|
|
|
|
|
#lang reader "../aoc-lang.rkt"
|
|
|
|
|
|
(require racket/sequence sugar/list)
|
|
|
|
|
|
(provide (rename-out [#%mb #%module-begin]))
|
|
|
|
|
|
|
|
|
|
|
|
(define-macro (#%mb (STARS) (STR) ...)
|
|
|
|
|
|
#`(#%module-begin
|
|
|
|
|
|
(time ((if (eq? 'STARS '★) one-star two-star) (format "~a" 'STR))) ...))
|
|
|
|
|
|
|
|
|
|
|
|
(define (knot-hashes str)
|
|
|
|
|
|
(for/list ([i (in-range 128)])
|
|
|
|
|
|
(knot-hash (format "~a-~a" str i))))
|
|
|
|
|
|
|
|
|
|
|
|
(define (one-star str)
|
|
|
|
|
|
(for*/sum ([kh (in-list (knot-hashes str))]
|
|
|
|
|
|
[int (in-list (kh->ints kh))])
|
|
|
|
|
|
int))
|
|
|
|
|
|
|
|
|
|
|
|
(define (two-star str)
|
|
|
|
|
|
(define vec (for*/vector ([kh (in-list (knot-hashes str))]
|
|
|
|
|
|
[int (in-list (kh->ints kh))])
|
|
|
|
|
|
(if (= int 1) 'used 'empty)))
|
|
|
|
|
|
(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 (<= 0 idx (sub1 (vector-length vec))) (eq? (vector-ref vec idx) 'used))
|
|
|
|
|
|
(vector-set! vec idx region)
|
|
|
|
|
|
(unless (at-left-edge? idx) (loop (sub1 idx)))
|
|
|
|
|
|
(unless (at-right-edge? idx) (loop (add1 idx)))
|
|
|
|
|
|
(loop (+ idx 128))
|
|
|
|
|
|
(loop (- idx 128))
|
|
|
|
|
|
(add1 region)]
|
|
|
|
|
|
[else region]))))
|
|
|
|
|
|
|
|
|
|
|
|
(define (kh->ints kh)
|
|
|
|
|
|
(for*/list ([c (in-string kh)]
|
|
|
|
|
|
[num (in-value (string->number (string c) 16))]
|
|
|
|
|
|
[c (in-string (~r num #:base 2 #:min-width 4 #:pad-string "0"))])
|
|
|
|
|
|
(if (char=? c #\1) 1 0)))
|
|
|
|
|
|
|
|
|
|
|
|
(define (knot-hash seed-str [range-in 256])
|
|
|
|
|
|
(define ascii-chars (map char->integer (string->list seed-str)))
|
|
|
|
|
|
(define nums (reverse-segments range-in (append ascii-chars '(17 31 73 47 23)) #:reps 64))
|
|
|
|
|
|
(define dense-hash (for/list ([vals (in-slice 16 nums)])
|
|
|
|
|
|
(apply bitwise-xor vals)))
|
|
|
|
|
|
(string-append* (for/list ([num (in-list dense-hash)])
|
|
|
|
|
|
(~r num #:base 16 #:min-width 2 #:pad-string "0"))))
|
|
|
|
|
|
|
|
|
|
|
|
(define (reverse-segments range-in lens #:reps [reps 1])
|
|
|
|
|
|
(define vec (list->vector (range range-in)))
|
|
|
|
|
|
(for*/fold ([current-position 0]
|
|
|
|
|
|
[skip-size 0])
|
|
|
|
|
|
([rep (in-range reps)]
|
|
|
|
|
|
[len (in-list lens)])
|
|
|
|
|
|
(define posns (for/list ([i (in-range len)])
|
|
|
|
|
|
(modulo (+ current-position i) range-in)))
|
|
|
|
|
|
(for ([val (in-list (map (λ (posn) (vector-ref vec posn)) posns))]
|
|
|
|
|
|
[posn (in-list (reverse posns))])
|
|
|
|
|
|
(vector-set! vec posn val))
|
|
|
|
|
|
(values (+ current-position len skip-size) (add1 skip-size)))
|
|
|
|
|
|
(vector->list vec))
|
