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