1d8e8ad8 |
1 | /* |
2 | * solo.c: the number-placing puzzle most popularly known as `Sudoku'. |
3 | * |
4 | * TODO: |
5 | * |
c8266e03 |
6 | * - reports from users are that `Trivial'-mode puzzles are still |
7 | * rather hard compared to newspapers' easy ones, so some better |
8 | * low-end difficulty grading would be nice |
9 | * + it's possible that really easy puzzles always have |
10 | * _several_ things you can do, so don't make you hunt too |
11 | * hard for the one deduction you can currently make |
12 | * + it's also possible that easy puzzles require fewer |
13 | * cross-eliminations: perhaps there's a higher incidence of |
14 | * things you can deduce by looking only at (say) rows, |
15 | * rather than things you have to check both rows and columns |
16 | * for |
17 | * + but really, what I need to do is find some really easy |
18 | * puzzles and _play_ them, to see what's actually easy about |
19 | * them |
20 | * + while I'm revamping this area, filling in the _last_ |
21 | * number in a nearly-full row or column should certainly be |
22 | * permitted even at the lowest difficulty level. |
23 | * + also Owen noticed that `Basic' grids requiring numeric |
24 | * elimination are actually very hard, so I wonder if a |
25 | * difficulty gradation between that and positional- |
26 | * elimination-only might be in order |
27 | * + but it's not good to have _too_ many difficulty levels, or |
28 | * it'll take too long to randomly generate a given level. |
29 | * |
ef57b17d |
30 | * - it might still be nice to do some prioritisation on the |
31 | * removal of numbers from the grid |
32 | * + one possibility is to try to minimise the maximum number |
33 | * of filled squares in any block, which in particular ought |
34 | * to enforce never leaving a completely filled block in the |
35 | * puzzle as presented. |
1d8e8ad8 |
36 | * |
37 | * - alternative interface modes |
38 | * + sudoku.com's Windows program has a palette of possible |
39 | * entries; you select a palette entry first and then click |
40 | * on the square you want it to go in, thus enabling |
41 | * mouse-only play. Useful for PDAs! I don't think it's |
42 | * actually incompatible with the current highlight-then-type |
43 | * approach: you _either_ highlight a palette entry and then |
44 | * click, _or_ you highlight a square and then type. At most |
45 | * one thing is ever highlighted at a time, so there's no way |
46 | * to confuse the two. |
c8266e03 |
47 | * + then again, I don't actually like sudoku.com's interface; |
48 | * it's too much like a paint package whereas I prefer to |
49 | * think of Solo as a text editor. |
50 | * + another PDA-friendly possibility is a drag interface: |
51 | * _drag_ numbers from the palette into the grid squares. |
52 | * Thought experiments suggest I'd prefer that to the |
53 | * sudoku.com approach, but I haven't actually tried it. |
1d8e8ad8 |
54 | */ |
55 | |
56 | /* |
57 | * Solo puzzles need to be square overall (since each row and each |
58 | * column must contain one of every digit), but they need not be |
59 | * subdivided the same way internally. I am going to adopt a |
60 | * convention whereby I _always_ refer to `r' as the number of rows |
61 | * of _big_ divisions, and `c' as the number of columns of _big_ |
62 | * divisions. Thus, a 2c by 3r puzzle looks something like this: |
63 | * |
64 | * 4 5 1 | 2 6 3 |
65 | * 6 3 2 | 5 4 1 |
66 | * ------+------ (Of course, you can't subdivide it the other way |
67 | * 1 4 5 | 6 3 2 or you'll get clashes; observe that the 4 in the |
68 | * 3 2 6 | 4 1 5 top left would conflict with the 4 in the second |
69 | * ------+------ box down on the left-hand side.) |
70 | * 5 1 4 | 3 2 6 |
71 | * 2 6 3 | 1 5 4 |
72 | * |
73 | * The need for a strong naming convention should now be clear: |
74 | * each small box is two rows of digits by three columns, while the |
75 | * overall puzzle has three rows of small boxes by two columns. So |
76 | * I will (hopefully) consistently use `r' to denote the number of |
77 | * rows _of small boxes_ (here 3), which is also the number of |
78 | * columns of digits in each small box; and `c' vice versa (here |
79 | * 2). |
80 | * |
81 | * I'm also going to choose arbitrarily to list c first wherever |
82 | * possible: the above is a 2x3 puzzle, not a 3x2 one. |
83 | */ |
84 | |
85 | #include <stdio.h> |
86 | #include <stdlib.h> |
87 | #include <string.h> |
88 | #include <assert.h> |
89 | #include <ctype.h> |
90 | #include <math.h> |
91 | |
7c568a48 |
92 | #ifdef STANDALONE_SOLVER |
93 | #include <stdarg.h> |
ab362080 |
94 | int solver_show_working, solver_recurse_depth; |
7c568a48 |
95 | #endif |
96 | |
1d8e8ad8 |
97 | #include "puzzles.h" |
98 | |
99 | /* |
100 | * To save space, I store digits internally as unsigned char. This |
101 | * imposes a hard limit of 255 on the order of the puzzle. Since |
102 | * even a 5x5 takes unacceptably long to generate, I don't see this |
103 | * as a serious limitation unless something _really_ impressive |
104 | * happens in computing technology; but here's a typedef anyway for |
105 | * general good practice. |
106 | */ |
107 | typedef unsigned char digit; |
108 | #define ORDER_MAX 255 |
109 | |
1e3e152d |
110 | #define PREFERRED_TILE_SIZE 32 |
111 | #define TILE_SIZE (ds->tilesize) |
112 | #define BORDER (TILE_SIZE / 2) |
1d8e8ad8 |
113 | |
114 | #define FLASH_TIME 0.4F |
115 | |
154bf9b1 |
116 | enum { SYMM_NONE, SYMM_ROT2, SYMM_ROT4, SYMM_REF2, SYMM_REF2D, SYMM_REF4, |
117 | SYMM_REF4D, SYMM_REF8 }; |
ef57b17d |
118 | |
7c568a48 |
119 | enum { DIFF_BLOCK, DIFF_SIMPLE, DIFF_INTERSECT, |
120 | DIFF_SET, DIFF_RECURSIVE, DIFF_AMBIGUOUS, DIFF_IMPOSSIBLE }; |
121 | |
1d8e8ad8 |
122 | enum { |
123 | COL_BACKGROUND, |
ef57b17d |
124 | COL_GRID, |
125 | COL_CLUE, |
126 | COL_USER, |
127 | COL_HIGHLIGHT, |
7b14a9ec |
128 | COL_ERROR, |
c8266e03 |
129 | COL_PENCIL, |
ef57b17d |
130 | NCOLOURS |
1d8e8ad8 |
131 | }; |
132 | |
133 | struct game_params { |
7c568a48 |
134 | int c, r, symm, diff; |
1d8e8ad8 |
135 | }; |
136 | |
137 | struct game_state { |
138 | int c, r; |
139 | digit *grid; |
c8266e03 |
140 | unsigned char *pencil; /* c*r*c*r elements */ |
1d8e8ad8 |
141 | unsigned char *immutable; /* marks which digits are clues */ |
2ac6d24e |
142 | int completed, cheated; |
1d8e8ad8 |
143 | }; |
144 | |
145 | static game_params *default_params(void) |
146 | { |
147 | game_params *ret = snew(game_params); |
148 | |
149 | ret->c = ret->r = 3; |
ef57b17d |
150 | ret->symm = SYMM_ROT2; /* a plausible default */ |
4f36adaa |
151 | ret->diff = DIFF_BLOCK; /* so is this */ |
1d8e8ad8 |
152 | |
153 | return ret; |
154 | } |
155 | |
1d8e8ad8 |
156 | static void free_params(game_params *params) |
157 | { |
158 | sfree(params); |
159 | } |
160 | |
161 | static game_params *dup_params(game_params *params) |
162 | { |
163 | game_params *ret = snew(game_params); |
164 | *ret = *params; /* structure copy */ |
165 | return ret; |
166 | } |
167 | |
7c568a48 |
168 | static int game_fetch_preset(int i, char **name, game_params **params) |
169 | { |
170 | static struct { |
171 | char *title; |
172 | game_params params; |
173 | } presets[] = { |
174 | { "2x2 Trivial", { 2, 2, SYMM_ROT2, DIFF_BLOCK } }, |
175 | { "2x3 Basic", { 2, 3, SYMM_ROT2, DIFF_SIMPLE } }, |
4f36adaa |
176 | { "3x3 Trivial", { 3, 3, SYMM_ROT2, DIFF_BLOCK } }, |
7c568a48 |
177 | { "3x3 Basic", { 3, 3, SYMM_ROT2, DIFF_SIMPLE } }, |
178 | { "3x3 Intermediate", { 3, 3, SYMM_ROT2, DIFF_INTERSECT } }, |
179 | { "3x3 Advanced", { 3, 3, SYMM_ROT2, DIFF_SET } }, |
de60d8bd |
180 | { "3x3 Unreasonable", { 3, 3, SYMM_ROT2, DIFF_RECURSIVE } }, |
ab53eb64 |
181 | #ifndef SLOW_SYSTEM |
7c568a48 |
182 | { "3x4 Basic", { 3, 4, SYMM_ROT2, DIFF_SIMPLE } }, |
183 | { "4x4 Basic", { 4, 4, SYMM_ROT2, DIFF_SIMPLE } }, |
ab53eb64 |
184 | #endif |
7c568a48 |
185 | }; |
186 | |
187 | if (i < 0 || i >= lenof(presets)) |
188 | return FALSE; |
189 | |
190 | *name = dupstr(presets[i].title); |
191 | *params = dup_params(&presets[i].params); |
192 | |
193 | return TRUE; |
194 | } |
195 | |
1185e3c5 |
196 | static void decode_params(game_params *ret, char const *string) |
1d8e8ad8 |
197 | { |
1d8e8ad8 |
198 | ret->c = ret->r = atoi(string); |
199 | while (*string && isdigit((unsigned char)*string)) string++; |
200 | if (*string == 'x') { |
201 | string++; |
202 | ret->r = atoi(string); |
203 | while (*string && isdigit((unsigned char)*string)) string++; |
204 | } |
7c568a48 |
205 | while (*string) { |
206 | if (*string == 'r' || *string == 'm' || *string == 'a') { |
154bf9b1 |
207 | int sn, sc, sd; |
7c568a48 |
208 | sc = *string++; |
154bf9b1 |
209 | if (*string == 'd') { |
210 | sd = TRUE; |
211 | string++; |
212 | } else { |
213 | sd = FALSE; |
214 | } |
7c568a48 |
215 | sn = atoi(string); |
216 | while (*string && isdigit((unsigned char)*string)) string++; |
154bf9b1 |
217 | if (sc == 'm' && sn == 8) |
218 | ret->symm = SYMM_REF8; |
7c568a48 |
219 | if (sc == 'm' && sn == 4) |
154bf9b1 |
220 | ret->symm = sd ? SYMM_REF4D : SYMM_REF4; |
221 | if (sc == 'm' && sn == 2) |
222 | ret->symm = sd ? SYMM_REF2D : SYMM_REF2; |
7c568a48 |
223 | if (sc == 'r' && sn == 4) |
224 | ret->symm = SYMM_ROT4; |
225 | if (sc == 'r' && sn == 2) |
226 | ret->symm = SYMM_ROT2; |
227 | if (sc == 'a') |
228 | ret->symm = SYMM_NONE; |
229 | } else if (*string == 'd') { |
230 | string++; |
231 | if (*string == 't') /* trivial */ |
232 | string++, ret->diff = DIFF_BLOCK; |
233 | else if (*string == 'b') /* basic */ |
234 | string++, ret->diff = DIFF_SIMPLE; |
235 | else if (*string == 'i') /* intermediate */ |
236 | string++, ret->diff = DIFF_INTERSECT; |
237 | else if (*string == 'a') /* advanced */ |
238 | string++, ret->diff = DIFF_SET; |
de60d8bd |
239 | else if (*string == 'u') /* unreasonable */ |
240 | string++, ret->diff = DIFF_RECURSIVE; |
7c568a48 |
241 | } else |
242 | string++; /* eat unknown character */ |
ef57b17d |
243 | } |
1d8e8ad8 |
244 | } |
245 | |
1185e3c5 |
246 | static char *encode_params(game_params *params, int full) |
1d8e8ad8 |
247 | { |
248 | char str[80]; |
249 | |
250 | sprintf(str, "%dx%d", params->c, params->r); |
1185e3c5 |
251 | if (full) { |
252 | switch (params->symm) { |
154bf9b1 |
253 | case SYMM_REF8: strcat(str, "m8"); break; |
1185e3c5 |
254 | case SYMM_REF4: strcat(str, "m4"); break; |
154bf9b1 |
255 | case SYMM_REF4D: strcat(str, "md4"); break; |
256 | case SYMM_REF2: strcat(str, "m2"); break; |
257 | case SYMM_REF2D: strcat(str, "md2"); break; |
1185e3c5 |
258 | case SYMM_ROT4: strcat(str, "r4"); break; |
259 | /* case SYMM_ROT2: strcat(str, "r2"); break; [default] */ |
260 | case SYMM_NONE: strcat(str, "a"); break; |
261 | } |
262 | switch (params->diff) { |
263 | /* case DIFF_BLOCK: strcat(str, "dt"); break; [default] */ |
264 | case DIFF_SIMPLE: strcat(str, "db"); break; |
265 | case DIFF_INTERSECT: strcat(str, "di"); break; |
266 | case DIFF_SET: strcat(str, "da"); break; |
267 | case DIFF_RECURSIVE: strcat(str, "du"); break; |
268 | } |
269 | } |
1d8e8ad8 |
270 | return dupstr(str); |
271 | } |
272 | |
273 | static config_item *game_configure(game_params *params) |
274 | { |
275 | config_item *ret; |
276 | char buf[80]; |
277 | |
278 | ret = snewn(5, config_item); |
279 | |
280 | ret[0].name = "Columns of sub-blocks"; |
281 | ret[0].type = C_STRING; |
282 | sprintf(buf, "%d", params->c); |
283 | ret[0].sval = dupstr(buf); |
284 | ret[0].ival = 0; |
285 | |
286 | ret[1].name = "Rows of sub-blocks"; |
287 | ret[1].type = C_STRING; |
288 | sprintf(buf, "%d", params->r); |
