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