1;;; mpuz.el --- multiplication puzzle for GNU Emacs
2
3;; Copyright (C) 1990, 2001, 2002, 2003, 2004, 2005,
4;;   2006, 2007 Free Software Foundation, Inc.
5
6;; Author: Philippe Schnoebelen <phs@lsv.ens-cachan.fr>
7;; Overhauled: Daniel Pfeiffer <occitan@esperanto.org>
8;; Keywords: games
9
10;; This file is part of GNU Emacs.
11
12;; GNU Emacs is free software; you can redistribute it and/or modify
13;; it under the terms of the GNU General Public License as published by
14;; the Free Software Foundation; either version 2, or (at your option)
15;; any later version.
16
17;; GNU Emacs is distributed in the hope that it will be useful,
18;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20;; GNU General Public License for more details.
21
22;; You should have received a copy of the GNU General Public License
23;; along with GNU Emacs; see the file COPYING.  If not, write to the
24;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
25;; Boston, MA 02110-1301, USA.
26
27;;; Commentary:
28
29;; `M-x mpuz' generates a random multiplication puzzle.  This is a
30;; multiplication example in which each digit has been consistently replaced
31;; with some letter.  Your job is to reconstruct the original digits.  Type
32;; `?' while the mode is active for detailed help.
33
34;;; Code:
35
36(defgroup mpuz nil
37  "Multiplication puzzle."
38  :prefix "mpuz-"
39  :group 'games)
40
41(random t)				; randomize
42
43(defcustom mpuz-silent 'error
44  "*Set this to nil if you want dings on inputs.
45t means never ding, and `error' means only ding on wrong input."
46  :type '(choice (const :tag "No" nil)
47		 (const :tag "Yes" t)
48		 (const :tag "If correct" error))
49  :group 'mpuz)
50
51(defcustom mpuz-solve-when-trivial t
52  "*Solve any row that can be trivially calculated from what you've found."
53  :type 'boolean
54  :group 'mpuz)
55
56(defcustom mpuz-allow-double-multiplicator nil
57  "*Allow 2nd factors like 33 or 77."
58  :type 'boolean
59  :group 'mpuz)
60
61(defface mpuz-unsolved
62  '((((class color)) (:foreground "red1" :bold t))
63    (t (:bold t)))
64  "*Face to use for letters to be solved."
65  :group 'mpuz)
66
67(defface mpuz-solved
68  '((((class color)) (:foreground "green1" :bold t))
69    (t (:bold t)))
70  "*Face to use for solved digits."
71  :group 'mpuz)
72
73(defface mpuz-trivial
74  '((((class color)) (:foreground "blue" :bold t))
75    (t (:bold t)))
76  "*Face to use for trivial digits solved for you."
77  :group 'mpuz)
78
79(defface mpuz-text
80  '((t (:inherit variable-pitch)))
81  "*Face to use for text on right."
82  :group 'mpuz)
83
84
85;; Mpuz mode and keymaps
86;;----------------------
87(defcustom mpuz-mode-hook nil
88  "Hook to run upon entry to mpuz."
89  :type 'hook
90  :group 'mpuz)
91
92(defvar mpuz-mode-map nil
93  "Local keymap to use in Mult Puzzle.")
94
95(if mpuz-mode-map nil
96  (setq mpuz-mode-map (make-sparse-keymap))
97  (define-key mpuz-mode-map "a" 'mpuz-try-letter)
98  (define-key mpuz-mode-map "b" 'mpuz-try-letter)
99  (define-key mpuz-mode-map "c" 'mpuz-try-letter)
100  (define-key mpuz-mode-map "d" 'mpuz-try-letter)
101  (define-key mpuz-mode-map "e" 'mpuz-try-letter)
102  (define-key mpuz-mode-map "f" 'mpuz-try-letter)
103  (define-key mpuz-mode-map "g" 'mpuz-try-letter)
104  (define-key mpuz-mode-map "h" 'mpuz-try-letter)
105  (define-key mpuz-mode-map "i" 'mpuz-try-letter)
106  (define-key mpuz-mode-map "j" 'mpuz-try-letter)
107  (define-key mpuz-mode-map "A" 'mpuz-try-letter)
108  (define-key mpuz-mode-map "B" 'mpuz-try-letter)
109  (define-key mpuz-mode-map "C" 'mpuz-try-letter)
110  (define-key mpuz-mode-map "D" 'mpuz-try-letter)
111  (define-key mpuz-mode-map "E" 'mpuz-try-letter)
112  (define-key mpuz-mode-map "F" 'mpuz-try-letter)
113  (define-key mpuz-mode-map "G" 'mpuz-try-letter)
114  (define-key mpuz-mode-map "H" 'mpuz-try-letter)
115  (define-key mpuz-mode-map "I" 'mpuz-try-letter)
116  (define-key mpuz-mode-map "J" 'mpuz-try-letter)
117  (define-key mpuz-mode-map "\C-g" 'mpuz-offer-abort)
118  (define-key mpuz-mode-map "?" 'describe-mode))
119
120(defun mpuz-mode ()
121  "Multiplication puzzle mode.