289 | ret[1].sval = dupstr(buf); |
290 | ret[1].ival = 0; |
291 | |
ef57b17d |
292 | ret[2].name = "Symmetry"; |
293 | ret[2].type = C_CHOICES; |
154bf9b1 |
294 | ret[2].sval = ":None:2-way rotation:4-way rotation:2-way mirror:" |
295 | "2-way diagonal mirror:4-way mirror:4-way diagonal mirror:" |
296 | "8-way mirror"; |
ef57b17d |
297 | ret[2].ival = params->symm; |
298 | |
7c568a48 |
299 | ret[3].name = "Difficulty"; |
300 | ret[3].type = C_CHOICES; |
de60d8bd |
301 | ret[3].sval = ":Trivial:Basic:Intermediate:Advanced:Unreasonable"; |
7c568a48 |
302 | ret[3].ival = params->diff; |
1d8e8ad8 |
303 | |
7c568a48 |
304 | ret[4].name = NULL; |
305 | ret[4].type = C_END; |
306 | ret[4].sval = NULL; |
307 | ret[4].ival = 0; |
1d8e8ad8 |
308 | |
309 | return ret; |
310 | } |
311 | |
312 | static game_params *custom_params(config_item *cfg) |
313 | { |
314 | game_params *ret = snew(game_params); |
315 | |
c1f743c8 |
316 | ret->c = atoi(cfg[0].sval); |
317 | ret->r = atoi(cfg[1].sval); |
ef57b17d |
318 | ret->symm = cfg[2].ival; |
7c568a48 |
319 | ret->diff = cfg[3].ival; |
1d8e8ad8 |
320 | |
321 | return ret; |
322 | } |
323 | |
3ff276f2 |
324 | static char *validate_params(game_params *params, int full) |
1d8e8ad8 |
325 | { |
326 | if (params->c < 2 || params->r < 2) |
327 | return "Both dimensions must be at least 2"; |
328 | if (params->c > ORDER_MAX || params->r > ORDER_MAX) |
329 | return "Dimensions greater than "STR(ORDER_MAX)" are not supported"; |
95057cc5 |
330 | if ((params->c * params->r) > 36) |
331 | return "Unable to support more than 36 distinct symbols in a puzzle"; |
1d8e8ad8 |
332 | return NULL; |
333 | } |
334 | |
335 | /* ---------------------------------------------------------------------- |
ab362080 |
336 | * Solver. |
337 | * |
338 | * This solver is used for several purposes: |
339 | * + to generate filled grids as the basis for new puzzles (by |
340 | * supplying no clue squares at all) |
341 | * + to check solubility of a grid as we gradually remove numbers |
342 | * from it |
343 | * + to solve an externally generated puzzle when the user selects |
344 | * `Solve'. |
345 | * |
1d8e8ad8 |
346 | * It supports a variety of specific modes of reasoning. By |
347 | * enabling or disabling subsets of these modes we can arrange a |
348 | * range of difficulty levels. |
349 | */ |
350 | |
351 | /* |
352 | * Modes of reasoning currently supported: |
353 | * |
354 | * - Positional elimination: a number must go in a particular |
355 | * square because all the other empty squares in a given |
356 | * row/col/blk are ruled out. |
357 | * |
358 | * - Numeric elimination: a square must have a particular number |
359 | * in because all the other numbers that could go in it are |
360 | * ruled out. |
361 | * |
7c568a48 |
362 | * - Intersectional analysis: given two domains which overlap |
1d8e8ad8 |
363 | * (hence one must be a block, and the other can be a row or |
364 | * col), if the possible locations for a particular number in |
365 | * one of the domains can be narrowed down to the overlap, then |
366 | * that number can be ruled out everywhere but the overlap in |
367 | * the other domain too. |
368 | * |
7c568a48 |
369 | * - Set elimination: if there is a subset of the empty squares |
370 | * within a domain such that the union of the possible numbers |
371 | * in that subset has the same size as the subset itself, then |
372 | * those numbers can be ruled out everywhere else in the domain. |
373 | * (For example, if there are five empty squares and the |
374 | * possible numbers in each are 12, 23, 13, 134 and 1345, then |
375 | * the first three empty squares form such a subset: the numbers |
376 | * 1, 2 and 3 _must_ be in those three squares in some |
377 | * permutation, and hence we can deduce none of them can be in |
378 | * the fourth or fifth squares.) |
379 | * + You can also see this the other way round, concentrating |
380 | * on numbers rather than squares: if there is a subset of |
381 | * the unplaced numbers within a domain such that the union |
382 | * of all their possible positions has the same size as the |
383 | * subset itself, then all other numbers can be ruled out for |
384 | * those positions. However, it turns out that this is |
385 | * exactly equivalent to the first formulation at all times: |
386 | * there is a 1-1 correspondence between suitable subsets of |
387 | * the unplaced numbers and suitable subsets of the unfilled |
388 | * places, found by taking the _complement_ of the union of |
389 | * the numbers' possible positions (or the spaces' possible |
390 | * contents). |
ab362080 |
391 | * |
392 | * - Recursion. If all else fails, we pick one of the currently |
393 | * most constrained empty squares and take a random guess at its |
394 | * contents, then continue solving on that basis and see if we |
395 | * get any further. |
1d8e8ad8 |
396 | */ |
397 | |
4846f788 |
398 | /* |
399 | * Within this solver, I'm going to transform all y-coordinates by |
400 | * inverting the significance of the block number and the position |
401 | * within the block. That is, we will start with the top row of |
402 | * each block in order, then the second row of each block in order, |
403 | * etc. |
404 | * |
405 | * This transformation has the enormous advantage that it means |
406 | * every row, column _and_ block is described by an arithmetic |
407 | * progression of coordinates within the cubic array, so that I can |
408 | * use the same very simple function to do blockwise, row-wise and |
409 | * column-wise elimination. |
410 | */ |
411 | #define YTRANS(y) (((y)%c)*r+(y)/c) |
412 | #define YUNTRANS(y) (((y)%r)*c+(y)/r) |
413 | |
ab362080 |
414 | struct solver_usage { |
1d8e8ad8 |
415 | int c, r, cr; |
416 | /* |
417 | * We set up a cubic array, indexed by x, y and digit; each |
418 | * element of this array is TRUE or FALSE according to whether |
419 | * or not that digit _could_ in principle go in that position. |
420 | * |
421 | * The way to index this array is cube[(x*cr+y)*cr+n-1]. |
4846f788 |
422 | * y-coordinates in here are transformed. |
1d8e8ad8 |
423 | */ |
424 | unsigned char *cube; |
425 | /* |
426 | * This is the grid in which we write down our final |
4846f788 |
427 | * deductions. y-coordinates in here are _not_ transformed. |
1d8e8ad8 |
428 | */ |
429 | digit *grid; |
430 | /* |
431 | * Now we keep track, at a slightly higher level, of what we |
432 | * have yet to work out, to prevent doing the same deduction |
433 | * many times. |
434 | */ |
435 | /* row[y*cr+n-1] TRUE if digit n has been placed in row y */ |
436 | unsigned char *row; |
437 | /* col[x*cr+n-1] TRUE if digit n has been placed in row x */ |
438 | unsigned char *col; |
439 | /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */ |
440 | unsigned char *blk; |
441 | }; |
4846f788 |
442 | #define cubepos(x,y,n) (((x)*usage->cr+(y))*usage->cr+(n)-1) |
443 | #define cube(x,y,n) (usage->cube[cubepos(x,y,n)]) |
1d8e8ad8 |
444 | |
445 | /* |
446 | * Function called when we are certain that a particular square has |
4846f788 |
447 | * a particular number in it. The y-coordinate passed in here is |
448 | * transformed. |
1d8e8ad8 |
449 | */ |
ab362080 |
450 | static void solver_place(struct solver_usage *usage, int x, int y, int n) |
1d8e8ad8 |
451 | { |
452 | int c = usage->c, r = usage->r, cr = usage->cr; |
453 | int i, j, bx, by; |
454 | |
455 | assert(cube(x,y,n)); |
456 | |
457 | /* |
458 | * Rule out all other numbers in this square. |
459 | */ |
460 | for (i = 1; i <= cr; i++) |
461 | if (i != n) |
462 | cube(x,y,i) = FALSE; |
463 | |
464 | /* |
465 | * Rule out this number in all other positions in the row. |
466 | */ |
467 | for (i = 0; i < cr; i++) |
468 | if (i != y) |
469 | cube(x,i,n) = FALSE; |
470 | |
471 | /* |
472 | * Rule out this number in all other positions in the column. |
473 | */ |
474 | for (i = 0; i < cr; i++) |
475 | if (i != x) |
476 | cube(i,y,n) = FALSE; |
477 | |
478 | /* |
479 | * Rule out this number in all other positions in the block. |
480 | */ |
481 | bx = (x/r)*r; |
4846f788 |
482 | by = y % r; |
1d8e8ad8 |
483 | for (i = 0; i < r; i++) |
484 | for (j = 0; j < c; j++) |
4846f788 |
485 | if (bx+i != x || by+j*r != y) |
486 | cube(bx+i,by+j*r,n) = FALSE; |
1d8e8ad8 |
487 | |
488 | /* |
489 | * Enter the number in the result grid. |
490 | */ |
4846f788 |
491 | usage->grid[YUNTRANS(y)*cr+x] = n; |
1d8e8ad8 |
492 | |
493 | /* |
494 | * Cross out this number from the list of numbers left to place |
495 | * in its row, its column and its block. |
496 | */ |
497 | usage->row[y*cr+n-1] = usage->col[x*cr+n-1] = |
7c568a48 |
498 | usage->blk[((y%r)*c+(x/r))*cr+n-1] = TRUE; |
1d8e8ad8 |
499 | } |
500 | |
ab362080 |
501 | static int solver_elim(struct solver_usage *usage, int start, int step |
7c568a48 |
502 | #ifdef STANDALONE_SOLVER |
503 | , char *fmt, ... |
504 | #endif |
505 | ) |
1d8e8ad8 |
506 | { |
4846f788 |
507 | int c = usage->c, r = usage->r, cr = c*r; |
508 | int fpos, m, i; |
1d8e8ad8 |
509 | |
510 | /* |
4846f788 |
511 | * Count the number of set bits within this section of the |
512 | * cube. |
1d8e8ad8 |
513 | */ |
514 | m = 0; |
4846f788 |
515 | fpos = -1; |
516 | for (i = 0; i < cr; i++) |
517 | if (usage->cube[start+i*step]) { |
518 | fpos = start+i*step; |
1d8e8ad8 |
519 | m++; |
520 | } |
521 | |
522 | if (m == 1) { |
4846f788 |
523 | int x, y, n; |
524 | assert(fpos >= 0); |
1d8e8ad8 |
525 | |
4846f788 |
526 | n = 1 + fpos % cr; |
527 | y = fpos / cr; |
528 | x = y / cr; |
529 | y %= cr; |
1d8e8ad8 |
530 | |
3ddae0ff |
531 | if (!usage->grid[YUNTRANS(y)*cr+x]) { |
7c568a48 |
532 | #ifdef STANDALONE_SOLVER |
533 | if (solver_show_working) { |
534 | va_list ap; |
fdb3b29a |
535 | printf("%*s", solver_recurse_depth*4, ""); |
7c568a48 |
536 | va_start(ap, fmt); |
537 | vprintf(fmt, ap); |
538 | va_end(ap); |
ab362080 |
539 | printf(":\n%*s placing %d at (%d,%d)\n", |
540 | solver_recurse_depth*4, "", n, 1+x, 1+YUNTRANS(y)); |
7c568a48 |
541 | } |
542 | #endif |
ab362080 |
543 | solver_place(usage, x, y, n); |
544 | return +1; |
3ddae0ff |
545 | } |
ab362080 |
546 | } else if (m == 0) { |
547 | #ifdef STANDALONE_SOLVER |
548 | if (solver_show_working) { |
ab362080 |
549 | va_list ap; |
fdb3b29a |
550 | printf("%*s", solver_recurse_depth*4, ""); |
ab362080 |
551 | va_start(ap, fmt); |
552 | vprintf(fmt, ap); |
553 | va_end(ap); |
554 | printf(":\n%*s no possibilities available\n", |
555 | solver_recurse_depth*4, ""); |
556 | } |
557 | #endif |
558 | return -1; |
1d8e8ad8 |
559 | } |
560 | |
ab362080 |
561 | return 0; |
1d8e8ad8 |
562 | } |
563 | |
ab362080 |
564 | static int solver_intersect(struct solver_usage *usage, |
7c568a48 |
565 | int start1, int step1, int start2, int step2 |
566 | #ifdef STANDALONE_SOLVER |
567 | , char *fmt, ... |
568 | #endif |
569 | ) |
570 | { |
571 | int c = usage->c, r = usage->r, cr = c*r; |
572 | int ret, i; |
573 | |
574 | /* |
575 | * Loop over the first domain and see if there's any set bit |
576 | * not also in the second. |
577 | */ |
578 | for (i = 0; i < cr; i++) { |
579 | int p = start1+i*step1; |
580 | if (usage->cube[p] && |
581 | !(p >= start2 && p < start2+cr*step2 && |
582 | (p - start2) % step2 == 0)) |
ab362080 |
583 | return 0; /* there is, so we can't deduce */ |
7c568a48 |
584 | } |
585 | |
586 | /* |
587 | * We have determined that all set bits in the first domain are |
588 | * within its overlap with the second. So loop over the second |
589 | * domain and remove all set bits that aren't also in that |
ab362080 |
