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 | |
44bf5f6f |
119 | enum { DIFF_BLOCK, DIFF_SIMPLE, DIFF_INTERSECT, DIFF_SET, DIFF_EXTREME, |
13c4d60d |
120 | DIFF_RECURSIVE, DIFF_AMBIGUOUS, DIFF_IMPOSSIBLE }; |
7c568a48 |
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 } }, |
44bf5f6f |
180 | { "3x3 Extreme", { 3, 3, SYMM_ROT2, DIFF_EXTREME } }, |
de60d8bd |
181 | { "3x3 Unreasonable", { 3, 3, SYMM_ROT2, DIFF_RECURSIVE } }, |
ab53eb64 |
182 | #ifndef SLOW_SYSTEM |
7c568a48 |
183 | { "3x4 Basic", { 3, 4, SYMM_ROT2, DIFF_SIMPLE } }, |
184 | { "4x4 Basic", { 4, 4, SYMM_ROT2, DIFF_SIMPLE } }, |
ab53eb64 |
185 | #endif |
7c568a48 |
186 | }; |
187 | |
188 | if (i < 0 || i >= lenof(presets)) |
189 | return FALSE; |
190 | |
191 | *name = dupstr(presets[i].title); |
192 | *params = dup_params(&presets[i].params); |
193 | |
194 | return TRUE; |
195 | } |
196 | |
1185e3c5 |
197 | static void decode_params(game_params *ret, char const *string) |
1d8e8ad8 |
198 | { |
1d8e8ad8 |
199 | ret->c = ret->r = atoi(string); |
200 | while (*string && isdigit((unsigned char)*string)) string++; |
201 | if (*string == 'x') { |
202 | string++; |
203 | ret->r = atoi(string); |
204 | while (*string && isdigit((unsigned char)*string)) string++; |
205 | } |
7c568a48 |
206 | while (*string) { |
207 | if (*string == 'r' || *string == 'm' || *string == 'a') { |
154bf9b1 |
208 | int sn, sc, sd; |
7c568a48 |
209 | sc = *string++; |
154bf9b1 |
210 | if (*string == 'd') { |
211 | sd = TRUE; |
212 | string++; |
213 | } else { |
214 | sd = FALSE; |
215 | } |
7c568a48 |
216 | sn = atoi(string); |
217 | while (*string && isdigit((unsigned char)*string)) string++; |
154bf9b1 |
218 | if (sc == 'm' && sn == 8) |
219 | ret->symm = SYMM_REF8; |
7c568a48 |
220 | if (sc == 'm' && sn == 4) |
154bf9b1 |
221 | ret->symm = sd ? SYMM_REF4D : SYMM_REF4; |
222 | if (sc == 'm' && sn == 2) |
223 | ret->symm = sd ? SYMM_REF2D : SYMM_REF2; |
7c568a48 |
224 | if (sc == 'r' && sn == 4) |
225 | ret->symm = SYMM_ROT4; |
226 | if (sc == 'r' && sn == 2) |
227 | ret->symm = SYMM_ROT2; |
228 | if (sc == 'a') |
229 | ret->symm = SYMM_NONE; |
230 | } else if (*string == 'd') { |
231 | string++; |
232 | if (*string == 't') /* trivial */ |
233 | string++, ret->diff = DIFF_BLOCK; |
234 | else if (*string == 'b') /* basic */ |
235 | string++, ret->diff = DIFF_SIMPLE; |
236 | else if (*string == 'i') /* intermediate */ |
237 | string++, ret->diff = DIFF_INTERSECT; |
238 | else if (*string == 'a') /* advanced */ |
239 | string++, ret->diff = DIFF_SET; |
13c4d60d |
240 | else if (*string == 'e') /* extreme */ |
44bf5f6f |
241 | string++, ret->diff = DIFF_EXTREME; |
de60d8bd |
242 | else if (*string == 'u') /* unreasonable */ |
243 | string++, ret->diff = DIFF_RECURSIVE; |
7c568a48 |
244 | } else |
245 | string++; /* eat unknown character */ |
ef57b17d |
246 | } |
1d8e8ad8 |
247 | } |
248 | |
1185e3c5 |
249 | static char *encode_params(game_params *params, int full) |
1d8e8ad8 |
250 | { |
251 | char str[80]; |
252 | |
253 | sprintf(str, "%dx%d", params->c, params->r); |
1185e3c5 |
254 | if (full) { |
255 | switch (params->symm) { |
154bf9b1 |
256 | case SYMM_REF8: strcat(str, "m8"); break; |
1185e3c5 |
257 | case SYMM_REF4: strcat(str, "m4"); break; |
154bf9b1 |
258 | case SYMM_REF4D: strcat(str, "md4"); break; |
259 | case SYMM_REF2: strcat(str, "m2"); break; |
260 | case SYMM_REF2D: strcat(str, "md2"); break; |
1185e3c5 |
261 | case SYMM_ROT4: strcat(str, "r4"); break; |
262 | /* case SYMM_ROT2: strcat(str, "r2"); break; [default] */ |
263 | case SYMM_NONE: strcat(str, "a"); break; |
264 | } |
265 | switch (params->diff) { |
266 | /* case DIFF_BLOCK: strcat(str, "dt"); break; [default] */ |
267 | case DIFF_SIMPLE: strcat(str, "db"); break; |
268 | case DIFF_INTERSECT: strcat(str, "di"); break; |
269 | case DIFF_SET: strcat(str, "da"); break; |
44bf5f6f |
270 | case DIFF_EXTREME: strcat(str, "de"); break; |
1185e3c5 |
271 | case DIFF_RECURSIVE: strcat(str, "du"); break; |
272 | } |
273 | } |
1d8e8ad8 |
274 | return dupstr(str); |
275 | } |
276 | |
277 | static config_item *game_configure(game_params *params) |
278 | { |
279 | config_item *ret; |
280 | char buf[80]; |
281 | |
282 | ret = snewn(5, config_item); |
283 | |
284 | ret[0].name = "Columns of sub-blocks"; |
285 | ret[0].type = C_STRING; |
286 | sprintf(buf, "%d", params->c); |
287 | ret[0].sval = dupstr(buf); |
288 | ret[0].ival = 0; |
289 | |
290 | ret[1].name = "Rows of sub-blocks"; |
291 | ret[1].type = C_STRING; |
292 | sprintf(buf, "%d", params->r); |
293 | ret[1].sval = dupstr(buf); |
294 | ret[1].ival = 0; |
295 | |
ef57b17d |
296 | ret[2].name = "Symmetry"; |
297 | ret[2].type = C_CHOICES; |
154bf9b1 |
298 | ret[2].sval = ":None:2-way rotation:4-way rotation:2-way mirror:" |
299 | "2-way diagonal mirror:4-way mirror:4-way diagonal mirror:" |
300 | "8-way mirror"; |
ef57b17d |
301 | ret[2].ival = params->symm; |
302 | |
7c568a48 |
303 | ret[3].name = "Difficulty"; |
304 | ret[3].type = C_CHOICES; |
13c4d60d |
305 | ret[3].sval = ":Trivial:Basic:Intermediate:Advanced:Extreme:Unreasonable"; |
7c568a48 |
306 | ret[3].ival = params->diff; |
1d8e8ad8 |
307 | |
7c568a48 |
308 | ret[4].name = NULL; |
309 | ret[4].type = C_END; |
310 | ret[4].sval = NULL; |
311 | ret[4].ival = 0; |
1d8e8ad8 |
312 | |
313 | return ret; |
314 | } |
315 | |
316 | static game_params *custom_params(config_item *cfg) |
317 | { |
318 | game_params *ret = snew(game_params); |
319 | |
c1f743c8 |
320 | ret->c = atoi(cfg[0].sval); |
321 | ret->r = atoi(cfg[1].sval); |
ef57b17d |
322 | ret->symm = cfg[2].ival; |
7c568a48 |
323 | ret->diff = cfg[3].ival; |
1d8e8ad8 |
324 | |
325 | return ret; |
326 | } |
327 | |
3ff276f2 |
328 | static char *validate_params(game_params *params, int full) |
1d8e8ad8 |
329 | { |
330 | if (params->c < 2 || params->r < 2) |
331 | return "Both dimensions must be at least 2"; |
332 | if (params->c > ORDER_MAX || params->r > ORDER_MAX) |
333 | return "Dimensions greater than "STR(ORDER_MAX)" are not supported"; |
498eab1d |
334 | if ((params->c * params->r) > 35) |
335 | return "Unable to support more than 35 distinct symbols in a puzzle"; |
1d8e8ad8 |
336 | return NULL; |
337 | } |
338 | |
339 | /* ---------------------------------------------------------------------- |
ab362080 |
340 | * Solver. |
341 | * |
13c4d60d |
342 | * This solver is used for two purposes: |
ab362080 |
343 | * + to check solubility of a grid as we gradually remove numbers |
344 | * from it |
345 | * + to solve an externally generated puzzle when the user selects |
346 | * `Solve'. |
347 | * |
1d8e8ad8 |
348 | * It supports a variety of specific modes of reasoning. By |
349 | * enabling or disabling subsets of these modes we can arrange a |
350 | * range of difficulty levels. |
351 | */ |
352 | |
353 | /* |
354 | * Modes of reasoning currently supported: |
355 | * |
356 | * - Positional elimination: a number must go in a particular |
357 | * square because all the other empty squares in a given |
358 | * row/col/blk are ruled out. |
359 | * |
360 | * - Numeric elimination: a square must have a particular number |
361 | * in because all the other numbers that could go in it are |
362 | * ruled out. |
363 | * |
7c568a48 |
364 | * - Intersectional analysis: given two domains which overlap |
1d8e8ad8 |
365 | * (hence one must be a block, and the other can be a row or |
366 | * col), if the possible locations for a particular number in |
367 | * one of the domains can be narrowed down to the overlap, then |
368 | * that number can be ruled out everywhere but the overlap in |
369 | * the other domain too. |
370 | * |
7c568a48 |
371 | * - Set elimination: if there is a subset of the empty squares |
372 | * within a domain such that the union of the possible numbers |
373 | * in that subset has the same size as the subset itself, then |