122
123You have to guess which letters stand for which digits in the
124multiplication displayed inside the `*Mult Puzzle*' buffer.
125
126You may enter a guess for a letter's value by typing first the letter,
127then the digit.  Thus, to guess that A=3, type `A 3'.
128
129To leave the game to do other editing work, just switch buffers.
130Then you may resume the game with M-x mpuz.
131You may abort a game by typing \\<mpuz-mode-map>\\[mpuz-offer-abort]."
132  (interactive)
133  (kill-all-local-variables)
134  (setq major-mode 'mpuz-mode
135	mode-name  "Mult Puzzle"
136	tab-width 30)
137  (use-local-map mpuz-mode-map)
138  (run-mode-hooks 'mpuz-mode-hook))
139
140
141;; Some variables for statistics
142;;------------------------------
143(defvar mpuz-nb-errors 0
144  "Number of errors made in current game.")
145
146(defvar mpuz-nb-completed-games 0
147  "Number of games completed.")
148
149(defvar mpuz-nb-cumulated-errors 0
150  "Number of errors made in previous games.")
151
152
153;; Some variables for game tracking
154;;---------------------------------
155(defvar mpuz-in-progress nil
156  "True if a game is currently in progress.")
157
158(defvar mpuz-found-digits (make-bool-vector 10 nil)
159  "A vector recording which digits have been decrypted.")
160
161(defvar mpuz-trivial-digits (make-bool-vector 10 nil)
162  "A vector recording which digits have been solved for you.")
163
164(defmacro mpuz-digit-solved-p (digit)
165  `(or (aref mpuz-found-digits ,digit)
166       (aref mpuz-trivial-digits ,digit)))
167
168
169;; A puzzle uses a permutation of [0..9] into itself.
170;; We use both the permutation and its inverse.
171;;---------------------------------------------------
172(defvar mpuz-digit-to-letter (make-vector 10 0)
173  "A permutation from [0..9] to [0..9].")
174
175(defvar mpuz-letter-to-digit (make-vector 10 0)
176  "The inverse of mpuz-digit-to-letter.")
177
178(defmacro mpuz-to-digit (letter)
179  (list 'aref 'mpuz-letter-to-digit letter))
180
181(defmacro mpuz-to-letter (digit)
182  (list 'aref 'mpuz-digit-to-letter digit))
183
184(defun mpuz-build-random-perm ()
185  "Initialize puzzle coding with a random permutation."
186  (let ((letters (list 0 1 2 3 4 5 6 7 8 9)) ; new cons cells, because of delq
187	(index 10)
188	elem)
189    (while letters
190      (setq elem    (nth (random index) letters)
191	    letters (delq elem letters)
192	    index   (1- index))
193      (aset mpuz-digit-to-letter index elem)
194      (aset mpuz-letter-to-digit elem index))))
195
196
197;; A puzzle also uses a board displaying a multiplication.
198;; Every digit appears in the board, crypted or not.
199;;------------------------------------------------------
200(defvar mpuz-board (make-vector 10 nil)
201  "The board associates to any digit the list of squares where it appears.")
202
203(defun mpuz-put-number-on-board (number row &rest l)
204  "Put (last digit of) NUMBER on ROW and COLUMNS of the puzzle board."
205  (let (digit)
206    (while l
207      (setq digit (% number 10)
208	    number (/ number 10))
209      (aset mpuz-board digit `((,row . ,(car l)) ,@(aref mpuz-board digit)))
210      (setq l (cdr l)))))
211
212(defun mpuz-check-all-solved (&optional row col)
213  "Check whether all digits have been solved. Return t if yes."
