Bulls and cows: Difference between revisions

m (→‎{{header|OCaml}}: don't fake C style syntax)
Line 2,699:
}
print(paste("You won in",attempts,"attempt(s)!"))</lang>
 
 
=={{header|Racket}}==
{{works with|DrRacket|5.3.3}}
<lang scheme>#lang racket
 
; secret : (listof exact-nonnegative-integer?)
(define secret
(foldr (λ (n result) (cons n
(map (λ (y) (if (>= y n)
(add1 y)
y))
result)))
'()
(map random '(10 9 8 7))))
 
; (count-bulls/cows guess) -> (values exact-nonnegative-integer?
; exact-nonnegative-integer?)
; guess : (listof exact-nonnegative-integer?)
(define (count-bulls/cows guess)
(let* ([bulls (map = guess secret)]
[cow-candidates (filter-map (λ (x y) (if (false? x) y #f))
bulls
secret)]
[cows (filter (curryr member cow-candidates) guess)])
(values (length (filter ((curry equal?) #t) bulls))
(length cows))))
 
; (valid-guess guess-str) -> (or/c (listof exact-nonnegative-integer?) #f)
; guess-str : string?
(define (valid-guess guess-str)
(define (char->digit c)
(- (char->integer c) (char->integer #\0)))
(if (regexp-match-exact? #px"[0-9]{4}" guess-str)
(let ([guess (map char->digit (string->list guess-str))])
(if (andmap (λ (x) (equal? (count ((curry equal?) x) guess) 1))
guess)
guess
#f))
#f))
; Game states
(define win #t)
(define game #f)
 
; (main-loop state step) -> void?
; state : boolean?
; step : exact-nonnegative-integer?
(define (main-loop state step)
(if (equal? state win)
(printf "You won after ~a guesses." step)
(begin
(let* ([guess-str (read-line)]
[guess (valid-guess guess-str)])
(if (false? guess)
(begin (displayln "Guess should include exactly four different digits")
(main-loop state step))
(let-values ([(bulls cows) (count-bulls/cows guess)])
(if (= bulls 4)
(main-loop win (add1 step))
(begin (printf "Bulls: ~a Cows: ~a\n" bulls cows)
(main-loop state (add1 step))))))))))
 
(main-loop game 0)</lang>
 
=={{header|REXX}}==
Anonymous user