590 | * overlap; return +1 iff we actually _did_ anything. |
7c568a48 |
591 | */ |
ab362080 |
592 | ret = 0; |
7c568a48 |
593 | for (i = 0; i < cr; i++) { |
594 | int p = start2+i*step2; |
595 | if (usage->cube[p] && |
596 | !(p >= start1 && p < start1+cr*step1 && (p - start1) % step1 == 0)) |
597 | { |
598 | #ifdef STANDALONE_SOLVER |
599 | if (solver_show_working) { |
600 | int px, py, pn; |
601 | |
602 | if (!ret) { |
603 | va_list ap; |
fdb3b29a |
604 | printf("%*s", solver_recurse_depth*4, ""); |
7c568a48 |
605 | va_start(ap, fmt); |
606 | vprintf(fmt, ap); |
607 | va_end(ap); |
608 | printf(":\n"); |
609 | } |
610 | |
611 | pn = 1 + p % cr; |
612 | py = p / cr; |
613 | px = py / cr; |
614 | py %= cr; |
615 | |
ab362080 |
616 | printf("%*s ruling out %d at (%d,%d)\n", |
617 | solver_recurse_depth*4, "", pn, 1+px, 1+YUNTRANS(py)); |
7c568a48 |
618 | } |
619 | #endif |
ab362080 |
620 | ret = +1; /* we did something */ |
7c568a48 |
621 | usage->cube[p] = 0; |
622 | } |
623 | } |
624 | |
625 | return ret; |
626 | } |
627 | |
ab362080 |
628 | struct solver_scratch { |
ab53eb64 |
629 | unsigned char *grid, *rowidx, *colidx, *set; |
630 | }; |
631 | |
ab362080 |
632 | static int solver_set(struct solver_usage *usage, |
633 | struct solver_scratch *scratch, |
7c568a48 |
634 | int start, int step1, int step2 |
635 | #ifdef STANDALONE_SOLVER |
636 | , char *fmt, ... |
637 | #endif |
638 | ) |
639 | { |
640 | int c = usage->c, r = usage->r, cr = c*r; |
641 | int i, j, n, count; |
ab53eb64 |
642 | unsigned char *grid = scratch->grid; |
643 | unsigned char *rowidx = scratch->rowidx; |
644 | unsigned char *colidx = scratch->colidx; |
645 | unsigned char *set = scratch->set; |
7c568a48 |
646 | |
647 | /* |
648 | * We are passed a cr-by-cr matrix of booleans. Our first job |
649 | * is to winnow it by finding any definite placements - i.e. |
650 | * any row with a solitary 1 - and discarding that row and the |
651 | * column containing the 1. |
652 | */ |
653 | memset(rowidx, TRUE, cr); |
654 | memset(colidx, TRUE, cr); |
655 | for (i = 0; i < cr; i++) { |
656 | int count = 0, first = -1; |
657 | for (j = 0; j < cr; j++) |
658 | if (usage->cube[start+i*step1+j*step2]) |
659 | first = j, count++; |
ab362080 |
660 | |
661 | /* |
662 | * If count == 0, then there's a row with no 1s at all and |
663 | * the puzzle is internally inconsistent. However, we ought |
664 | * to have caught this already during the simpler reasoning |
665 | * methods, so we can safely fail an assertion if we reach |
666 | * this point here. |
667 | */ |
668 | assert(count > 0); |
7c568a48 |
669 | if (count == 1) |
670 | rowidx[i] = colidx[first] = FALSE; |
671 | } |
672 | |
673 | /* |
674 | * Convert each of rowidx/colidx from a list of 0s and 1s to a |
675 | * list of the indices of the 1s. |
676 | */ |
677 | for (i = j = 0; i < cr; i++) |
678 | if (rowidx[i]) |
679 | rowidx[j++] = i; |
680 | n = j; |
681 | for (i = j = 0; i < cr; i++) |
682 | if (colidx[i]) |
683 | colidx[j++] = i; |
684 | assert(n == j); |
685 | |
686 | /* |
687 | * And create the smaller matrix. |
688 | */ |
689 | for (i = 0; i < n; i++) |
690 | for (j = 0; j < n; j++) |
691 | grid[i*cr+j] = usage->cube[start+rowidx[i]*step1+colidx[j]*step2]; |
692 | |
693 | /* |
694 | * Having done that, we now have a matrix in which every row |
695 | * has at least two 1s in. Now we search to see if we can find |
696 | * a rectangle of zeroes (in the set-theoretic sense of |
697 | * `rectangle', i.e. a subset of rows crossed with a subset of |
698 | * columns) whose width and height add up to n. |
699 | */ |
700 | |
701 | memset(set, 0, n); |
702 | count = 0; |
703 | while (1) { |
704 | /* |
705 | * We have a candidate set. If its size is <=1 or >=n-1 |
706 | * then we move on immediately. |
707 | */ |
708 | if (count > 1 && count < n-1) { |
709 | /* |
710 | * The number of rows we need is n-count. See if we can |
711 | * find that many rows which each have a zero in all |
712 | * the positions listed in `set'. |
713 | */ |
714 | int rows = 0; |
715 | for (i = 0; i < n; i++) { |
716 | int ok = TRUE; |
717 | for (j = 0; j < n; j++) |
718 | if (set[j] && grid[i*cr+j]) { |
719 | ok = FALSE; |
720 | break; |
721 | } |
722 | if (ok) |
723 | rows++; |
724 | } |
725 | |
726 | /* |
727 | * We expect never to be able to get _more_ than |
728 | * n-count suitable rows: this would imply that (for |
729 | * example) there are four numbers which between them |
730 | * have at most three possible positions, and hence it |
731 | * indicates a faulty deduction before this point or |
732 | * even a bogus clue. |
733 | */ |
ab362080 |
734 | if (rows > n - count) { |
735 | #ifdef STANDALONE_SOLVER |
736 | if (solver_show_working) { |
fdb3b29a |
737 | va_list ap; |
ab362080 |
738 | printf("%*s", solver_recurse_depth*4, |
739 | ""); |
ab362080 |
740 | va_start(ap, fmt); |
741 | vprintf(fmt, ap); |
742 | va_end(ap); |
743 | printf(":\n%*s contradiction reached\n", |
744 | solver_recurse_depth*4, ""); |
745 | } |
746 | #endif |
747 | return -1; |
748 | } |
749 | |
7c568a48 |
750 | if (rows >= n - count) { |
751 | int progress = FALSE; |
752 | |
753 | /* |
754 | * We've got one! Now, for each row which _doesn't_ |
755 | * satisfy the criterion, eliminate all its set |
756 | * bits in the positions _not_ listed in `set'. |
ab362080 |
757 | * Return +1 (meaning progress has been made) if we |
758 | * successfully eliminated anything at all. |
7c568a48 |
759 | * |
760 | * This involves referring back through |
761 | * rowidx/colidx in order to work out which actual |
762 | * positions in the cube to meddle with. |
763 | */ |
764 | for (i = 0; i < n; i++) { |
765 | int ok = TRUE; |
766 | for (j = 0; j < n; j++) |
767 | if (set[j] && grid[i*cr+j]) { |
768 | ok = FALSE; |
769 | break; |
770 | } |
771 | if (!ok) { |
772 | for (j = 0; j < n; j++) |
773 | if (!set[j] && grid[i*cr+j]) { |
774 | int fpos = (start+rowidx[i]*step1+ |
775 | colidx[j]*step2); |
776 | #ifdef STANDALONE_SOLVER |
777 | if (solver_show_working) { |
778 | int px, py, pn; |
ab362080 |
779 | |
7c568a48 |
780 | if (!progress) { |
fdb3b29a |
781 | va_list ap; |
ab362080 |
782 | printf("%*s", solver_recurse_depth*4, |
783 | ""); |
7c568a48 |
784 | va_start(ap, fmt); |
785 | vprintf(fmt, ap); |
786 | va_end(ap); |
787 | printf(":\n"); |
788 | } |
789 | |
790 | pn = 1 + fpos % cr; |
791 | py = fpos / cr; |
792 | px = py / cr; |
793 | py %= cr; |
794 | |
ab362080 |
795 | printf("%*s ruling out %d at (%d,%d)\n", |
796 | solver_recurse_depth*4, "", |
7c568a48 |
797 | pn, 1+px, 1+YUNTRANS(py)); |
798 | } |
799 | #endif |
800 | progress = TRUE; |
801 | usage->cube[fpos] = FALSE; |
802 | } |
803 | } |
804 | } |
805 | |
806 | if (progress) { |
ab362080 |
807 | return +1; |
7c568a48 |
808 | } |
809 | } |
810 | } |
811 | |
812 | /* |
813 | * Binary increment: change the rightmost 0 to a 1, and |
814 | * change all 1s to the right of it to 0s. |
815 | */ |
816 | i = n; |
817 | while (i > 0 && set[i-1]) |
818 | set[--i] = 0, count--; |
819 | if (i > 0) |
820 | set[--i] = 1, count++; |
821 | else |
822 | break; /* done */ |
823 | } |
824 | |
ab362080 |
825 | return 0; |
7c568a48 |
826 | } |
827 | |
ab362080 |
828 | static struct solver_scratch *solver_new_scratch(struct solver_usage *usage) |
ab53eb64 |
829 | { |
ab362080 |
830 | struct solver_scratch *scratch = snew(struct solver_scratch); |
ab53eb64 |
831 | int cr = usage->cr; |
832 | scratch->grid = snewn(cr*cr, unsigned char); |
833 | scratch->rowidx = snewn(cr, unsigned char); |
834 | scratch->colidx = snewn(cr, unsigned char); |
835 | scratch->set = snewn(cr, unsigned char); |
836 | return scratch; |
837 | } |
838 | |
ab362080 |
839 | static void solver_free_scratch(struct solver_scratch *scratch) |
ab53eb64 |
840 | { |
841 | sfree(scratch->set); |
842 | sfree(scratch->colidx); |
843 | sfree(scratch->rowidx); |
844 | sfree(scratch->grid); |
845 | sfree(scratch); |
846 | } |
847 | |
947a07d6 |
848 | static int solver(int c, int r, digit *grid, int maxdiff) |
1d8e8ad8 |
849 | { |
ab362080 |
850 | struct solver_usage *usage; |
851 | struct solver_scratch *scratch; |
1d8e8ad8 |
852 | int cr = c*r; |
ab362080 |
853 | int x, y, n, ret; |
7c568a48 |
854 | int diff = DIFF_BLOCK; |
1d8e8ad8 |
855 | |
856 | /* |
857 | * Set up a usage structure as a clean slate (everything |
858 | * possible). |
859 | */ |
ab362080 |
860 | usage = snew(struct solver_usage); |
1d8e8ad8 |
861 | usage->c = c; |
862 | usage->r = r; |
863 | usage->cr = cr; |
864 | usage->cube = snewn(cr*cr*cr, unsigned char); |
865 | usage->grid = grid; /* write straight back to the input */ |
866 | memset(usage->cube, TRUE, cr*cr*cr); |
867 | |
868 | usage->row = snewn(cr * cr, unsigned char); |
869 | usage->col = snewn(cr * cr, unsigned char); |
870 | usage->blk = snewn(cr * cr, unsigned char); |
871 | memset(usage->row, FALSE, cr * cr); |
872 | memset(usage->col, FALSE, cr * cr); |
873 | memset(usage->blk, FALSE, cr * cr); |
874 | |
ab362080 |
875 | scratch = solver_new_scratch(usage); |
ab53eb64 |
876 | |
1d8e8ad8 |
877 | /* |
878 | * Place all the clue numbers we are given. |
879 | */ |
880 | for (x = 0; x < cr; x++) |
881 | for (y = 0; y < cr; y++) |
882 | if (grid[y*cr+x]) |
ab362080 |
883 | solver_place(usage, x, YTRANS(y), grid[y*cr+x]); |
1d8e8ad8 |
884 | |
885 | /* |
886 | * Now loop over the grid repeatedly trying all permitted modes |
887 | * of reasoning. The loop terminates if we complete an |
888 | * iteration without making any progress; we then return |
889 | * failure or success depending on whether the grid is full or |
890 | * not. |
891 | */ |
892 | while (1) { |
7c568a48 |
893 | /* |
894 | * I'd like to write `continue;' inside each of the |
895 | * following loops, so that the solver returns here after |
896 | * making some progress. However, I can't specify that I |
897 | * want to continue an outer loop rather than the innermost |
898 | * one, so I'm apologetically resorting to a goto. |
899 | */ |
3ddae0ff |
900 | cont: |
901 | |
1d8e8ad8 |
902 | /* |
903 | * Blockwise positional elimination. |
904 | */ |
4846f788 |
905 | for (x = 0; x < cr; x += r) |
1d8e8ad8 |
906 | for (y = 0; y < r; y++) |
907 | for (n = 1; n <= cr; n++) |
ab362080 |
908 | if (!usage->blk[(y*c+(x/r))*cr+n-1]) { |
909 | ret = solver_elim(usage, cubepos(x,y,n), r*cr |
7c568a48 |
910 | #ifdef STANDALONE_SOLVER |
ab362080 |
911 | , "positional elimination," |
912 | " %d in block (%d,%d)", n, 1+x/r, 1+y |
7c568a48 |
913 | #endif |
ab362080 |
914 | ); |
915 | if (ret < 0) { |
916 | diff = DIFF_IMPOSSIBLE; |
917 | goto got_result; |
918 | } else if (ret > 0) { |
919 | diff = max(diff, DIFF_BLOCK); |
920 | goto cont; |
921 | } |
7c568a48 |
922 | } |
1d8e8ad8 |
923 | |
ab362080 |
924 | if (maxdiff <= DIFF_BLOCK) |
925 | break; |
926 | |
1d8e8ad8 |
927 | /* |
928 | * Row-wise positional elimination. |
929 | */ |
930 | for (y = 0; y < cr; y++) |
931 | for (n = 1; n <= cr; n++) |
ab362080 |
932 | if (!usage->row[y*cr+n-1]) { |
933 | ret = solver_elim(usage, cubepos(0,y,n), cr*cr |
7c568a48 |
934 | #ifdef STANDALONE_SOLVER |
ab362080 |
935 | , "positional elimination," |
936 | " %d in row %d", n, 1+YUNTRANS(y) |
7c568a48 |
937 | #endif |
ab362080 |
938 | ); |
939 | if (ret < 0) { |
940 | diff = DIFF_IMPOSSIBLE; |
941 | goto got_result; |
942 | } else if (ret > 0) { |
943 | diff = max(diff, DIFF_SIMPLE); |
944 | goto cont; |
945 | } |
7c568a48 |
946 | } |
1d8e8ad8 |
947 | /* |
948 | * Column-wise positional elimination. |
949 | */ |
950 | for (x = 0; x < cr; x++) |
951 | for (n = 1; n <= cr; n++) |
