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