RosettaCodeData/Task/Flipping-bits-game/Racket/flipping-bits-game.rkt

72 lines
2.7 KiB
Racket

#lang racket
(define (flip-row! pzzl r)
(define N (integer-sqrt (bytes-length pzzl)))
(for* ((c (in-range N)))
(define idx (+ c (* N r)))
(bytes-set! pzzl idx (- 1 (bytes-ref pzzl idx)))))
(define (flip-col! pzzl c)
(define N (integer-sqrt (bytes-length pzzl)))
(for* ((r (in-range N)))
(define idx (+ c (* N r)))
(bytes-set! pzzl idx (- 1 (bytes-ref pzzl idx)))))
(define (new-game N (flips 10))
(define N2 (sqr N))
(define targ (list->bytes (for/list ((_ N2)) (random 2))))
(define strt (bytes-copy targ))
(for ((_ flips))
(case (random 2)
((0) (flip-col! strt (random N)))
((1) (flip-row! strt (random N)))))
(if (equal? strt targ) (new-game N) (values targ strt)))
(define (show-games #:sep (pzl-sep " | ") . pzzls)
(define N (integer-sqrt (bytes-length (first pzzls))))
(define caption (string-join (for/list ((c (in-range N))) (~a (add1 c))) ""))
(define ruler (string-join (for/list ((c (in-range N))) "-") ""))
(define ((pzzle-row r) p)
(string-join (for/list ((c (in-range N))) (~a (bytes-ref p (+ c (* N r))))) ""))
(displayln
(string-join
(list*
(format " ~a" (string-join (for/list ((_ pzzls)) caption) pzl-sep))
(format " ~a" (string-join (for/list ((_ pzzls)) ruler) pzl-sep))
(for/list ((r (in-range N)) (R (in-naturals (char->integer #\a))))
(format "~a ~a" (integer->char R) (string-join (map (pzzle-row r) pzzls) pzl-sep))))
"\n")))
(define (play N)
(define-values (end start) (new-game N))
(define (turn n (show? #t))
(cond
[(equal? end start) (printf "you won on turn #~a~%" n)]
[else
(when show? ;; don't show after whitespace
(printf "turn #~a~%" n)
(show-games start end))
(match (read-char)
[(? eof-object?) (printf "sad to see you go :-(~%")]
[(? char-whitespace?) (turn n #f)]
[(? char-numeric? c)
(define cnum (- (char->integer c) (char->integer #\1)))
(cond [(< -1 cnum N)
(printf "flipping col ~a~%" (add1 cnum))
(flip-col! start cnum)
(turn (add1 n))]
[else (printf "column number out of range ~a > ~a~%" (add1 cnum) N)
(turn n)])]
[(? char-lower-case? c)
(define rnum (- (char->integer c) (char->integer #\a)))
(cond [(< -1 rnum N)
(printf "flipping row ~a~%" (add1 rnum))
(flip-row! start rnum)
(turn (add1 n))]
[else (printf "row number out of range ~a > ~a~%" (add1 rnum) (sub1 N))
(turn n)])]
[else (printf "unrecognised character in input: ~s~%" else)
(turn n)])]))
(turn 0))