ab362080 |
952 | if (!usage->col[x*cr+n-1]) { |
953 | ret = solver_elim(usage, cubepos(x,0,n), cr |
7c568a48 |
954 | #ifdef STANDALONE_SOLVER |
ab362080 |
955 | , "positional elimination," |
956 | " %d in column %d", n, 1+x |
7c568a48 |
957 | #endif |
ab362080 |
958 | ); |
959 | if (ret < 0) { |
960 | diff = DIFF_IMPOSSIBLE; |
961 | goto got_result; |
962 | } else if (ret > 0) { |
963 | diff = max(diff, DIFF_SIMPLE); |
964 | goto cont; |
965 | } |
7c568a48 |
966 | } |
1d8e8ad8 |
967 | |
968 | /* |
969 | * Numeric elimination. |
970 | */ |
971 | for (x = 0; x < cr; x++) |
972 | for (y = 0; y < cr; y++) |
ab362080 |
973 | if (!usage->grid[YUNTRANS(y)*cr+x]) { |
974 | ret = solver_elim(usage, cubepos(x,y,1), 1 |
7c568a48 |
975 | #ifdef STANDALONE_SOLVER |
ab362080 |
976 | , "numeric elimination at (%d,%d)", 1+x, |
977 | 1+YUNTRANS(y) |
7c568a48 |
978 | #endif |
ab362080 |
979 | ); |
980 | if (ret < 0) { |
981 | diff = DIFF_IMPOSSIBLE; |
982 | goto got_result; |
983 | } else if (ret > 0) { |
984 | diff = max(diff, DIFF_SIMPLE); |
985 | goto cont; |
986 | } |
7c568a48 |
987 | } |
988 | |
ab362080 |
989 | if (maxdiff <= DIFF_SIMPLE) |
990 | break; |
991 | |
7c568a48 |
992 | /* |
993 | * Intersectional analysis, rows vs blocks. |
994 | */ |
995 | for (y = 0; y < cr; y++) |
996 | for (x = 0; x < cr; x += r) |
997 | for (n = 1; n <= cr; n++) |
ab362080 |
998 | /* |
999 | * solver_intersect() never returns -1. |
1000 | */ |
7c568a48 |
1001 | if (!usage->row[y*cr+n-1] && |
1002 | !usage->blk[((y%r)*c+(x/r))*cr+n-1] && |
ab362080 |
1003 | (solver_intersect(usage, cubepos(0,y,n), cr*cr, |
7c568a48 |
1004 | cubepos(x,y%r,n), r*cr |
1005 | #ifdef STANDALONE_SOLVER |
1006 | , "intersectional analysis," |
ab362080 |
1007 | " %d in row %d vs block (%d,%d)", |
1008 | n, 1+YUNTRANS(y), 1+x/r, 1+y%r |
7c568a48 |
1009 | #endif |
1010 | ) || |
ab362080 |
1011 | solver_intersect(usage, cubepos(x,y%r,n), r*cr, |
7c568a48 |
1012 | cubepos(0,y,n), cr*cr |
1013 | #ifdef STANDALONE_SOLVER |
1014 | , "intersectional analysis," |
ab362080 |
1015 | " %d in block (%d,%d) vs row %d", |
1016 | n, 1+x/r, 1+y%r, 1+YUNTRANS(y) |
7c568a48 |
1017 | #endif |
1018 | ))) { |
1019 | diff = max(diff, DIFF_INTERSECT); |
1020 | goto cont; |
1021 | } |
1022 | |
1023 | /* |
1024 | * Intersectional analysis, columns vs blocks. |
1025 | */ |
1026 | for (x = 0; x < cr; x++) |
1027 | for (y = 0; y < r; y++) |
1028 | for (n = 1; n <= cr; n++) |
1029 | if (!usage->col[x*cr+n-1] && |
1030 | !usage->blk[(y*c+(x/r))*cr+n-1] && |
ab362080 |
1031 | (solver_intersect(usage, cubepos(x,0,n), cr, |
7c568a48 |
1032 | cubepos((x/r)*r,y,n), r*cr |
1033 | #ifdef STANDALONE_SOLVER |
1034 | , "intersectional analysis," |
ab362080 |
1035 | " %d in column %d vs block (%d,%d)", |
1036 | n, 1+x, 1+x/r, 1+y |
7c568a48 |
1037 | #endif |
1038 | ) || |
ab362080 |
1039 | solver_intersect(usage, cubepos((x/r)*r,y,n), r*cr, |
7c568a48 |
1040 | cubepos(x,0,n), cr |
1041 | #ifdef STANDALONE_SOLVER |
1042 | , "intersectional analysis," |
ab362080 |
1043 | " %d in block (%d,%d) vs column %d", |
1044 | n, 1+x/r, 1+y, 1+x |
7c568a48 |
1045 | #endif |
1046 | ))) { |
1047 | diff = max(diff, DIFF_INTERSECT); |
1048 | goto cont; |
1049 | } |
1050 | |
ab362080 |
1051 | if (maxdiff <= DIFF_INTERSECT) |
1052 | break; |
1053 | |
7c568a48 |
1054 | /* |
1055 | * Blockwise set elimination. |
1056 | */ |
1057 | for (x = 0; x < cr; x += r) |
ab362080 |
1058 | for (y = 0; y < r; y++) { |
1059 | ret = solver_set(usage, scratch, cubepos(x,y,1), r*cr, 1 |
7c568a48 |
1060 | #ifdef STANDALONE_SOLVER |
ab362080 |
1061 | , "set elimination, block (%d,%d)", 1+x/r, 1+y |
7c568a48 |
1062 | #endif |
ab362080 |
1063 | ); |
1064 | if (ret < 0) { |
1065 | diff = DIFF_IMPOSSIBLE; |
1066 | goto got_result; |
1067 | } else if (ret > 0) { |
1068 | diff = max(diff, DIFF_SET); |
1069 | goto cont; |
1070 | } |
1071 | } |
7c568a48 |
1072 | |
1073 | /* |
1074 | * Row-wise set elimination. |
1075 | */ |
ab362080 |
1076 | for (y = 0; y < cr; y++) { |
1077 | ret = solver_set(usage, scratch, cubepos(0,y,1), cr*cr, 1 |
7c568a48 |
1078 | #ifdef STANDALONE_SOLVER |
ab362080 |
1079 | , "set elimination, row %d", 1+YUNTRANS(y) |
7c568a48 |
1080 | #endif |
ab362080 |
1081 | ); |
1082 | if (ret < 0) { |
1083 | diff = DIFF_IMPOSSIBLE; |
1084 | goto got_result; |
1085 | } else if (ret > 0) { |
1086 | diff = max(diff, DIFF_SET); |
1087 | goto cont; |
1088 | } |
1089 | } |
7c568a48 |
1090 | |
1091 | /* |
1092 | * Column-wise set elimination. |
1093 | */ |
ab362080 |
1094 | for (x = 0; x < cr; x++) { |
1095 | ret = solver_set(usage, scratch, cubepos(x,0,1), cr, 1 |
7c568a48 |
1096 | #ifdef STANDALONE_SOLVER |
ab362080 |
1097 | , "set elimination, column %d", 1+x |
7c568a48 |
1098 | #endif |
ab362080 |
1099 | ); |
1100 | if (ret < 0) { |
1101 | diff = DIFF_IMPOSSIBLE; |
1102 | goto got_result; |
1103 | } else if (ret > 0) { |
1104 | diff = max(diff, DIFF_SET); |
1105 | goto cont; |
1106 | } |
1107 | } |
1d8e8ad8 |
1108 | |
1109 | /* |
1110 | * If we reach here, we have made no deductions in this |
1111 | * iteration, so the algorithm terminates. |
1112 | */ |
1113 | break; |
1114 | } |
1115 | |
ab362080 |
1116 | /* |
1117 | * Last chance: if we haven't fully solved the puzzle yet, try |
1118 | * recursing based on guesses for a particular square. We pick |
1119 | * one of the most constrained empty squares we can find, which |
1120 | * has the effect of pruning the search tree as much as |
1121 | * possible. |
1122 | */ |
1123 | if (maxdiff >= DIFF_RECURSIVE) { |
947a07d6 |
1124 | int best, bestcount; |
ab362080 |
1125 | |
1126 | best = -1; |
1127 | bestcount = cr+1; |
ab362080 |
1128 | |
1129 | for (y = 0; y < cr; y++) |
1130 | for (x = 0; x < cr; x++) |
1131 | if (!grid[y*cr+x]) { |
1132 | int count; |
1133 | |
1134 | /* |
1135 | * An unfilled square. Count the number of |
1136 | * possible digits in it. |
1137 | */ |
1138 | count = 0; |
1139 | for (n = 1; n <= cr; n++) |
1140 | if (cube(x,YTRANS(y),n)) |
1141 | count++; |
1142 | |
1143 | /* |
1144 | * We should have found any impossibilities |
1145 | * already, so this can safely be an assert. |
1146 | */ |
1147 | assert(count > 1); |
1148 | |
1149 | if (count < bestcount) { |
1150 | bestcount = count; |
947a07d6 |
1151 | best = y*cr+x; |
ab362080 |
1152 | } |
1153 | } |
1154 | |
1155 | if (best != -1) { |
1156 | int i, j; |
1157 | digit *list, *ingrid, *outgrid; |
1158 | |
1159 | diff = DIFF_IMPOSSIBLE; /* no solution found yet */ |
1160 | |
1161 | /* |
1162 | * Attempt recursion. |
1163 | */ |
1164 | y = best / cr; |
1165 | x = best % cr; |
1166 | |
1167 | list = snewn(cr, digit); |
1168 | ingrid = snewn(cr * cr, digit); |
1169 | outgrid = snewn(cr * cr, digit); |
1170 | memcpy(ingrid, grid, cr * cr); |
1171 | |
1172 | /* Make a list of the possible digits. */ |
1173 | for (j = 0, n = 1; n <= cr; n++) |
1174 | if (cube(x,YTRANS(y),n)) |
1175 | list[j++] = n; |
1176 | |
1177 | #ifdef STANDALONE_SOLVER |
1178 | if (solver_show_working) { |
1179 | char *sep = ""; |
1180 | printf("%*srecursing on (%d,%d) [", |
1181 | solver_recurse_depth*4, "", x, y); |
1182 | for (i = 0; i < j; i++) { |
1183 | printf("%s%d", sep, list[i]); |
1184 | sep = " or "; |
1185 | } |
1186 | printf("]\n"); |
1187 | } |
1188 | #endif |
1189 | |
ab362080 |
1190 | /* |
1191 | * And step along the list, recursing back into the |
1192 | * main solver at every stage. |
1193 | */ |
1194 | for (i = 0; i < j; i++) { |
1195 | int ret; |
1196 | |
1197 | memcpy(outgrid, ingrid, cr * cr); |
1198 | outgrid[y*cr+x] = list[i]; |
1199 | |
1200 | #ifdef STANDALONE_SOLVER |
1201 | if (solver_show_working) |
1202 | printf("%*sguessing %d at (%d,%d)\n", |
1203 | solver_recurse_depth*4, "", list[i], x, y); |
1204 | solver_recurse_depth++; |
1205 | #endif |
1206 | |
947a07d6 |
1207 | ret = solver(c, r, outgrid, maxdiff); |
ab362080 |
1208 | |
1209 | #ifdef STANDALONE_SOLVER |
1210 | solver_recurse_depth--; |
1211 | if (solver_show_working) { |
1212 | printf("%*sretracting %d at (%d,%d)\n", |
1213 | solver_recurse_depth*4, "", list[i], x, y); |
1214 | } |
1215 | #endif |
1216 | |
1217 | /* |
1218 | * If we have our first solution, copy it into the |
1219 | * grid we will return. |
1220 | */ |
1221 | if (diff == DIFF_IMPOSSIBLE && ret != DIFF_IMPOSSIBLE) |
1222 | memcpy(grid, outgrid, cr*cr); |
1223 | |
1224 | if (ret == DIFF_AMBIGUOUS) |
1225 | diff = DIFF_AMBIGUOUS; |
1226 | else if (ret == DIFF_IMPOSSIBLE) |
1227 | /* do not change our return value */; |
1228 | else { |
1229 | /* the recursion turned up exactly one solution */ |
1230 | if (diff == DIFF_IMPOSSIBLE) |
1231 | diff = DIFF_RECURSIVE; |
1232 | else |
1233 | diff = DIFF_AMBIGUOUS; |
1234 | } |
1235 | |
1236 | /* |
1237 | * As soon as we've found more than one solution, |
1238 | * give up immediately. |
1239 | */ |
1240 | if (diff == DIFF_AMBIGUOUS) |
1241 | break; |
1242 | } |
1243 | |
1244 | sfree(outgrid); |
1245 | sfree(ingrid); |
1246 | sfree(list); |
1247 | } |
1248 | |
1249 | } else { |
1250 | /* |
1251 | * We're forbidden to use recursion, so we just see whether |
1252 | * our grid is fully solved, and return DIFF_IMPOSSIBLE |
1253 | * otherwise. |
1254 | */ |
1255 | for (y = 0; y < cr; y++) |
1256 | for (x = 0; x < cr; x++) |
1257 | if (!grid[y*cr+x]) |
1258 | diff = DIFF_IMPOSSIBLE; |
1259 | } |
1260 | |
1261 | got_result:; |
1262 | |
1263 | #ifdef STANDALONE_SOLVER |
1264 | if (solver_show_working) |
1265 | printf("%*s%s found\n", |
1266 | solver_recurse_depth*4, "", |
1267 | diff == DIFF_IMPOSSIBLE ? "no solution" : |
1268 | diff == DIFF_AMBIGUOUS ? "multiple solutions" : |
1269 | "one solution"); |
1270 | #endif |
ab53eb64 |
1271 | |
1d8e8ad8 |
1272 | sfree(usage->cube); |
1273 | sfree(usage->row); |
1274 | sfree(usage->col); |
1275 | sfree(usage->blk); |
1276 | sfree(usage); |
1277 | |
ab362080 |
1278 | solver_free_scratch(scratch); |
1279 | |
7c568a48 |
1280 | return diff; |
1d8e8ad8 |
1281 | } |
1282 | |
1283 | /* ---------------------------------------------------------------------- |
ab362080 |
1284 | * End of solver code. |
1285 | */ |
1286 | |
1287 | /* ---------------------------------------------------------------------- |
1288 | * Solo filled-grid generator. |
1289 | * |
1290 | * This grid generator works by essentially trying to solve a grid |
1291 | * starting from no clues, and not worrying that there's more than |
1292 | * one possible solution. Unfortunately, it isn't computationally |
1293 | * feasible to do this by calling the above solver with an empty |
1294 | * grid, because that one needs to allocate a lot of scratch space |
1295 | * at every recursion level. Instead, I have a much simpler |
1296 | * algorithm which I shamelessly copied from a Python solver |
1297 | * written by Andrew Wilkinson (which is GPLed, but I've reused |
1298 | * only ideas and no code). It mostly just does the obvious |
1299 | * recursive thing: pick an empty square, put one of the possible |
1300 | * digits in it, recurse until all squares are filled, backtrack |
1301 | * and change some choices if necessary. |
1302 | * |
1303 | * The clever bit is that every time it chooses which square to |
1304 | * fill in next, it does so by counting the number of _possible_ |
1305 | * numbers that can go in each square, and it prioritises so that |
1306 | * it picks a square with the _lowest_ number of possibilities. The |
1307 | * idea is that filling in lots of the obvious bits (particularly |
1308 | * any squares with only one possibility) will cut down on the list |
