1d8e8ad8 |
1 | /* |
2 | * solo.c: the number-placing puzzle most popularly known as `Sudoku'. |
3 | * |
4 | * TODO: |
5 | * |
c8266e03 |
6 | * - reports from users are that `Trivial'-mode puzzles are still |
7 | * rather hard compared to newspapers' easy ones, so some better |
8 | * low-end difficulty grading would be nice |
9 | * + it's possible that really easy puzzles always have |
10 | * _several_ things you can do, so don't make you hunt too |
11 | * hard for the one deduction you can currently make |
12 | * + it's also possible that easy puzzles require fewer |
13 | * cross-eliminations: perhaps there's a higher incidence of |
14 | * things you can deduce by looking only at (say) rows, |
15 | * rather than things you have to check both rows and columns |
16 | * for |
17 | * + but really, what I need to do is find some really easy |
18 | * puzzles and _play_ them, to see what's actually easy about |
19 | * them |
20 | * + while I'm revamping this area, filling in the _last_ |
21 | * number in a nearly-full row or column should certainly be |
22 | * permitted even at the lowest difficulty level. |
23 | * + also Owen noticed that `Basic' grids requiring numeric |
24 | * elimination are actually very hard, so I wonder if a |
25 | * difficulty gradation between that and positional- |
26 | * elimination-only might be in order |
27 | * + but it's not good to have _too_ many difficulty levels, or |
28 | * it'll take too long to randomly generate a given level. |
29 | * |
ef57b17d |
30 | * - it might still be nice to do some prioritisation on the |
31 | * removal of numbers from the grid |
32 | * + one possibility is to try to minimise the maximum number |
33 | * of filled squares in any block, which in particular ought |
34 | * to enforce never leaving a completely filled block in the |
35 | * puzzle as presented. |
1d8e8ad8 |
36 | * |
37 | * - alternative interface modes |
38 | * + sudoku.com's Windows program has a palette of possible |
39 | * entries; you select a palette entry first and then click |
40 | * on the square you want it to go in, thus enabling |
41 | * mouse-only play. Useful for PDAs! I don't think it's |
42 | * actually incompatible with the current highlight-then-type |
43 | * approach: you _either_ highlight a palette entry and then |
44 | * click, _or_ you highlight a square and then type. At most |
45 | * one thing is ever highlighted at a time, so there's no way |
46 | * to confuse the two. |
c8266e03 |
47 | * + then again, I don't actually like sudoku.com's interface; |
48 | * it's too much like a paint package whereas I prefer to |
49 | * think of Solo as a text editor. |
50 | * + another PDA-friendly possibility is a drag interface: |
51 | * _drag_ numbers from the palette into the grid squares. |
52 | * Thought experiments suggest I'd prefer that to the |
53 | * sudoku.com approach, but I haven't actually tried it. |
1d8e8ad8 |
54 | */ |
55 | |
56 | /* |
57 | * Solo puzzles need to be square overall (since each row and each |
58 | * column must contain one of every digit), but they need not be |
59 | * subdivided the same way internally. I am going to adopt a |
60 | * convention whereby I _always_ refer to `r' as the number of rows |
61 | * of _big_ divisions, and `c' as the number of columns of _big_ |
62 | * divisions. Thus, a 2c by 3r puzzle looks something like this: |
63 | * |
64 | * 4 5 1 | 2 6 3 |
65 | * 6 3 2 | 5 4 1 |
66 | * ------+------ (Of course, you can't subdivide it the other way |
67 | * 1 4 5 | 6 3 2 or you'll get clashes; observe that the 4 in the |
68 | * 3 2 6 | 4 1 5 top left would conflict with the 4 in the second |
69 | * ------+------ box down on the left-hand side.) |
70 | * 5 1 4 | 3 2 6 |
71 | * 2 6 3 | 1 5 4 |
72 | * |
73 | * The need for a strong naming convention should now be clear: |
74 | * each small box is two rows of digits by three columns, while the |
75 | * overall puzzle has three rows of small boxes by two columns. So |
76 | * I will (hopefully) consistently use `r' to denote the number of |
77 | * rows _of small boxes_ (here 3), which is also the number of |
78 | * columns of digits in each small box; and `c' vice versa (here |
79 | * 2). |
80 | * |
81 | * I'm also going to choose arbitrarily to list c first wherever |
82 | * possible: the above is a 2x3 puzzle, not a 3x2 one. |
83 | */ |
84 | |
85 | #include <stdio.h> |
86 | #include <stdlib.h> |
87 | #include <string.h> |
88 | #include <assert.h> |
89 | #include <ctype.h> |
90 | #include <math.h> |
91 | |
7c568a48 |
92 | #ifdef STANDALONE_SOLVER |
93 | #include <stdarg.h> |
94 | int solver_show_working; |
95 | #endif |
96 | |
1d8e8ad8 |
97 | #include "puzzles.h" |
98 | |
99 | /* |
100 | * To save space, I store digits internally as unsigned char. This |
101 | * imposes a hard limit of 255 on the order of the puzzle. Since |
102 | * even a 5x5 takes unacceptably long to generate, I don't see this |
103 | * as a serious limitation unless something _really_ impressive |
104 | * happens in computing technology; but here's a typedef anyway for |
105 | * general good practice. |
106 | */ |
107 | typedef unsigned char digit; |
108 | #define ORDER_MAX 255 |
109 | |
110 | #define TILE_SIZE 32 |
111 | #define BORDER 18 |
112 | |
113 | #define FLASH_TIME 0.4F |
114 | |
ef57b17d |
115 | enum { SYMM_NONE, SYMM_ROT2, SYMM_ROT4, SYMM_REF4 }; |
116 | |
7c568a48 |
117 | enum { DIFF_BLOCK, DIFF_SIMPLE, DIFF_INTERSECT, |
118 | DIFF_SET, DIFF_RECURSIVE, DIFF_AMBIGUOUS, DIFF_IMPOSSIBLE }; |
119 | |
1d8e8ad8 |
120 | enum { |
121 | COL_BACKGROUND, |
ef57b17d |
122 | COL_GRID, |
123 | COL_CLUE, |
124 | COL_USER, |
125 | COL_HIGHLIGHT, |
7b14a9ec |
126 | COL_ERROR, |
c8266e03 |
127 | COL_PENCIL, |
ef57b17d |
128 | NCOLOURS |
1d8e8ad8 |
129 | }; |
130 | |
131 | struct game_params { |
7c568a48 |
132 | int c, r, symm, diff; |
1d8e8ad8 |
133 | }; |
134 | |
135 | struct game_state { |
136 | int c, r; |
137 | digit *grid; |
c8266e03 |
138 | unsigned char *pencil; /* c*r*c*r elements */ |
1d8e8ad8 |
139 | unsigned char *immutable; /* marks which digits are clues */ |
2ac6d24e |
140 | int completed, cheated; |
1d8e8ad8 |
141 | }; |
142 | |
143 | static game_params *default_params(void) |
144 | { |
145 | game_params *ret = snew(game_params); |
146 | |
147 | ret->c = ret->r = 3; |
ef57b17d |
148 | ret->symm = SYMM_ROT2; /* a plausible default */ |
4f36adaa |
149 | ret->diff = DIFF_BLOCK; /* so is this */ |
1d8e8ad8 |
150 | |
151 | return ret; |
152 | } |
153 | |
1d8e8ad8 |
154 | static void free_params(game_params *params) |
155 | { |
156 | sfree(params); |
157 | } |
158 | |
159 | static game_params *dup_params(game_params *params) |
160 | { |
161 | game_params *ret = snew(game_params); |
162 | *ret = *params; /* structure copy */ |
163 | return ret; |
164 | } |
165 | |
7c568a48 |
166 | static int game_fetch_preset(int i, char **name, game_params **params) |
167 | { |
168 | static struct { |
169 | char *title; |
170 | game_params params; |
171 | } presets[] = { |
172 | { "2x2 Trivial", { 2, 2, SYMM_ROT2, DIFF_BLOCK } }, |
173 | { "2x3 Basic", { 2, 3, SYMM_ROT2, DIFF_SIMPLE } }, |
4f36adaa |
174 | { "3x3 Trivial", { 3, 3, SYMM_ROT2, DIFF_BLOCK } }, |
7c568a48 |
175 | { "3x3 Basic", { 3, 3, SYMM_ROT2, DIFF_SIMPLE } }, |
176 | { "3x3 Intermediate", { 3, 3, SYMM_ROT2, DIFF_INTERSECT } }, |
177 | { "3x3 Advanced", { 3, 3, SYMM_ROT2, DIFF_SET } }, |
de60d8bd |
178 | { "3x3 Unreasonable", { 3, 3, SYMM_ROT2, DIFF_RECURSIVE } }, |
ab53eb64 |
179 | #ifndef SLOW_SYSTEM |
7c568a48 |
180 | { "3x4 Basic", { 3, 4, SYMM_ROT2, DIFF_SIMPLE } }, |
181 | { "4x4 Basic", { 4, 4, SYMM_ROT2, DIFF_SIMPLE } }, |
ab53eb64 |
182 | #endif |
7c568a48 |
183 | }; |
184 | |
185 | if (i < 0 || i >= lenof(presets)) |
186 | return FALSE; |
187 | |
188 | *name = dupstr(presets[i].title); |
189 | *params = dup_params(&presets[i].params); |
190 | |
191 | return TRUE; |
192 | } |
193 | |
1185e3c5 |
194 | static void decode_params(game_params *ret, char const *string) |
1d8e8ad8 |
195 | { |
1d8e8ad8 |
196 | ret->c = ret->r = atoi(string); |
197 | while (*string && isdigit((unsigned char)*string)) string++; |
198 | if (*string == 'x') { |
199 | string++; |
200 | ret->r = atoi(string); |
201 | while (*string && isdigit((unsigned char)*string)) string++; |
202 | } |
7c568a48 |
203 | while (*string) { |
204 | if (*string == 'r' || *string == 'm' || *string == 'a') { |
205 | int sn, sc; |
206 | sc = *string++; |
207 | sn = atoi(string); |
208 | while (*string && isdigit((unsigned char)*string)) string++; |
209 | if (sc == 'm' && sn == 4) |
210 | ret->symm = SYMM_REF4; |
211 | if (sc == 'r' && sn == 4) |
212 | ret->symm = SYMM_ROT4; |
213 | if (sc == 'r' && sn == 2) |
214 | ret->symm = SYMM_ROT2; |
215 | if (sc == 'a') |
216 | ret->symm = SYMM_NONE; |
217 | } else if (*string == 'd') { |
218 | string++; |
219 | if (*string == 't') /* trivial */ |
220 | string++, ret->diff = DIFF_BLOCK; |
221 | else if (*string == 'b') /* basic */ |
222 | string++, ret->diff = DIFF_SIMPLE; |
223 | else if (*string == 'i') /* intermediate */ |
224 | string++, ret->diff = DIFF_INTERSECT; |
225 | else if (*string == 'a') /* advanced */ |
226 | string++, ret->diff = DIFF_SET; |
de60d8bd |
227 | else if (*string == 'u') /* unreasonable */ |
228 | string++, ret->diff = DIFF_RECURSIVE; |
7c568a48 |
229 | } else |
230 | string++; /* eat unknown character */ |
ef57b17d |
231 | } |
1d8e8ad8 |
232 | } |
233 | |
1185e3c5 |
234 | static char *encode_params(game_params *params, int full) |
1d8e8ad8 |
235 | { |
236 | char str[80]; |
237 | |
238 | sprintf(str, "%dx%d", params->c, params->r); |
1185e3c5 |
239 | if (full) { |
240 | switch (params->symm) { |
241 | case SYMM_REF4: strcat(str, "m4"); break; |
242 | case SYMM_ROT4: strcat(str, "r4"); break; |
243 | /* case SYMM_ROT2: strcat(str, "r2"); break; [default] */ |
244 | case SYMM_NONE: strcat(str, "a"); break; |
245 | } |
246 | switch (params->diff) { |
247 | /* case DIFF_BLOCK: strcat(str, "dt"); break; [default] */ |
