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#lang racket
(require advent-of-code
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) (string-split "\n\n")))
(define (ticket-scanning-error-rate ticket rules)
(for/sum ([ticket-field (in-list ticket)]
[ticket-rule (in-list rules)]
#:do [(match-define (field-rule _ r1 r2) ticket-rule)]
#:unless (or (range-contains? r1 ticket-field) (range-contains? r2 ticket-field)))
ticket-field))
(for/sum ([ticket (in-list other-tickets)]) (ticket-scanning-error-rate ticket ticket-rules))
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