374 | * those numbers can be ruled out everywhere else in the domain. |
375 | * (For example, if there are five empty squares and the |
376 | * possible numbers in each are 12, 23, 13, 134 and 1345, then |
377 | * the first three empty squares form such a subset: the numbers |
378 | * 1, 2 and 3 _must_ be in those three squares in some |
379 | * permutation, and hence we can deduce none of them can be in |
380 | * the fourth or fifth squares.) |
381 | * + You can also see this the other way round, concentrating |
382 | * on numbers rather than squares: if there is a subset of |
383 | * the unplaced numbers within a domain such that the union |
384 | * of all their possible positions has the same size as the |
385 | * subset itself, then all other numbers can be ruled out for |
386 | * those positions. However, it turns out that this is |
387 | * exactly equivalent to the first formulation at all times: |
388 | * there is a 1-1 correspondence between suitable subsets of |
389 | * the unplaced numbers and suitable subsets of the unfilled |
390 | * places, found by taking the _complement_ of the union of |
391 | * the numbers' possible positions (or the spaces' possible |
392 | * contents). |
ab362080 |
393 | * |
13c4d60d |
394 | * - Mutual neighbour elimination: find two squares A,B and a |
395 | * number N in the possible set of A, such that putting N in A |
396 | * would rule out enough possibilities from the mutual |
397 | * neighbours of A and B that there would be no possibilities |
398 | * left for B. Thereby rule out N in A. |
399 | * + The simplest case of this is if B has two possibilities |
400 | * (wlog {1,2}), and there are two mutual neighbours of A and |
401 | * B which have possibilities {1,3} and {2,3}. Thus, if A |
402 | * were to be 3, then those neighbours would contain 1 and 2, |
403 | * and hence there would be nothing left which could go in B. |
404 | * + There can be more complex cases of it too: if A and B are |
405 | * in the same column of large blocks, then they can have |
406 | * more than two mutual neighbours, some of which can also be |
407 | * neighbours of one another. Suppose, for example, that B |
408 | * has possibilities {1,2,3}; there's one square P in the |
409 | * same column as B and the same block as A, with |
410 | * possibilities {1,4}; and there are _two_ squares Q,R in |
411 | * the same column as A and the same block as B with |
412 | * possibilities {2,3,4}. Then if A contained 4, P would |
413 | * contain 1, and Q and R would have to contain 2 and 3 in |
414 | * _some_ order; therefore, once again, B would have no |
415 | * remaining possibilities. |
416 | * |
ab362080 |
417 | * - Recursion. If all else fails, we pick one of the currently |
418 | * most constrained empty squares and take a random guess at its |
419 | * contents, then continue solving on that basis and see if we |
420 | * get any further. |
1d8e8ad8 |
421 | */ |
422 | |
4846f788 |
423 | /* |
424 | * Within this solver, I'm going to transform all y-coordinates by |
425 | * inverting the significance of the block number and the position |
426 | * within the block. That is, we will start with the top row of |
427 | * each block in order, then the second row of each block in order, |
428 | * etc. |
429 | * |
430 | * This transformation has the enormous advantage that it means |
431 | * every row, column _and_ block is described by an arithmetic |
432 | * progression of coordinates within the cubic array, so that I can |
433 | * use the same very simple function to do blockwise, row-wise and |
434 | * column-wise elimination. |
435 | */ |
436 | #define YTRANS(y) (((y)%c)*r+(y)/c) |
437 | #define YUNTRANS(y) (((y)%r)*c+(y)/r) |
438 | |
ab362080 |
439 | struct solver_usage { |
1d8e8ad8 |
440 | int c, r, cr; |
441 | /* |
442 | * We set up a cubic array, indexed by x, y and digit; each |
443 | * element of this array is TRUE or FALSE according to whether |
444 | * or not that digit _could_ in principle go in that position. |
445 | * |
446 | * The way to index this array is cube[(x*cr+y)*cr+n-1]. |
4846f788 |
447 | * y-coordinates in here are transformed. |
1d8e8ad8 |
448 | */ |
449 | unsigned char *cube; |
450 | /* |
451 | * This is the grid in which we write down our final |
4846f788 |
452 | * deductions. y-coordinates in here are _not_ transformed. |
1d8e8ad8 |
453 | */ |
454 | digit *grid; |
455 | /* |
456 | * Now we keep track, at a slightly higher level, of what we |
457 | * have yet to work out, to prevent doing the same deduction |
458 | * many times. |
459 | */ |
460 | /* row[y*cr+n-1] TRUE if digit n has been placed in row y */ |
461 | unsigned char *row; |
462 | /* col[x*cr+n-1] TRUE if digit n has been placed in row x */ |
463 | unsigned char *col; |
464 | /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */ |
465 | unsigned char *blk; |
466 | }; |
4846f788 |
467 | #define cubepos(x,y,n) (((x)*usage->cr+(y))*usage->cr+(n)-1) |
468 | #define cube(x,y,n) (usage->cube[cubepos(x,y,n)]) |
1d8e8ad8 |
469 | |
470 | /* |
471 | * Function called when we are certain that a particular square has |
4846f788 |
472 | * a particular number in it. The y-coordinate passed in here is |
473 | * transformed. |
1d8e8ad8 |
474 | */ |
ab362080 |
475 | static void solver_place(struct solver_usage *usage, int x, int y, int n) |
1d8e8ad8 |
476 | { |
477 | int c = usage->c, r = usage->r, cr = usage->cr; |
478 | int i, j, bx, by; |
479 | |
480 | assert(cube(x,y,n)); |
481 | |
482 | /* |
483 | * Rule out all other numbers in this square. |
484 | */ |
485 | for (i = 1; i <= cr; i++) |
486 | if (i != n) |
487 | cube(x,y,i) = FALSE; |
488 | |
489 | /* |
490 | * Rule out this number in all other positions in the row. |
491 | */ |
492 | for (i = 0; i < cr; i++) |
493 | if (i != y) |
494 | cube(x,i,n) = FALSE; |
495 | |
496 | /* |
497 | * Rule out this number in all other positions in the column. |
498 | */ |
499 | for (i = 0; i < cr; i++) |
500 | if (i != x) |
501 | cube(i,y,n) = FALSE; |
502 | |
503 | /* |
504 | * Rule out this number in all other positions in the block. |
505 | */ |
506 | bx = (x/r)*r; |
4846f788 |
507 | by = y % r; |
1d8e8ad8 |
508 | for (i = 0; i < r; i++) |
509 | for (j = 0; j < c; j++) |
4846f788 |
510 | if (bx+i != x || by+j*r != y) |
511 | cube(bx+i,by+j*r,n) = FALSE; |
1d8e8ad8 |
512 | |
513 | /* |
514 | * Enter the number in the result grid. |
515 | */ |
4846f788 |
516 | usage->grid[YUNTRANS(y)*cr+x] = n; |
1d8e8ad8 |
517 | |
518 | /* |
519 | * Cross out this number from the list of numbers left to place |
520 | * in its row, its column and its block. |
521 | */ |
522 | usage->row[y*cr+n-1] = usage->col[x*cr+n-1] = |
7c568a48 |
523 | usage->blk[((y%r)*c+(x/r))*cr+n-1] = TRUE; |
1d8e8ad8 |
524 | } |
525 | |
ab362080 |
526 | static int solver_elim(struct solver_usage *usage, int start, int step |
7c568a48 |
527 | #ifdef STANDALONE_SOLVER |
528 | , char *fmt, ... |
529 | #endif |
530 | ) |
1d8e8ad8 |
531 | { |
4846f788 |
532 | int c = usage->c, r = usage->r, cr = c*r; |
533 | int fpos, m, i; |
1d8e8ad8 |
534 | |
535 | /* |
4846f788 |
536 | * Count the number of set bits within this section of the |
537 | * cube. |
1d8e8ad8 |
538 | */ |
539 | m = 0; |
4846f788 |
540 | fpos = -1; |
541 | for (i = 0; i < cr; i++) |
542 | if (usage->cube[start+i*step]) { |
543 | fpos = start+i*step; |
1d8e8ad8 |
544 | m++; |
545 | } |
546 | |
547 | if (m == 1) { |
4846f788 |
548 | int x, y, n; |
549 | assert(fpos >= 0); |
1d8e8ad8 |
550 | |
4846f788 |
551 | n = 1 + fpos % cr; |
552 | y = fpos / cr; |
553 | x = y / cr; |
554 | y %= cr; |
1d8e8ad8 |
555 | |
3ddae0ff |
556 | if (!usage->grid[YUNTRANS(y)*cr+x]) { |
7c568a48 |
557 | #ifdef STANDALONE_SOLVER |
558 | if (solver_show_working) { |
559 | va_list ap; |
fdb3b29a |
560 | printf("%*s", solver_recurse_depth*4, ""); |
7c568a48 |
561 | va_start(ap, fmt); |
562 | vprintf(fmt, ap); |