248 | case DIFF_SIMPLE: strcat(str, "db"); break; |
249 | case DIFF_INTERSECT: strcat(str, "di"); break; |
250 | case DIFF_SET: strcat(str, "da"); break; |
251 | case DIFF_RECURSIVE: strcat(str, "du"); break; |
252 | } |
253 | } |
1d8e8ad8 |
254 | return dupstr(str); |
255 | } |
256 | |
257 | static config_item *game_configure(game_params *params) |
258 | { |
259 | config_item *ret; |
260 | char buf[80]; |
261 | |
262 | ret = snewn(5, config_item); |
263 | |
264 | ret[0].name = "Columns of sub-blocks"; |
265 | ret[0].type = C_STRING; |
266 | sprintf(buf, "%d", params->c); |
267 | ret[0].sval = dupstr(buf); |
268 | ret[0].ival = 0; |
269 | |
270 | ret[1].name = "Rows of sub-blocks"; |
271 | ret[1].type = C_STRING; |
272 | sprintf(buf, "%d", params->r); |
273 | ret[1].sval = dupstr(buf); |
274 | ret[1].ival = 0; |
275 | |
ef57b17d |
276 | ret[2].name = "Symmetry"; |
277 | ret[2].type = C_CHOICES; |
278 | ret[2].sval = ":None:2-way rotation:4-way rotation:4-way mirror"; |
279 | ret[2].ival = params->symm; |
280 | |
7c568a48 |
281 | ret[3].name = "Difficulty"; |
282 | ret[3].type = C_CHOICES; |
de60d8bd |
283 | ret[3].sval = ":Trivial:Basic:Intermediate:Advanced:Unreasonable"; |
7c568a48 |
284 | ret[3].ival = params->diff; |
1d8e8ad8 |
285 | |
7c568a48 |
286 | ret[4].name = NULL; |
287 | ret[4].type = C_END; |
288 | ret[4].sval = NULL; |
289 | ret[4].ival = 0; |
1d8e8ad8 |
290 | |
291 | return ret; |
292 | } |
293 | |
294 | static game_params *custom_params(config_item *cfg) |
295 | { |
296 | game_params *ret = snew(game_params); |
297 | |
c1f743c8 |
298 | ret->c = atoi(cfg[0].sval); |
299 | ret->r = atoi(cfg[1].sval); |
ef57b17d |
300 | ret->symm = cfg[2].ival; |
7c568a48 |
301 | ret->diff = cfg[3].ival; |
1d8e8ad8 |
302 | |
303 | return ret; |
304 | } |
305 | |
306 | static char *validate_params(game_params *params) |
307 | { |
308 | if (params->c < 2 || params->r < 2) |
309 | return "Both dimensions must be at least 2"; |
310 | if (params->c > ORDER_MAX || params->r > ORDER_MAX) |
311 | return "Dimensions greater than "STR(ORDER_MAX)" are not supported"; |
312 | return NULL; |
313 | } |
314 | |
315 | /* ---------------------------------------------------------------------- |
316 | * Full recursive Solo solver. |
317 | * |
318 | * The algorithm for this solver is shamelessly copied from a |
319 | * Python solver written by Andrew Wilkinson (which is GPLed, but |
320 | * I've reused only ideas and no code). It mostly just does the |
321 | * obvious recursive thing: pick an empty square, put one of the |
322 | * possible digits in it, recurse until all squares are filled, |
323 | * backtrack and change some choices if necessary. |
324 | * |
325 | * The clever bit is that every time it chooses which square to |
326 | * fill in next, it does so by counting the number of _possible_ |
327 | * numbers that can go in each square, and it prioritises so that |
328 | * it picks a square with the _lowest_ number of possibilities. The |
329 | * idea is that filling in lots of the obvious bits (particularly |
330 | * any squares with only one possibility) will cut down on the list |
331 | * of possibilities for other squares and hence reduce the enormous |
332 | * search space as much as possible as early as possible. |
333 | * |
334 | * In practice the algorithm appeared to work very well; run on |
335 | * sample problems from the Times it completed in well under a |
336 | * second on my G5 even when written in Python, and given an empty |
337 | * grid (so that in principle it would enumerate _all_ solved |
338 | * grids!) it found the first valid solution just as quickly. So |
339 | * with a bit more randomisation I see no reason not to use this as |
340 | * my grid generator. |
341 | */ |
342 | |
343 | /* |
344 | * Internal data structure used in solver to keep track of |
345 | * progress. |
346 | */ |
347 | struct rsolve_coord { int x, y, r; }; |
348 | struct rsolve_usage { |
349 | int c, r, cr; /* cr == c*r */ |
350 | /* grid is a copy of the input grid, modified as we go along */ |
351 | digit *grid; |
352 | /* row[y*cr+n-1] TRUE if digit n has been placed in row y */ |
353 | unsigned char *row; |
354 | /* col[x*cr+n-1] TRUE if digit n has been placed in row x */ |
355 | unsigned char *col; |
356 | /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */ |
357 | unsigned char *blk; |
358 | /* This lists all the empty spaces remaining in the grid. */ |
359 | struct rsolve_coord *spaces; |
360 | int nspaces; |
361 | /* If we need randomisation in the solve, this is our random state. */ |
362 | random_state *rs; |
363 | /* Number of solutions so far found, and maximum number we care about. */ |
364 | int solns, maxsolns; |
365 | }; |
366 | |
367 | /* |
368 | * The real recursive step in the solving function. |
369 | */ |
370 | static void rsolve_real(struct rsolve_usage *usage, digit *grid) |
371 | { |
372 | int c = usage->c, r = usage->r, cr = usage->cr; |
373 | int i, j, n, sx, sy, bestm, bestr; |
374 | int *digits; |
375 | |
376 | /* |
377 | * Firstly, check for completion! If there are no spaces left |
378 | * in the grid, we have a solution. |
379 | */ |
380 | if (usage->nspaces == 0) { |
381 | if (!usage->solns) { |
382 | /* |
383 | * This is our first solution, so fill in the output grid. |
384 | */ |
385 | memcpy(grid, usage->grid, cr * cr); |
386 | } |
387 | usage->solns++; |
388 | return; |
389 | } |
390 | |
391 | /* |
392 | * Otherwise, there must be at least one space. Find the most |
393 | * constrained space, using the `r' field as a tie-breaker. |
394 | */ |
395 | bestm = cr+1; /* so that any space will beat it */ |
396 | bestr = 0; |
397 | i = sx = sy = -1; |
398 | for (j = 0; j < usage->nspaces; j++) { |
399 | int x = usage->spaces[j].x, y = usage->spaces[j].y; |
400 | int m; |
401 | |
402 | /* |
403 | * Find the number of digits that could go in this space. |
404 | */ |
405 | m = 0; |
406 | for (n = 0; n < cr; n++) |
407 | if (!usage->row[y*cr+n] && !usage->col[x*cr+n] && |
408 | !usage->blk[((y/c)*c+(x/r))*cr+n]) |
409 | m++; |
410 | |
411 | if (m < bestm || (m == bestm && usage->spaces[j].r < bestr)) { |
412 | bestm = m; |
413 | bestr = usage->spaces[j].r; |
414 | sx = x; |
415 | sy = y; |
416 | i = j; |
417 | } |
418 | } |
419 | |
420 | /* |
421 | * Swap that square into the final place in the spaces array, |
422 | * so that decrementing nspaces will remove it from the list. |
423 | */ |
424 | if (i != usage->nspaces-1) { |
425 | struct rsolve_coord t; |
426 | t = usage->spaces[usage->nspaces-1]; |
427 | usage->spaces[usage->nspaces-1] = usage->spaces[i]; |
428 | usage->spaces[i] = t; |
429 | } |
430 | |
431 | /* |
432 | * Now we've decided which square to start our recursion at, |
433 | * simply go through all possible values, shuffling them |
434 | * randomly first if necessary. |
435 | */ |
436 | digits = snewn(bestm, int); |
437 | j = 0; |
438 | for (n = 0; n < cr; n++) |
439 | if (!usage->row[sy*cr+n] && !usage->col[sx*cr+n] && |
440 | !usage->blk[((sy/c)*c+(sx/r))*cr+n]) { |
441 | digits[j++] = n+1; |
442 | } |
443 | |
444 | if (usage->rs) { |
445 | /* shuffle */ |
446 | for (i = j; i > 1; i--) { |
447 | int p = random_upto(usage->rs, i); |
448 | if (p != i-1) { |
449 | int t = digits[p]; |
450 | digits[p] = digits[i-1]; |
451 | digits[i-1] = t; |
452 | } |
453 | } |
454 | } |
455 | |
456 | /* And finally, go through the digit list and actually recurse. */ |
457 | for (i = 0; i < j; i++) { |
458 | n = digits[i]; |
459 | |
460 | /* Update the usage structure to reflect the placing of this digit. */ |
461 | usage->row[sy*cr+n-1] = usage->col[sx*cr+n-1] = |
462 | usage->blk[((sy/c)*c+(sx/r))*cr+n-1] = TRUE; |
463 | usage->grid[sy*cr+sx] = n; |
464 | usage->nspaces--; |
465 | |
466 | /* Call the solver recursively. */ |
467 | rsolve_real(usage, grid); |
468 | |
469 | /* |
470 | * If we have seen as many solutions as we need, terminate |
471 | * all processing immediately. |
472 | */ |
473 | if (usage->solns >= usage->maxsolns) |
474 | break; |
475 | |
476 | /* Revert the usage structure. */ |
477 | usage->row[sy*cr+n-1] = usage->col[sx*cr+n-1] = |
478 | usage->blk[((sy/c)*c+(sx/r))*cr+n-1] = FALSE; |
479 | usage->grid[sy*cr+sx] = 0; |
480 | usage->nspaces++; |
481 | } |
482 | |
483 | sfree(digits); |
484 | } |
485 | |
486 | /* |
487 | * Entry point to solver. You give it dimensions and a starting |
488 | * grid, which is simply an array of N^4 digits. In that array, 0 |
489 | * means an empty square, and 1..N mean a clue square. |
490 | * |
491 | * Return value is the number of solutions found; searching will |
492 | * stop after the provided `max'. (Thus, you can pass max==1 to |
493 | * indicate that you only care about finding _one_ solution, or |
494 | * max==2 to indicate that you want to know the difference between |
495 | * a unique and non-unique solution.) The input parameter `grid' is |
496 | * also filled in with the _first_ (or only) solution found by the |
497 | * solver. |
498 | */ |
499 | static int rsolve(int c, int r, digit *grid, random_state *rs, int max) |
500 | { |
501 | struct rsolve_usage *usage; |
502 | int x, y, cr = c*r; |
503 | int ret; |
504 | |
505 | /* |
506 | * Create an rsolve_usage structure. |
507 | */ |
508 | usage = snew(struct rsolve_usage); |
509 | |
510 | usage->c = c; |
511 | usage->r = r; |
512 | usage->cr = cr; |
513 | |
514 | usage->grid = snewn(cr * cr, digit); |
515 | memcpy(usage->grid, grid, cr * cr); |
516 | |
517 | usage->row = snewn(cr * cr, unsigned char); |
518 | usage->col = snewn(cr * cr, unsigned char); |
519 | usage->blk = snewn(cr * cr, unsigned char); |
520 | memset(usage->row, FALSE, cr * cr); |
521 | memset(usage->col, FALSE, cr * cr); |
522 | memset(usage->blk, FALSE, cr * cr); |
523 | |
524 | usage->spaces = snewn(cr * cr, struct rsolve_coord); |
525 | usage->nspaces = 0; |
526 | |
527 | usage->solns = 0; |
528 | usage->maxsolns = max; |
529 | |
530 | usage->rs = rs; |
531 | |
532 | /* |
533 | * Now fill it in with data from the input grid. |