1309 | * of possibilities for other squares and hence reduce the enormous |
1310 | * search space as much as possible as early as possible. |
1311 | */ |
1312 | |
1313 | /* |
1314 | * Internal data structure used in gridgen to keep track of |
1315 | * progress. |
1316 | */ |
1317 | struct gridgen_coord { int x, y, r; }; |
1318 | struct gridgen_usage { |
1319 | int c, r, cr; /* cr == c*r */ |
1320 | /* grid is a copy of the input grid, modified as we go along */ |
1321 | digit *grid; |
1322 | /* row[y*cr+n-1] TRUE if digit n has been placed in row y */ |
1323 | unsigned char *row; |
1324 | /* col[x*cr+n-1] TRUE if digit n has been placed in row x */ |
1325 | unsigned char *col; |
1326 | /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */ |
1327 | unsigned char *blk; |
1328 | /* This lists all the empty spaces remaining in the grid. */ |
1329 | struct gridgen_coord *spaces; |
1330 | int nspaces; |
1331 | /* If we need randomisation in the solve, this is our random state. */ |
1332 | random_state *rs; |
1333 | }; |
1334 | |
1335 | /* |
1336 | * The real recursive step in the generating function. |
1337 | */ |
1338 | static int gridgen_real(struct gridgen_usage *usage, digit *grid) |
1339 | { |
1340 | int c = usage->c, r = usage->r, cr = usage->cr; |
1341 | int i, j, n, sx, sy, bestm, bestr, ret; |
1342 | int *digits; |
1343 | |
1344 | /* |
1345 | * Firstly, check for completion! If there are no spaces left |
1346 | * in the grid, we have a solution. |
1347 | */ |
1348 | if (usage->nspaces == 0) { |
1349 | memcpy(grid, usage->grid, cr * cr); |
1350 | return TRUE; |
1351 | } |
1352 | |
1353 | /* |
1354 | * Otherwise, there must be at least one space. Find the most |
1355 | * constrained space, using the `r' field as a tie-breaker. |
1356 | */ |
1357 | bestm = cr+1; /* so that any space will beat it */ |
1358 | bestr = 0; |
1359 | i = sx = sy = -1; |
1360 | for (j = 0; j < usage->nspaces; j++) { |
1361 | int x = usage->spaces[j].x, y = usage->spaces[j].y; |
1362 | int m; |
1363 | |
1364 | /* |
1365 | * Find the number of digits that could go in this space. |
1366 | */ |
1367 | m = 0; |
1368 | for (n = 0; n < cr; n++) |
1369 | if (!usage->row[y*cr+n] && !usage->col[x*cr+n] && |
1370 | !usage->blk[((y/c)*c+(x/r))*cr+n]) |
1371 | m++; |
1372 | |
1373 | if (m < bestm || (m == bestm && usage->spaces[j].r < bestr)) { |
1374 | bestm = m; |
1375 | bestr = usage->spaces[j].r; |
1376 | sx = x; |
1377 | sy = y; |
1378 | i = j; |
1379 | } |
1380 | } |
1381 | |
1382 | /* |
1383 | * Swap that square into the final place in the spaces array, |
1384 | * so that decrementing nspaces will remove it from the list. |
1385 | */ |
1386 | if (i != usage->nspaces-1) { |
1387 | struct gridgen_coord t; |
1388 | t = usage->spaces[usage->nspaces-1]; |
1389 | usage->spaces[usage->nspaces-1] = usage->spaces[i]; |
1390 | usage->spaces[i] = t; |
1391 | } |
1392 | |
1393 | /* |
1394 | * Now we've decided which square to start our recursion at, |
1395 | * simply go through all possible values, shuffling them |
1396 | * randomly first if necessary. |
1397 | */ |
1398 | digits = snewn(bestm, int); |
1399 | j = 0; |
1400 | for (n = 0; n < cr; n++) |
1401 | if (!usage->row[sy*cr+n] && !usage->col[sx*cr+n] && |
1402 | !usage->blk[((sy/c)*c+(sx/r))*cr+n]) { |
1403 | digits[j++] = n+1; |
1404 | } |
1405 | |
947a07d6 |
1406 | if (usage->rs) |
1407 | shuffle(digits, j, sizeof(*digits), usage->rs); |
ab362080 |
1408 | |
1409 | /* And finally, go through the digit list and actually recurse. */ |
1410 | ret = FALSE; |
1411 | for (i = 0; i < j; i++) { |
1412 | n = digits[i]; |
1413 | |
1414 | /* Update the usage structure to reflect the placing of this digit. */ |
1415 | usage->row[sy*cr+n-1] = usage->col[sx*cr+n-1] = |
1416 | usage->blk[((sy/c)*c+(sx/r))*cr+n-1] = TRUE; |
1417 | usage->grid[sy*cr+sx] = n; |
1418 | usage->nspaces--; |
1419 | |
1420 | /* Call the solver recursively. Stop when we find a solution. */ |
1421 | if (gridgen_real(usage, grid)) |
1422 | ret = TRUE; |
1423 | |
1424 | /* Revert the usage structure. */ |
1425 | usage->row[sy*cr+n-1] = usage->col[sx*cr+n-1] = |
1426 | usage->blk[((sy/c)*c+(sx/r))*cr+n-1] = FALSE; |
1427 | usage->grid[sy*cr+sx] = 0; |
1428 | usage->nspaces++; |
1429 | |
1430 | if (ret) |
1431 | break; |
1432 | } |
1433 | |
1434 | sfree(digits); |
1435 | return ret; |
1436 | } |
1437 | |
1438 | /* |
1439 | * Entry point to generator. You give it dimensions and a starting |
1440 | * grid, which is simply an array of cr*cr digits. |
1441 | */ |
1442 | static void gridgen(int c, int r, digit *grid, random_state *rs) |
1443 | { |
1444 | struct gridgen_usage *usage; |
1445 | int x, y, cr = c*r; |
1446 | |
1447 | /* |
1448 | * Clear the grid to start with. |
1449 | */ |
1450 | memset(grid, 0, cr*cr); |
1451 | |
1452 | /* |
1453 | * Create a gridgen_usage structure. |
1454 | */ |
1455 | usage = snew(struct gridgen_usage); |
1456 | |
1457 | usage->c = c; |
1458 | usage->r = r; |
1459 | usage->cr = cr; |
1460 | |
1461 | usage->grid = snewn(cr * cr, digit); |
1462 | memcpy(usage->grid, grid, cr * cr); |
1463 | |
1464 | usage->row = snewn(cr * cr, unsigned char); |
1465 | usage->col = snewn(cr * cr, unsigned char); |
1466 | usage->blk = snewn(cr * cr, unsigned char); |
1467 | memset(usage->row, FALSE, cr * cr); |
1468 | memset(usage->col, FALSE, cr * cr); |
1469 | memset(usage->blk, FALSE, cr * cr); |
1470 | |
1471 | usage->spaces = snewn(cr * cr, struct gridgen_coord); |
1472 | usage->nspaces = 0; |
1473 | |
1474 | usage->rs = rs; |
1475 | |
1476 | /* |
1477 | * Initialise the list of grid spaces. |
1478 | */ |
1479 | for (y = 0; y < cr; y++) { |
1480 | for (x = 0; x < cr; x++) { |
1481 | usage->spaces[usage->nspaces].x = x; |
1482 | usage->spaces[usage->nspaces].y = y; |
1483 | usage->spaces[usage->nspaces].r = random_bits(rs, 31); |
1484 | usage->nspaces++; |
1485 | } |
1486 | } |
1487 | |
1488 | /* |
1489 | * Run the real generator function. |
1490 | */ |
1491 | gridgen_real(usage, grid); |
1492 | |
1493 | /* |
1494 | * Clean up the usage structure now we have our answer. |
1495 | */ |
1496 | sfree(usage->spaces); |
1497 | sfree(usage->blk); |
1498 | sfree(usage->col); |
1499 | sfree(usage->row); |
1500 | sfree(usage->grid); |
1501 | sfree(usage); |
1502 | } |
1503 | |
1504 | /* ---------------------------------------------------------------------- |
1505 | * End of grid generator code. |
1d8e8ad8 |
1506 | */ |
1507 | |
1508 | /* |
1509 | * Check whether a grid contains a valid complete puzzle. |
1510 | */ |
1511 | static int check_valid(int c, int r, digit *grid) |
1512 | { |
1513 | int cr = c*r; |
1514 | unsigned char *used; |
1515 | int x, y, n; |
1516 | |
1517 | used = snewn(cr, unsigned char); |
1518 | |
1519 | /* |
1520 | * Check that each row contains precisely one of everything. |
1521 | */ |
1522 | for (y = 0; y < cr; y++) { |
1523 | memset(used, FALSE, cr); |
1524 | for (x = 0; x < cr; x++) |
1525 | if (grid[y*cr+x] > 0 && grid[y*cr+x] <= cr) |
1526 | used[grid[y*cr+x]-1] = TRUE; |
1527 | for (n = 0; n < cr; n++) |
1528 | if (!used[n]) { |
1529 | sfree(used); |
1530 | return FALSE; |
1531 | } |
1532 | } |
1533 | |
1534 | /* |
1535 | * Check that each column contains precisely one of everything. |
1536 | */ |
1537 | for (x = 0; x < cr; x++) { |
1538 | memset(used, FALSE, cr); |
1539 | for (y = 0; y < cr; y++) |
1540 | if (grid[y*cr+x] > 0 && grid[y*cr+x] <= cr) |
1541 | used[grid[y*cr+x]-1] = TRUE; |
1542 | for (n = 0; n < cr; n++) |
1543 | if (!used[n]) { |
1544 | sfree(used); |
1545 | return FALSE; |
1546 | } |
1547 | } |
1548 | |
1549 | /* |
1550 | * Check that each block contains precisely one of everything. |
1551 | */ |
1552 | for (x = 0; x < cr; x += r) { |
1553 | for (y = 0; y < cr; y += c) { |
1554 | int xx, yy; |
1555 | memset(used, FALSE, cr); |
1556 | for (xx = x; xx < x+r; xx++) |
1557 | for (yy = 0; yy < y+c; yy++) |
1558 | if (grid[yy*cr+xx] > 0 && grid[yy*cr+xx] <= cr) |
1559 | used[grid[yy*cr+xx]-1] = TRUE; |
1560 | for (n = 0; n < cr; n++) |
1561 | if (!used[n]) { |
1562 | sfree(used); |
1563 | return FALSE; |
1564 | } |
1565 | } |
1566 | } |
1567 | |
1568 | sfree(used); |
1569 | return TRUE; |
1570 | } |
1571 | |
ef57b17d |
1572 | static int symmetries(game_params *params, int x, int y, int *output, int s) |
1573 | { |
1574 | int c = params->c, r = params->r, cr = c*r; |
1575 | int i = 0; |
1576 | |
154bf9b1 |
1577 | #define ADD(x,y) (*output++ = (x), *output++ = (y), i++) |
1578 | |
1579 | ADD(x, y); |
ef57b17d |
1580 | |
1581 | switch (s) { |
1582 | case SYMM_NONE: |
1583 | break; /* just x,y is all we need */ |
ef57b17d |
1584 | case SYMM_ROT2: |
154bf9b1 |
1585 | ADD(cr - 1 - x, cr - 1 - y); |
1586 | break; |
1587 | case SYMM_ROT4: |
1588 | ADD(cr - 1 - y, x); |
1589 | ADD(y, cr - 1 - x); |
1590 | ADD(cr - 1 - x, cr - 1 - y); |
1591 | break; |
1592 | case SYMM_REF2: |
1593 | ADD(cr - 1 - x, y); |
1594 | break; |
1595 | case SYMM_REF2D: |
1596 | ADD(y, x); |
1597 | break; |
1598 | case SYMM_REF4: |
1599 | ADD(cr - 1 - x, y); |
1600 | ADD(x, cr - 1 - y); |
1601 | ADD(cr - 1 - x, cr - 1 - y); |
1602 | break; |
1603 | case SYMM_REF4D: |
1604 | ADD(y, x); |
1605 | ADD(cr - 1 - x, cr - 1 - y); |
1606 | ADD(cr - 1 - y, cr - 1 - x); |
1607 | break; |
1608 | case SYMM_REF8: |
1609 | ADD(cr - 1 - x, y); |
1610 | ADD(x, cr - 1 - y); |
1611 | ADD(cr - 1 - x, cr - 1 - y); |
1612 | ADD(y, x); |
1613 | ADD(y, cr - 1 - x); |
1614 | ADD(cr - 1 - y, x); |
1615 | ADD(cr - 1 - y, cr - 1 - x); |
1616 | break; |
ef57b17d |
1617 | } |
1618 | |
154bf9b1 |
1619 | #undef ADD |
1620 | |
ef57b17d |
1621 | return i; |
1622 | } |
1623 | |
c566778e |
1624 | static char *encode_solve_move(int cr, digit *grid) |
1625 | { |
1626 | int i, len; |
1627 | char *ret, *p, *sep; |
1628 | |
1629 | /* |
1630 | * It's surprisingly easy to work out _exactly_ how long this |
1631 | * string needs to be. To decimal-encode all the numbers from 1 |
1632 | * to n: |
1633 | * |
1634 | * - every number has a units digit; total is n. |
1635 | * - all numbers above 9 have a tens digit; total is max(n-9,0). |
1636 | * - all numbers above 99 have a hundreds digit; total is max(n-99,0). |
1637 | * - and so on. |
1638 | */ |
1639 | len = 0; |
1640 | for (i = 1; i <= cr; i *= 10) |
1641 | len += max(cr - i + 1, 0); |
1642 | len += cr; /* don't forget the commas */ |
1643 | len *= cr; /* there are cr rows of these */ |
1644 | |
1645 | /* |
1646 | * Now len is one bigger than the total size of the |
1647 | * comma-separated numbers (because we counted an |
1648 | * additional leading comma). We need to have a leading S |
1649 | * and a trailing NUL, so we're off by one in total. |
1650 | */ |
1651 | len++; |
1652 | |
1653 | ret = snewn(len, char); |
1654 | p = ret; |
1655 | *p++ = 'S'; |
1656 | sep = ""; |
1657 | for (i = 0; i < cr*cr; i++) { |
1658 | p += sprintf(p, "%s%d", sep, grid[i]); |
1659 | sep = ","; |
1660 | } |
1661 | *p++ = '\0'; |
1662 | assert(p - ret == len); |
1663 | |
1664 | return ret; |
1665 | } |
3220eba4 |
1666 | |
1185e3c5 |
1667 | static char *new_game_desc(game_params *params, random_state *rs, |
c566778e |
1668 | char **aux, int interactive) |
1d8e8ad8 |
1669 | { |
1670 | int c = params->c, r = params->r, cr = c*r; |
1671 | int area = cr*cr; |
1672 | digit *grid, *grid2; |
1673 | struct xy { int x, y; } *locs; |
1674 | int nlocs; |
1185e3c5 |
1675 | char *desc; |
ef57b17d |
1676 | int coords[16], ncoords; |
154bf9b1 |
1677 | int *symmclasses, nsymmclasses; |
de60d8bd |
1678 | int maxdiff, recursing; |
1d8e8ad8 |
1679 | |
1680 | /* |
7c568a48 |