563 | va_end(ap); |
ab362080 |
564 | printf(":\n%*s placing %d at (%d,%d)\n", |
565 | solver_recurse_depth*4, "", n, 1+x, 1+YUNTRANS(y)); |
7c568a48 |
566 | } |
567 | #endif |
ab362080 |
568 | solver_place(usage, x, y, n); |
569 | return +1; |
3ddae0ff |
570 | } |
ab362080 |
571 | } else if (m == 0) { |
572 | #ifdef STANDALONE_SOLVER |
573 | if (solver_show_working) { |
ab362080 |
574 | va_list ap; |
fdb3b29a |
575 | printf("%*s", solver_recurse_depth*4, ""); |
ab362080 |
576 | va_start(ap, fmt); |
577 | vprintf(fmt, ap); |
578 | va_end(ap); |
579 | printf(":\n%*s no possibilities available\n", |
580 | solver_recurse_depth*4, ""); |
581 | } |
582 | #endif |
583 | return -1; |
1d8e8ad8 |
584 | } |
585 | |
ab362080 |
586 | return 0; |
1d8e8ad8 |
587 | } |
588 | |
ab362080 |
589 | static int solver_intersect(struct solver_usage *usage, |
7c568a48 |
590 | int start1, int step1, int start2, int step2 |
591 | #ifdef STANDALONE_SOLVER |
592 | , char *fmt, ... |
593 | #endif |
594 | ) |
595 | { |
596 | int c = usage->c, r = usage->r, cr = c*r; |
597 | int ret, i; |
598 | |
599 | /* |
600 | * Loop over the first domain and see if there's any set bit |
601 | * not also in the second. |
602 | */ |
603 | for (i = 0; i < cr; i++) { |
604 | int p = start1+i*step1; |
605 | if (usage->cube[p] && |
606 | !(p >= start2 && p < start2+cr*step2 && |
607 | (p - start2) % step2 == 0)) |
ab362080 |
608 | return 0; /* there is, so we can't deduce */ |
7c568a48 |
609 | } |
610 | |
611 | /* |
612 | * We have determined that all set bits in the first domain are |
613 | * within its overlap with the second. So loop over the second |
614 | * domain and remove all set bits that aren't also in that |
ab362080 |
615 | * overlap; return +1 iff we actually _did_ anything. |
7c568a48 |
616 | */ |
ab362080 |
617 | ret = 0; |
7c568a48 |
618 | for (i = 0; i < cr; i++) { |
619 | int p = start2+i*step2; |
620 | if (usage->cube[p] && |
621 | !(p >= start1 && p < start1+cr*step1 && (p - start1) % step1 == 0)) |
622 | { |
623 | #ifdef STANDALONE_SOLVER |
624 | if (solver_show_working) { |
625 | int px, py, pn; |
626 | |
627 | if (!ret) { |
628 | va_list ap; |
fdb3b29a |
629 | printf("%*s", solver_recurse_depth*4, ""); |
7c568a48 |
630 | va_start(ap, fmt); |
631 | vprintf(fmt, ap); |
632 | va_end(ap); |
633 | printf(":\n"); |
634 | } |
635 | |
636 | pn = 1 + p % cr; |
637 | py = p / cr; |
638 | px = py / cr; |
639 | py %= cr; |
640 | |
ab362080 |
641 | printf("%*s ruling out %d at (%d,%d)\n", |
642 | solver_recurse_depth*4, "", pn, 1+px, 1+YUNTRANS(py)); |
7c568a48 |
643 | } |
644 | #endif |
ab362080 |
645 | ret = +1; /* we did something */ |
7c568a48 |
646 | usage->cube[p] = 0; |
647 | } |
648 | } |
649 | |
650 | return ret; |
651 | } |
652 | |
ab362080 |
653 | struct solver_scratch { |
ab53eb64 |
654 | unsigned char *grid, *rowidx, *colidx, *set; |
44bf5f6f |
655 | int *neighbours, *bfsqueue; |
656 | #ifdef STANDALONE_SOLVER |
657 | int *bfsprev; |
658 | #endif |
ab53eb64 |
659 | }; |
660 | |
ab362080 |
661 | static int solver_set(struct solver_usage *usage, |
662 | struct solver_scratch *scratch, |
7c568a48 |
663 | int start, int step1, int step2 |
664 | #ifdef STANDALONE_SOLVER |
665 | , char *fmt, ... |
666 | #endif |
667 | ) |
668 | { |
669 | int c = usage->c, r = usage->r, cr = c*r; |
670 | int i, j, n, count; |
ab53eb64 |
671 | unsigned char *grid = scratch->grid; |
672 | unsigned char *rowidx = scratch->rowidx; |
673 | unsigned char *colidx = scratch->colidx; |
674 | unsigned char *set = scratch->set; |
7c568a48 |
675 | |
676 | /* |
677 | * We are passed a cr-by-cr matrix of booleans. Our first job |
678 | * is to winnow it by finding any definite placements - i.e. |
679 | * any row with a solitary 1 - and discarding that row and the |
680 | * column containing the 1. |
681 | */ |
682 | memset(rowidx, TRUE, cr); |
683 | memset(colidx, TRUE, cr); |
684 | for (i = 0; i < cr; i++) { |
685 | int count = 0, first = -1; |
686 | for (j = 0; j < cr; j++) |
687 | if (usage->cube[start+i*step1+j*step2]) |
688 | first = j, count++; |
ab362080 |
689 | |
690 | /* |
691 | * If count == 0, then there's a row with no 1s at all and |
692 | * the puzzle is internally inconsistent. However, we ought |
693 | * to have caught this already during the simpler reasoning |
694 | * methods, so we can safely fail an assertion if we reach |
695 | * this point here. |
696 | */ |
697 | assert(count > 0); |
7c568a48 |
698 | if (count == 1) |
699 | rowidx[i] = colidx[first] = FALSE; |
700 | } |
701 | |
702 | /* |
703 | * Convert each of rowidx/colidx from a list of 0s and 1s to a |
704 | * list of the indices of the 1s. |
705 | */ |
706 | for (i = j = 0; i < cr; i++) |
707 | if (rowidx[i]) |
708 | rowidx[j++] = i; |
709 | n = j; |
710 | for (i = j = 0; i < cr; i++) |
711 | if (colidx[i]) |
712 | colidx[j++] = i; |
713 | assert(n == j); |
714 | |
715 | /* |
716 | * And create the smaller matrix. |
717 | */ |
718 | for (i = 0; i < n; i++) |
719 | for (j = 0; j < n; j++) |
720 | grid[i*cr+j] = usage->cube[start+rowidx[i]*step1+colidx[j]*step2]; |
721 | |
722 | /* |
723 | * Having done that, we now have a matrix in which every row |
724 | * has at least two 1s in. Now we search to see if we can find |
725 | * a rectangle of zeroes (in the set-theoretic sense of |
726 | * `rectangle', i.e. a subset of rows crossed with a subset of |
727 | * columns) whose width and height add up to n. |
728 | */ |
729 | |
730 | memset(set, 0, n); |
731 | count = 0; |
732 | while (1) { |
733 | /* |
734 | * We have a candidate set. If its size is <=1 or >=n-1 |
735 | * then we move on immediately. |
736 | */ |
737 | if (count > 1 && count < n-1) { |
738 | /* |
739 | * The number of rows we need is n-count. See if we can |
740 | * find that many rows which each have a zero in all |
741 | * the positions listed in `set'. |
742 | */ |
743 | int rows = 0; |
744 | for (i = 0; i < n; i++) { |
745 | int ok = TRUE; |
746 | for (j = 0; j < n; j++) |
747 | if (set[j] && grid[i*cr+j]) { |
748 | ok = FALSE; |
749 | break; |
750 | } |
751 | if (ok) |
752 | rows++; |
753 | } |
754 | |
755 | /* |
756 | * We expect never to be able to get _more_ than |
757 | * n-count suitable rows: this would imply that (for |
758 | * example) there are four numbers which between them |
759 | * have at most three possible positions, and hence it |
760 | * indicates a faulty deduction before this point or |
761 | * even a bogus clue. |
762 | */ |
ab362080 |
763 | if (rows > n - count) { |
764 | #ifdef STANDALONE_SOLVER |
765 | if (solver_show_working) { |
fdb3b29a |
766 | va_list ap; |
ab362080 |
767 | printf("%*s", solver_recurse_depth*4, |
768 | ""); |
ab362080 |
769 | va_start(ap, fmt); |
770 | vprintf(fmt, ap); |
771 | va_end(ap); |
772 | printf(":\n%*s contradiction reached\n", |
773 | solver_recurse_depth*4, ""); |
774 | } |
775 | #endif |
776 | return -1; |
777 | } |
778 | |
7c568a48 |
779 | if (rows >= n - count) { |
780 | int progress = FALSE; |
781 | |
782 | /* |
783 | * We've got one! Now, for each row which _doesn't_ |
784 | * satisfy the criterion, eliminate all its set |
785 | * bits in the positions _not_ listed in `set'. |
ab362080 |
786 | * Return +1 (meaning progress has been made) if we |
787 | * successfully eliminated anything at all. |
7c568a48 |
788 | * |
789 | * This involves referring back through |
790 | * rowidx/colidx in order to work out which actual |
791 | * positions in the cube to meddle with. |
792 | */ |
793 | for (i = 0; i < n; i++) { |
794 | int ok = TRUE; |
795 | for (j = 0; j < n; j++) |
796 | if (set[j] && grid[i*cr+j]) { |
797 | ok = FALSE; |
798 | break; |
799 | } |
800 | if (!ok) { |
801 | for (j = 0; j < n; j++) |
802 | if (!set[j] && grid[i*cr+j]) { |
803 | int fpos = (start+rowidx[i]*step1+ |
804 | colidx[j]*step2); |
805 | #ifdef STANDALONE_SOLVER |