214  (catch 'solved
215    (let (A B1 B2 C D E squares)
216      (and mpuz-solve-when-trivial
217	   (not row)
218	   (while
219	       (cond ((or (and (setq B1 (or B1 (mpuz-check-all-solved 4 7))
220				     B2 (or B2 (mpuz-check-all-solved 4 9))
221				     E (or E (mpuz-check-all-solved 10))
222				     A (or A (mpuz-check-all-solved 2)))
223			       B1 B2)
224			  (and E (or A (and B1 B2))))
225		      (mpuz-solve)
226		      (mpuz-paint-board)
227		      (throw 'solved t))
228		     ((and (setq D (or D (mpuz-check-all-solved 8))
229				 C (or C (mpuz-check-all-solved 6)))
230			   D (not E))
231		      (mpuz-solve 10))
232		     ((and E (not (eq C D)))
233		      (mpuz-solve (if D 6 8)))
234		     ((and A (not (eq B2 C)))
235		      (mpuz-solve (if C 4 6) (if C 9)))
236		     ((and A (not (eq B1 D)))
237		      (mpuz-solve (if D 4 8) (if D 7)))
238		     ((and (not A) (or (and B2 C) (and B1 D)))
239		      (mpuz-solve 2)))))
240      (mpuz-paint-board)
241      (mapc (lambda (digit)
242	      (and (not (mpuz-digit-solved-p digit)) ; unsolved
243		   (setq squares (aref mpuz-board digit))
244		   (if row
245		       (if col
246			   (member (cons row col) squares)
247			 (assq row squares))
248		     squares) ; and appearing in the puzzle!
249		   (throw 'solved nil)))
250	    [0 1 2 3 4 5 6 7 8 9]))
251    t))
252
253
254;; To build a puzzle, we take two random numbers and multiply them.
255;; We also take a random permutation for encryption.
256;; The random numbers are only use to see which digit appears in which square
257;; of the board. Everything is stored in individual squares.
258;;---------------------------------------------------------------------------
259(defun mpuz-random-puzzle ()
260  "Draw random values to be multiplied in a puzzle."
261  (mpuz-build-random-perm)
262  (fillarray mpuz-board nil)		; erase the board
263  ;; A,B,C,D & E, are the five rows of our multiplication.
264  ;; Choose random values, discarding cases with leading zeros in C or D.
265  (let* ((A (if mpuz-allow-double-multiplicator (+ 112 (random 888))
266	      (+ 125 (random 875))))
267	 (min (1+ (/ 999 A)))
268	 (B1 (+ min (random (- 10 min))))
269	 B2 C D E)
270    (while (if (= B1 (setq B2 (+ min (random (- 10 min)))))
271	       (not mpuz-allow-double-multiplicator)))
272    (setq C (* A B2)
273	  D (* A B1)
274	  E (+ C (* D 10)))
275    ;; Individual digits are now put on their respective squares.
276    ;; [NB: A square is a pair (row . column) of the screen.]
277    (mpuz-put-number-on-board A	2		 9 7 5)
278    (mpuz-put-number-on-board (+ (* B1 10) B2) 4 9 7)
279    (mpuz-put-number-on-board C	6		 9 7 5 3)
280    (mpuz-put-number-on-board D 8		   7 5 3 1)
281    (mpuz-put-number-on-board E	10		 9 7 5 3 1)))
282
283;; Display
284;;--------
285(defconst mpuz-framework
286  "
287     . . .
288	Number of errors (this game):	0
289    x  . .
290   -------
291   . . . .
292	Number of completed games:	0
293 . . . .
294 ---------	Average number of errors:	0.00
295 . . . . ."
296  "The general picture of the puzzle screen, as a string.")
297
298(defun mpuz-create-buffer ()
299  "Create (or recreate) the puzzle buffer. Return it."
300  (let ((buf (get-buffer-create "*Mult Puzzle*"))
301	(face '(face mpuz-text))
302	buffer-read-only)
303    (save-excursion
304      (set-buffer buf)
305      (erase-buffer)
306      (insert mpuz-framework)
307      (set-text-properties 13 42 face)
308      (set-text-properties 79 105 face)
309      (set-text-properties 128 153 face)
310      (mpuz-paint-board)
311      (mpuz-paint-errors)
312      (mpuz-paint-statistics))
313    buf))
314
315(defun mpuz-paint-number (n &optional eol words)
316  (end-of-line eol)
317  (let (buffer-read-only)
318    (delete-region (point)
319		   (progn (backward-word (or words 1)) (point)))
320    (insert n)))
321
322(defun mpuz-paint-errors ()
323  "Paint error count on the puzzle screen."