1681 | * Adjust the maximum difficulty level to be consistent with |
1682 | * the puzzle size: all 2x2 puzzles appear to be Trivial |
1683 | * (DIFF_BLOCK) so we cannot hold out for even a Basic |
1684 | * (DIFF_SIMPLE) one. |
1d8e8ad8 |
1685 | */ |
7c568a48 |
1686 | maxdiff = params->diff; |
1687 | if (c == 2 && r == 2) |
1688 | maxdiff = DIFF_BLOCK; |
1d8e8ad8 |
1689 | |
7c568a48 |
1690 | grid = snewn(area, digit); |
ef57b17d |
1691 | locs = snewn(area, struct xy); |
1d8e8ad8 |
1692 | grid2 = snewn(area, digit); |
1d8e8ad8 |
1693 | |
7c568a48 |
1694 | /* |
154bf9b1 |
1695 | * Find the set of equivalence classes of squares permitted |
1696 | * by the selected symmetry. We do this by enumerating all |
1697 | * the grid squares which have no symmetric companion |
1698 | * sorting lower than themselves. |
1699 | */ |
1700 | nsymmclasses = 0; |
1701 | symmclasses = snewn(cr * cr, int); |
1702 | { |
1703 | int x, y; |
1704 | |
1705 | for (y = 0; y < cr; y++) |
1706 | for (x = 0; x < cr; x++) { |
1707 | int i = y*cr+x; |
1708 | int j; |
1709 | |
1710 | ncoords = symmetries(params, x, y, coords, params->symm); |
1711 | for (j = 0; j < ncoords; j++) |
1712 | if (coords[2*j+1]*cr+coords[2*j] < i) |
1713 | break; |
1714 | if (j == ncoords) |
1715 | symmclasses[nsymmclasses++] = i; |
1716 | } |
1717 | } |
1718 | |
1719 | /* |
7c568a48 |
1720 | * Loop until we get a grid of the required difficulty. This is |
1721 | * nasty, but it seems to be unpleasantly hard to generate |
1722 | * difficult grids otherwise. |
1723 | */ |
1724 | do { |
1725 | /* |
ab362080 |
1726 | * Generate a random solved state. |
7c568a48 |
1727 | */ |
ab362080 |
1728 | gridgen(c, r, grid, rs); |
7c568a48 |
1729 | assert(check_valid(c, r, grid)); |
1730 | |
3220eba4 |
1731 | /* |
c566778e |
1732 | * Save the solved grid in aux. |
3220eba4 |
1733 | */ |
1734 | { |
ab53eb64 |
1735 | /* |
1736 | * We might already have written *aux the last time we |
1737 | * went round this loop, in which case we should free |
c566778e |
1738 | * the old aux before overwriting it with the new one. |
ab53eb64 |
1739 | */ |
1740 | if (*aux) { |
ab53eb64 |
1741 | sfree(*aux); |
1742 | } |
c566778e |
1743 | |
1744 | *aux = encode_solve_move(cr, grid); |
3220eba4 |
1745 | } |
1746 | |
7c568a48 |
1747 | /* |
1748 | * Now we have a solved grid, start removing things from it |
1749 | * while preserving solubility. |
1750 | */ |
de60d8bd |
1751 | recursing = FALSE; |
7c568a48 |
1752 | while (1) { |
1753 | int x, y, i, j; |
1754 | |
1755 | /* |
1756 | * Iterate over the grid and enumerate all the filled |
1757 | * squares we could empty. |
1758 | */ |
1759 | nlocs = 0; |
1760 | |
154bf9b1 |
1761 | for (i = 0; i < nsymmclasses; i++) { |
1762 | x = symmclasses[i] % cr; |
1763 | y = symmclasses[i] / cr; |
1764 | if (grid[y*cr+x]) { |
1765 | locs[nlocs].x = x; |
1766 | locs[nlocs].y = y; |
1767 | nlocs++; |
1768 | } |
1769 | } |
7c568a48 |
1770 | |
1771 | /* |
1772 | * Now shuffle that list. |
1773 | */ |
947a07d6 |
1774 | shuffle(locs, nlocs, sizeof(*locs), rs); |
7c568a48 |
1775 | |
1776 | /* |
1777 | * Now loop over the shuffled list and, for each element, |
1778 | * see whether removing that element (and its reflections) |
1779 | * from the grid will still leave the grid soluble by |
ab362080 |
1780 | * solver. |
7c568a48 |
1781 | */ |
1782 | for (i = 0; i < nlocs; i++) { |
de60d8bd |
1783 | int ret; |
1784 | |
7c568a48 |
1785 | x = locs[i].x; |
1786 | y = locs[i].y; |
1787 | |
1788 | memcpy(grid2, grid, area); |
1789 | ncoords = symmetries(params, x, y, coords, params->symm); |
1790 | for (j = 0; j < ncoords; j++) |
1791 | grid2[coords[2*j+1]*cr+coords[2*j]] = 0; |
1792 | |
947a07d6 |
1793 | ret = solver(c, r, grid2, maxdiff); |
ab362080 |
1794 | if (ret != DIFF_IMPOSSIBLE && ret != DIFF_AMBIGUOUS) { |
7c568a48 |
1795 | for (j = 0; j < ncoords; j++) |
1796 | grid[coords[2*j+1]*cr+coords[2*j]] = 0; |
1797 | break; |
1798 | } |
1799 | } |
1800 | |
1801 | if (i == nlocs) { |
1802 | /* |
de60d8bd |
1803 | * There was nothing we could remove without |
ab362080 |
1804 | * destroying solvability. Give up. |
7c568a48 |
1805 | */ |
ab362080 |
1806 | break; |
7c568a48 |
1807 | } |
1808 | } |
1d8e8ad8 |
1809 | |
7c568a48 |
1810 | memcpy(grid2, grid, area); |
947a07d6 |
1811 | } while (solver(c, r, grid2, maxdiff) < maxdiff); |
1d8e8ad8 |
1812 | |
1d8e8ad8 |
1813 | sfree(grid2); |
1814 | sfree(locs); |
1815 | |
154bf9b1 |
1816 | sfree(symmclasses); |
1817 | |
1d8e8ad8 |
1818 | /* |
1819 | * Now we have the grid as it will be presented to the user. |
1185e3c5 |
1820 | * Encode it in a game desc. |
1d8e8ad8 |
1821 | */ |
1822 | { |
1823 | char *p; |
1824 | int run, i; |
1825 | |
1185e3c5 |
1826 | desc = snewn(5 * area, char); |
1827 | p = desc; |
1d8e8ad8 |
1828 | run = 0; |
1829 | for (i = 0; i <= area; i++) { |
1830 | int n = (i < area ? grid[i] : -1); |
1831 | |
1832 | if (!n) |
1833 | run++; |
1834 | else { |
1835 | if (run) { |
1836 | while (run > 0) { |
1837 | int c = 'a' - 1 + run; |
1838 | if (run > 26) |
1839 | c = 'z'; |
1840 | *p++ = c; |
1841 | run -= c - ('a' - 1); |
1842 | } |
1843 | } else { |
1844 | /* |
1845 | * If there's a number in the very top left or |
1846 | * bottom right, there's no point putting an |
1847 | * unnecessary _ before or after it. |
1848 | */ |
1185e3c5 |
1849 | if (p > desc && n > 0) |
1d8e8ad8 |
1850 | *p++ = '_'; |
1851 | } |
1852 | if (n > 0) |
1853 | p += sprintf(p, "%d", n); |
1854 | run = 0; |
1855 | } |
1856 | } |
1185e3c5 |
1857 | assert(p - desc < 5 * area); |
1d8e8ad8 |
1858 | *p++ = '\0'; |
1185e3c5 |
1859 | desc = sresize(desc, p - desc, char); |
1d8e8ad8 |
1860 | } |
1861 | |
1862 | sfree(grid); |
1863 | |
1185e3c5 |
1864 | return desc; |
1d8e8ad8 |
1865 | } |
1866 | |
1185e3c5 |
1867 | static char *validate_desc(game_params *params, char *desc) |
1d8e8ad8 |
1868 | { |
1869 | int area = params->r * params->r * params->c * params->c; |
1870 | int squares = 0; |
1871 | |
1185e3c5 |
1872 | while (*desc) { |
1873 | int n = *desc++; |
1d8e8ad8 |
1874 | if (n >= 'a' && n <= 'z') { |
1875 | squares += n - 'a' + 1; |
1876 | } else if (n == '_') { |
1877 | /* do nothing */; |
1878 | } else if (n > '0' && n <= '9') { |
1879 | squares++; |
1185e3c5 |
1880 | while (*desc >= '0' && *desc <= '9') |
1881 | desc++; |
1d8e8ad8 |
1882 | } else |
1185e3c5 |
1883 | return "Invalid character in game description"; |
1d8e8ad8 |
1884 | } |
1885 | |
1886 | if (squares < area) |
1887 | return "Not enough data to fill grid"; |
1888 | |
1889 | if (squares > area) |
1890 | return "Too much data to fit in grid"; |
1891 | |
1892 | return NULL; |
1893 | } |
1894 | |
c380832d |
1895 | static game_state *new_game(midend_data *me, game_params *params, char *desc) |
1d8e8ad8 |
1896 | { |
1897 | game_state *state = snew(game_state); |
1898 | int c = params->c, r = params->r, cr = c*r, area = cr * cr; |
1899 | int i; |
1900 | |
1901 | state->c = params->c; |
1902 | state->r = params->r; |
1903 | |
1904 | state->grid = snewn(area, digit); |
c8266e03 |
1905 | state->pencil = snewn(area * cr, unsigned char); |
1906 | memset(state->pencil, 0, area * cr); |
1d8e8ad8 |
1907 | state->immutable = snewn(area, unsigned char); |
1908 | memset(state->immutable, FALSE, area); |
1909 | |
2ac6d24e |
1910 | state->completed = state->cheated = FALSE; |
1d8e8ad8 |
1911 | |
1912 | i = 0; |
1185e3c5 |
1913 | while (*desc) { |
1914 | int n = *desc++; |
1d8e8ad8 |
1915 | if (n >= 'a' && n <= 'z') { |
1916 | int run = n - 'a' + 1; |
1917 | assert(i + run <= area); |
1918 | while (run-- > 0) |
1919 | state->grid[i++] = 0; |
1920 | } else if (n == '_') { |
1921 | /* do nothing */; |
1922 | } else if (n > '0' && n <= '9') { |
1923 | assert(i < area); |
1924 | state->immutable[i] = TRUE; |
1185e3c5 |
1925 | state->grid[i++] = atoi(desc-1); |
1926 | while (*desc >= '0' && *desc <= '9') |
1927 | desc++; |
1d8e8ad8 |
1928 | } else { |
1929 | assert(!"We can't get here"); |
1930 | } |
1931 | } |
1932 | assert(i == area); |
1933 | |
1934 | return state; |
1935 | } |
1936 | |
1937 | static game_state *dup_game(game_state *state) |
1938 | { |
1939 | game_state *ret = snew(game_state); |
1940 | int c = state->c, r = state->r, cr = c*r, area = cr * cr; |
1941 | |
1942 | ret->c = state->c; |
1943 | ret->r = state->r; |
1944 | |
1945 | ret->grid = snewn(area, digit); |
1946 | memcpy(ret->grid, state->grid, area); |
1947 | |
c8266e03 |
1948 | ret->pencil = snewn(area * cr, unsigned char); |
1949 | memcpy(ret->pencil, state->pencil, area * cr); |
1950 | |
1d8e8ad8 |
1951 | ret->immutable = snewn(area, unsigned char); |
1952 | memcpy(ret->immutable, state->immutable, area); |
1953 | |
1954 | ret->completed = state->completed; |
2ac6d24e |
1955 | ret->cheated = state->cheated; |
1d8e8ad8 |
1956 | |
1957 | return ret; |
1958 | } |
1959 | |
1960 | static void free_game(game_state *state) |
1961 | { |
1962 | sfree(state->immutable); |
c8266e03 |
1963 | sfree(state->pencil); |
1d8e8ad8 |
1964 | sfree(state->grid); |
1965 | sfree(state); |
1966 | } |
1967 | |
df11cd4e |
1968 | static char *solve_game(game_state *state, game_state *currstate, |
c566778e |
1969 | char *ai, char **error) |
2ac6d24e |
1970 | { |
3220eba4 |
1971 | int c = state->c, r = state->r, cr = c*r; |
c566778e |
1972 | char *ret; |
df11cd4e |
1973 | digit *grid; |
ab362080 |
1974 | int solve_ret; |
2ac6d24e |
1975 | |
3220eba4 |
1976 | /* |
c566778e |
1977 | * If we already have the solution in ai, save ourselves some |
1978 | * time. |
3220eba4 |
1979 | */ |
c566778e |
1980 | if (ai) |
1981 | return dupstr(ai); |
3220eba4 |
1982 | |
c566778e |
1983 | grid = snewn(cr*cr, digit); |
1984 | memcpy(grid, state->grid, cr*cr); |
947a07d6 |
1985 | solve_ret = solver(c, r, grid, DIFF_RECURSIVE); |
ab362080 |
1986 | |
1987 | *error = NULL; |
df11cd4e |
1988 | |
ab362080 |
1989 | if (solve_ret == DIFF_IMPOSSIBLE) |
1990 | *error = "No solution exists for this puzzle"; |
1991 | else if (solve_ret == DIFF_AMBIGUOUS) |
1992 | *error = "Multiple solutions exist for this puzzle"; |
1993 | |
1994 | if (*error) { |
c566778e |
1995 | sfree(grid); |
c566778e |
1996 | return NULL; |
df11cd4e |
1997 | } |
1998 | |
c566778e |
1999 | ret = encode_solve_move(cr, grid); |
df11cd4e |
2000 | |
c566778e |
2001 | sfree(grid); |
2ac6d24e |
2002 | |
2003 | return ret; |
2004 | } |
2005 | |
9b4b03d3 |
2006 | static char *grid_text_format(int c, int r, digit *grid) |
2007 | { |
2008 | int cr = c*r; |
2009 | int x, y; |
2010 | int maxlen; |
2011 | char *ret, *p; |
2012 | |
2013 | /* |
2014 | * There are cr lines of digits, plus r-1 lines of block |
2015 | * separators. Each line contains cr digits, cr-1 separating |
2016 | * spaces, and c-1 two-character block separators. Thus, the |
2017 | * total length of a line is 2*cr+2*c-3 (not counting the |
2018 | * newline), and there are cr+r-1 of them. |
2019 | */ |
2020 | maxlen = (cr+r-1) * (2*cr+2*c-2); |
2021 | ret = snewn(maxlen+1, char); |
2022 | p = ret; |
2023 | |
2024 | for (y = 0; y < cr; y++) { |
2025 | for (x = 0; x < cr; x++) { |
2026 | int ch = grid[y * cr + x]; |
2027 | if (ch == 0) |
2028 | ch = ' '; |
2029 | else if (ch <= 9) |
2030 | ch = '0' + ch; |
2031 | else |
2032 | ch = 'a' + ch-10; |
2033 | *p++ = ch; |
2034 | if (x+1 < cr) { |
2035 | *p++ = ' '; |
2036 | if ((x+1) % r == 0) { |
2037 | *p++ = '|'; |
2038 | *p++ = ' '; |
2039 | } |
2040 | } |
2041 | } |
2042 | *p++ = '\n'; |
2043 | if (y+1 < cr && (y+1) % c == 0) { |
2044 | for (x = 0; x < cr; x++) { |
2045 | *p++ = '-'; |
2046 | if (x+1 < cr) { |
2047 | *p++ = '-'; |
2048 | if ((x+1) % r == 0) { |
2049 | *p++ = '+'; |