806 | if (solver_show_working) { |
807 | int px, py, pn; |
ab362080 |
808 | |
7c568a48 |
809 | if (!progress) { |
fdb3b29a |
810 | va_list ap; |
ab362080 |
811 | printf("%*s", solver_recurse_depth*4, |
812 | ""); |
7c568a48 |
813 | va_start(ap, fmt); |
814 | vprintf(fmt, ap); |
815 | va_end(ap); |
816 | printf(":\n"); |
817 | } |
818 | |
819 | pn = 1 + fpos % cr; |
820 | py = fpos / cr; |
821 | px = py / cr; |
822 | py %= cr; |
823 | |
ab362080 |
824 | printf("%*s ruling out %d at (%d,%d)\n", |
825 | solver_recurse_depth*4, "", |
7c568a48 |
826 | pn, 1+px, 1+YUNTRANS(py)); |
827 | } |
828 | #endif |
829 | progress = TRUE; |
830 | usage->cube[fpos] = FALSE; |
831 | } |
832 | } |
833 | } |
834 | |
835 | if (progress) { |
ab362080 |
836 | return +1; |
7c568a48 |
837 | } |
838 | } |
839 | } |
840 | |
841 | /* |
842 | * Binary increment: change the rightmost 0 to a 1, and |
843 | * change all 1s to the right of it to 0s. |
844 | */ |
845 | i = n; |
846 | while (i > 0 && set[i-1]) |
847 | set[--i] = 0, count--; |
848 | if (i > 0) |
849 | set[--i] = 1, count++; |
850 | else |
851 | break; /* done */ |
852 | } |
853 | |
ab362080 |
854 | return 0; |
7c568a48 |
855 | } |
856 | |
13c4d60d |
857 | /* |
858 | * Try to find a number in the possible set of (x1,y1) which can be |
859 | * ruled out because it would leave no possibilities for (x2,y2). |
860 | */ |
861 | static int solver_mne(struct solver_usage *usage, |
862 | struct solver_scratch *scratch, |
863 | int x1, int y1, int x2, int y2) |
864 | { |
865 | int c = usage->c, r = usage->r, cr = c*r; |
866 | int *nb[2]; |
867 | unsigned char *set = scratch->set; |
868 | unsigned char *numbers = scratch->rowidx; |
869 | unsigned char *numbersleft = scratch->colidx; |
870 | int nnb, count; |
871 | int i, j, n, nbi; |
872 | |
44bf5f6f |
873 | nb[0] = scratch->neighbours; |
874 | nb[1] = scratch->neighbours + cr; |
13c4d60d |
875 | |
876 | /* |
877 | * First, work out the mutual neighbour squares of the two. We |
878 | * can assert that they're not actually in the same block, |
879 | * which leaves two possibilities: they're in different block |
880 | * rows _and_ different block columns (thus their mutual |
881 | * neighbours are precisely the other two corners of the |
882 | * rectangle), or they're in the same row (WLOG) and different |
883 | * columns, in which case their mutual neighbours are the |
884 | * column of each block aligned with the other square. |
885 | * |
886 | * We divide the mutual neighbours into two separate subsets |
887 | * nb[0] and nb[1]; squares in the same subset are not only |
888 | * adjacent to both our key squares, but are also always |
889 | * adjacent to one another. |
890 | */ |
891 | if (x1 / r != x2 / r && y1 % r != y2 % r) { |
892 | /* Corners of the rectangle. */ |
893 | nnb = 1; |
894 | nb[0][0] = cubepos(x2, y1, 1); |
895 | nb[1][0] = cubepos(x1, y2, 1); |
896 | } else if (x1 / r != x2 / r) { |
897 | /* Same row of blocks; different blocks within that row. */ |
898 | int x1b = x1 - (x1 % r); |
899 | int x2b = x2 - (x2 % r); |
900 | |
901 | nnb = r; |
902 | for (i = 0; i < r; i++) { |
903 | nb[0][i] = cubepos(x2b+i, y1, 1); |
904 | nb[1][i] = cubepos(x1b+i, y2, 1); |
905 | } |
906 | } else { |
907 | /* Same column of blocks; different blocks within that column. */ |
908 | int y1b = y1 % r; |
909 | int y2b = y2 % r; |
910 | |
911 | assert(y1 % r != y2 % r); |
912 | |
913 | nnb = c; |
914 | for (i = 0; i < c; i++) { |
915 | nb[0][i] = cubepos(x2, y1b+i*r, 1); |
916 | nb[1][i] = cubepos(x1, y2b+i*r, 1); |
917 | } |
918 | } |
919 | |
920 | /* |
921 | * Right. Now loop over each possible number. |
922 | */ |
923 | for (n = 1; n <= cr; n++) { |
924 | if (!cube(x1, y1, n)) |
925 | continue; |
926 | for (j = 0; j < cr; j++) |
927 | numbersleft[j] = cube(x2, y2, j+1); |
928 | |
929 | /* |
930 | * Go over every possible subset of each neighbour list, |
931 | * and see if its union of possible numbers minus n has the |
932 | * same size as the subset. If so, add the numbers in that |
933 | * subset to the set of things which would be ruled out |
934 | * from (x2,y2) if n were placed at (x1,y1). |
935 | */ |
936 | memset(set, 0, nnb); |
937 | count = 0; |
938 | while (1) { |
939 | /* |
940 | * Binary increment: change the rightmost 0 to a 1, and |
941 | * change all 1s to the right of it to 0s. |
942 | */ |
943 | i = nnb; |
944 | while (i > 0 && set[i-1]) |
945 | set[--i] = 0, count--; |
946 | if (i > 0) |
947 | set[--i] = 1, count++; |
948 | else |
949 | break; /* done */ |
950 | |
951 | /* |
952 | * Examine this subset of each neighbour set. |
953 | */ |
954 | for (nbi = 0; nbi < 2; nbi++) { |
955 | int *nbs = nb[nbi]; |
956 | |
957 | memset(numbers, 0, cr); |
958 | |
959 | for (i = 0; i < nnb; i++) |
960 | if (set[i]) |
961 | for (j = 0; j < cr; j++) |
962 | if (j != n-1 && usage->cube[nbs[i] + j]) |
963 | numbers[j] = 1; |
964 | |
965 | for (i = j = 0; j < cr; j++) |
966 | i += numbers[j]; |
967 | |
968 | if (i == count) { |
969 | /* |
970 | * Got one. This subset of nbs, in the absence |
971 | * of n, would definitely contain all the |
972 | * numbers listed in `numbers'. Rule them out |
973 | * of `numbersleft'. |
974 | */ |
975 | for (j = 0; j < cr; j++) |
976 | if (numbers[j]) |
977 | numbersleft[j] = 0; |
978 | } |
979 | } |
980 | } |
981 | |
982 | /* |
983 | * If we've got nothing left in `numbersleft', we have a |
984 | * successful mutual neighbour elimination. |
985 | */ |
986 | for (j = 0; j < cr; j++) |
987 | if (numbersleft[j]) |
988 | break; |
989 | |
990 | if (j == cr) { |
991 | #ifdef STANDALONE_SOLVER |
992 | if (solver_show_working) { |
993 | printf("%*smutual neighbour elimination, (%d,%d) vs (%d,%d):\n", |
994 | solver_recurse_depth*4, "", |
995 | 1+x1, 1+YUNTRANS(y1), 1+x2, 1+YUNTRANS(y2)); |
996 | printf("%*s ruling out %d at (%d,%d)\n", |
997 | solver_recurse_depth*4, "", |
998 | n, 1+x1, 1+YUNTRANS(y1)); |
999 | } |
1000 | #endif |
1001 | cube(x1, y1, n) = FALSE; |
1002 | return +1; |
1003 | } |
1004 | } |
1005 | |
1006 | return 0; /* nothing found */ |
1007 | } |
1008 | |
44bf5f6f |
1009 | /* |
1010 | * Look for forcing chains. A forcing chain is a path of |
1011 | * pairwise-exclusive squares (i.e. each pair of adjacent squares |
1012 | * in the path are in the same row, column or block) with the |
1013 | * following properties: |
1014 | * |
1015 | * (a) Each square on the path has precisely two possible numbers. |
1016 | * |
1017 | * (b) Each pair of squares which are adjacent on the path share |
1018 | * at least one possible number in common. |
1019 | * |
1020 | * (c) Each square in the middle of the path shares _both_ of its |
1021 | * numbers with at least one of its neighbours (not the same |
1022 | * one with both neighbours). |
1023 | * |
1024 | * These together imply that at least one of the possible number |
1025 | * choices at one end of the path forces _all_ the rest of the |
1026 | * numbers along the path. In order to make real use of this, we |
1027 | * need further properties: |
1028 | * |
1029 | * (c) Ruling out some number N from the square at one end |
1030 | * of the path forces the square at the other end to |
1031 | * take number N. |
1032 | * |
1033 | * (d) The two end squares are both in line with some third |
1034 | * square. |
1035 | * |
1036 | * (e) That third square currently has N as a possibility. |
1037 | * |
1038 | * If we can find all of that lot, we can deduce that at least one |
1039 | * of the two ends of the forcing chain has number N, and that |
1040 | * therefore the mutually adjacent third square does not. |
1041 | * |
1042 | * To find forcing chains, we're going to start a bfs at each |
1043 | * suitable square, once for each of its two possible numbers. |
1044 | */ |
1045 | static int solver_forcing(struct solver_usage *usage, |
1046 | struct solver_scratch *scratch) |
1047 | { |