534 | */ |
535 | for (y = 0; y < cr; y++) { |
536 | for (x = 0; x < cr; x++) { |
537 | int v = grid[y*cr+x]; |
538 | if (v == 0) { |
539 | usage->spaces[usage->nspaces].x = x; |
540 | usage->spaces[usage->nspaces].y = y; |
541 | if (rs) |
542 | usage->spaces[usage->nspaces].r = random_bits(rs, 31); |
543 | else |
544 | usage->spaces[usage->nspaces].r = usage->nspaces; |
545 | usage->nspaces++; |
546 | } else { |
547 | usage->row[y*cr+v-1] = TRUE; |
548 | usage->col[x*cr+v-1] = TRUE; |
549 | usage->blk[((y/c)*c+(x/r))*cr+v-1] = TRUE; |
550 | } |
551 | } |
552 | } |
553 | |
554 | /* |
555 | * Run the real recursive solving function. |
556 | */ |
557 | rsolve_real(usage, grid); |
558 | ret = usage->solns; |
559 | |
560 | /* |
561 | * Clean up the usage structure now we have our answer. |
562 | */ |
563 | sfree(usage->spaces); |
564 | sfree(usage->blk); |
565 | sfree(usage->col); |
566 | sfree(usage->row); |
567 | sfree(usage->grid); |
568 | sfree(usage); |
569 | |
570 | /* |
571 | * And return. |
572 | */ |
573 | return ret; |
574 | } |
575 | |
576 | /* ---------------------------------------------------------------------- |
577 | * End of recursive solver code. |
578 | */ |
579 | |
580 | /* ---------------------------------------------------------------------- |
581 | * Less capable non-recursive solver. This one is used to check |
582 | * solubility of a grid as we gradually remove numbers from it: by |
583 | * verifying a grid using this solver we can ensure it isn't _too_ |
584 | * hard (e.g. does not actually require guessing and backtracking). |
585 | * |
586 | * It supports a variety of specific modes of reasoning. By |
587 | * enabling or disabling subsets of these modes we can arrange a |
588 | * range of difficulty levels. |
589 | */ |
590 | |
591 | /* |
592 | * Modes of reasoning currently supported: |
593 | * |
594 | * - Positional elimination: a number must go in a particular |
595 | * square because all the other empty squares in a given |
596 | * row/col/blk are ruled out. |
597 | * |
598 | * - Numeric elimination: a square must have a particular number |
599 | * in because all the other numbers that could go in it are |
600 | * ruled out. |
601 | * |
7c568a48 |
602 | * - Intersectional analysis: given two domains which overlap |
1d8e8ad8 |
603 | * (hence one must be a block, and the other can be a row or |
604 | * col), if the possible locations for a particular number in |
605 | * one of the domains can be narrowed down to the overlap, then |
606 | * that number can be ruled out everywhere but the overlap in |
607 | * the other domain too. |
608 | * |
7c568a48 |
609 | * - Set elimination: if there is a subset of the empty squares |
610 | * within a domain such that the union of the possible numbers |
611 | * in that subset has the same size as the subset itself, then |
612 | * those numbers can be ruled out everywhere else in the domain. |
613 | * (For example, if there are five empty squares and the |
614 | * possible numbers in each are 12, 23, 13, 134 and 1345, then |
615 | * the first three empty squares form such a subset: the numbers |
616 | * 1, 2 and 3 _must_ be in those three squares in some |
617 | * permutation, and hence we can deduce none of them can be in |
618 | * the fourth or fifth squares.) |
619 | * + You can also see this the other way round, concentrating |
620 | * on numbers rather than squares: if there is a subset of |
621 | * the unplaced numbers within a domain such that the union |
622 | * of all their possible positions has the same size as the |
623 | * subset itself, then all other numbers can be ruled out for |
624 | * those positions. However, it turns out that this is |
625 | * exactly equivalent to the first formulation at all times: |
626 | * there is a 1-1 correspondence between suitable subsets of |
627 | * the unplaced numbers and suitable subsets of the unfilled |
628 | * places, found by taking the _complement_ of the union of |
629 | * the numbers' possible positions (or the spaces' possible |
630 | * contents). |
1d8e8ad8 |
631 | */ |
632 | |
4846f788 |
633 | /* |
634 | * Within this solver, I'm going to transform all y-coordinates by |
635 | * inverting the significance of the block number and the position |
636 | * within the block. That is, we will start with the top row of |
637 | * each block in order, then the second row of each block in order, |
638 | * etc. |
639 | * |
640 | * This transformation has the enormous advantage that it means |
641 | * every row, column _and_ block is described by an arithmetic |
642 | * progression of coordinates within the cubic array, so that I can |
643 | * use the same very simple function to do blockwise, row-wise and |
644 | * column-wise elimination. |
645 | */ |
646 | #define YTRANS(y) (((y)%c)*r+(y)/c) |
647 | #define YUNTRANS(y) (((y)%r)*c+(y)/r) |
648 | |
1d8e8ad8 |
649 | struct nsolve_usage { |
650 | int c, r, cr; |
651 | /* |
652 | * We set up a cubic array, indexed by x, y and digit; each |
653 | * element of this array is TRUE or FALSE according to whether |
654 | * or not that digit _could_ in principle go in that position. |
655 | * |
656 | * The way to index this array is cube[(x*cr+y)*cr+n-1]. |
4846f788 |
657 | * y-coordinates in here are transformed. |
1d8e8ad8 |
658 | */ |
659 | unsigned char *cube; |
660 | /* |
661 | * This is the grid in which we write down our final |
4846f788 |
662 | * deductions. y-coordinates in here are _not_ transformed. |
1d8e8ad8 |
663 | */ |
664 | digit *grid; |
665 | /* |
666 | * Now we keep track, at a slightly higher level, of what we |
667 | * have yet to work out, to prevent doing the same deduction |
668 | * many times. |
669 | */ |
670 | /* row[y*cr+n-1] TRUE if digit n has been placed in row y */ |
671 | unsigned char *row; |
672 | /* col[x*cr+n-1] TRUE if digit n has been placed in row x */ |
673 | unsigned char *col; |
674 | /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */ |
675 | unsigned char *blk; |
676 | }; |
4846f788 |
677 | #define cubepos(x,y,n) (((x)*usage->cr+(y))*usage->cr+(n)-1) |
678 | #define cube(x,y,n) (usage->cube[cubepos(x,y,n)]) |
1d8e8ad8 |
679 | |
680 | /* |
681 | * Function called when we are certain that a particular square has |
4846f788 |
682 | * a particular number in it. The y-coordinate passed in here is |
683 | * transformed. |
1d8e8ad8 |
684 | */ |
685 | static void nsolve_place(struct nsolve_usage *usage, int x, int y, int n) |
686 | { |
687 | int c = usage->c, r = usage->r, cr = usage->cr; |
688 | int i, j, bx, by; |
689 | |
690 | assert(cube(x,y,n)); |
691 | |
692 | /* |
693 | * Rule out all other numbers in this square. |
694 | */ |
695 | for (i = 1; i <= cr; i++) |
696 | if (i != n) |
697 | cube(x,y,i) = FALSE; |
698 | |
699 | /* |
700 | * Rule out this number in all other positions in the row. |
701 | */ |
702 | for (i = 0; i < cr; i++) |
703 | if (i != y) |
704 | cube(x,i,n) = FALSE; |
705 | |
706 | /* |
707 | * Rule out this number in all other positions in the column. |
708 | */ |
709 | for (i = 0; i < cr; i++) |
710 | if (i != x) |
711 | cube(i,y,n) = FALSE; |
712 | |
713 | /* |
714 | * Rule out this number in all other positions in the block. |
715 | */ |
716 | bx = (x/r)*r; |
4846f788 |
717 | by = y % r; |
1d8e8ad8 |
718 | for (i = 0; i < r; i++) |
719 | for (j = 0; j < c; j++) |
4846f788 |
720 | if (bx+i != x || by+j*r != y) |
721 | cube(bx+i,by+j*r,n) = FALSE; |
1d8e8ad8 |
722 | |
723 | /* |
724 | * Enter the number in the result grid. |
725 | */ |
4846f788 |
726 | usage->grid[YUNTRANS(y)*cr+x] = n; |
1d8e8ad8 |
727 | |
728 | /* |
729 | * Cross out this number from the list of numbers left to place |
730 | * in its row, its column and its block. |
731 | */ |
732 | usage->row[y*cr+n-1] = usage->col[x*cr+n-1] = |
7c568a48 |
733 | usage->blk[((y%r)*c+(x/r))*cr+n-1] = TRUE; |
1d8e8ad8 |
734 | } |
735 | |
7c568a48 |
736 | static int nsolve_elim(struct nsolve_usage *usage, int start, int step |
737 | #ifdef STANDALONE_SOLVER |
738 | , char *fmt, ... |
739 | #endif |
740 | ) |
1d8e8ad8 |
741 | { |
4846f788 |
742 | int c = usage->c, r = usage->r, cr = c*r; |
743 | int fpos, m, i; |
1d8e8ad8 |
744 | |
745 | /* |
4846f788 |
746 | * Count the number of set bits within this section of the |
747 | * cube. |
1d8e8ad8 |
748 | */ |
749 | m = 0; |
4846f788 |
750 | fpos = -1; |
751 | for (i = 0; i < cr; i++) |
752 | if (usage->cube[start+i*step]) { |
753 | fpos = start+i*step; |
1d8e8ad8 |
754 | m++; |
755 | } |
756 | |
757 | if (m == 1) { |
4846f788 |
758 | int x, y, n; |
759 | assert(fpos >= 0); |
1d8e8ad8 |
760 | |
4846f788 |
761 | n = 1 + fpos % cr; |
762 | y = fpos / cr; |
763 | x = y / cr; |
764 | y %= cr; |
1d8e8ad8 |
765 | |
3ddae0ff |
766 | if (!usage->grid[YUNTRANS(y)*cr+x]) { |
7c568a48 |
767 | #ifdef STANDALONE_SOLVER |
768 | if (solver_show_working) { |
769 | va_list ap; |
770 | va_start(ap, fmt); |
771 | vprintf(fmt, ap); |
772 | va_end(ap); |
773 | printf(":\n placing %d at (%d,%d)\n", |
774 | n, 1+x, 1+YUNTRANS(y)); |
775 | } |
776 | #endif |
3ddae0ff |
777 | nsolve_place(usage, x, y, n); |
778 | return TRUE; |
779 | } |
1d8e8ad8 |
780 | } |
781 | |
782 | return FALSE; |
783 | } |
784 | |
7c568a48 |
785 | static int nsolve_intersect(struct nsolve_usage *usage, |
786 | int start1, int step1, int start2, int step2 |
787 | #ifdef STANDALONE_SOLVER |
788 | , char *fmt, ... |
789 | #endif |
790 | ) |
791 | { |
792 | int c = usage->c, r = usage->r, cr = c*r; |
793 | int ret, i; |
794 | |
795 | /* |
796 | * Loop over the first domain and see if there's any set bit |
797 | * not also in the second. |
798 | */ |
799 | for (i = 0; i < cr; i++) { |
800 | int p = start1+i*step1; |
801 | if (usage->cube[p] && |
802 | !(p >= start2 && p < start2+cr*step2 && |
803 | (p - start2) % step2 == 0)) |
804 | return FALSE; /* there is, so we can't deduce */ |
805 | } |
806 | |
807 | /* |
808 | * We have determined that all set bits in the first domain are |
809 | * within its overlap with the second. So loop over the second |
