master
Matthew Butterick 6 years ago
parent 10fd78b85a
commit c7ce78ff38

@ -1,16 +1,35 @@
#lang reader "../aoc-lang.rkt"
(require racket/sequence)
(require racket/sequence sugar/list)
(provide (rename-out [#%mb #%module-begin]))
(define-macro (#%mb (STARS) (STR) ...)
#`(#%module-begin
((if (eq? 'STARS ') one-star (λ (x) #f)) (format "~a" 'STR)) ...))
((if (eq? 'STARS ') one-star two-star) (format "~a" 'STR)) ...))
(define (one-star str)
(for*/sum ([i (in-range 128)]
[digit (in-list (kh->ints (knot-hash (format "~a-~a" str i))))])
digit))
(define (two-star str)
(define vec (for*/vector ([i (in-range 128)]
[int (in-list (kh->ints (knot-hash (format "~a-~a" str i))))])
(if (= int 1) "#" ".")))
(define (at-left-edge? idx) (= (modulo idx 128) 0))
(define (at-right-edge? idx) (= (modulo idx 128) 127))
(for/fold ([region 0])
([(val idx) (in-indexed vec)]
#:unless (number? val))
(let loop ([idx idx])
(cond
[(and (< -1 idx (vector-length vec)) (equal? (vector-ref vec idx) "#"))
(vector-set! vec idx region)
(unless (at-left-edge? idx) (loop (sub1 idx)))
(unless (at-right-edge? idx) (loop (add1 idx)))
(map loop (list (+ idx 128) (- idx 128)))
(add1 region)]
[else region]))))
(define (kh->ints kh)
(for*/list ([c (in-string kh)]
[num (in-value (string->number (string c) 16))]

@ -0,0 +1,2 @@
#lang reader "main.rkt" ★★ ; 1093
hxtvlmkl

@ -0,0 +1,2 @@
#lang reader "main.rkt" ★★ ; 1242
flqrgnkx