1048 | int c = usage->c, r = usage->r, cr = c*r; |
1049 | int *bfsqueue = scratch->bfsqueue; |
1050 | #ifdef STANDALONE_SOLVER |
1051 | int *bfsprev = scratch->bfsprev; |
1052 | #endif |
1053 | unsigned char *number = scratch->grid; |
1054 | int *neighbours = scratch->neighbours; |
1055 | int x, y; |
1056 | |
1057 | for (y = 0; y < cr; y++) |
1058 | for (x = 0; x < cr; x++) { |
1059 | int count, t, n; |
1060 | |
1061 | /* |
1062 | * If this square doesn't have exactly two candidate |
1063 | * numbers, don't try it. |
1064 | * |
1065 | * In this loop we also sum the candidate numbers, |
1066 | * which is a nasty hack to allow us to quickly find |
1067 | * `the other one' (since we will shortly know there |
1068 | * are exactly two). |
1069 | */ |
1070 | for (count = t = 0, n = 1; n <= cr; n++) |
1071 | if (cube(x, y, n)) |
1072 | count++, t += n; |
1073 | if (count != 2) |
1074 | continue; |
1075 | |
1076 | /* |
1077 | * Now attempt a bfs for each candidate. |
1078 | */ |
1079 | for (n = 1; n <= cr; n++) |
1080 | if (cube(x, y, n)) { |
1081 | int orign, currn, head, tail; |
1082 | |
1083 | /* |
1084 | * Begin a bfs. |
1085 | */ |
1086 | orign = n; |
1087 | |
1088 | memset(number, cr+1, cr*cr); |
1089 | head = tail = 0; |
1090 | bfsqueue[tail++] = y*cr+x; |
1091 | #ifdef STANDALONE_SOLVER |
1092 | bfsprev[y*cr+x] = -1; |
1093 | #endif |
1094 | number[y*cr+x] = t - n; |
1095 | |
1096 | while (head < tail) { |
1097 | int xx, yy, nneighbours, xt, yt, xblk, i; |
1098 | |
1099 | xx = bfsqueue[head++]; |
1100 | yy = xx / cr; |
1101 | xx %= cr; |
1102 | |
1103 | currn = number[yy*cr+xx]; |
1104 | |
1105 | /* |
1106 | * Find neighbours of yy,xx. |
1107 | */ |
1108 | nneighbours = 0; |
1109 | for (yt = 0; yt < cr; yt++) |
1110 | neighbours[nneighbours++] = yt*cr+xx; |
1111 | for (xt = 0; xt < cr; xt++) |
1112 | neighbours[nneighbours++] = yy*cr+xt; |
1113 | xblk = xx - (xx % r); |
1114 | for (yt = yy % r; yt < cr; yt += r) |
1115 | for (xt = xblk; xt < xblk+r; xt++) |
1116 | neighbours[nneighbours++] = yt*cr+xt; |
1117 | |
1118 | /* |
1119 | * Try visiting each of those neighbours. |
1120 | */ |
1121 | for (i = 0; i < nneighbours; i++) { |
1122 | int cc, tt, nn; |
1123 | |
1124 | xt = neighbours[i] % cr; |
1125 | yt = neighbours[i] / cr; |
1126 | |
1127 | /* |
1128 | * We need this square to not be |
1129 | * already visited, and to include |
1130 | * currn as a possible number. |
1131 | */ |
1132 | if (number[yt*cr+xt] <= cr) |
1133 | continue; |
1134 | if (!cube(xt, yt, currn)) |
1135 | continue; |
1136 | |
1137 | /* |
1138 | * Don't visit _this_ square a second |
1139 | * time! |
1140 | */ |
1141 | if (xt == xx && yt == yy) |
1142 | continue; |
1143 | |
1144 | /* |
1145 | * To continue with the bfs, we need |
1146 | * this square to have exactly two |
1147 | * possible numbers. |
1148 | */ |
1149 | for (cc = tt = 0, nn = 1; nn <= cr; nn++) |
1150 | if (cube(xt, yt, nn)) |
1151 | cc++, tt += nn; |
1152 | if (cc == 2) { |
1153 | bfsqueue[tail++] = yt*cr+xt; |
1154 | #ifdef STANDALONE_SOLVER |
1155 | bfsprev[yt*cr+xt] = yy*cr+xx; |
1156 | #endif |
1157 | number[yt*cr+xt] = tt - currn; |
1158 | } |
1159 | |
1160 | /* |
1161 | * One other possibility is that this |
1162 | * might be the square in which we can |
1163 | * make a real deduction: if it's |
1164 | * adjacent to x,y, and currn is equal |
1165 | * to the original number we ruled out. |
1166 | */ |
1167 | if (currn == orign && |
1168 | (xt == x || yt == y || |
1169 | (xt / r == x / r && yt % r == y % r))) { |
1170 | #ifdef STANDALONE_SOLVER |
1171 | if (solver_show_working) { |
1172 | char *sep = ""; |
1173 | int xl, yl; |
1174 | printf("%*sforcing chain, %d at ends of ", |
1175 | solver_recurse_depth*4, "", orign); |
1176 | xl = xx; |
1177 | yl = yy; |
1178 | while (1) { |
1179 | printf("%s(%d,%d)", sep, 1+xl, |
1180 | 1+YUNTRANS(yl)); |
1181 | xl = bfsprev[yl*cr+xl]; |
1182 | if (xl < 0) |
1183 | break; |
1184 | yl = xl / cr; |
1185 | xl %= cr; |
1186 | sep = "-"; |
1187 | } |
1188 | printf("\n%*s ruling out %d at (%d,%d)\n", |
1189 | solver_recurse_depth*4, "", |
1190 | orign, 1+xt, 1+YUNTRANS(yt)); |
1191 | } |
1192 | #endif |
1193 | cube(xt, yt, orign) = FALSE; |
1194 | return 1; |
1195 | } |
1196 | } |
1197 | } |
1198 | } |
1199 | } |
1200 | |
1201 | return 0; |
1202 | } |
1203 | |
ab362080 |
1204 | static struct solver_scratch *solver_new_scratch(struct solver_usage *usage) |
ab53eb64 |
1205 | { |
ab362080 |
1206 | struct solver_scratch *scratch = snew(struct solver_scratch); |
ab53eb64 |
1207 | int cr = usage->cr; |
1208 | scratch->grid = snewn(cr*cr, unsigned char); |
1209 | scratch->rowidx = snewn(cr, unsigned char); |
1210 | scratch->colidx = snewn(cr, unsigned char); |
1211 | scratch->set = snewn(cr, unsigned char); |
44bf5f6f |
1212 | scratch->neighbours = snewn(3*cr, int); |
1213 | scratch->bfsqueue = snewn(cr*cr, int); |
1214 | #ifdef STANDALONE_SOLVER |
1215 | scratch->bfsprev = snewn(cr*cr, int); |
1216 | #endif |
ab53eb64 |
1217 | return scratch; |
1218 | } |
1219 | |
ab362080 |
1220 | static void solver_free_scratch(struct solver_scratch *scratch) |
ab53eb64 |
1221 | { |
44bf5f6f |
1222 | #ifdef STANDALONE_SOLVER |
1223 | sfree(scratch->bfsprev); |
1224 | #endif |
1225 | sfree(scratch->bfsqueue); |
1226 | sfree(scratch->neighbours); |
ab53eb64 |
1227 | sfree(scratch->set); |
1228 | sfree(scratch->colidx); |
1229 | sfree(scratch->rowidx); |
1230 | sfree(scratch->grid); |
1231 | sfree(scratch); |
1232 | } |
1233 | |
947a07d6 |
1234 | static int solver(int c, int r, digit *grid, int maxdiff) |
1d8e8ad8 |
1235 | { |
ab362080 |
1236 | struct solver_usage *usage; |
1237 | struct solver_scratch *scratch; |
1d8e8ad8 |
1238 | int cr = c*r; |
13c4d60d |
1239 | int x, y, x2, y2, n, ret; |
7c568a48 |
1240 | int diff = DIFF_BLOCK; |
1d8e8ad8 |
1241 | |
1242 | /* |
1243 | * Set up a usage structure as a clean slate (everything |
1244 | * possible). |
1245 | */ |
ab362080 |
1246 | usage = snew(struct solver_usage); |
1d8e8ad8 |
1247 | usage->c = c; |
1248 | usage->r = r; |
1249 | usage->cr = cr; |
1250 | usage->cube = snewn(cr*cr*cr, unsigned char); |
1251 | usage->grid = grid; /* write straight back to the input */ |
1252 | memset(usage->cube, TRUE, cr*cr*cr); |
1253 | |
1254 | usage->row = snewn(cr * cr, unsigned char); |
1255 | usage->col = snewn(cr * cr, unsigned char); |
1256 | usage->blk = snewn(cr * cr, unsigned char); |
1257 | memset(usage->row, FALSE, cr * cr); |
1258 | memset(usage->col, FALSE, cr * cr); |
1259 | memset(usage->blk, FALSE, cr * cr); |
1260 | |
ab362080 |
1261 | scratch = solver_new_scratch(usage); |
ab53eb64 |
1262 | |
1d8e8ad8 |
1263 | /* |
1264 | * Place all the clue numbers we are given. |
1265 | */ |
1266 | for (x = 0; x < cr; x++) |
1267 | for (y = 0; y < cr; y++) |
1268 | if (grid[y*cr+x]) |
ab362080 |
1269 | solver_place(usage, x, YTRANS(y), grid[y*cr+x]); |
1d8e8ad8 |
1270 | |
1271 | /* |
1272 | * Now loop over the grid repeatedly trying all permitted modes |
1273 | * of reasoning. The loop terminates if we complete an |
1274 | * iteration without making any progress; we then return |
1275 | * failure or success depending on whether the grid is full or |
1276 | * not. |
1277 | */ |
1278 | while (1) { |
7c568a48 |
1279 | /* |
1280 | * I'd like to write `continue;' inside each of the |
1281 | * following loops, so that the solver returns here after |
1282 | * making some progress. However, I can't specify that I |
1283 | * want to continue an outer loop rather than the innermost |
1284 | * one, so I'm apologetically resorting to a goto. |
1285 | */ |
3ddae0ff |
1286 | cont: |
1287 | |
1d8e8ad8 |
1288 | /* |
1289 | * Blockwise positional elimination. |
1290 | */ |
4846f788 |
1291 | for (x = 0; x < cr; x += r) |
1d8e8ad8 |
1292 | for (y = 0; y < r; y++) |
1293 | for (n = 1; n <= cr; n++) |
ab362080 |
1294 | if (!usage->blk[(y*c+(x/r))*cr+n-1]) { |
