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Diffstat (limited to 'aoc2020/day-16/day-16.rkt')
-rw-r--r-- | aoc2020/day-16/day-16.rkt | 52 |
1 files changed, 0 insertions, 52 deletions
diff --git a/aoc2020/day-16/day-16.rkt b/aoc2020/day-16/day-16.rkt deleted file mode 100644 index 9a38eda..0000000 --- a/aoc2020/day-16/day-16.rkt +++ /dev/null @@ -1,52 +0,0 @@ -#lang racket - -(require racket/struct - advent-of-code - fancy-app - relation - threading - rebellion/base/range) - -(struct field-rule (name range1 range2) #:transparent) - -(define (make-lines strs) - (string-split strs "\n")) -(define (seperate-fields strs) - (~>> (string-split strs ",") (map ->number))) - -(define (process-rules str) - (match str - [(regexp - #px"(.+): (\\d+)-(\\d+) or (\\d+)-(\\d+)" - (list _ name (app ->number min1) (app ->number max1) (app ->number min2) (app ->number max2))) - (field-rule name (closed-range min1 max1) (closed-range min2 max2))])) - -(match-define (list (app (λ~>> make-lines (map process-rules)) ticket-rules) - (app (λ~>> make-lines second seperate-fields) your-ticket) - (app (λ~>> make-lines rest (map seperate-fields)) other-tickets)) - (~> (fetch-aoc-input (find-session) 2020 16 #:cache #true) (string-split "\n\n"))) - -;; part 1 -(define (fails-all-checks? field rules) - (define rule-list (~>> rules (map (λ~> struct->list rest)) flatten)) - (for/and ([rule (in-list rule-list)]) - (not (range-contains? rule field)))) - -(define (ticket-scanning-error-rate tickets rules) - (for*/sum - ([ticket (in-list tickets)] (field (in-list ticket)) #:when (fails-all-checks? field rules)) - field)) - -(ticket-scanning-error-rate other-tickets ticket-rules) - -;; part 2 -(define valid-tickets (filter (ormap (fails-all-checks? _ ticket-rules) _) other-tickets)) - -(define fields (apply map list valid-tickets)) - -(for/list ([field (in-list fields)]) - (for*/list ( - [rule (in-list ticket-rules)] - #:unless (not (or (range-contains? (field-rule-range1 rule) value) - (range-contains? (field-rule-range2 rule) value)))) - (field-rule-name rule))) |