2050 | *p++ = '-'; |
2051 | } |
2052 | } |
2053 | } |
2054 | *p++ = '\n'; |
2055 | } |
2056 | } |
2057 | |
2058 | assert(p - ret == maxlen); |
2059 | *p = '\0'; |
2060 | return ret; |
2061 | } |
2062 | |
2063 | static char *game_text_format(game_state *state) |
2064 | { |
2065 | return grid_text_format(state->c, state->r, state->grid); |
2066 | } |
2067 | |
1d8e8ad8 |
2068 | struct game_ui { |
2069 | /* |
2070 | * These are the coordinates of the currently highlighted |
2071 | * square on the grid, or -1,-1 if there isn't one. When there |
2072 | * is, pressing a valid number or letter key or Space will |
2073 | * enter that number or letter in the grid. |
2074 | */ |
2075 | int hx, hy; |
c8266e03 |
2076 | /* |
2077 | * This indicates whether the current highlight is a |
2078 | * pencil-mark one or a real one. |
2079 | */ |
2080 | int hpencil; |
1d8e8ad8 |
2081 | }; |
2082 | |
2083 | static game_ui *new_ui(game_state *state) |
2084 | { |
2085 | game_ui *ui = snew(game_ui); |
2086 | |
2087 | ui->hx = ui->hy = -1; |
c8266e03 |
2088 | ui->hpencil = 0; |
1d8e8ad8 |
2089 | |
2090 | return ui; |
2091 | } |
2092 | |
2093 | static void free_ui(game_ui *ui) |
2094 | { |
2095 | sfree(ui); |
2096 | } |
2097 | |
844f605f |
2098 | static char *encode_ui(game_ui *ui) |
ae8290c6 |
2099 | { |
2100 | return NULL; |
2101 | } |
2102 | |
844f605f |
2103 | static void decode_ui(game_ui *ui, char *encoding) |
ae8290c6 |
2104 | { |
2105 | } |
2106 | |
07dfb697 |
2107 | static void game_changed_state(game_ui *ui, game_state *oldstate, |
2108 | game_state *newstate) |
2109 | { |
2110 | int c = newstate->c, r = newstate->r, cr = c*r; |
2111 | /* |
2112 | * We prevent pencil-mode highlighting of a filled square. So |
2113 | * if the user has just filled in a square which we had a |
2114 | * pencil-mode highlight in (by Undo, or by Redo, or by Solve), |
2115 | * then we cancel the highlight. |
2116 | */ |
2117 | if (ui->hx >= 0 && ui->hy >= 0 && ui->hpencil && |
2118 | newstate->grid[ui->hy * cr + ui->hx] != 0) { |
2119 | ui->hx = ui->hy = -1; |
2120 | } |
2121 | } |
2122 | |
1e3e152d |
2123 | struct game_drawstate { |
2124 | int started; |
2125 | int c, r, cr; |
2126 | int tilesize; |
2127 | digit *grid; |
2128 | unsigned char *pencil; |
2129 | unsigned char *hl; |
2130 | /* This is scratch space used within a single call to game_redraw. */ |
2131 | int *entered_items; |
2132 | }; |
2133 | |
df11cd4e |
2134 | static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, |
2135 | int x, int y, int button) |
1d8e8ad8 |
2136 | { |
df11cd4e |
2137 | int c = state->c, r = state->r, cr = c*r; |
1d8e8ad8 |
2138 | int tx, ty; |
df11cd4e |
2139 | char buf[80]; |
1d8e8ad8 |
2140 | |
f0ee053c |
2141 | button &= ~MOD_MASK; |
3c833d45 |
2142 | |
ae812854 |
2143 | tx = (x + TILE_SIZE - BORDER) / TILE_SIZE - 1; |
2144 | ty = (y + TILE_SIZE - BORDER) / TILE_SIZE - 1; |
1d8e8ad8 |
2145 | |
39d682c9 |
2146 | if (tx >= 0 && tx < cr && ty >= 0 && ty < cr) { |
2147 | if (button == LEFT_BUTTON) { |
df11cd4e |
2148 | if (state->immutable[ty*cr+tx]) { |
39d682c9 |
2149 | ui->hx = ui->hy = -1; |
2150 | } else if (tx == ui->hx && ty == ui->hy && ui->hpencil == 0) { |
2151 | ui->hx = ui->hy = -1; |
2152 | } else { |
2153 | ui->hx = tx; |
2154 | ui->hy = ty; |
2155 | ui->hpencil = 0; |
2156 | } |
df11cd4e |
2157 | return ""; /* UI activity occurred */ |
39d682c9 |
2158 | } |
2159 | if (button == RIGHT_BUTTON) { |
2160 | /* |
2161 | * Pencil-mode highlighting for non filled squares. |
2162 | */ |
df11cd4e |
2163 | if (state->grid[ty*cr+tx] == 0) { |
39d682c9 |
2164 | if (tx == ui->hx && ty == ui->hy && ui->hpencil) { |
2165 | ui->hx = ui->hy = -1; |
2166 | } else { |
2167 | ui->hpencil = 1; |
2168 | ui->hx = tx; |
2169 | ui->hy = ty; |
2170 | } |
2171 | } else { |
2172 | ui->hx = ui->hy = -1; |
2173 | } |
df11cd4e |
2174 | return ""; /* UI activity occurred */ |
39d682c9 |
2175 | } |
1d8e8ad8 |
2176 | } |
2177 | |
2178 | if (ui->hx != -1 && ui->hy != -1 && |
2179 | ((button >= '1' && button <= '9' && button - '0' <= cr) || |
2180 | (button >= 'a' && button <= 'z' && button - 'a' + 10 <= cr) || |
2181 | (button >= 'A' && button <= 'Z' && button - 'A' + 10 <= cr) || |
2182 | button == ' ')) { |
2183 | int n = button - '0'; |
2184 | if (button >= 'A' && button <= 'Z') |
2185 | n = button - 'A' + 10; |
2186 | if (button >= 'a' && button <= 'z') |
2187 | n = button - 'a' + 10; |
2188 | if (button == ' ') |
2189 | n = 0; |
2190 | |
39d682c9 |
2191 | /* |
2192 | * Can't overwrite this square. In principle this shouldn't |
2193 | * happen anyway because we should never have even been |
2194 | * able to highlight the square, but it never hurts to be |
2195 | * careful. |
2196 | */ |
df11cd4e |
2197 | if (state->immutable[ui->hy*cr+ui->hx]) |
39d682c9 |
2198 | return NULL; |
1d8e8ad8 |
2199 | |
c8266e03 |
2200 | /* |
2201 | * Can't make pencil marks in a filled square. In principle |
2202 | * this shouldn't happen anyway because we should never |
2203 | * have even been able to pencil-highlight the square, but |
2204 | * it never hurts to be careful. |
2205 | */ |
df11cd4e |
2206 | if (ui->hpencil && state->grid[ui->hy*cr+ui->hx]) |
c8266e03 |
2207 | return NULL; |
2208 | |
df11cd4e |
2209 | sprintf(buf, "%c%d,%d,%d", |
871bf294 |
2210 | (char)(ui->hpencil && n > 0 ? 'P' : 'R'), ui->hx, ui->hy, n); |
df11cd4e |
2211 | |
2212 | ui->hx = ui->hy = -1; |
2213 | |
2214 | return dupstr(buf); |
2215 | } |
2216 | |
2217 | return NULL; |
2218 | } |
2219 | |
2220 | static game_state *execute_move(game_state *from, char *move) |
2221 | { |
2222 | int c = from->c, r = from->r, cr = c*r; |
2223 | game_state *ret; |
2224 | int x, y, n; |
2225 | |
2226 | if (move[0] == 'S') { |
2227 | char *p; |
2228 | |
1d8e8ad8 |
2229 | ret = dup_game(from); |
df11cd4e |
2230 | ret->completed = ret->cheated = TRUE; |
2231 | |
2232 | p = move+1; |
2233 | for (n = 0; n < cr*cr; n++) { |
2234 | ret->grid[n] = atoi(p); |
2235 | |
2236 | if (!*p || ret->grid[n] < 1 || ret->grid[n] > cr) { |
2237 | free_game(ret); |
2238 | return NULL; |
2239 | } |
2240 | |
2241 | while (*p && isdigit((unsigned char)*p)) p++; |
2242 | if (*p == ',') p++; |
2243 | } |
2244 | |
2245 | return ret; |
2246 | } else if ((move[0] == 'P' || move[0] == 'R') && |
2247 | sscanf(move+1, "%d,%d,%d", &x, &y, &n) == 3 && |
2248 | x >= 0 && x < cr && y >= 0 && y < cr && n >= 0 && n <= cr) { |
2249 | |
2250 | ret = dup_game(from); |
2251 | if (move[0] == 'P' && n > 0) { |
2252 | int index = (y*cr+x) * cr + (n-1); |
c8266e03 |
2253 | ret->pencil[index] = !ret->pencil[index]; |
2254 | } else { |
df11cd4e |
2255 | ret->grid[y*cr+x] = n; |
2256 | memset(ret->pencil + (y*cr+x)*cr, 0, cr); |
1d8e8ad8 |
2257 | |
c8266e03 |
2258 | /* |
2259 | * We've made a real change to the grid. Check to see |
2260 | * if the game has been completed. |
2261 | */ |
2262 | if (!ret->completed && check_valid(c, r, ret->grid)) { |
2263 | ret->completed = TRUE; |
2264 | } |
2265 | } |
df11cd4e |
2266 | return ret; |
2267 | } else |
2268 | return NULL; /* couldn't parse move string */ |
1d8e8ad8 |
2269 | } |
2270 | |
2271 | /* ---------------------------------------------------------------------- |
2272 | * Drawing routines. |
2273 | */ |
2274 | |
1e3e152d |
2275 | #define SIZE(cr) ((cr) * TILE_SIZE + 2*BORDER + 1) |
871bf294 |
2276 | #define GETTILESIZE(cr, w) ( (double)(w-1) / (double)(cr+1) ) |
1d8e8ad8 |
2277 | |
1f3ee4ee |
2278 | static void game_compute_size(game_params *params, int tilesize, |
2279 | int *x, int *y) |
1d8e8ad8 |
2280 | { |
1f3ee4ee |
2281 | /* Ick: fake up `ds->tilesize' for macro expansion purposes */ |
2282 | struct { int tilesize; } ads, *ds = &ads; |
2283 | ads.tilesize = tilesize; |
1e3e152d |
2284 | |
1f3ee4ee |
2285 | *x = SIZE(params->c * params->r); |
2286 | *y = SIZE(params->c * params->r); |
2287 | } |
1d8e8ad8 |
2288 | |
1f3ee4ee |
2289 | static void game_set_size(game_drawstate *ds, game_params *params, |
2290 | int tilesize) |
2291 | { |
2292 | ds->tilesize = tilesize; |
1d8e8ad8 |
2293 | } |
2294 | |
2295 | static float *game_colours(frontend *fe, game_state *state, int *ncolours) |
2296 | { |
2297 | float *ret = snewn(3 * NCOLOURS, float); |
2298 | |
2299 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
2300 | |
2301 | ret[COL_GRID * 3 + 0] = 0.0F; |
2302 | ret[COL_GRID * 3 + 1] = 0.0F; |
2303 | ret[COL_GRID * 3 + 2] = 0.0F; |
2304 | |
2305 | ret[COL_CLUE * 3 + 0] = 0.0F; |
2306 | ret[COL_CLUE * 3 + 1] = 0.0F; |
2307 | ret[COL_CLUE * 3 + 2] = 0.0F; |
2308 | |
2309 | ret[COL_USER * 3 + 0] = 0.0F; |
2310 | ret[COL_USER * 3 + 1] = 0.6F * ret[COL_BACKGROUND * 3 + 1]; |
2311 | ret[COL_USER * 3 + 2] = 0.0F; |
2312 | |
2313 | ret[COL_HIGHLIGHT * 3 + 0] = 0.85F * ret[COL_BACKGROUND * 3 + 0]; |
2314 | ret[COL_HIGHLIGHT * 3 + 1] = 0.85F * ret[COL_BACKGROUND * 3 + 1]; |
2315 | ret[COL_HIGHLIGHT * 3 + 2] = 0.85F * ret[COL_BACKGROUND * 3 + 2]; |
2316 | |
7b14a9ec |
2317 | ret[COL_ERROR * 3 + 0] = 1.0F; |
2318 | ret[COL_ERROR * 3 + 1] = 0.0F; |
2319 | ret[COL_ERROR * 3 + 2] = 0.0F; |
2320 | |
c8266e03 |
2321 | ret[COL_PENCIL * 3 + 0] = 0.5F * ret[COL_BACKGROUND * 3 + 0]; |
2322 | ret[COL_PENCIL * 3 + 1] = 0.5F * ret[COL_BACKGROUND * 3 + 1]; |
2323 | ret[COL_PENCIL * 3 + 2] = ret[COL_BACKGROUND * 3 + 2]; |
2324 | |
1d8e8ad8 |
2325 | *ncolours = NCOLOURS; |
2326 | return ret; |
2327 | } |
2328 | |
2329 | static game_drawstate *game_new_drawstate(game_state *state) |
2330 | { |
2331 | struct game_drawstate *ds = snew(struct game_drawstate); |
2332 | int c = state->c, r = state->r, cr = c*r; |
2333 | |
2334 | ds->started = FALSE; |
2335 | ds->c = c; |
2336 | ds->r = r; |
2337 | ds->cr = cr; |
2338 | ds->grid = snewn(cr*cr, digit); |
2339 | memset(ds->grid, 0, cr*cr); |
c8266e03 |
2340 | ds->pencil = snewn(cr*cr*cr, digit); |
2341 | memset(ds->pencil, 0, cr*cr*cr); |
1d8e8ad8 |
2342 | ds->hl = snewn(cr*cr, unsigned char); |
2343 | memset(ds->hl, 0, cr*cr); |
b71dd7fc |
2344 | ds->entered_items = snewn(cr*cr, int); |
1e3e152d |
2345 | ds->tilesize = 0; /* not decided yet */ |
1d8e8ad8 |
2346 | return ds; |
2347 | } |
2348 | |
2349 | static void game_free_drawstate(game_drawstate *ds) |
2350 | { |
2351 | sfree(ds->hl); |
c8266e03 |
2352 | sfree(ds->pencil); |
1d8e8ad8 |
2353 | sfree(ds->grid); |
b71dd7fc |
2354 | sfree(ds->entered_items); |
1d8e8ad8 |
2355 | sfree(ds); |
2356 | } |
2357 | |
2358 | static void draw_number(frontend *fe, game_drawstate *ds, game_state *state, |
2359 | int x, int y, int hl) |
2360 | { |
2361 | int c = state->c, r = state->r, cr = c*r; |
2362 | int tx, ty; |
2363 | int cx, cy, cw, ch; |
2364 | char str[2]; |
2365 | |
c8266e03 |
2366 | if (ds->grid[y*cr+x] == state->grid[y*cr+x] && |
2367 | ds->hl[y*cr+x] == hl && |
2368 | !memcmp(ds->pencil+(y*cr+x)*cr, state->pencil+(y*cr+x)*cr, cr)) |
1d8e8ad8 |
2369 | return; /* no change required */ |
2370 | |
2371 | tx = BORDER + x * TILE_SIZE + 2; |
2372 | ty = BORDER + y * TILE_SIZE + 2; |
2373 | |
2374 | cx = tx; |
2375 | cy = ty; |
2376 | cw = TILE_SIZE-3; |
2377 | ch = TILE_SIZE-3; |
2378 | |
2379 | if (x % r) |
2380 | cx--, cw++; |
2381 | if ((x+1) % r) |
2382 | cw++; |
2383 | if (y % c) |
2384 | cy--, ch++; |
2385 | if ((y+1) % c) |
2386 | ch++; |
2387 | |
2388 | clip(fe, cx, cy, cw, ch); |
2389 | |
c8266e03 |
2390 | /* background needs erasing */ |
7b14a9ec |
2391 | draw_rect(fe, cx, cy, cw, ch, (hl & 15) == 1 ? COL_HIGHLIGHT : COL_BACKGROUND); |
c8266e03 |
2392 | |
2393 | /* pencil-mode highlight */ |
7b14a9ec |
2394 | if ((hl & 15) == 2) { |
c8266e03 |
2395 | int coords[6]; |
