticket tickets]
[field ticket])
(if (any-valid-ranges/c field) 0 field)))
[field ticket]
#:unless (any-valid-ranges/c field))
field))
(define part2
(let ([fields (length ticket)])
(let ([fields (length ticket)]
[valid-tickets (filter #{andmap any-valid-ranges/c %} tickets)])
(define valid-ranges-fields
(for*/fold ([valid-ranges-fields (make-list fields (range fields))])
([valid-ticket (filter #{andmap any-valid-ranges/c %} tickets)]
[i fields]
(for*/fold ([valid-ranges-fields (make-list fields '())])
([i fields]
[j fields])
(let ([valid-range/c (list-ref valid-range/cs j)]
[valid-range-fields (list-ref valid-ranges-fields j)])
(if (valid-range/c (list-ref valid-ticket i))
valid-ranges-fields
(list-set valid-ranges-fields j (remove i valid-range-fields))))))
(if (andmap #{(list-ref valid-range/cs j) (list-ref % i)} valid-tickets)
(list-update valid-ranges-fields j #{cons i %})
valid-ranges-fields)))
(define (solve valid-ranges-fields)
(let ([j (index-where valid-ranges-fields (and/c list? singleton?))])
(if j
(let* ([i (first (list-ref valid-ranges-fields j))]
[valid-ranges-fields (map #{if (list? %) (remove i %) %}
valid-ranges-fields)])
(solve (list-set valid-ranges-fields j i)))
(let* ([i (first (list-ref valid-ranges-fields j))])
(solve (map #{if (list? %) (remove i %) %}
(list-set valid-ranges-fields j i))))
valid-ranges-fields)))
(apply * (map #{list-ref ticket %}
(take (solve valid-ranges-fields) 6)))))