; ; Bulls and Cows game v2 - 6th March 2020 - see http://forum.ulisp.com/t/bulls-cows-game-using-assembler/501 ; (defvar *spectrum* nil) ; Calculate number of bulls and cows between two numbers (defun bullcow (digits guess code) (let ((score 0)) (dotimes (i 16) (setf (nth i *spectrum*) 0)) (dotimes (d digits) (let ((da (mod guess 16)) (db (mod code 16))) (cond ((= da db) (incf score 16)) (t (when (<= (incf (nth da *spectrum*)) 0) (incf score)) (when (>= (decf (nth db *spectrum*)) 0) (incf score)))) (setq guess (truncate guess 16)) (setq code (truncate code 16)))) score)) ; Convert a decimal number to bcd: 123 -> #x123 (defun bcd (n) (cond ((zerop n) 0) (t (+ (mod n 10) (* 16 (bcd (truncate n 10))))))) ; Print n digits with leading zeros (defun printn (n d) (cond ((= n 0) nil) (t (printn (1- n) (truncate d 16)) (princ (mod d 16))))) ; Next valid bcd number (defun incbcd (n) (cond ((< (logand n #xf) 9) (1+ n)) (t (ash (incbcd (ash n -4)) 4)))) ; Return t only if every call of fun a b succeeds (defun every* (fun a b) (cond ((or (null a) (null b)) t) ((null (funcall fun (car a) (car b))) nil) (t (every* fun (cdr a) (cdr b))))) ; Find guess compatible with all my guesses and your replies (defun computer-choose (digits start try guesses replies) (let ((s (ash 1 (* digits 4)))) (loop (setq try (mod (incbcd try) s)) (when (= try start) (return nil)) (when (every* (lambda (guess reply) (= (bullcow digits try guess) reply)) guesses replies) (return try))))) ; Invite player to guess my code (defun player-guess (digits i-playing mycode) (princ " Your guess: ") (let* ((your-guess (bcd (read))) (result (bullcow digits your-guess mycode)) (you-playing (if (= result (* digits #x10)) nil result))) (princ " Score: ") (printn 2 result) (unless you-playing (terpri) (if i-playing (princ "You win!") (princ "You got it!")) (terpri) (princ " ")) you-playing)) ; Let me have a guess (defun computer-guess (digits you-playing try) (princ " My guess: ") (printn digits try) (princ " Score: ") (let* ((your-reply (bcd (read))) (i-playing (if (= your-reply (* digits #x10)) nil your-reply))) (unless i-playing (terpri) (if you-playing (princ "I win!") (princ "I got it!"))) i-playing)) ; Play the game (defun play (digits) (setq *spectrum* (let (lst) (dotimes (i 16 lst) (push 0 lst)))) (let* ((s (expt 10 digits)) (mycode (bcd (random s))) (start (bcd (random s))) (try start) (turn 0) (i-playing 0) (you-playing 0) guesses replies) (loop (terpri) (princ "[") (princ (incf turn)) (princ "]") (when you-playing (setq you-playing (player-guess digits i-playing mycode))) (when i-playing (setq i-playing (computer-guess digits you-playing try)) (when i-playing (push try guesses) (push i-playing replies) (setq try (computer-choose digits start try guesses replies)) (unless try (terpri) (princ "I think you gave an incorrect answer") (setq i-playing nil)))) (when (and (not you-playing) (not i-playing)) (return)))))