324  (mpuz-switch-to-window)
325  (goto-line 3)
326  (mpuz-paint-number (prin1-to-string mpuz-nb-errors)))
327
328(defun mpuz-paint-statistics ()
329  "Paint statistics about previous games on the puzzle screen."
330  (goto-line 7)
331  (mpuz-paint-number (prin1-to-string mpuz-nb-completed-games))
332  (mpuz-paint-number
333   (format "%.2f"
334	   (if (zerop mpuz-nb-completed-games)
335	       0
336	     (/ (+ 0.0 mpuz-nb-cumulated-errors)
337		mpuz-nb-completed-games)))
338   3 2))
339
340(defun mpuz-paint-board ()
341  "Paint board situation on the puzzle screen."
342  (mpuz-switch-to-window)
343  (mapc 'mpuz-paint-digit [0 1 2 3 4 5 6 7 8 9])
344  (goto-char (point-min)))
345
346(defun mpuz-paint-digit (digit)
347  "Paint all occurrences of DIGIT on the puzzle board."
348  (let ((char (if (mpuz-digit-solved-p digit)
349		  (+ digit ?0)
350		(+ (mpuz-to-letter digit) ?A)))
351	(face `(face
352		,(cond ((aref mpuz-trivial-digits digit) 'mpuz-trivial)
353		       ((aref mpuz-found-digits digit) 'mpuz-solved)
354		       ('mpuz-unsolved))))
355	buffer-read-only)
356    (mapc (lambda (square)
357	    (goto-line (car square))	; line before column!
358	    (move-to-column (cdr square))
359	    (insert char)
360	    (set-text-properties (1- (point)) (point) face)
361	    (delete-char 1))
362	  (aref mpuz-board digit))))
363
364(defun mpuz-get-buffer ()
365  "Get the puzzle buffer if it exists."
366  (get-buffer "*Mult Puzzle*"))
367
368(defun mpuz-switch-to-window ()
369  "Find or create the Mult-Puzzle buffer, and display it."
370  (let ((buf (mpuz-get-buffer)))
371    (or buf (setq buf (mpuz-create-buffer)))
372    (switch-to-buffer buf)
373    (setq buffer-read-only t)
374    (mpuz-mode)))
375
376
377;; Game control
378;;-------------
379(defun mpuz-start-new-game ()
380  "Start a new puzzle."
381  (message "Here we go...")
382  (setq mpuz-nb-errors 0
383	mpuz-in-progress t)
384  (fillarray mpuz-found-digits nil)	; initialize mpuz-found-digits
385  (fillarray mpuz-trivial-digits nil)
386  (mpuz-random-puzzle)
387  (mpuz-switch-to-window)
388  (mpuz-paint-board)
389  (mpuz-paint-errors)
390  (mpuz-ask-for-try))
391
392;;;###autoload
393(defun mpuz ()
394  "Multiplication puzzle with GNU Emacs."
395  ;; Main entry point
396  (interactive)
397  (mpuz-switch-to-window)
398  (if mpuz-in-progress
399      (mpuz-offer-abort)
400    (mpuz-start-new-game)))
401
402(defun mpuz-offer-abort ()
403  "Ask if user wants to abort current puzzle."
404  (interactive)
405  (if (y-or-n-p "Abort game? ")
406      (let ((buf (mpuz-get-buffer)))
407	(message "Mult Puzzle aborted.")
408	(setq mpuz-in-progress nil
409	      mpuz-nb-errors 0)
410	(fillarray mpuz-board nil)
411	(if buf (kill-buffer buf)))
412    (mpuz-ask-for-try)))
413
414(defun mpuz-ask-for-try ()
415  "Ask for user proposal in puzzle."
416  (message "Your try?"))
417
418(defun mpuz-ding (error)
419  "Dings, unless global variable `mpuz-silent' forbids it."
420  (cond ((eq mpuz-silent t))
421	((not mpuz-silent) (ding t))
422	(error (ding t))))
423
424(defun mpuz-try-letter ()
425  "Propose a digit for a letter in puzzle."
