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.
39 lines
1017 B
Racket
39 lines
1017 B
Racket
8 years ago
|
#lang br/quicklang ;; http://adventofcode.com/2016/day/16
|
||
|
|
(require openssl/md5)
|
||
|
|
(provide read-syntax
|
||
|
|
(rename-out [mb #%module-begin]))
|
||
|
|
|
||
|
|
(define (read-syntax path port)
|
||
|
|
(strip-bindings
|
||
|
|
#`(module mod "lang.rkt"
|
||
|
|
#,@(string-split (string-trim (port->string port)) ", "))))
|
||
|
|
|
||
|
|
(define-macro (mb SIZE INIT)
|
||
|
|
#'(#%module-begin
|
||
|
|
(display (list->string (checksum (fill-disk (string->list INIT) (string->number SIZE)))))))
|
||
|
|
|
||
|
|
(define (dragonize cs)
|
||
|
|
(append cs '(#\0)
|
||
|
|
(for/list ([c (in-list (reverse cs))])
|
||
|
|
(if (eqv? c #\1)
|
||
|
|
#\0
|
||
|
|
#\1))))
|
||
|
|
|
||
|
|
(define (fill-disk init size)
|
||
|
|
(let loop ([cs init])
|
||
|
|
(if (>= (length cs) size)
|
||
|
|
(take cs size)
|
||
|
|
(loop (dragonize cs)))))
|
||
|
|
|
||
|
|
(require sugar/list)
|
||
|
|
(define (checksum cs)
|
||
|
|
(let loop ([cs cs])
|
||
|
|
(if (odd? (length cs))
|
||
|
|
cs
|
||
|
|
(loop
|
||
|
|
(for/list ([match (in-list (slice-at cs 2))])
|
||
|
|
(if (member match '((#\0 #\0) (#\1 #\1)))
|
||
|
|
#\1
|
||
|
|
#\0))))))
|
||
|
|
|