1295 | ret = solver_elim(usage, cubepos(x,y,n), r*cr |
7c568a48 |
1296 | #ifdef STANDALONE_SOLVER |
ab362080 |
1297 | , "positional elimination," |
1298 | " %d in block (%d,%d)", n, 1+x/r, 1+y |
7c568a48 |
1299 | #endif |
ab362080 |
1300 | ); |
1301 | if (ret < 0) { |
1302 | diff = DIFF_IMPOSSIBLE; |
1303 | goto got_result; |
1304 | } else if (ret > 0) { |
1305 | diff = max(diff, DIFF_BLOCK); |
1306 | goto cont; |
1307 | } |
7c568a48 |
1308 | } |
1d8e8ad8 |
1309 | |
ab362080 |
1310 | if (maxdiff <= DIFF_BLOCK) |
1311 | break; |
1312 | |
1d8e8ad8 |
1313 | /* |
1314 | * Row-wise positional elimination. |
1315 | */ |
1316 | for (y = 0; y < cr; y++) |
1317 | for (n = 1; n <= cr; n++) |
ab362080 |
1318 | if (!usage->row[y*cr+n-1]) { |
1319 | ret = solver_elim(usage, cubepos(0,y,n), cr*cr |
7c568a48 |
1320 | #ifdef STANDALONE_SOLVER |
ab362080 |
1321 | , "positional elimination," |
1322 | " %d in row %d", n, 1+YUNTRANS(y) |
7c568a48 |
1323 | #endif |
ab362080 |
1324 | ); |
1325 | if (ret < 0) { |
1326 | diff = DIFF_IMPOSSIBLE; |
1327 | goto got_result; |
1328 | } else if (ret > 0) { |
1329 | diff = max(diff, DIFF_SIMPLE); |
1330 | goto cont; |
1331 | } |
7c568a48 |
1332 | } |
1d8e8ad8 |
1333 | /* |
1334 | * Column-wise positional elimination. |
1335 | */ |
1336 | for (x = 0; x < cr; x++) |
1337 | for (n = 1; n <= cr; n++) |
ab362080 |
1338 | if (!usage->col[x*cr+n-1]) { |
1339 | ret = solver_elim(usage, cubepos(x,0,n), cr |
7c568a48 |
1340 | #ifdef STANDALONE_SOLVER |
ab362080 |
1341 | , "positional elimination," |
1342 | " %d in column %d", n, 1+x |
7c568a48 |
1343 | #endif |
ab362080 |
1344 | ); |
1345 | if (ret < 0) { |
1346 | diff = DIFF_IMPOSSIBLE; |
1347 | goto got_result; |
1348 | } else if (ret > 0) { |
1349 | diff = max(diff, DIFF_SIMPLE); |
1350 | goto cont; |
1351 | } |
7c568a48 |
1352 | } |
1d8e8ad8 |
1353 | |
1354 | /* |
1355 | * Numeric elimination. |
1356 | */ |
1357 | for (x = 0; x < cr; x++) |
1358 | for (y = 0; y < cr; y++) |
ab362080 |
1359 | if (!usage->grid[YUNTRANS(y)*cr+x]) { |
1360 | ret = solver_elim(usage, cubepos(x,y,1), 1 |
7c568a48 |
1361 | #ifdef STANDALONE_SOLVER |
ab362080 |
1362 | , "numeric elimination at (%d,%d)", 1+x, |
1363 | 1+YUNTRANS(y) |
7c568a48 |
1364 | #endif |
ab362080 |
1365 | ); |
1366 | if (ret < 0) { |
1367 | diff = DIFF_IMPOSSIBLE; |
1368 | goto got_result; |
1369 | } else if (ret > 0) { |
1370 | diff = max(diff, DIFF_SIMPLE); |
1371 | goto cont; |
1372 | } |
7c568a48 |
1373 | } |
1374 | |
ab362080 |
1375 | if (maxdiff <= DIFF_SIMPLE) |
1376 | break; |
1377 | |
7c568a48 |
1378 | /* |
1379 | * Intersectional analysis, rows vs blocks. |
1380 | */ |
1381 | for (y = 0; y < cr; y++) |
1382 | for (x = 0; x < cr; x += r) |
1383 | for (n = 1; n <= cr; n++) |
ab362080 |
1384 | /* |
1385 | * solver_intersect() never returns -1. |
1386 | */ |
7c568a48 |
1387 | if (!usage->row[y*cr+n-1] && |
1388 | !usage->blk[((y%r)*c+(x/r))*cr+n-1] && |
ab362080 |
1389 | (solver_intersect(usage, cubepos(0,y,n), cr*cr, |
7c568a48 |
1390 | cubepos(x,y%r,n), r*cr |
1391 | #ifdef STANDALONE_SOLVER |
1392 | , "intersectional analysis," |
ab362080 |
1393 | " %d in row %d vs block (%d,%d)", |
1394 | n, 1+YUNTRANS(y), 1+x/r, 1+y%r |
7c568a48 |
1395 | #endif |
1396 | ) || |
ab362080 |
1397 | solver_intersect(usage, cubepos(x,y%r,n), r*cr, |
7c568a48 |
1398 | cubepos(0,y,n), cr*cr |
1399 | #ifdef STANDALONE_SOLVER |
1400 | , "intersectional analysis," |
ab362080 |
1401 | " %d in block (%d,%d) vs row %d", |
1402 | n, 1+x/r, 1+y%r, 1+YUNTRANS(y) |
7c568a48 |
1403 | #endif |
1404 | ))) { |
1405 | diff = max(diff, DIFF_INTERSECT); |
1406 | goto cont; |
1407 | } |
1408 | |
1409 | /* |
1410 | * Intersectional analysis, columns vs blocks. |
1411 | */ |
1412 | for (x = 0; x < cr; x++) |
1413 | for (y = 0; y < r; y++) |
1414 | for (n = 1; n <= cr; n++) |
1415 | if (!usage->col[x*cr+n-1] && |
1416 | !usage->blk[(y*c+(x/r))*cr+n-1] && |
ab362080 |
1417 | (solver_intersect(usage, cubepos(x,0,n), cr, |
7c568a48 |
1418 | cubepos((x/r)*r,y,n), r*cr |
1419 | #ifdef STANDALONE_SOLVER |
1420 | , "intersectional analysis," |
ab362080 |
1421 | " %d in column %d vs block (%d,%d)", |
1422 | n, 1+x, 1+x/r, 1+y |
7c568a48 |
1423 | #endif |
1424 | ) || |
ab362080 |
1425 | solver_intersect(usage, cubepos((x/r)*r,y,n), r*cr, |
7c568a48 |
1426 | cubepos(x,0,n), cr |
1427 | #ifdef STANDALONE_SOLVER |
1428 | , "intersectional analysis," |
ab362080 |
1429 | " %d in block (%d,%d) vs column %d", |
1430 | n, 1+x/r, 1+y, 1+x |
7c568a48 |
1431 | #endif |
1432 | ))) { |
1433 | diff = max(diff, DIFF_INTERSECT); |
1434 | goto cont; |
1435 | } |
1436 | |
ab362080 |
1437 | if (maxdiff <= DIFF_INTERSECT) |
1438 | break; |
1439 | |
7c568a48 |
1440 | /* |
1441 | * Blockwise set elimination. |
1442 | */ |
1443 | for (x = 0; x < cr; x += r) |
ab362080 |
1444 | for (y = 0; y < r; y++) { |
1445 | ret = solver_set(usage, scratch, cubepos(x,y,1), r*cr, 1 |
7c568a48 |
1446 | #ifdef STANDALONE_SOLVER |
ab362080 |
1447 | , "set elimination, block (%d,%d)", 1+x/r, 1+y |
7c568a48 |
1448 | #endif |
ab362080 |
1449 | ); |
1450 | if (ret < 0) { |
1451 | diff = DIFF_IMPOSSIBLE; |
1452 | goto got_result; |
1453 | } else if (ret > 0) { |
1454 | diff = max(diff, DIFF_SET); |
1455 | goto cont; |
1456 | } |
1457 | } |
7c568a48 |
1458 | |
1459 | /* |
1460 | * Row-wise set elimination. |
1461 | */ |
ab362080 |
1462 | for (y = 0; y < cr; y++) { |
1463 | ret = solver_set(usage, scratch, cubepos(0,y,1), cr*cr, 1 |
7c568a48 |
1464 | #ifdef STANDALONE_SOLVER |
ab362080 |
1465 | , "set elimination, row %d", 1+YUNTRANS(y) |
7c568a48 |
1466 | #endif |
ab362080 |
1467 | ); |
1468 | if (ret < 0) { |
1469 | diff = DIFF_IMPOSSIBLE; |
1470 | goto got_result; |
1471 | } else if (ret > 0) { |
1472 | diff = max(diff, DIFF_SET); |
1473 | goto cont; |
1474 | } |
1475 | } |
7c568a48 |
1476 | |
1477 | /* |
1478 | * Column-wise set elimination. |
1479 | */ |
ab362080 |
1480 | for (x = 0; x < cr; x++) { |
1481 | ret = solver_set(usage, scratch, cubepos(x,0,1), cr, 1 |
7c568a48 |
1482 | #ifdef STANDALONE_SOLVER |
ab362080 |
1483 | , "set elimination, column %d", 1+x |
7c568a48 |
1484 | #endif |
ab362080 |
1485 | ); |
1486 | if (ret < 0) { |
1487 | diff = DIFF_IMPOSSIBLE; |
1488 | goto got_result; |
1489 | } else if (ret > 0) { |
1490 | diff = max(diff, DIFF_SET); |
1491 | goto cont; |
1492 | } |
1493 | } |
1d8e8ad8 |
1494 | |
1495 | /* |
44bf5f6f |
1496 | * Row-vs-column set elimination on a single number. |
1497 | */ |
1498 | for (n = 1; n <= cr; n++) { |
1499 | ret = solver_set(usage, scratch, cubepos(0,0,n), cr*cr, cr |
1500 | #ifdef STANDALONE_SOLVER |
1501 | , "positional set elimination, number %d", n |
1502 | #endif |
1503 | ); |
1504 | if (ret < 0) { |
1505 | diff = DIFF_IMPOSSIBLE; |
1506 | goto got_result; |
1507 | } else if (ret > 0) { |
1508 | diff = max(diff, DIFF_EXTREME); |
1509 | goto cont; |
1510 | } |
1511 | } |
1512 | |
1513 | /* |
13c4d60d |
1514 | * Mutual neighbour elimination. |
1515 | */ |
1516 | for (y = 0; y+1 < cr; y++) { |
1517 | for (x = 0; x+1 < cr; x++) { |
1518 | for (y2 = y+1; y2 < cr; y2++) { |
1519 | for (x2 = x+1; x2 < cr; x2++) { |
1520 | /* |
1521 | * Can't do mutual neighbour elimination |
1522 | * between elements of the same actual |
1523 | * block. |
1524 | */ |
1525 | if (x/r == x2/r && y%r == y2%r) |
1526 | continue; |
1527 | |
1528 | /* |
1529 | * Otherwise, try (x,y) vs (x2,y2) in both |
1530 | * directions, and likewise (x2,y) vs |
1531 | * (x,y2). |
1532 | */ |
1533 | if (!usage->grid[YUNTRANS(y)*cr+x] && |
1534 | !usage->grid[YUNTRANS(y2)*cr+x2] && |
1535 | (solver_mne(usage, scratch, x, y, x2, y2) || |
1536 | solver_mne(usage, scratch, x2, y2, x, y))) { |
44bf5f6f |
1537 | diff = max(diff, DIFF_EXTREME); |
13c4d60d |
1538 | goto cont; |
1539 | } |
1540 | if (!usage->grid[YUNTRANS(y)*cr+x2] && |