810 | * domain and remove all set bits that aren't also in that |
811 | * overlap; return TRUE iff we actually _did_ anything. |
812 | */ |
813 | ret = FALSE; |
814 | for (i = 0; i < cr; i++) { |
815 | int p = start2+i*step2; |
816 | if (usage->cube[p] && |
817 | !(p >= start1 && p < start1+cr*step1 && (p - start1) % step1 == 0)) |
818 | { |
819 | #ifdef STANDALONE_SOLVER |
820 | if (solver_show_working) { |
821 | int px, py, pn; |
822 | |
823 | if (!ret) { |
824 | va_list ap; |
825 | va_start(ap, fmt); |
826 | vprintf(fmt, ap); |
827 | va_end(ap); |
828 | printf(":\n"); |
829 | } |
830 | |
831 | pn = 1 + p % cr; |
832 | py = p / cr; |
833 | px = py / cr; |
834 | py %= cr; |
835 | |
836 | printf(" ruling out %d at (%d,%d)\n", |
837 | pn, 1+px, 1+YUNTRANS(py)); |
838 | } |
839 | #endif |
840 | ret = TRUE; /* we did something */ |
841 | usage->cube[p] = 0; |
842 | } |
843 | } |
844 | |
845 | return ret; |
846 | } |
847 | |
ab53eb64 |
848 | struct nsolve_scratch { |
849 | unsigned char *grid, *rowidx, *colidx, *set; |
850 | }; |
851 | |
7c568a48 |
852 | static int nsolve_set(struct nsolve_usage *usage, |
ab53eb64 |
853 | struct nsolve_scratch *scratch, |
7c568a48 |
854 | int start, int step1, int step2 |
855 | #ifdef STANDALONE_SOLVER |
856 | , char *fmt, ... |
857 | #endif |
858 | ) |
859 | { |
860 | int c = usage->c, r = usage->r, cr = c*r; |
861 | int i, j, n, count; |
ab53eb64 |
862 | unsigned char *grid = scratch->grid; |
863 | unsigned char *rowidx = scratch->rowidx; |
864 | unsigned char *colidx = scratch->colidx; |
865 | unsigned char *set = scratch->set; |
7c568a48 |
866 | |
867 | /* |
868 | * We are passed a cr-by-cr matrix of booleans. Our first job |
869 | * is to winnow it by finding any definite placements - i.e. |
870 | * any row with a solitary 1 - and discarding that row and the |
871 | * column containing the 1. |
872 | */ |
873 | memset(rowidx, TRUE, cr); |
874 | memset(colidx, TRUE, cr); |
875 | for (i = 0; i < cr; i++) { |
876 | int count = 0, first = -1; |
877 | for (j = 0; j < cr; j++) |
878 | if (usage->cube[start+i*step1+j*step2]) |
879 | first = j, count++; |
880 | if (count == 0) { |
881 | /* |
882 | * This condition actually marks a completely insoluble |
883 | * (i.e. internally inconsistent) puzzle. We return and |
884 | * report no progress made. |
885 | */ |
886 | return FALSE; |
887 | } |
888 | if (count == 1) |
889 | rowidx[i] = colidx[first] = FALSE; |
890 | } |
891 | |
892 | /* |
893 | * Convert each of rowidx/colidx from a list of 0s and 1s to a |
894 | * list of the indices of the 1s. |
895 | */ |
896 | for (i = j = 0; i < cr; i++) |
897 | if (rowidx[i]) |
898 | rowidx[j++] = i; |
899 | n = j; |
900 | for (i = j = 0; i < cr; i++) |
901 | if (colidx[i]) |
902 | colidx[j++] = i; |
903 | assert(n == j); |
904 | |
905 | /* |
906 | * And create the smaller matrix. |
907 | */ |
908 | for (i = 0; i < n; i++) |
909 | for (j = 0; j < n; j++) |
910 | grid[i*cr+j] = usage->cube[start+rowidx[i]*step1+colidx[j]*step2]; |
911 | |
912 | /* |
913 | * Having done that, we now have a matrix in which every row |
914 | * has at least two 1s in. Now we search to see if we can find |
915 | * a rectangle of zeroes (in the set-theoretic sense of |
916 | * `rectangle', i.e. a subset of rows crossed with a subset of |
917 | * columns) whose width and height add up to n. |
918 | */ |
919 | |
920 | memset(set, 0, n); |
921 | count = 0; |
922 | while (1) { |
923 | /* |
924 | * We have a candidate set. If its size is <=1 or >=n-1 |
925 | * then we move on immediately. |
926 | */ |
927 | if (count > 1 && count < n-1) { |
928 | /* |
929 | * The number of rows we need is n-count. See if we can |
930 | * find that many rows which each have a zero in all |
931 | * the positions listed in `set'. |
932 | */ |
933 | int rows = 0; |
934 | for (i = 0; i < n; i++) { |
935 | int ok = TRUE; |
936 | for (j = 0; j < n; j++) |
937 | if (set[j] && grid[i*cr+j]) { |
938 | ok = FALSE; |
939 | break; |
940 | } |
941 | if (ok) |
942 | rows++; |
943 | } |
944 | |
945 | /* |
946 | * We expect never to be able to get _more_ than |
947 | * n-count suitable rows: this would imply that (for |
948 | * example) there are four numbers which between them |
949 | * have at most three possible positions, and hence it |
950 | * indicates a faulty deduction before this point or |
951 | * even a bogus clue. |
952 | */ |
953 | assert(rows <= n - count); |
954 | if (rows >= n - count) { |
955 | int progress = FALSE; |
956 | |
957 | /* |
958 | * We've got one! Now, for each row which _doesn't_ |
959 | * satisfy the criterion, eliminate all its set |
960 | * bits in the positions _not_ listed in `set'. |
961 | * Return TRUE (meaning progress has been made) if |
962 | * we successfully eliminated anything at all. |
963 | * |
964 | * This involves referring back through |
965 | * rowidx/colidx in order to work out which actual |
966 | * positions in the cube to meddle with. |
967 | */ |
968 | for (i = 0; i < n; i++) { |
969 | int ok = TRUE; |
970 | for (j = 0; j < n; j++) |
971 | if (set[j] && grid[i*cr+j]) { |
972 | ok = FALSE; |
973 | break; |
974 | } |
975 | if (!ok) { |
976 | for (j = 0; j < n; j++) |
977 | if (!set[j] && grid[i*cr+j]) { |
978 | int fpos = (start+rowidx[i]*step1+ |
979 | colidx[j]*step2); |
980 | #ifdef STANDALONE_SOLVER |
981 | if (solver_show_working) { |
982 | int px, py, pn; |
983 | |
984 | if (!progress) { |
985 | va_list ap; |
986 | va_start(ap, fmt); |
987 | vprintf(fmt, ap); |
988 | va_end(ap); |
989 | printf(":\n"); |
990 | } |
991 | |
992 | pn = 1 + fpos % cr; |
993 | py = fpos / cr; |
994 | px = py / cr; |
995 | py %= cr; |
996 | |
997 | printf(" ruling out %d at (%d,%d)\n", |
998 | pn, 1+px, 1+YUNTRANS(py)); |
999 | } |
1000 | #endif |
1001 | progress = TRUE; |
1002 | usage->cube[fpos] = FALSE; |
1003 | } |
1004 | } |
1005 | } |
1006 | |
1007 | if (progress) { |
7c568a48 |
1008 | return TRUE; |
1009 | } |
1010 | } |
1011 | } |
1012 | |
1013 | /* |
1014 | * Binary increment: change the rightmost 0 to a 1, and |
1015 | * change all 1s to the right of it to 0s. |
1016 | */ |
1017 | i = n; |
1018 | while (i > 0 && set[i-1]) |
1019 | set[--i] = 0, count--; |
1020 | if (i > 0) |
1021 | set[--i] = 1, count++; |
1022 | else |
1023 | break; /* done */ |
1024 | } |
1025 | |
7c568a48 |
1026 | return FALSE; |
1027 | } |
1028 | |
ab53eb64 |
1029 | static struct nsolve_scratch *nsolve_new_scratch(struct nsolve_usage *usage) |
1030 | { |
1031 | struct nsolve_scratch *scratch = snew(struct nsolve_scratch); |
1032 | int cr = usage->cr; |
1033 | scratch->grid = snewn(cr*cr, unsigned char); |
1034 | scratch->rowidx = snewn(cr, unsigned char); |
1035 | scratch->colidx = snewn(cr, unsigned char); |
1036 | scratch->set = snewn(cr, unsigned char); |
1037 | return scratch; |
1038 | } |
1039 | |
1040 | static void nsolve_free_scratch(struct nsolve_scratch *scratch) |
1041 | { |
1042 | sfree(scratch->set); |
1043 | sfree(scratch->colidx); |
1044 | sfree(scratch->rowidx); |
1045 | sfree(scratch->grid); |
1046 | sfree(scratch); |
1047 | } |
1048 | |
1d8e8ad8 |
1049 | static int nsolve(int c, int r, digit *grid) |
1050 | { |
1051 | struct nsolve_usage *usage; |
ab53eb64 |
1052 | struct nsolve_scratch *scratch; |
1d8e8ad8 |
1053 | int cr = c*r; |
1054 | int x, y, n; |
7c568a48 |
1055 | int diff = DIFF_BLOCK; |
1d8e8ad8 |
1056 | |
1057 | /* |
1058 | * Set up a usage structure as a clean slate (everything |
1059 | * possible). |
1060 | */ |
1061 | usage = snew(struct nsolve_usage); |
1062 | usage->c = c; |
1063 | usage->r = r; |
1064 | usage->cr = cr; |
1065 | usage->cube = snewn(cr*cr*cr, unsigned char); |
1066 | usage->grid = grid; /* write straight back to the input */ |
1067 | memset(usage->cube, TRUE, cr*cr*cr); |
1068 | |
1069 | usage->row = snewn(cr * cr, unsigned char); |
1070 | usage->col = snewn(cr * cr, unsigned char); |
1071 | usage->blk = snewn(cr * cr, unsigned char); |
1072 | memset(usage->row, FALSE, cr * cr); |
1073 | memset(usage->col, FALSE, cr * cr); |
1074 | memset(usage->blk, FALSE, cr * cr); |
1075 | |
ab53eb64 |
1076 | scratch = nsolve_new_scratch(usage); |
1077 | |
1d8e8ad8 |
1078 | /* |
1079 | * Place all the clue numbers we are given. |
1080 | */ |
1081 | for (x = 0; x < cr; x++) |
1082 | for (y = 0; y < cr; y++) |
1083 | if (grid[y*cr+x]) |
4846f788 |
1084 | nsolve_place(usage, x, YTRANS(y), grid[y*cr+x]); |
1d8e8ad8 |
1085 | |
1086 | /* |
1087 | * Now loop over the grid repeatedly trying all permitted modes |
1088 | * of reasoning. The loop terminates if we complete an |
1089 | * iteration without making any progress; we then return |
1090 | * failure or success depending on whether the grid is full or |
1091 | * not. |
1092 | */ |
1093 | while (1) { |
7c568a48 |
1094 | /* |
1095 | * I'd like to write `continue;' inside each of the |
1096 | * following loops, so that the solver returns here after |
1097 | * making some progress. However, I can't specify that I |
1098 | * want to continue an outer loop rather than the innermost |
1099 | * one, so I'm apologetically resorting to a goto. |
1100 | */ |
3ddae0ff |
1101 | cont: |
1102 | |
1d8e8ad8 |
1103 | /* |
1104 | * Blockwise positional elimination. |
1105 | */ |
4846f788 |
1106 | for (x = 0; x < cr; x += r) |
1d8e8ad8 |
1107 | for (y = 0; y < r; y++) |
1108 | for (n = 1; n <= cr; n++) |
4846f788 |
1109 | if (!usage->blk[(y*c+(x/r))*cr+n-1] && |
7c568a48 |
1110 | nsolve_elim(usage, cubepos(x,y,n), r*cr |
1111 | #ifdef STANDALONE_SOLVER |
1112 | , "positional elimination," |
1113 | " block (%d,%d)", 1+x/r, 1+y |
1114 | #endif |
1115 | )) { |
1116 | diff = max(diff, DIFF_BLOCK); |
3ddae0ff |
1117 | goto cont; |
7c568a48 |
1118 | } |
1d8e8ad8 |
1119 | |
1120 | /* |
1121 | * Row-wise positional elimination. |
1122 | */ |
1123 | for (y = 0; y < cr; y++) |
1124 | for (n = 1; n <= cr; n++) |
1125 | if (!usage->row[y*cr+n-1] && |
7c568a48 |
1126 | nsolve_elim(usage, cubepos(0,y,n), cr*cr |
1127 | #ifdef STANDALONE_SOLVER |