2396 | coords[0] = cx; |
2397 | coords[1] = cy; |
2398 | coords[2] = cx+cw/2; |
2399 | coords[3] = cy; |
2400 | coords[4] = cx; |
2401 | coords[5] = cy+ch/2; |
28b5987d |
2402 | draw_polygon(fe, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT); |
c8266e03 |
2403 | } |
1d8e8ad8 |
2404 | |
2405 | /* new number needs drawing? */ |
2406 | if (state->grid[y*cr+x]) { |
2407 | str[1] = '\0'; |
2408 | str[0] = state->grid[y*cr+x] + '0'; |
2409 | if (str[0] > '9') |
2410 | str[0] += 'a' - ('9'+1); |
2411 | draw_text(fe, tx + TILE_SIZE/2, ty + TILE_SIZE/2, |
2412 | FONT_VARIABLE, TILE_SIZE/2, ALIGN_VCENTRE | ALIGN_HCENTRE, |
7b14a9ec |
2413 | state->immutable[y*cr+x] ? COL_CLUE : (hl & 16) ? COL_ERROR : COL_USER, str); |
c8266e03 |
2414 | } else { |
edf63745 |
2415 | int i, j, npencil; |
2416 | int pw, ph, pmax, fontsize; |
2417 | |
2418 | /* count the pencil marks required */ |
2419 | for (i = npencil = 0; i < cr; i++) |
2420 | if (state->pencil[(y*cr+x)*cr+i]) |
2421 | npencil++; |
2422 | |
2423 | /* |
2424 | * It's not sensible to arrange pencil marks in the same |
2425 | * layout as the squares within a block, because this leads |
2426 | * to the font being too small. Instead, we arrange pencil |
2427 | * marks in the nearest thing we can to a square layout, |
2428 | * and we adjust the square layout depending on the number |
2429 | * of pencil marks in the square. |
2430 | */ |
2431 | for (pw = 1; pw * pw < npencil; pw++); |
2432 | if (pw < 3) pw = 3; /* otherwise it just looks _silly_ */ |
2433 | ph = (npencil + pw - 1) / pw; |
2434 | if (ph < 2) ph = 2; /* likewise */ |
2435 | pmax = max(pw, ph); |
2436 | fontsize = TILE_SIZE/(pmax*(11-pmax)/8); |
c8266e03 |
2437 | |
2438 | for (i = j = 0; i < cr; i++) |
2439 | if (state->pencil[(y*cr+x)*cr+i]) { |
edf63745 |
2440 | int dx = j % pw, dy = j / pw; |
2441 | |
c8266e03 |
2442 | str[1] = '\0'; |
2443 | str[0] = i + '1'; |
2444 | if (str[0] > '9') |
2445 | str[0] += 'a' - ('9'+1); |
edf63745 |
2446 | draw_text(fe, tx + (4*dx+3) * TILE_SIZE / (4*pw+2), |
2447 | ty + (4*dy+3) * TILE_SIZE / (4*ph+2), |
2448 | FONT_VARIABLE, fontsize, |
c8266e03 |
2449 | ALIGN_VCENTRE | ALIGN_HCENTRE, COL_PENCIL, str); |
2450 | j++; |
2451 | } |
1d8e8ad8 |
2452 | } |
2453 | |
2454 | unclip(fe); |
2455 | |
2456 | draw_update(fe, cx, cy, cw, ch); |
2457 | |
2458 | ds->grid[y*cr+x] = state->grid[y*cr+x]; |
c8266e03 |
2459 | memcpy(ds->pencil+(y*cr+x)*cr, state->pencil+(y*cr+x)*cr, cr); |
1d8e8ad8 |
2460 | ds->hl[y*cr+x] = hl; |
2461 | } |
2462 | |
2463 | static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, |
2464 | game_state *state, int dir, game_ui *ui, |
2465 | float animtime, float flashtime) |
2466 | { |
2467 | int c = state->c, r = state->r, cr = c*r; |
2468 | int x, y; |
2469 | |
2470 | if (!ds->started) { |
2471 | /* |
2472 | * The initial contents of the window are not guaranteed |
2473 | * and can vary with front ends. To be on the safe side, |
2474 | * all games should start by drawing a big |
2475 | * background-colour rectangle covering the whole window. |
2476 | */ |
1e3e152d |
2477 | draw_rect(fe, 0, 0, SIZE(cr), SIZE(cr), COL_BACKGROUND); |
1d8e8ad8 |
2478 | |
2479 | /* |
2480 | * Draw the grid. |
2481 | */ |
2482 | for (x = 0; x <= cr; x++) { |
2483 | int thick = (x % r ? 0 : 1); |
2484 | draw_rect(fe, BORDER + x*TILE_SIZE - thick, BORDER-1, |
2485 | 1+2*thick, cr*TILE_SIZE+3, COL_GRID); |
2486 | } |
2487 | for (y = 0; y <= cr; y++) { |
2488 | int thick = (y % c ? 0 : 1); |
2489 | draw_rect(fe, BORDER-1, BORDER + y*TILE_SIZE - thick, |
2490 | cr*TILE_SIZE+3, 1+2*thick, COL_GRID); |
2491 | } |
2492 | } |
2493 | |
2494 | /* |
7b14a9ec |
2495 | * This array is used to keep track of rows, columns and boxes |
2496 | * which contain a number more than once. |
2497 | */ |
2498 | for (x = 0; x < cr * cr; x++) |
b71dd7fc |
2499 | ds->entered_items[x] = 0; |
7b14a9ec |
2500 | for (x = 0; x < cr; x++) |
2501 | for (y = 0; y < cr; y++) { |
2502 | digit d = state->grid[y*cr+x]; |
2503 | if (d) { |
2504 | int box = (x/r)+(y/c)*c; |
b71dd7fc |
2505 | ds->entered_items[x*cr+d-1] |= ((ds->entered_items[x*cr+d-1] & 1) << 1) | 1; |
2506 | ds->entered_items[y*cr+d-1] |= ((ds->entered_items[y*cr+d-1] & 4) << 1) | 4; |
2507 | ds->entered_items[box*cr+d-1] |= ((ds->entered_items[box*cr+d-1] & 16) << 1) | 16; |
7b14a9ec |
2508 | } |
2509 | } |
2510 | |
2511 | /* |
1d8e8ad8 |
2512 | * Draw any numbers which need redrawing. |
2513 | */ |
2514 | for (x = 0; x < cr; x++) { |
2515 | for (y = 0; y < cr; y++) { |
c8266e03 |
2516 | int highlight = 0; |
7b14a9ec |
2517 | digit d = state->grid[y*cr+x]; |
2518 | |
c8266e03 |
2519 | if (flashtime > 0 && |
2520 | (flashtime <= FLASH_TIME/3 || |
2521 | flashtime >= FLASH_TIME*2/3)) |
2522 | highlight = 1; |
7b14a9ec |
2523 | |
2524 | /* Highlight active input areas. */ |
c8266e03 |
2525 | if (x == ui->hx && y == ui->hy) |
2526 | highlight = ui->hpencil ? 2 : 1; |
7b14a9ec |
2527 | |
2528 | /* Mark obvious errors (ie, numbers which occur more than once |
2529 | * in a single row, column, or box). */ |
5d744557 |
2530 | if (d && ((ds->entered_items[x*cr+d-1] & 2) || |
2531 | (ds->entered_items[y*cr+d-1] & 8) || |
2532 | (ds->entered_items[((x/r)+(y/c)*c)*cr+d-1] & 32))) |
7b14a9ec |
2533 | highlight |= 16; |
2534 | |
c8266e03 |
2535 | draw_number(fe, ds, state, x, y, highlight); |
1d8e8ad8 |
2536 | } |
2537 | } |
2538 | |
2539 | /* |
2540 | * Update the _entire_ grid if necessary. |
2541 | */ |
2542 | if (!ds->started) { |
1e3e152d |
2543 | draw_update(fe, 0, 0, SIZE(cr), SIZE(cr)); |
1d8e8ad8 |
2544 | ds->started = TRUE; |
2545 | } |
2546 | } |
2547 | |
2548 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
e3f21163 |
2549 | int dir, game_ui *ui) |
1d8e8ad8 |
2550 | { |
2551 | return 0.0F; |
2552 | } |
2553 | |
2554 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
e3f21163 |
2555 | int dir, game_ui *ui) |
1d8e8ad8 |
2556 | { |
2ac6d24e |
2557 | if (!oldstate->completed && newstate->completed && |
2558 | !oldstate->cheated && !newstate->cheated) |
1d8e8ad8 |
2559 | return FLASH_TIME; |
2560 | return 0.0F; |
2561 | } |
2562 | |
2563 | static int game_wants_statusbar(void) |
2564 | { |
2565 | return FALSE; |
2566 | } |
2567 | |
4d08de49 |
2568 | static int game_timing_state(game_state *state, game_ui *ui) |
48dcdd62 |
2569 | { |
2570 | return TRUE; |
2571 | } |
2572 | |
1d8e8ad8 |
2573 | #ifdef COMBINED |
2574 | #define thegame solo |
2575 | #endif |
2576 | |
2577 | const struct game thegame = { |
1d228b10 |
2578 | "Solo", "games.solo", |
1d8e8ad8 |
2579 | default_params, |
2580 | game_fetch_preset, |
2581 | decode_params, |
2582 | encode_params, |
2583 | free_params, |
2584 | dup_params, |
1d228b10 |
2585 | TRUE, game_configure, custom_params, |
1d8e8ad8 |
2586 | validate_params, |
1185e3c5 |
2587 | new_game_desc, |
1185e3c5 |
2588 | validate_desc, |
1d8e8ad8 |
2589 | new_game, |
2590 | dup_game, |
2591 | free_game, |
2ac6d24e |
2592 | TRUE, solve_game, |
9b4b03d3 |
2593 | TRUE, game_text_format, |
1d8e8ad8 |
2594 | new_ui, |
2595 | free_ui, |
ae8290c6 |
2596 | encode_ui, |
2597 | decode_ui, |
07dfb697 |
2598 | game_changed_state, |
df11cd4e |
2599 | interpret_move, |
2600 | execute_move, |
1f3ee4ee |
2601 | PREFERRED_TILE_SIZE, game_compute_size, game_set_size, |
1d8e8ad8 |
2602 | game_colours, |
2603 | game_new_drawstate, |
2604 | game_free_drawstate, |
2605 | game_redraw, |
2606 | game_anim_length, |
2607 | game_flash_length, |
2608 | game_wants_statusbar, |
48dcdd62 |
2609 | FALSE, game_timing_state, |
93b1da3d |
2610 | 0, /* mouse_priorities */ |
1d8e8ad8 |
2611 | }; |
3ddae0ff |
2612 | |
2613 | #ifdef STANDALONE_SOLVER |
2614 | |
7c568a48 |
2615 | /* |
2616 | * gcc -DSTANDALONE_SOLVER -o solosolver solo.c malloc.c |
2617 | */ |
2618 | |
3ddae0ff |
2619 | void frontend_default_colour(frontend *fe, float *output) {} |
2620 | void draw_text(frontend *fe, int x, int y, int fonttype, int fontsize, |
2621 | int align, int colour, char *text) {} |
2622 | void draw_rect(frontend *fe, int x, int y, int w, int h, int colour) {} |
2623 | void draw_line(frontend *fe, int x1, int y1, int x2, int y2, int colour) {} |
2624 | void draw_polygon(frontend *fe, int *coords, int npoints, |
28b5987d |
2625 | int fillcolour, int outlinecolour) {} |
3ddae0ff |
2626 | void clip(frontend *fe, int x, int y, int w, int h) {} |
2627 | void unclip(frontend *fe) {} |
2628 | void start_draw(frontend *fe) {} |
2629 | void draw_update(frontend *fe, int x, int y, int w, int h) {} |
2630 | void end_draw(frontend *fe) {} |
7c568a48 |
2631 | unsigned long random_bits(random_state *state, int bits) |
2632 | { assert(!"Shouldn't get randomness"); return 0; } |
2633 | unsigned long random_upto(random_state *state, unsigned long limit) |
2634 | { assert(!"Shouldn't get randomness"); return 0; } |
947a07d6 |
2635 | void shuffle(void *array, int nelts, int eltsize, random_state *rs) |
2636 | { assert(!"Shouldn't get randomness"); } |
3ddae0ff |
2637 | |
2638 | void fatal(char *fmt, ...) |
2639 | { |
2640 | va_list ap; |
2641 | |
2642 | fprintf(stderr, "fatal error: "); |
2643 | |
2644 | va_start(ap, fmt); |
2645 | vfprintf(stderr, fmt, ap); |
2646 | va_end(ap); |
2647 | |
2648 | fprintf(stderr, "\n"); |
2649 | exit(1); |
2650 | } |
2651 | |
2652 | int main(int argc, char **argv) |
2653 | { |
2654 | game_params *p; |
2655 | game_state *s; |
1185e3c5 |
2656 | char *id = NULL, *desc, *err; |
7c568a48 |
2657 | int grade = FALSE; |
ab362080 |
2658 | int ret; |
3ddae0ff |
2659 | |
2660 | while (--argc > 0) { |
2661 | char *p = *++argv; |
ab362080 |
2662 | if (!strcmp(p, "-v")) { |
7c568a48 |
2663 | solver_show_working = TRUE; |
7c568a48 |
2664 | } else if (!strcmp(p, "-g")) { |
2665 | grade = TRUE; |
3ddae0ff |
2666 | } else if (*p == '-') { |
8317499a |
2667 | fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p); |
3ddae0ff |
2668 | return 1; |
2669 | } else { |
2670 | id = p; |
2671 | } |
2672 | } |
2673 | |
2674 | if (!id) { |
ab362080 |
2675 | fprintf(stderr, "usage: %s [-g | -v] <game_id>\n", argv[0]); |
3ddae0ff |
2676 | return 1; |
2677 | } |
2678 | |
1185e3c5 |
2679 | desc = strchr(id, ':'); |
2680 | if (!desc) { |
3ddae0ff |
2681 | fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]); |
2682 | return 1; |
2683 | } |
1185e3c5 |
2684 | *desc++ = '\0'; |
3ddae0ff |
2685 | |
1733f4ca |
2686 | p = default_params(); |
2687 | decode_params(p, id); |
1185e3c5 |
2688 | err = validate_desc(p, desc); |
3ddae0ff |
2689 | if (err) { |
2690 | fprintf(stderr, "%s: %s\n", argv[0], err); |
2691 | return 1; |
2692 | } |
39d682c9 |
2693 | s = new_game(NULL, p, desc); |
3ddae0ff |
2694 | |
947a07d6 |
2695 | ret = solver(p->c, p->r, s->grid, DIFF_RECURSIVE); |
ab362080 |
2696 | if (grade) { |
2697 | printf("Difficulty rating: %s\n", |
2698 | ret==DIFF_BLOCK ? "Trivial (blockwise positional elimination only)": |
2699 | ret==DIFF_SIMPLE ? "Basic (row/column/number elimination required)": |
2700 | ret==DIFF_INTERSECT ? "Intermediate (intersectional analysis required)": |
2701 | ret==DIFF_SET ? "Advanced (set elimination required)": |
2702 | ret==DIFF_RECURSIVE ? "Unreasonable (guesswork and backtracking required)": |
2703 | ret==DIFF_AMBIGUOUS ? "Ambiguous (multiple solutions exist)": |
2704 | ret==DIFF_IMPOSSIBLE ? "Impossible (no solution exists)": |
2705 | "INTERNAL ERROR: unrecognised difficulty code"); |
3ddae0ff |
2706 | } else { |
ab362080 |
2707 | printf("%s\n", grid_text_format(p->c, p->r, s->grid)); |
3ddae0ff |
2708 | } |
2709 | |
3ddae0ff |
2710 | return 0; |
2711 | } |
2712 | |
2713 | #endif |