1541 | !usage->grid[YUNTRANS(y2)*cr+x] && |
1542 | (solver_mne(usage, scratch, x2, y, x, y2) || |
1543 | solver_mne(usage, scratch, x, y2, x2, y))) { |
44bf5f6f |
1544 | diff = max(diff, DIFF_EXTREME); |
13c4d60d |
1545 | goto cont; |
1546 | } |
1547 | } |
1548 | } |
1549 | } |
1550 | } |
1551 | |
44bf5f6f |
1552 | /* |
1553 | * Forcing chains. |
1554 | */ |
1555 | if (solver_forcing(usage, scratch)) { |
1556 | diff = max(diff, DIFF_EXTREME); |
1557 | goto cont; |
1558 | } |
1559 | |
13c4d60d |
1560 | /* |
1d8e8ad8 |
1561 | * If we reach here, we have made no deductions in this |
1562 | * iteration, so the algorithm terminates. |
1563 | */ |
1564 | break; |
1565 | } |
1566 | |
ab362080 |
1567 | /* |
1568 | * Last chance: if we haven't fully solved the puzzle yet, try |
1569 | * recursing based on guesses for a particular square. We pick |
1570 | * one of the most constrained empty squares we can find, which |
1571 | * has the effect of pruning the search tree as much as |
1572 | * possible. |
1573 | */ |
1574 | if (maxdiff >= DIFF_RECURSIVE) { |
947a07d6 |
1575 | int best, bestcount; |
ab362080 |
1576 | |
1577 | best = -1; |
1578 | bestcount = cr+1; |
ab362080 |
1579 | |
1580 | for (y = 0; y < cr; y++) |
1581 | for (x = 0; x < cr; x++) |
1582 | if (!grid[y*cr+x]) { |
1583 | int count; |
1584 | |
1585 | /* |
1586 | * An unfilled square. Count the number of |
1587 | * possible digits in it. |
1588 | */ |
1589 | count = 0; |
1590 | for (n = 1; n <= cr; n++) |
1591 | if (cube(x,YTRANS(y),n)) |
1592 | count++; |
1593 | |
1594 | /* |
1595 | * We should have found any impossibilities |
1596 | * already, so this can safely be an assert. |
1597 | */ |
1598 | assert(count > 1); |
1599 | |
1600 | if (count < bestcount) { |
1601 | bestcount = count; |
947a07d6 |
1602 | best = y*cr+x; |
ab362080 |
1603 | } |
1604 | } |
1605 | |
1606 | if (best != -1) { |
1607 | int i, j; |
1608 | digit *list, *ingrid, *outgrid; |
1609 | |
1610 | diff = DIFF_IMPOSSIBLE; /* no solution found yet */ |
1611 | |
1612 | /* |
1613 | * Attempt recursion. |
1614 | */ |
1615 | y = best / cr; |
1616 | x = best % cr; |
1617 | |
1618 | list = snewn(cr, digit); |
1619 | ingrid = snewn(cr * cr, digit); |
1620 | outgrid = snewn(cr * cr, digit); |
1621 | memcpy(ingrid, grid, cr * cr); |
1622 | |
1623 | /* Make a list of the possible digits. */ |
1624 | for (j = 0, n = 1; n <= cr; n++) |
1625 | if (cube(x,YTRANS(y),n)) |
1626 | list[j++] = n; |
1627 | |
1628 | #ifdef STANDALONE_SOLVER |
1629 | if (solver_show_working) { |
1630 | char *sep = ""; |
1631 | printf("%*srecursing on (%d,%d) [", |
1632 | solver_recurse_depth*4, "", x, y); |
1633 | for (i = 0; i < j; i++) { |
1634 | printf("%s%d", sep, list[i]); |
1635 | sep = " or "; |
1636 | } |
1637 | printf("]\n"); |
1638 | } |
1639 | #endif |
1640 | |
ab362080 |
1641 | /* |
1642 | * And step along the list, recursing back into the |
1643 | * main solver at every stage. |
1644 | */ |
1645 | for (i = 0; i < j; i++) { |
1646 | int ret; |
1647 | |
1648 | memcpy(outgrid, ingrid, cr * cr); |
1649 | outgrid[y*cr+x] = list[i]; |
1650 | |
1651 | #ifdef STANDALONE_SOLVER |
1652 | if (solver_show_working) |
1653 | printf("%*sguessing %d at (%d,%d)\n", |
1654 | solver_recurse_depth*4, "", list[i], x, y); |
1655 | solver_recurse_depth++; |
1656 | #endif |
1657 | |
947a07d6 |
1658 | ret = solver(c, r, outgrid, maxdiff); |
ab362080 |
1659 | |
1660 | #ifdef STANDALONE_SOLVER |
1661 | solver_recurse_depth--; |
1662 | if (solver_show_working) { |
1663 | printf("%*sretracting %d at (%d,%d)\n", |
1664 | solver_recurse_depth*4, "", list[i], x, y); |
1665 | } |
1666 | #endif |
1667 | |
1668 | /* |
1669 | * If we have our first solution, copy it into the |
1670 | * grid we will return. |
1671 | */ |
1672 | if (diff == DIFF_IMPOSSIBLE && ret != DIFF_IMPOSSIBLE) |
1673 | memcpy(grid, outgrid, cr*cr); |
1674 | |
1675 | if (ret == DIFF_AMBIGUOUS) |
1676 | diff = DIFF_AMBIGUOUS; |
1677 | else if (ret == DIFF_IMPOSSIBLE) |
1678 | /* do not change our return value */; |
1679 | else { |
1680 | /* the recursion turned up exactly one solution */ |
1681 | if (diff == DIFF_IMPOSSIBLE) |
1682 | diff = DIFF_RECURSIVE; |
1683 | else |
1684 | diff = DIFF_AMBIGUOUS; |
1685 | } |
1686 | |
1687 | /* |
1688 | * As soon as we've found more than one solution, |
1689 | * give up immediately. |
1690 | */ |
1691 | if (diff == DIFF_AMBIGUOUS) |
1692 | break; |
1693 | } |
1694 | |
1695 | sfree(outgrid); |
1696 | sfree(ingrid); |
1697 | sfree(list); |
1698 | } |
1699 | |
1700 | } else { |
1701 | /* |
1702 | * We're forbidden to use recursion, so we just see whether |
1703 | * our grid is fully solved, and return DIFF_IMPOSSIBLE |
1704 | * otherwise. |
1705 | */ |
1706 | for (y = 0; y < cr; y++) |
1707 | for (x = 0; x < cr; x++) |
1708 | if (!grid[y*cr+x]) |
1709 | diff = DIFF_IMPOSSIBLE; |
1710 | } |
1711 | |
1712 | got_result:; |
1713 | |
1714 | #ifdef STANDALONE_SOLVER |
1715 | if (solver_show_working) |
1716 | printf("%*s%s found\n", |
1717 | solver_recurse_depth*4, "", |
1718 | diff == DIFF_IMPOSSIBLE ? "no solution" : |
1719 | diff == DIFF_AMBIGUOUS ? "multiple solutions" : |
1720 | "one solution"); |
1721 | #endif |
ab53eb64 |
1722 | |
1d8e8ad8 |
1723 | sfree(usage->cube); |
1724 | sfree(usage->row); |
1725 | sfree(usage->col); |
1726 | sfree(usage->blk); |
1727 | sfree(usage); |
1728 | |
ab362080 |
1729 | solver_free_scratch(scratch); |
1730 | |
7c568a48 |
1731 | return diff; |
1d8e8ad8 |
1732 | } |
1733 | |
1734 | /* ---------------------------------------------------------------------- |
ab362080 |
1735 | * End of solver code. |
1736 | */ |
1737 | |
1738 | /* ---------------------------------------------------------------------- |
1739 | * Solo filled-grid generator. |
1740 | * |
1741 | * This grid generator works by essentially trying to solve a grid |
1742 | * starting from no clues, and not worrying that there's more than |
1743 | * one possible solution. Unfortunately, it isn't computationally |
1744 | * feasible to do this by calling the above solver with an empty |
1745 | * grid, because that one needs to allocate a lot of scratch space |
1746 | * at every recursion level. Instead, I have a much simpler |
1747 | * algorithm which I shamelessly copied from a Python solver |
1748 | * written by Andrew Wilkinson (which is GPLed, but I've reused |
1749 | * only ideas and no code). It mostly just does the obvious |
1750 | * recursive thing: pick an empty square, put one of the possible |
1751 | * digits in it, recurse until all squares are filled, backtrack |
1752 | * and change some choices if necessary. |
1753 | * |
1754 | * The clever bit is that every time it chooses which square to |
1755 | * fill in next, it does so by counting the number of _possible_ |
1756 | * numbers that can go in each square, and it prioritises so that |
1757 | * it picks a square with the _lowest_ number of possibilities. The |
1758 | * idea is that filling in lots of the obvious bits (particularly |
1759 | * any squares with only one possibility) will cut down on the list |
1760 | * of possibilities for other squares and hence reduce the enormous |
1761 | * search space as much as possible as early as possible. |
1762 | */ |
1763 | |
1764 | /* |
1765 | * Internal data structure used in gridgen to keep track of |
1766 | * progress. |
1767 | */ |
1768 | struct gridgen_coord { int x, y, r; }; |
1769 | struct gridgen_usage { |
1770 | int c, r, cr; /* cr == c*r */ |
1771 | /* grid is a copy of the input grid, modified as we go along */ |
1772 | digit *grid; |
1773 | /* row[y*cr+n-1] TRUE if digit n has been placed in row y */ |
1774 | unsigned char *row; |
1775 | /* col[x*cr+n-1] TRUE if digit n has been placed in row x */ |
1776 | unsigned char *col; |
1777 | /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */ |
1778 | unsigned char *blk; |
1779 | /* This lists all the empty spaces remaining in the grid. */ |