1128 | , "positional elimination," |
1129 | " row %d", 1+YUNTRANS(y) |
1130 | #endif |
1131 | )) { |
1132 | diff = max(diff, DIFF_SIMPLE); |
3ddae0ff |
1133 | goto cont; |
7c568a48 |
1134 | } |
1d8e8ad8 |
1135 | /* |
1136 | * Column-wise positional elimination. |
1137 | */ |
1138 | for (x = 0; x < cr; x++) |
1139 | for (n = 1; n <= cr; n++) |
1140 | if (!usage->col[x*cr+n-1] && |
7c568a48 |
1141 | nsolve_elim(usage, cubepos(x,0,n), cr |
1142 | #ifdef STANDALONE_SOLVER |
1143 | , "positional elimination," " column %d", 1+x |
1144 | #endif |
1145 | )) { |
1146 | diff = max(diff, DIFF_SIMPLE); |
3ddae0ff |
1147 | goto cont; |
7c568a48 |
1148 | } |
1d8e8ad8 |
1149 | |
1150 | /* |
1151 | * Numeric elimination. |
1152 | */ |
1153 | for (x = 0; x < cr; x++) |
1154 | for (y = 0; y < cr; y++) |
4846f788 |
1155 | if (!usage->grid[YUNTRANS(y)*cr+x] && |
7c568a48 |
1156 | nsolve_elim(usage, cubepos(x,y,1), 1 |
1157 | #ifdef STANDALONE_SOLVER |
1158 | , "numeric elimination at (%d,%d)", 1+x, |
1159 | 1+YUNTRANS(y) |
1160 | #endif |
1161 | )) { |
1162 | diff = max(diff, DIFF_SIMPLE); |
1163 | goto cont; |
1164 | } |
1165 | |
1166 | /* |
1167 | * Intersectional analysis, rows vs blocks. |
1168 | */ |
1169 | for (y = 0; y < cr; y++) |
1170 | for (x = 0; x < cr; x += r) |
1171 | for (n = 1; n <= cr; n++) |
1172 | if (!usage->row[y*cr+n-1] && |
1173 | !usage->blk[((y%r)*c+(x/r))*cr+n-1] && |
1174 | (nsolve_intersect(usage, cubepos(0,y,n), cr*cr, |
1175 | cubepos(x,y%r,n), r*cr |
1176 | #ifdef STANDALONE_SOLVER |
1177 | , "intersectional analysis," |
1178 | " row %d vs block (%d,%d)", |
b37c4d5f |
1179 | 1+YUNTRANS(y), 1+x/r, 1+y%r |
7c568a48 |
1180 | #endif |
1181 | ) || |
1182 | nsolve_intersect(usage, cubepos(x,y%r,n), r*cr, |
1183 | cubepos(0,y,n), cr*cr |
1184 | #ifdef STANDALONE_SOLVER |
1185 | , "intersectional analysis," |
1186 | " block (%d,%d) vs row %d", |
b37c4d5f |
1187 | 1+x/r, 1+y%r, 1+YUNTRANS(y) |
7c568a48 |
1188 | #endif |
1189 | ))) { |
1190 | diff = max(diff, DIFF_INTERSECT); |
1191 | goto cont; |
1192 | } |
1193 | |
1194 | /* |
1195 | * Intersectional analysis, columns vs blocks. |
1196 | */ |
1197 | for (x = 0; x < cr; x++) |
1198 | for (y = 0; y < r; y++) |
1199 | for (n = 1; n <= cr; n++) |
1200 | if (!usage->col[x*cr+n-1] && |
1201 | !usage->blk[(y*c+(x/r))*cr+n-1] && |
1202 | (nsolve_intersect(usage, cubepos(x,0,n), cr, |
1203 | cubepos((x/r)*r,y,n), r*cr |
1204 | #ifdef STANDALONE_SOLVER |
1205 | , "intersectional analysis," |
1206 | " column %d vs block (%d,%d)", |
1207 | 1+x, 1+x/r, 1+y |
1208 | #endif |
1209 | ) || |
1210 | nsolve_intersect(usage, cubepos((x/r)*r,y,n), r*cr, |
1211 | cubepos(x,0,n), cr |
1212 | #ifdef STANDALONE_SOLVER |
1213 | , "intersectional analysis," |
1214 | " block (%d,%d) vs column %d", |
1215 | 1+x/r, 1+y, 1+x |
1216 | #endif |
1217 | ))) { |
1218 | diff = max(diff, DIFF_INTERSECT); |
1219 | goto cont; |
1220 | } |
1221 | |
1222 | /* |
1223 | * Blockwise set elimination. |
1224 | */ |
1225 | for (x = 0; x < cr; x += r) |
1226 | for (y = 0; y < r; y++) |
ab53eb64 |
1227 | if (nsolve_set(usage, scratch, cubepos(x,y,1), r*cr, 1 |
7c568a48 |
1228 | #ifdef STANDALONE_SOLVER |
1229 | , "set elimination, block (%d,%d)", 1+x/r, 1+y |
1230 | #endif |
1231 | )) { |
1232 | diff = max(diff, DIFF_SET); |
1233 | goto cont; |
1234 | } |
1235 | |
1236 | /* |
1237 | * Row-wise set elimination. |
1238 | */ |
1239 | for (y = 0; y < cr; y++) |
ab53eb64 |
1240 | if (nsolve_set(usage, scratch, cubepos(0,y,1), cr*cr, 1 |
7c568a48 |
1241 | #ifdef STANDALONE_SOLVER |
1242 | , "set elimination, row %d", 1+YUNTRANS(y) |
1243 | #endif |
1244 | )) { |
1245 | diff = max(diff, DIFF_SET); |
1246 | goto cont; |
1247 | } |
1248 | |
1249 | /* |
1250 | * Column-wise set elimination. |
1251 | */ |
1252 | for (x = 0; x < cr; x++) |
ab53eb64 |
1253 | if (nsolve_set(usage, scratch, cubepos(x,0,1), cr, 1 |
7c568a48 |
1254 | #ifdef STANDALONE_SOLVER |
1255 | , "set elimination, column %d", 1+x |
1256 | #endif |
1257 | )) { |
1258 | diff = max(diff, DIFF_SET); |
1259 | goto cont; |
1260 | } |
1d8e8ad8 |
1261 | |
1262 | /* |
1263 | * If we reach here, we have made no deductions in this |
1264 | * iteration, so the algorithm terminates. |
1265 | */ |
1266 | break; |
1267 | } |
1268 | |
ab53eb64 |
1269 | nsolve_free_scratch(scratch); |
1270 | |
1d8e8ad8 |
1271 | sfree(usage->cube); |
1272 | sfree(usage->row); |
1273 | sfree(usage->col); |
1274 | sfree(usage->blk); |
1275 | sfree(usage); |
1276 | |
1277 | for (x = 0; x < cr; x++) |
1278 | for (y = 0; y < cr; y++) |
1279 | if (!grid[y*cr+x]) |
7c568a48 |
1280 | return DIFF_IMPOSSIBLE; |
1281 | return diff; |
1d8e8ad8 |
1282 | } |
1283 | |
1284 | /* ---------------------------------------------------------------------- |
1285 | * End of non-recursive solver code. |
1286 | */ |
1287 | |
1288 | /* |
1289 | * Check whether a grid contains a valid complete puzzle. |
1290 | */ |
1291 | static int check_valid(int c, int r, digit *grid) |
1292 | { |
1293 | int cr = c*r; |
1294 | unsigned char *used; |
1295 | int x, y, n; |
1296 | |
1297 | used = snewn(cr, unsigned char); |
1298 | |
1299 | /* |
1300 | * Check that each row contains precisely one of everything. |
1301 | */ |
1302 | for (y = 0; y < cr; y++) { |
1303 | memset(used, FALSE, cr); |
1304 | for (x = 0; x < cr; x++) |
1305 | if (grid[y*cr+x] > 0 && grid[y*cr+x] <= cr) |
1306 | used[grid[y*cr+x]-1] = TRUE; |
1307 | for (n = 0; n < cr; n++) |
1308 | if (!used[n]) { |
1309 | sfree(used); |
1310 | return FALSE; |
1311 | } |
1312 | } |
1313 | |
1314 | /* |
1315 | * Check that each column contains precisely one of everything. |
1316 | */ |
1317 | for (x = 0; x < cr; x++) { |
1318 | memset(used, FALSE, cr); |
1319 | for (y = 0; y < cr; y++) |
1320 | if (grid[y*cr+x] > 0 && grid[y*cr+x] <= cr) |
1321 | used[grid[y*cr+x]-1] = TRUE; |
1322 | for (n = 0; n < cr; n++) |
1323 | if (!used[n]) { |
1324 | sfree(used); |
1325 | return FALSE; |
1326 | } |
1327 | } |
1328 | |
1329 | /* |
1330 | * Check that each block contains precisely one of everything. |
1331 | */ |
1332 | for (x = 0; x < cr; x += r) { |
1333 | for (y = 0; y < cr; y += c) { |
1334 | int xx, yy; |
1335 | memset(used, FALSE, cr); |
1336 | for (xx = x; xx < x+r; xx++) |
1337 | for (yy = 0; yy < y+c; yy++) |
1338 | if (grid[yy*cr+xx] > 0 && grid[yy*cr+xx] <= cr) |
1339 | used[grid[yy*cr+xx]-1] = TRUE; |
1340 | for (n = 0; n < cr; n++) |
1341 | if (!used[n]) { |
1342 | sfree(used); |
1343 | return FALSE; |
1344 | } |
1345 | } |
1346 | } |
1347 | |
1348 | sfree(used); |
1349 | return TRUE; |
1350 | } |
1351 | |
ef57b17d |
1352 | static void symmetry_limit(game_params *params, int *xlim, int *ylim, int s) |
1353 | { |
1354 | int c = params->c, r = params->r, cr = c*r; |
1355 | |
1356 | switch (s) { |
1357 | case SYMM_NONE: |
1358 | *xlim = *ylim = cr; |
1359 | break; |
1360 | case SYMM_ROT2: |
1361 | *xlim = (cr+1) / 2; |
1362 | *ylim = cr; |
1363 | break; |
1364 | case SYMM_REF4: |
1365 | case SYMM_ROT4: |
1366 | *xlim = *ylim = (cr+1) / 2; |
1367 | break; |
1368 | } |
1369 | } |
1370 | |
1371 | static int symmetries(game_params *params, int x, int y, int *output, int s) |
1372 | { |
1373 | int c = params->c, r = params->r, cr = c*r; |
1374 | int i = 0; |
1375 | |
1376 | *output++ = x; |
1377 | *output++ = y; |
1378 | i++; |
1379 | |
1380 | switch (s) { |
1381 | case SYMM_NONE: |
1382 | break; /* just x,y is all we need */ |
1383 | case SYMM_REF4: |
1384 | case SYMM_ROT4: |
1385 | switch (s) { |
1386 | case SYMM_REF4: |
1387 | *output++ = cr - 1 - x; |
1388 | *output++ = y; |
1389 | i++; |
1390 | |
1391 | *output++ = x; |
1392 | *output++ = cr - 1 - y; |
1393 | i++; |
1394 | break; |
1395 | case SYMM_ROT4: |
1396 | *output++ = cr - 1 - y; |
1397 | *output++ = x; |
1398 | i++; |
1399 | |
1400 | *output++ = y; |
1401 | *output++ = cr - 1 - x; |
1402 | i++; |
1403 | break; |
1404 | } |
1405 | /* fall through */ |
1406 | case SYMM_ROT2: |
1407 | *output++ = cr - 1 - x; |
1408 | *output++ = cr - 1 - y; |
1409 | i++; |
1410 | break; |
1411 | } |
1412 | |
1413 | return i; |
1414 | } |
1415 | |
3220eba4 |
1416 | struct game_aux_info { |
1417 | int c, r; |
1418 | digit *grid; |
1419 | }; |
1420 | |
1185e3c5 |
1421 | static char *new_game_desc(game_params *params, random_state *rs, |
6aa6af4c |
1422 | game_aux_info **aux, int interactive) |
1d8e8ad8 |
1423 | { |
1424 | int c = params->c, r = params->r, cr = c*r; |
1425 | int area = cr*cr; |
1426 | digit *grid, *grid2; |
1427 | struct xy { int x, y; } *locs; |
1428 | int nlocs; |
1429 | int ret; |
1185e3c5 |
1430 | char *desc; |
ef57b17d |
1431 | int coords[16], ncoords; |
1432 | int xlim, ylim; |
de60d8bd |
1433 | int maxdiff, recursing; |
1d8e8ad8 |
1434 | |
1435 | /* |
7c568a48 |
1436 | * Adjust the maximum difficulty level to be consistent with |
1437 | * the puzzle size: all 2x2 puzzles appear to be Trivial |
1438 | * (DIFF_BLOCK) so we cannot hold out for even a Basic |
1439 | * (DIFF_SIMPLE) one. |
1d8e8ad8 |
1440 | */ |
7c568a48 |
1441 | maxdiff = params->diff; |
1442 | if (c == 2 && r == 2) |
1443 | maxdiff = DIFF_BLOCK; |
1d8e8ad8 |
1444 | |
7c568a48 |
1445 | grid = snewn(area, digit); |
ef57b17d |
1446 | locs = snewn(area, struct xy); |
1d8e8ad8 |
1447 | grid2 = snewn(area, digit); |
1d8e8ad8 |
1448 | |
7c568a48 |
1449 | /* |
1450 | * Loop until we get a grid of the required difficulty. This is |
1451 | * nasty, but it seems to be unpleasantly hard to generate |
1452 | * difficult grids otherwise. |
1453 | */ |
1454 | do { |
1455 | /* |
1456 | * Start the recursive solver with an empty grid to generate a |
1457 | * random solved state. |
1458 | */ |
1459 | memset(grid, 0, area); |
1460 | ret = rsolve(c, r, grid, rs, 1); |
1461 | assert(ret == 1); |
1462 | assert(check_valid(c, r, grid)); |
1463 | |
3220eba4 |
1464 | /* |
1465 | * Save the solved grid in the aux_info. |
1466 | */ |
1467 | { |
1468 | game_aux_info *ai = snew(game_aux_info); |
1469 | ai->c = c; |
1470 | ai->r = r; |
1471 | ai->grid = snewn(cr * cr, digit); |
