You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
23 lines
831 B
Racket
23 lines
831 B
Racket
#lang br/quicklang
|
|
(require sugar/list)
|
|
|
|
(module+ reader
|
|
(require syntax/strip-context)
|
|
(provide read-syntax)
|
|
(define (read-syntax path port)
|
|
(strip-context #`(module day1 aoc-racket/2017/d1
|
|
#,@(for/list ([datum (in-port read port)])
|
|
datum)))))
|
|
|
|
(provide (rename-out [mb #%module-begin]))
|
|
(define-macro (mb SELECTOR CAPTCHA-STR ...)
|
|
#'(#%module-begin (captcha-sum 'SELECTOR CAPTCHA-STR) ...))
|
|
|
|
(define (captcha-sum offset-sig num)
|
|
(define digits (for/list ([c (in-string (number->string num))])
|
|
(string->number (string c))))
|
|
(define offset (if (eq? offset-sig '★) -1 (/ (length digits) 2)))
|
|
(for/sum ([digit (in-list digits)]
|
|
[other-digit (in-list (shift-cycle digits offset))]
|
|
#:when (= digit other-digit))
|
|
digit)) |