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@dvanhorn
Created December 5, 2020 22:33
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Advent of Code, Day 5, Part II
#lang racket
(define in "...")
(define ss
(sort (for/list ([l (in-list (with-input-from-string in port->lines))])
(string->number
(string-append "#b"
(regexp-replaces l '(("F" "0")
("B" "1")
("L" "0")
("R" "1"))))))
<))
(for/first ([s (in-list ss)]
[s+1 (in-list (rest ss))]
#:when (= (+ s 2) s+1))
(add1 s))
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