1472 | memcpy(ai->grid, grid, cr * cr * sizeof(digit)); |
ab53eb64 |
1473 | /* |
1474 | * We might already have written *aux the last time we |
1475 | * went round this loop, in which case we should free |
1476 | * the old aux_info before overwriting it with the new |
1477 | * one. |
1478 | */ |
1479 | if (*aux) { |
1480 | sfree((*aux)->grid); |
1481 | sfree(*aux); |
1482 | } |
3220eba4 |
1483 | *aux = ai; |
1484 | } |
1485 | |
7c568a48 |
1486 | /* |
1487 | * Now we have a solved grid, start removing things from it |
1488 | * while preserving solubility. |
1489 | */ |
1490 | symmetry_limit(params, &xlim, &ylim, params->symm); |
de60d8bd |
1491 | recursing = FALSE; |
7c568a48 |
1492 | while (1) { |
1493 | int x, y, i, j; |
1494 | |
1495 | /* |
1496 | * Iterate over the grid and enumerate all the filled |
1497 | * squares we could empty. |
1498 | */ |
1499 | nlocs = 0; |
1500 | |
1501 | for (x = 0; x < xlim; x++) |
1502 | for (y = 0; y < ylim; y++) |
1503 | if (grid[y*cr+x]) { |
1504 | locs[nlocs].x = x; |
1505 | locs[nlocs].y = y; |
1506 | nlocs++; |
1507 | } |
1508 | |
1509 | /* |
1510 | * Now shuffle that list. |
1511 | */ |
1512 | for (i = nlocs; i > 1; i--) { |
1513 | int p = random_upto(rs, i); |
1514 | if (p != i-1) { |
1515 | struct xy t = locs[p]; |
1516 | locs[p] = locs[i-1]; |
1517 | locs[i-1] = t; |
1518 | } |
1519 | } |
1520 | |
1521 | /* |
1522 | * Now loop over the shuffled list and, for each element, |
1523 | * see whether removing that element (and its reflections) |
1524 | * from the grid will still leave the grid soluble by |
1525 | * nsolve. |
1526 | */ |
1527 | for (i = 0; i < nlocs; i++) { |
de60d8bd |
1528 | int ret; |
1529 | |
7c568a48 |
1530 | x = locs[i].x; |
1531 | y = locs[i].y; |
1532 | |
1533 | memcpy(grid2, grid, area); |
1534 | ncoords = symmetries(params, x, y, coords, params->symm); |
1535 | for (j = 0; j < ncoords; j++) |
1536 | grid2[coords[2*j+1]*cr+coords[2*j]] = 0; |
1537 | |
de60d8bd |
1538 | if (recursing) |
1539 | ret = (rsolve(c, r, grid2, NULL, 2) == 1); |
1540 | else |
1541 | ret = (nsolve(c, r, grid2) <= maxdiff); |
1542 | |
1543 | if (ret) { |
7c568a48 |
1544 | for (j = 0; j < ncoords; j++) |
1545 | grid[coords[2*j+1]*cr+coords[2*j]] = 0; |
1546 | break; |
1547 | } |
1548 | } |
1549 | |
1550 | if (i == nlocs) { |
1551 | /* |
de60d8bd |
1552 | * There was nothing we could remove without |
1553 | * destroying solvability. If we're trying to |
1554 | * generate a recursion-only grid and haven't |
1555 | * switched over to rsolve yet, we now do; |
1556 | * otherwise we give up. |
7c568a48 |
1557 | */ |
de60d8bd |
1558 | if (maxdiff == DIFF_RECURSIVE && !recursing) { |
1559 | recursing = TRUE; |
1560 | } else { |
1561 | break; |
1562 | } |
7c568a48 |
1563 | } |
1564 | } |
1d8e8ad8 |
1565 | |
7c568a48 |
1566 | memcpy(grid2, grid, area); |
de60d8bd |
1567 | } while (nsolve(c, r, grid2) < maxdiff); |
1d8e8ad8 |
1568 | |
1d8e8ad8 |
1569 | sfree(grid2); |
1570 | sfree(locs); |
1571 | |
1d8e8ad8 |
1572 | /* |
1573 | * Now we have the grid as it will be presented to the user. |
1185e3c5 |
1574 | * Encode it in a game desc. |
1d8e8ad8 |
1575 | */ |
1576 | { |
1577 | char *p; |
1578 | int run, i; |
1579 | |
1185e3c5 |
1580 | desc = snewn(5 * area, char); |
1581 | p = desc; |
1d8e8ad8 |
1582 | run = 0; |
1583 | for (i = 0; i <= area; i++) { |
1584 | int n = (i < area ? grid[i] : -1); |
1585 | |
1586 | if (!n) |
1587 | run++; |
1588 | else { |
1589 | if (run) { |
1590 | while (run > 0) { |
1591 | int c = 'a' - 1 + run; |
1592 | if (run > 26) |
1593 | c = 'z'; |
1594 | *p++ = c; |
1595 | run -= c - ('a' - 1); |
1596 | } |
1597 | } else { |
1598 | /* |
1599 | * If there's a number in the very top left or |
1600 | * bottom right, there's no point putting an |
1601 | * unnecessary _ before or after it. |
1602 | */ |
1185e3c5 |
1603 | if (p > desc && n > 0) |
1d8e8ad8 |
1604 | *p++ = '_'; |
1605 | } |
1606 | if (n > 0) |
1607 | p += sprintf(p, "%d", n); |
1608 | run = 0; |
1609 | } |
1610 | } |
1185e3c5 |
1611 | assert(p - desc < 5 * area); |
1d8e8ad8 |
1612 | *p++ = '\0'; |
1185e3c5 |
1613 | desc = sresize(desc, p - desc, char); |
1d8e8ad8 |
1614 | } |
1615 | |
1616 | sfree(grid); |
1617 | |
1185e3c5 |
1618 | return desc; |
1d8e8ad8 |
1619 | } |
1620 | |
2ac6d24e |
1621 | static void game_free_aux_info(game_aux_info *aux) |
6f2d8d7c |
1622 | { |
3220eba4 |
1623 | sfree(aux->grid); |
1624 | sfree(aux); |
6f2d8d7c |
1625 | } |
1626 | |
1185e3c5 |
1627 | static char *validate_desc(game_params *params, char *desc) |
1d8e8ad8 |
1628 | { |
1629 | int area = params->r * params->r * params->c * params->c; |
1630 | int squares = 0; |
1631 | |
1185e3c5 |
1632 | while (*desc) { |
1633 | int n = *desc++; |
1d8e8ad8 |
1634 | if (n >= 'a' && n <= 'z') { |
1635 | squares += n - 'a' + 1; |
1636 | } else if (n == '_') { |
1637 | /* do nothing */; |
1638 | } else if (n > '0' && n <= '9') { |
1639 | squares++; |
1185e3c5 |
1640 | while (*desc >= '0' && *desc <= '9') |
1641 | desc++; |
1d8e8ad8 |
1642 | } else |
1185e3c5 |
1643 | return "Invalid character in game description"; |
1d8e8ad8 |
1644 | } |
1645 | |
1646 | if (squares < area) |
1647 | return "Not enough data to fill grid"; |
1648 | |
1649 | if (squares > area) |
1650 | return "Too much data to fit in grid"; |
1651 | |
1652 | return NULL; |
1653 | } |
1654 | |
c380832d |
1655 | static game_state *new_game(midend_data *me, game_params *params, char *desc) |
1d8e8ad8 |
1656 | { |
1657 | game_state *state = snew(game_state); |
1658 | int c = params->c, r = params->r, cr = c*r, area = cr * cr; |
1659 | int i; |
1660 | |
1661 | state->c = params->c; |
1662 | state->r = params->r; |
1663 | |
1664 | state->grid = snewn(area, digit); |
c8266e03 |
1665 | state->pencil = snewn(area * cr, unsigned char); |
1666 | memset(state->pencil, 0, area * cr); |
1d8e8ad8 |
1667 | state->immutable = snewn(area, unsigned char); |
1668 | memset(state->immutable, FALSE, area); |
1669 | |
2ac6d24e |
1670 | state->completed = state->cheated = FALSE; |
1d8e8ad8 |
1671 | |
1672 | i = 0; |
1185e3c5 |
1673 | while (*desc) { |
1674 | int n = *desc++; |
1d8e8ad8 |
1675 | if (n >= 'a' && n <= 'z') { |
1676 | int run = n - 'a' + 1; |
1677 | assert(i + run <= area); |
1678 | while (run-- > 0) |
1679 | state->grid[i++] = 0; |
1680 | } else if (n == '_') { |
1681 | /* do nothing */; |
1682 | } else if (n > '0' && n <= '9') { |
1683 | assert(i < area); |
1684 | state->immutable[i] = TRUE; |
1185e3c5 |
1685 | state->grid[i++] = atoi(desc-1); |
1686 | while (*desc >= '0' && *desc <= '9') |
1687 | desc++; |
1d8e8ad8 |
1688 | } else { |
1689 | assert(!"We can't get here"); |
1690 | } |
1691 | } |
1692 | assert(i == area); |
1693 | |
1694 | return state; |
1695 | } |
1696 | |
1697 | static game_state *dup_game(game_state *state) |
1698 | { |
1699 | game_state *ret = snew(game_state); |
1700 | int c = state->c, r = state->r, cr = c*r, area = cr * cr; |
1701 | |
1702 | ret->c = state->c; |
1703 | ret->r = state->r; |
1704 | |
1705 | ret->grid = snewn(area, digit); |
1706 | memcpy(ret->grid, state->grid, area); |
1707 | |
c8266e03 |
1708 | ret->pencil = snewn(area * cr, unsigned char); |
1709 | memcpy(ret->pencil, state->pencil, area * cr); |
1710 | |
1d8e8ad8 |
1711 | ret->immutable = snewn(area, unsigned char); |
1712 | memcpy(ret->immutable, state->immutable, area); |
1713 | |
1714 | ret->completed = state->completed; |
2ac6d24e |
1715 | ret->cheated = state->cheated; |
1d8e8ad8 |
1716 | |
1717 | return ret; |
1718 | } |
1719 | |
1720 | static void free_game(game_state *state) |
1721 | { |
1722 | sfree(state->immutable); |
c8266e03 |
1723 | sfree(state->pencil); |
1d8e8ad8 |
1724 | sfree(state->grid); |
1725 | sfree(state); |
1726 | } |
1727 | |
3220eba4 |
1728 | static game_state *solve_game(game_state *state, game_aux_info *ai, |
2ac6d24e |
1729 | char **error) |
1730 | { |
1731 | game_state *ret; |
3220eba4 |
1732 | int c = state->c, r = state->r, cr = c*r; |
2ac6d24e |
1733 | int rsolve_ret; |
1734 | |
2ac6d24e |
1735 | ret = dup_game(state); |
1736 | ret->completed = ret->cheated = TRUE; |
1737 | |
3220eba4 |
1738 | /* |
1739 | * If we already have the solution in the aux_info, save |
1740 | * ourselves some time. |
1741 | */ |
1742 | if (ai) { |
1743 | |
1744 | assert(c == ai->c); |
1745 | assert(r == ai->r); |
1746 | memcpy(ret->grid, ai->grid, cr * cr * sizeof(digit)); |
1747 | |
1748 | } else { |
1749 | rsolve_ret = rsolve(c, r, ret->grid, NULL, 2); |
1750 | |
1751 | if (rsolve_ret != 1) { |
1752 | free_game(ret); |
1753 | if (rsolve_ret == 0) |
1754 | *error = "No solution exists for this puzzle"; |
1755 | else |
1756 | *error = "Multiple solutions exist for this puzzle"; |
1757 | return NULL; |
1758 | } |
2ac6d24e |
1759 | } |
1760 | |
1761 | return ret; |
1762 | } |
1763 | |
9b4b03d3 |
1764 | static char *grid_text_format(int c, int r, digit *grid) |
1765 | { |
1766 | int cr = c*r; |
1767 | int x, y; |
1768 | int maxlen; |
1769 | char *ret, *p; |
1770 | |
1771 | /* |
1772 | * There are cr lines of digits, plus r-1 lines of block |
1773 | * separators. Each line contains cr digits, cr-1 separating |
1774 | * spaces, and c-1 two-character block separators. Thus, the |
1775 | * total length of a line is 2*cr+2*c-3 (not counting the |
1776 | * newline), and there are cr+r-1 of them. |
1777 | */ |
1778 | maxlen = (cr+r-1) * (2*cr+2*c-2); |
1779 | ret = snewn(maxlen+1, char); |
1780 | p = ret; |
1781 | |
1782 | for (y = 0; y < cr; y++) { |
1783 | for (x = 0; x < cr; x++) { |
1784 | int ch = grid[y * cr + x]; |
1785 | if (ch == 0) |
1786 | ch = ' '; |
1787 | else if (ch <= 9) |
1788 | ch = '0' + ch; |
1789 | else |
1790 | ch = 'a' + ch-10; |
1791 | *p++ = ch; |
1792 | if (x+1 < cr) { |
1793 | *p++ = ' '; |
1794 | if ((x+1) % r == 0) { |
1795 | *p++ = '|'; |
1796 | *p++ = ' '; |
1797 | } |
1798 | } |
1799 | } |
1800 | *p++ = '\n'; |
1801 | if (y+1 < cr && (y+1) % c == 0) { |
1802 | for (x = 0; x < cr; x++) { |
1803 | *p++ = '-'; |
1804 | if (x+1 < cr) { |