426  (interactive)
427  (if mpuz-in-progress
428      (let (letter-char digit digit-char message)
429	(setq letter-char (upcase last-command-char)
430	      digit (mpuz-to-digit (- letter-char ?A)))
431	(cond ((mpuz-digit-solved-p digit)
432	       (message "%c already solved." letter-char)
433	       (mpuz-ding t))
434	      ((null (aref mpuz-board digit))
435	       (message "%c does not appear." letter-char)
436	       (mpuz-ding t))
437	      ((progn (message "%c = " letter-char)
438		      ;; <char> has been entered.
439		      ;; Print "<char> =" and
440		      ;; read <num> or = <num>
441		      (setq digit-char (read-char))
442		      (if (eq digit-char ?=)
443			  (setq digit-char (read-char)))
444		      (or (> digit-char ?9) (< digit-char ?0))) ; bad input
445	       (message "%c = %c" letter-char digit-char)
446	       (mpuz-ding t))
447	      (t
448	       (mpuz-try-proposal letter-char digit-char))))
449    (if (y-or-n-p "Start a new game? ")
450	(mpuz-start-new-game)
451      (message "OK. I won't."))))
452
453(defun mpuz-try-proposal (letter-char digit-char)
454  "Propose LETTER-CHAR as code for DIGIT-CHAR."
455  (let* ((letter (- letter-char ?A))
456	 (digit (- digit-char ?0))
457	 (correct-digit (mpuz-to-digit letter))
458	 (game mpuz-nb-completed-games))
459    (cond ((mpuz-digit-solved-p correct-digit)
460	   (message "%c has already been found." (+ correct-digit ?0)))
461	  ((mpuz-digit-solved-p digit)
462	   (message "%c has already been placed." digit-char))
463	  ((= digit correct-digit)
464	   (message "%c = %c correct!" letter-char digit-char)
465	   (mpuz-ding nil)
466	   (aset mpuz-found-digits digit t)	; Mark digit as solved
467	   (and (mpuz-check-all-solved)
468		(mpuz-close-game)))
469	  (t ;;; incorrect guess
470	   (message "%c = %c incorrect!" letter-char digit-char)
471	   (mpuz-ding t)
472	   (setq mpuz-nb-errors (1+ mpuz-nb-errors))
473	   (mpuz-paint-errors)))))
474
475(defun mpuz-close-game ()
476  "Housecleaning when puzzle has been solved."
477  (setq mpuz-in-progress nil
478	mpuz-nb-cumulated-errors (+ mpuz-nb-cumulated-errors mpuz-nb-errors)
479	mpuz-nb-completed-games (1+ mpuz-nb-completed-games))
480  (mpuz-paint-statistics)
481  (let ((message (format "Puzzle solved with %d error%s. That's %s"
482			 mpuz-nb-errors
483			 (if (= mpuz-nb-errors 1) "" "s")
484			 (cond ((= mpuz-nb-errors 0)	"perfect!")
485			       ((= mpuz-nb-errors 1)	"very good!")
486			       ((= mpuz-nb-errors 2)	"good.")
487			       ((= mpuz-nb-errors 3)	"not bad.")
488			       ((= mpuz-nb-errors 4)	"not too bad...")
489			       ((< mpuz-nb-errors 10)	"bad!")
490			       ((< mpuz-nb-errors 15)	"awful.")
491			       (t			"not serious.")))))
492    (message message)
493    (sit-for 4)
494    (if (y-or-n-p (concat message "  Start a new game? "))
495	(mpuz-start-new-game)
496      (message "Good Bye!"))))
497
498(defun mpuz-solve (&optional row col)
499  "Find solution for autosolving."
500  (mapc (lambda (digit)
501	  (or (mpuz-digit-solved-p digit)
502	      (if row
503		  (not (if col
504			   (member (cons row col) (aref mpuz-board digit))
505			 (assq row (aref mpuz-board digit)))))
506	      (aset mpuz-trivial-digits digit t)))
507	[0 1 2 3 4 5 6 7 8 9])
508  t)
509
510(defun mpuz-show-solution (row)
511  "Display solution for debugging purposes."
512  (interactive "P")
513  (mpuz-switch-to-window)
514  (mpuz-solve (if row (* 2 (prefix-numeric-value row))))
515  (mpuz-paint-board)
516  (if (mpuz-check-all-solved)
517      (mpuz-close-game)))
518
519(provide 'mpuz)
520
521;;; arch-tag: 2781d6ba-89e7-43b5-85c7-5d3a2e73feb1
522;;; mpuz.el ends here
523