1805 | *p++ = '-'; |
1806 | if ((x+1) % r == 0) { |
1807 | *p++ = '+'; |
1808 | *p++ = '-'; |
1809 | } |
1810 | } |
1811 | } |
1812 | *p++ = '\n'; |
1813 | } |
1814 | } |
1815 | |
1816 | assert(p - ret == maxlen); |
1817 | *p = '\0'; |
1818 | return ret; |
1819 | } |
1820 | |
1821 | static char *game_text_format(game_state *state) |
1822 | { |
1823 | return grid_text_format(state->c, state->r, state->grid); |
1824 | } |
1825 | |
1d8e8ad8 |
1826 | struct game_ui { |
1827 | /* |
1828 | * These are the coordinates of the currently highlighted |
1829 | * square on the grid, or -1,-1 if there isn't one. When there |
1830 | * is, pressing a valid number or letter key or Space will |
1831 | * enter that number or letter in the grid. |
1832 | */ |
1833 | int hx, hy; |
c8266e03 |
1834 | /* |
1835 | * This indicates whether the current highlight is a |
1836 | * pencil-mark one or a real one. |
1837 | */ |
1838 | int hpencil; |
1d8e8ad8 |
1839 | }; |
1840 | |
1841 | static game_ui *new_ui(game_state *state) |
1842 | { |
1843 | game_ui *ui = snew(game_ui); |
1844 | |
1845 | ui->hx = ui->hy = -1; |
c8266e03 |
1846 | ui->hpencil = 0; |
1d8e8ad8 |
1847 | |
1848 | return ui; |
1849 | } |
1850 | |
1851 | static void free_ui(game_ui *ui) |
1852 | { |
1853 | sfree(ui); |
1854 | } |
1855 | |
c0361acd |
1856 | static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, |
1857 | int x, int y, int button) |
1d8e8ad8 |
1858 | { |
1859 | int c = from->c, r = from->r, cr = c*r; |
1860 | int tx, ty; |
1861 | game_state *ret; |
1862 | |
f0ee053c |
1863 | button &= ~MOD_MASK; |
3c833d45 |
1864 | |
ae812854 |
1865 | tx = (x + TILE_SIZE - BORDER) / TILE_SIZE - 1; |
1866 | ty = (y + TILE_SIZE - BORDER) / TILE_SIZE - 1; |
1d8e8ad8 |
1867 | |
39d682c9 |
1868 | if (tx >= 0 && tx < cr && ty >= 0 && ty < cr) { |
1869 | if (button == LEFT_BUTTON) { |
1870 | if (from->immutable[ty*cr+tx]) { |
1871 | ui->hx = ui->hy = -1; |
1872 | } else if (tx == ui->hx && ty == ui->hy && ui->hpencil == 0) { |
1873 | ui->hx = ui->hy = -1; |
1874 | } else { |
1875 | ui->hx = tx; |
1876 | ui->hy = ty; |
1877 | ui->hpencil = 0; |
1878 | } |
1879 | return from; /* UI activity occurred */ |
1880 | } |
1881 | if (button == RIGHT_BUTTON) { |
1882 | /* |
1883 | * Pencil-mode highlighting for non filled squares. |
1884 | */ |
1885 | if (from->grid[ty*cr+tx] == 0) { |
1886 | if (tx == ui->hx && ty == ui->hy && ui->hpencil) { |
1887 | ui->hx = ui->hy = -1; |
1888 | } else { |
1889 | ui->hpencil = 1; |
1890 | ui->hx = tx; |
1891 | ui->hy = ty; |
1892 | } |
1893 | } else { |
1894 | ui->hx = ui->hy = -1; |
1895 | } |
1896 | return from; /* UI activity occurred */ |
1897 | } |
1d8e8ad8 |
1898 | } |
1899 | |
1900 | if (ui->hx != -1 && ui->hy != -1 && |
1901 | ((button >= '1' && button <= '9' && button - '0' <= cr) || |
1902 | (button >= 'a' && button <= 'z' && button - 'a' + 10 <= cr) || |
1903 | (button >= 'A' && button <= 'Z' && button - 'A' + 10 <= cr) || |
1904 | button == ' ')) { |
1905 | int n = button - '0'; |
1906 | if (button >= 'A' && button <= 'Z') |
1907 | n = button - 'A' + 10; |
1908 | if (button >= 'a' && button <= 'z') |
1909 | n = button - 'a' + 10; |
1910 | if (button == ' ') |
1911 | n = 0; |
1912 | |
39d682c9 |
1913 | /* |
1914 | * Can't overwrite this square. In principle this shouldn't |
1915 | * happen anyway because we should never have even been |
1916 | * able to highlight the square, but it never hurts to be |
1917 | * careful. |
1918 | */ |
1d8e8ad8 |
1919 | if (from->immutable[ui->hy*cr+ui->hx]) |
39d682c9 |
1920 | return NULL; |
1d8e8ad8 |
1921 | |
c8266e03 |
1922 | /* |
1923 | * Can't make pencil marks in a filled square. In principle |
1924 | * this shouldn't happen anyway because we should never |
1925 | * have even been able to pencil-highlight the square, but |
1926 | * it never hurts to be careful. |
1927 | */ |
1928 | if (ui->hpencil && from->grid[ui->hy*cr+ui->hx]) |
1929 | return NULL; |
1930 | |
1d8e8ad8 |
1931 | ret = dup_game(from); |
c8266e03 |
1932 | if (ui->hpencil && n > 0) { |
1933 | int index = (ui->hy*cr+ui->hx) * cr + (n-1); |
1934 | ret->pencil[index] = !ret->pencil[index]; |
1935 | } else { |
1936 | ret->grid[ui->hy*cr+ui->hx] = n; |
1937 | memset(ret->pencil + (ui->hy*cr+ui->hx)*cr, 0, cr); |
1d8e8ad8 |
1938 | |
c8266e03 |
1939 | /* |
1940 | * We've made a real change to the grid. Check to see |
1941 | * if the game has been completed. |
1942 | */ |
1943 | if (!ret->completed && check_valid(c, r, ret->grid)) { |
1944 | ret->completed = TRUE; |
1945 | } |
1946 | } |
1947 | ui->hx = ui->hy = -1; |
1d8e8ad8 |
1948 | |
1949 | return ret; /* made a valid move */ |
1950 | } |
1951 | |
1952 | return NULL; |
1953 | } |
1954 | |
1955 | /* ---------------------------------------------------------------------- |
1956 | * Drawing routines. |
1957 | */ |
1958 | |
1959 | struct game_drawstate { |
1960 | int started; |
1961 | int c, r, cr; |
1962 | digit *grid; |
c8266e03 |
1963 | unsigned char *pencil; |
1d8e8ad8 |
1964 | unsigned char *hl; |
b71dd7fc |
1965 | /* This is scratch space used within a single call to game_redraw. */ |
1966 | int *entered_items; |
1d8e8ad8 |
1967 | }; |
1968 | |
1969 | #define XSIZE(cr) ((cr) * TILE_SIZE + 2*BORDER + 1) |
1970 | #define YSIZE(cr) ((cr) * TILE_SIZE + 2*BORDER + 1) |
1971 | |
1972 | static void game_size(game_params *params, int *x, int *y) |
1973 | { |
1974 | int c = params->c, r = params->r, cr = c*r; |
1975 | |
1976 | *x = XSIZE(cr); |
1977 | *y = YSIZE(cr); |
1978 | } |
1979 | |
1980 | static float *game_colours(frontend *fe, game_state *state, int *ncolours) |
1981 | { |
1982 | float *ret = snewn(3 * NCOLOURS, float); |
1983 | |
1984 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
1985 | |
1986 | ret[COL_GRID * 3 + 0] = 0.0F; |
1987 | ret[COL_GRID * 3 + 1] = 0.0F; |
1988 | ret[COL_GRID * 3 + 2] = 0.0F; |
1989 | |
1990 | ret[COL_CLUE * 3 + 0] = 0.0F; |
1991 | ret[COL_CLUE * 3 + 1] = 0.0F; |
1992 | ret[COL_CLUE * 3 + 2] = 0.0F; |
1993 | |
1994 | ret[COL_USER * 3 + 0] = 0.0F; |
1995 | ret[COL_USER * 3 + 1] = 0.6F * ret[COL_BACKGROUND * 3 + 1]; |
1996 | ret[COL_USER * 3 + 2] = 0.0F; |
1997 | |
1998 | ret[COL_HIGHLIGHT * 3 + 0] = 0.85F * ret[COL_BACKGROUND * 3 + 0]; |
1999 | ret[COL_HIGHLIGHT * 3 + 1] = 0.85F * ret[COL_BACKGROUND * 3 + 1]; |
2000 | ret[COL_HIGHLIGHT * 3 + 2] = 0.85F * ret[COL_BACKGROUND * 3 + 2]; |
2001 | |
7b14a9ec |
2002 | ret[COL_ERROR * 3 + 0] = 1.0F; |
2003 | ret[COL_ERROR * 3 + 1] = 0.0F; |
2004 | ret[COL_ERROR * 3 + 2] = 0.0F; |
2005 | |
c8266e03 |
2006 | ret[COL_PENCIL * 3 + 0] = 0.5F * ret[COL_BACKGROUND * 3 + 0]; |
2007 | ret[COL_PENCIL * 3 + 1] = 0.5F * ret[COL_BACKGROUND * 3 + 1]; |
2008 | ret[COL_PENCIL * 3 + 2] = ret[COL_BACKGROUND * 3 + 2]; |
2009 | |
1d8e8ad8 |
2010 | *ncolours = NCOLOURS; |
2011 | return ret; |
2012 | } |
2013 | |
2014 | static game_drawstate *game_new_drawstate(game_state *state) |
2015 | { |
2016 | struct game_drawstate *ds = snew(struct game_drawstate); |
2017 | int c = state->c, r = state->r, cr = c*r; |
2018 | |
2019 | ds->started = FALSE; |
2020 | ds->c = c; |
2021 | ds->r = r; |
2022 | ds->cr = cr; |
2023 | ds->grid = snewn(cr*cr, digit); |
2024 | memset(ds->grid, 0, cr*cr); |
c8266e03 |
2025 | ds->pencil = snewn(cr*cr*cr, digit); |
2026 | memset(ds->pencil, 0, cr*cr*cr); |
1d8e8ad8 |
2027 | ds->hl = snewn(cr*cr, unsigned char); |
2028 | memset(ds->hl, 0, cr*cr); |
b71dd7fc |
2029 | ds->entered_items = snewn(cr*cr, int); |
1d8e8ad8 |
2030 | |
2031 | return ds; |
2032 | } |
2033 | |
2034 | static void game_free_drawstate(game_drawstate *ds) |
2035 | { |
2036 | sfree(ds->hl); |
c8266e03 |
2037 | sfree(ds->pencil); |
1d8e8ad8 |
2038 | sfree(ds->grid); |
b71dd7fc |
2039 | sfree(ds->entered_items); |
1d8e8ad8 |
2040 | sfree(ds); |
2041 | } |
2042 | |
2043 | static void draw_number(frontend *fe, game_drawstate *ds, game_state *state, |
2044 | int x, int y, int hl) |
2045 | { |
2046 | int c = state->c, r = state->r, cr = c*r; |
2047 | int tx, ty; |
2048 | int cx, cy, cw, ch; |
2049 | char str[2]; |
2050 | |
c8266e03 |
2051 | if (ds->grid[y*cr+x] == state->grid[y*cr+x] && |
2052 | ds->hl[y*cr+x] == hl && |
2053 | !memcmp(ds->pencil+(y*cr+x)*cr, state->pencil+(y*cr+x)*cr, cr)) |
1d8e8ad8 |
2054 | return; /* no change required */ |
2055 | |
2056 | tx = BORDER + x * TILE_SIZE + 2; |
2057 | ty = BORDER + y * TILE_SIZE + 2; |
2058 | |
2059 | cx = tx; |
2060 | cy = ty; |
2061 | cw = TILE_SIZE-3; |
2062 | ch = TILE_SIZE-3; |
2063 | |
2064 | if (x % r) |
2065 | cx--, cw++; |
2066 | if ((x+1) % r) |
2067 | cw++; |
2068 | if (y % c) |
2069 | cy--, ch++; |
2070 | if ((y+1) % c) |
2071 | ch++; |
2072 | |
2073 | clip(fe, cx, cy, cw, ch); |
2074 | |
c8266e03 |
2075 | /* background needs erasing */ |
7b14a9ec |
2076 | draw_rect(fe, cx, cy, cw, ch, (hl & 15) == 1 ? COL_HIGHLIGHT : COL_BACKGROUND); |
c8266e03 |
2077 | |
2078 | /* pencil-mode highlight */ |
7b14a9ec |
2079 | if ((hl & 15) == 2) { |
c8266e03 |
2080 | int coords[6]; |
2081 | coords[0] = cx; |
2082 | coords[1] = cy; |
2083 | coords[2] = cx+cw/2; |
2084 | coords[3] = cy; |
2085 | coords[4] = cx; |
2086 | coords[5] = cy+ch/2; |
2087 | draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT); |
2088 | } |
1d8e8ad8 |
2089 | |
2090 | /* new number needs drawing? */ |
2091 | if (state->grid[y*cr+x]) { |
2092 | str[1] = '\0'; |
2093 | str[0] = state->grid[y*cr+x] + '0'; |
2094 | if (str[0] > '9') |
2095 | str[0] += 'a' - ('9'+1); |
2096 | draw_text(fe, tx + TILE_SIZE/2, ty + TILE_SIZE/2, |
2097 | FONT_VARIABLE, TILE_SIZE/2, ALIGN_VCENTRE | ALIGN_HCENTRE, |
7b14a9ec |
2098 | state->immutable[y*cr+x] ? COL_CLUE : (hl & 16) ? COL_ERROR : COL_USER, str); |
c8266e03 |
2099 | } else { |
2100 | /* pencil marks required? */ |
2101 | int i, j; |
2102 | |
2103 | for (i = j = 0; i < cr; i++) |
2104 | if (state->pencil[(y*cr+x)*cr+i]) { |
2105 | int dx = j % r, dy = j / r, crm = max(c, r); |
2106 | str[1] = '\0'; |
2107 | str[0] = i + '1'; |
2108 | if (str[0] > '9') |
2109 | str[0] += 'a' - ('9'+1); |
2110 | draw_text(fe, tx + (4*dx+3) * TILE_SIZE / (4*r+2), |
2111 | ty + (4*dy+3) * TILE_SIZE / (4*c+2), |
2112 | FONT_VARIABLE, TILE_SIZE/(crm*5/4), |
2113 | ALIGN_VCENTRE | ALIGN_HCENTRE, COL_PENCIL, str); |
2114 | j++; |
2115 | } |
1d8e8ad8 |
2116 | } |
2117 | |
2118 | unclip(fe); |
2119 | |
2120 | draw_update(fe, cx, cy, cw, ch); |
2121 | |
2122 | ds->grid[y*cr+x] = state->grid[y*cr+x]; |
c8266e03 |
2123 | memcpy(ds->pencil+(y*cr+x)*cr, state->pencil+(y*cr+x)*cr, cr); |
1d8e8ad8 |
2124 | ds->hl[y*cr+x] = hl; |
2125 | } |
2126 | |
2127 | static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, |
2128 | game_state *state, int dir, game_ui *ui, |
2129 | float animtime, float flashtime) |
2130 | { |
2131 | int c = state->c, r = state->r, cr = c*r; |
2132 | int x, y; |
2133 | |
2134 | if (!ds->started) { |
2135 | /* |
2136 | * The initial contents of the window are not guaranteed |
2137 | * and can vary with front ends. To be on the safe side, |
2138 | * all games should start by drawing a big |
2139 | * background-colour rectangle covering the whole window. |
2140 | */ |
2141 | draw_rect(fe, 0, 0, XSIZE(cr), YSIZE(cr), COL_BACKGROUND); |
2142 | |
2143 | /* |
2144 | * Draw the grid. |
2145 | */ |
2146 | for (x = 0; x <= cr; x++) { |
2147 | int thick = (x % r ? 0 : 1); |
2148 | draw_rect(fe, BORDER + x*TILE_SIZE - thick, BORDER-1, |
2149 | 1+2*thick, cr*TILE_SIZE+3, COL_GRID); |
2150 | } |
2151 | for (y = 0; y <= cr; y++) { |
2152 | int thick = (y % c ? 0 : 1); |
2153 | draw_rect(fe, BORDER-1, BORDER + y*TILE_SIZE - thick, |
2154 | cr*TILE_SIZE+3, 1+2*thick, COL_GRID); |
2155 | } |
2156 | } |
2157 | |
2158 | /* |
7b14a9ec |
2159 | * This array is used to keep track of rows, columns and boxes |
2160 | * which contain a number more than once. |
2161 | */ |
2162 | for (x = 0; x < cr * cr; x++) |
b71dd7fc |
2163 | ds->entered_items[x] = 0; |
7b14a9ec |
2164 | for (x = 0; x < cr; x++) |
2165 | for (y = 0; y < cr; y++) { |
2166 | digit d = state->grid[y*cr+x]; |
2167 | if (d) { |
2168 | int box = (x/r)+(y/c)*c; |
b71dd7fc |
2169 | ds->entered_items[x*cr+d-1] |= ((ds->entered_items[x*cr+d-1] & 1) << 1) | 1; |
2170 | ds->entered_items[y*cr+d-1] |= ((ds->entered_items[y*cr+d-1] & 4) << 1) | 4; |
2171 | ds->entered_items[box*cr+d-1] |= ((ds->entered_items[box*cr+d-1] & 16) << 1) | 16; |
7b14a9ec |
2172 | } |
2173 | } |
2174 | |
2175 | /* |
1d8e8ad8 |
2176 | * Draw any numbers which need redrawing. |
2177 | */ |
2178 | for (x = 0; x < cr; x++) { |
2179 | for (y = 0; y < cr; y++) { |
c8266e03 |
2180 | int highlight = 0; |
7b14a9ec |
2181 | digit d = state->grid[y*cr+x]; |
2182 | |
c8266e03 |
2183 | if (flashtime > 0 && |
2184 | (flashtime <= FLASH_TIME/3 || |
2185 | flashtime >= FLASH_TIME*2/3)) |
2186 | highlight = 1; |
7b14a9ec |
2187 | |
2188 | /* Highlight active input areas. */ |
c8266e03 |
2189 | if (x == ui->hx && y == ui->hy) |
2190 | highlight = ui->hpencil ? 2 : 1; |
7b14a9ec |
2191 | |
2192 | /* Mark obvious errors (ie, numbers which occur more than once |
2193 | * in a single row, column, or box). */ |
b71dd7fc |
2194 | if ((ds->entered_items[x*cr+d-1] & 2) || |
2195 | (ds->entered_items[y*cr+d-1] & 8) || |
2196 | (ds->entered_items[((x/r)+(y/c)*c)*cr+d-1] & 32)) |
7b14a9ec |
2197 | highlight |= 16; |
2198 | |
c8266e03 |
2199 | draw_number(fe, ds, state, x, y, highlight); |
1d8e8ad8 |
2200 | } |
2201 | } |
2202 | |
2203 | /* |
2204 | * Update the _entire_ grid if necessary. |
2205 | */ |
2206 | if (!ds->started) { |
2207 | draw_update(fe, 0, 0, XSIZE(cr), YSIZE(cr)); |
2208 | ds->started = TRUE; |
2209 | } |
2210 | } |
2211 | |
2212 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
e3f21163 |
2213 | int dir, game_ui *ui) |
1d8e8ad8 |
2214 | { |
2215 | return 0.0F; |
2216 | } |
2217 | |
2218 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
e3f21163 |
2219 | int dir, game_ui *ui) |
1d8e8ad8 |
2220 | { |
2ac6d24e |
2221 | if (!oldstate->completed && newstate->completed && |
2222 | !oldstate->cheated && !newstate->cheated) |
1d8e8ad8 |
2223 | return FLASH_TIME; |
2224 | return 0.0F; |
2225 | } |
2226 | |
2227 | static int game_wants_statusbar(void) |
2228 | { |
2229 | return FALSE; |
2230 | } |
2231 | |
48dcdd62 |
2232 | static int game_timing_state(game_state *state) |
2233 | { |
2234 | return TRUE; |
2235 | } |
2236 | |
1d8e8ad8 |
2237 | #ifdef COMBINED |
2238 | #define thegame solo |
2239 | #endif |
2240 | |
2241 | const struct game thegame = { |
1d228b10 |
2242 | "Solo", "games.solo", |
1d8e8ad8 |
2243 | default_params, |
2244 | game_fetch_preset, |
2245 | decode_params, |
2246 | encode_params, |
2247 | free_params, |
2248 | dup_params, |
1d228b10 |
2249 | TRUE, game_configure, custom_params, |
1d8e8ad8 |
2250 | validate_params, |
1185e3c5 |
2251 | new_game_desc, |
6f2d8d7c |
2252 | game_free_aux_info, |
1185e3c5 |
2253 | validate_desc, |
1d8e8ad8 |
2254 | new_game, |
2255 | dup_game, |
2256 | free_game, |
2ac6d24e |
2257 | TRUE, solve_game, |
9b4b03d3 |
2258 | TRUE, game_text_format, |
1d8e8ad8 |
2259 | new_ui, |
2260 | free_ui, |
2261 | make_move, |
2262 | game_size, |
2263 | game_colours, |
2264 | game_new_drawstate, |
2265 | game_free_drawstate, |
2266 | game_redraw, |
2267 | game_anim_length, |
2268 | game_flash_length, |
2269 | game_wants_statusbar, |
48dcdd62 |
2270 | FALSE, game_timing_state, |
93b1da3d |
2271 | 0, /* mouse_priorities */ |
1d8e8ad8 |
2272 | }; |
3ddae0ff |
2273 | |
2274 | #ifdef STANDALONE_SOLVER |
2275 | |
7c568a48 |
2276 | /* |
2277 | * gcc -DSTANDALONE_SOLVER -o solosolver solo.c malloc.c |
2278 | */ |
2279 | |
3ddae0ff |
2280 | void frontend_default_colour(frontend *fe, float *output) {} |
2281 | void draw_text(frontend *fe, int x, int y, int fonttype, int fontsize, |
2282 | int align, int colour, char *text) {} |
2283 | void draw_rect(frontend *fe, int x, int y, int w, int h, int colour) {} |
2284 | void draw_line(frontend *fe, int x1, int y1, int x2, int y2, int colour) {} |
2285 | void draw_polygon(frontend *fe, int *coords, int npoints, |
2286 | int fill, int colour) {} |
2287 | void clip(frontend *fe, int x, int y, int w, int h) {} |
2288 | void unclip(frontend *fe) {} |
2289 | void start_draw(frontend *fe) {} |
2290 | void draw_update(frontend *fe, int x, int y, int w, int h) {} |
2291 | void end_draw(frontend *fe) {} |
7c568a48 |
2292 | unsigned long random_bits(random_state *state, int bits) |
2293 | { assert(!"Shouldn't get randomness"); return 0; } |
2294 | unsigned long random_upto(random_state *state, unsigned long limit) |
2295 | { assert(!"Shouldn't get randomness"); return 0; } |
3ddae0ff |
2296 | |
2297 | void fatal(char *fmt, ...) |
2298 | { |
2299 | va_list ap; |
2300 | |
2301 | fprintf(stderr, "fatal error: "); |
2302 | |
2303 | va_start(ap, fmt); |
2304 | vfprintf(stderr, fmt, ap); |
2305 | va_end(ap); |
2306 | |
2307 | fprintf(stderr, "\n"); |
2308 | exit(1); |
2309 | } |
2310 | |
2311 | int main(int argc, char **argv) |
2312 | { |
2313 | game_params *p; |
2314 | game_state *s; |
7c568a48 |
2315 | int recurse = TRUE; |
1185e3c5 |
2316 | char *id = NULL, *desc, *err; |
3ddae0ff |
2317 | int y, x; |
7c568a48 |
2318 | int grade = FALSE; |
3ddae0ff |
2319 | |
2320 | while (--argc > 0) { |
2321 | char *p = *++argv; |
2322 | if (!strcmp(p, "-r")) { |
2323 | recurse = TRUE; |
2324 | } else if (!strcmp(p, "-n")) { |
2325 | recurse = FALSE; |
7c568a48 |
2326 | } else if (!strcmp(p, "-v")) { |
2327 | solver_show_working = TRUE; |
2328 | recurse = FALSE; |
2329 | } else if (!strcmp(p, "-g")) { |
2330 | grade = TRUE; |
2331 | recurse = FALSE; |
3ddae0ff |
2332 | } else if (*p == '-') { |
2333 | fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0]); |
2334 | return 1; |
2335 | } else { |
2336 | id = p; |
2337 | } |
2338 | } |
2339 | |
2340 | if (!id) { |
7c568a48 |
2341 | fprintf(stderr, "usage: %s [-n | -r | -g | -v] <game_id>\n", argv[0]); |
3ddae0ff |
2342 | return 1; |
2343 | } |
2344 | |
1185e3c5 |
2345 | desc = strchr(id, ':'); |
2346 | if (!desc) { |
3ddae0ff |
2347 | fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]); |
2348 | return 1; |
2349 | } |
1185e3c5 |
2350 | *desc++ = '\0'; |
3ddae0ff |
2351 | |
1733f4ca |
2352 | p = default_params(); |
2353 | decode_params(p, id); |
1185e3c5 |
2354 | err = validate_desc(p, desc); |
3ddae0ff |
2355 | if (err) { |
2356 | fprintf(stderr, "%s: %s\n", argv[0], err); |
2357 | return 1; |
2358 | } |
39d682c9 |
2359 | s = new_game(NULL, p, desc); |
3ddae0ff |
2360 | |
2361 | if (recurse) { |
2362 | int ret = rsolve(p->c, p->r, s->grid, NULL, 2); |
2363 | if (ret > 1) { |
7c568a48 |
2364 | fprintf(stderr, "%s: rsolve: multiple solutions detected\n", |
2365 | argv[0]); |
3ddae0ff |
2366 | } |
2367 | } else { |
7c568a48 |
2368 | int ret = nsolve(p->c, p->r, s->grid); |
2369 | if (grade) { |
2370 | if (ret == DIFF_IMPOSSIBLE) { |
2371 | /* |
2372 | * Now resort to rsolve to determine whether it's |
2373 | * really soluble. |
2374 | */ |
2375 | ret = rsolve(p->c, p->r, s->grid, NULL, 2); |
2376 | if (ret == 0) |
2377 | ret = DIFF_IMPOSSIBLE; |
2378 | else if (ret == 1) |
2379 | ret = DIFF_RECURSIVE; |
2380 | else |
2381 | ret = DIFF_AMBIGUOUS; |
2382 | } |
d5958d3f |
2383 | printf("Difficulty rating: %s\n", |
2384 | ret==DIFF_BLOCK ? "Trivial (blockwise positional elimination only)": |
2385 | ret==DIFF_SIMPLE ? "Basic (row/column/number elimination required)": |
2386 | ret==DIFF_INTERSECT ? "Intermediate (intersectional analysis required)": |
2387 | ret==DIFF_SET ? "Advanced (set elimination required)": |
2388 | ret==DIFF_RECURSIVE ? "Unreasonable (guesswork and backtracking required)": |
2389 | ret==DIFF_AMBIGUOUS ? "Ambiguous (multiple solutions exist)": |
2390 | ret==DIFF_IMPOSSIBLE ? "Impossible (no solution exists)": |
7c568a48 |
2391 | "INTERNAL ERROR: unrecognised difficulty code"); |
2392 | } |
3ddae0ff |
2393 | } |
2394 | |
9b4b03d3 |
2395 | printf("%s\n", grid_text_format(p->c, p->r, s->grid)); |
3ddae0ff |
2396 | |
2397 | return 0; |
2398 | } |
2399 | |
2400 | #endif |