1780 | struct gridgen_coord *spaces; |
1781 | int nspaces; |
1782 | /* If we need randomisation in the solve, this is our random state. */ |
1783 | random_state *rs; |
1784 | }; |
1785 | |
1786 | /* |
1787 | * The real recursive step in the generating function. |
1788 | */ |
1789 | static int gridgen_real(struct gridgen_usage *usage, digit *grid) |
1790 | { |
1791 | int c = usage->c, r = usage->r, cr = usage->cr; |
1792 | int i, j, n, sx, sy, bestm, bestr, ret; |
1793 | int *digits; |
1794 | |
1795 | /* |
1796 | * Firstly, check for completion! If there are no spaces left |
1797 | * in the grid, we have a solution. |
1798 | */ |
1799 | if (usage->nspaces == 0) { |
1800 | memcpy(grid, usage->grid, cr * cr); |
1801 | return TRUE; |
1802 | } |
1803 | |
1804 | /* |
1805 | * Otherwise, there must be at least one space. Find the most |
1806 | * constrained space, using the `r' field as a tie-breaker. |
1807 | */ |
1808 | bestm = cr+1; /* so that any space will beat it */ |
1809 | bestr = 0; |
1810 | i = sx = sy = -1; |
1811 | for (j = 0; j < usage->nspaces; j++) { |
1812 | int x = usage->spaces[j].x, y = usage->spaces[j].y; |
1813 | int m; |
1814 | |
1815 | /* |
1816 | * Find the number of digits that could go in this space. |
1817 | */ |
1818 | m = 0; |
1819 | for (n = 0; n < cr; n++) |
1820 | if (!usage->row[y*cr+n] && !usage->col[x*cr+n] && |
1821 | !usage->blk[((y/c)*c+(x/r))*cr+n]) |
1822 | m++; |
1823 | |
1824 | if (m < bestm || (m == bestm && usage->spaces[j].r < bestr)) { |
1825 | bestm = m; |
1826 | bestr = usage->spaces[j].r; |
1827 | sx = x; |
1828 | sy = y; |
1829 | i = j; |
1830 | } |
1831 | } |
1832 | |
1833 | /* |
1834 | * Swap that square into the final place in the spaces array, |
1835 | * so that decrementing nspaces will remove it from the list. |
1836 | */ |
1837 | if (i != usage->nspaces-1) { |
1838 | struct gridgen_coord t; |
1839 | t = usage->spaces[usage->nspaces-1]; |
1840 | usage->spaces[usage->nspaces-1] = usage->spaces[i]; |
1841 | usage->spaces[i] = t; |
1842 | } |
1843 | |
1844 | /* |
1845 | * Now we've decided which square to start our recursion at, |
1846 | * simply go through all possible values, shuffling them |
1847 | * randomly first if necessary. |
1848 | */ |
1849 | digits = snewn(bestm, int); |
1850 | j = 0; |
1851 | for (n = 0; n < cr; n++) |
1852 | if (!usage->row[sy*cr+n] && !usage->col[sx*cr+n] && |
1853 | !usage->blk[((sy/c)*c+(sx/r))*cr+n]) { |
1854 | digits[j++] = n+1; |
1855 | } |
1856 | |
947a07d6 |
1857 | if (usage->rs) |
1858 | shuffle(digits, j, sizeof(*digits), usage->rs); |
ab362080 |
1859 | |
1860 | /* And finally, go through the digit list and actually recurse. */ |
1861 | ret = FALSE; |
1862 | for (i = 0; i < j; i++) { |
1863 | n = digits[i]; |
1864 | |
1865 | /* Update the usage structure to reflect the placing of this digit. */ |
1866 | usage->row[sy*cr+n-1] = usage->col[sx*cr+n-1] = |
1867 | usage->blk[((sy/c)*c+(sx/r))*cr+n-1] = TRUE; |
1868 | usage->grid[sy*cr+sx] = n; |
1869 | usage->nspaces--; |
1870 | |
1871 | /* Call the solver recursively. Stop when we find a solution. */ |
1872 | if (gridgen_real(usage, grid)) |
1873 | ret = TRUE; |
1874 | |
1875 | /* Revert the usage structure. */ |
1876 | usage->row[sy*cr+n-1] = usage->col[sx*cr+n-1] = |
1877 | usage->blk[((sy/c)*c+(sx/r))*cr+n-1] = FALSE; |
1878 | usage->grid[sy*cr+sx] = 0; |
1879 | usage->nspaces++; |
1880 | |
1881 | if (ret) |
1882 | break; |
1883 | } |
1884 | |
1885 | sfree(digits); |
1886 | return ret; |
1887 | } |
1888 | |
1889 | /* |
1890 | * Entry point to generator. You give it dimensions and a starting |
1891 | * grid, which is simply an array of cr*cr digits. |
1892 | */ |
1893 | static void gridgen(int c, int r, digit *grid, random_state *rs) |
1894 | { |
1895 | struct gridgen_usage *usage; |
1896 | int x, y, cr = c*r; |
1897 | |
1898 | /* |
1899 | * Clear the grid to start with. |
1900 | */ |
1901 | memset(grid, 0, cr*cr); |
1902 | |
1903 | /* |
1904 | * Create a gridgen_usage structure. |
1905 | */ |
1906 | usage = snew(struct gridgen_usage); |
1907 | |
1908 | usage->c = c; |
1909 | usage->r = r; |
1910 | usage->cr = cr; |
1911 | |
1912 | usage->grid = snewn(cr * cr, digit); |
1913 | memcpy(usage->grid, grid, cr * cr); |
1914 | |
1915 | usage->row = snewn(cr * cr, unsigned char); |
1916 | usage->col = snewn(cr * cr, unsigned char); |
1917 | usage->blk = snewn(cr * cr, unsigned char); |
1918 | memset(usage->row, FALSE, cr * cr); |
1919 | memset(usage->col, FALSE, cr * cr); |
1920 | memset(usage->blk, FALSE, cr * cr); |
1921 | |
1922 | usage->spaces = snewn(cr * cr, struct gridgen_coord); |
1923 | usage->nspaces = 0; |
1924 | |
1925 | usage->rs = rs; |
1926 | |
1927 | /* |
1928 | * Initialise the list of grid spaces. |
1929 | */ |
1930 | for (y = 0; y < cr; y++) { |
1931 | for (x = 0; x < cr; x++) { |
1932 | usage->spaces[usage->nspaces].x = x; |
1933 | usage->spaces[usage->nspaces].y = y; |
1934 | usage->spaces[usage->nspaces].r = random_bits(rs, 31); |
1935 | usage->nspaces++; |
1936 | } |
1937 | } |
1938 | |
1939 | /* |
1940 | * Run the real generator function. |
1941 | */ |
1942 | gridgen_real(usage, grid); |
1943 | |
1944 | /* |
1945 | * Clean up the usage structure now we have our answer. |
1946 | */ |
1947 | sfree(usage->spaces); |
1948 | sfree(usage->blk); |
1949 | sfree(usage->col); |
1950 | sfree(usage->row); |
1951 | sfree(usage->grid); |
1952 | sfree(usage); |
1953 | } |
1954 | |
1955 | /* ---------------------------------------------------------------------- |
1956 | * End of grid generator code. |
1d8e8ad8 |
1957 | */ |
1958 | |
1959 | /* |
1960 | * Check whether a grid contains a valid complete puzzle. |
1961 | */ |
1962 | static int check_valid(int c, int r, digit *grid) |
1963 | { |
1964 | int cr = c*r; |
1965 | unsigned char *used; |
1966 | int x, y, n; |
1967 | |
1968 | used = snewn(cr, unsigned char); |
1969 | |
1970 | /* |
1971 | * Check that each row contains precisely one of everything. |
1972 | */ |
1973 | for (y = 0; y < cr; y++) { |
1974 | memset(used, FALSE, cr); |
1975 | for (x = 0; x < cr; x++) |
1976 | if (grid[y*cr+x] > 0 && grid[y*cr+x] <= cr) |
1977 | used[grid[y*cr+x]-1] = TRUE; |
1978 | for (n = 0; n < cr; n++) |
1979 | if (!used[n]) { |
1980 | sfree(used); |
1981 | return FALSE; |
1982 | } |
1983 | } |
1984 | |
1985 | /* |
1986 | * Check that each column contains precisely one of everything. |
1987 | */ |
1988 | for (x = 0; x < cr; x++) { |
1989 | memset(used, FALSE, cr); |
1990 | for (y = 0; y < cr; y++) |
1991 | if (grid[y*cr+x] > 0 && grid[y*cr+x] <= cr) |
1992 | used[grid[y*cr+x]-1] = TRUE; |
1993 | for (n = 0; n < cr; n++) |
1994 | if (!used[n]) { |
1995 | sfree(used); |
1996 | return FALSE; |
1997 | } |
1998 | } |
1999 | |
2000 | /* |
2001 | * Check that each block contains precisely one of everything. |
2002 | */ |
2003 | for (x = 0; x < cr; x += r) { |
2004 | for (y = 0; y < cr; y += c) { |
2005 | int xx, yy; |
2006 | memset(used, FALSE, cr); |
2007 | for (xx = x; xx < x+r; xx++) |
2008 | for (yy = 0; yy < y+c; yy++) |
2009 | if (grid[yy*cr+xx] > 0 && grid[yy*cr+xx] <= cr) |
2010 | used[grid[yy*cr+xx]-1] = TRUE; |
2011 | for (n = 0; n < cr; n++) |
2012 | if (!used[n]) { |
2013 | sfree(used); |
2014 | return FALSE; |
2015 | } |
2016 | } |
2017 | } |
2018 | |
2019 | sfree(used); |
2020 | return TRUE; |
2021 | } |
2022 | |
ef57b17d |
2023 | static int symmetries(game_params *params, int x, int y, int *output, int s) |
2024 | { |
2025 | int c = params->c, r = params->r, cr = c*r; |
2026 | int i = 0; |
2027 | |
154bf9b1 |
2028 | #define ADD(x,y) (*output++ = (x), *output++ = (y), i++) |
2029 | |
2030 | ADD(x, y); |
ef57b17d |
2031 | |
2032 | switch (s) { |
2033 | case SYMM_NONE: |
2034 | break; /* just x,y is all we need */ |
ef57b17d |
2035 | case SYMM_ROT2: |
154bf9b1 |
2036 | ADD(cr - 1 - x, cr - 1 - y); |
2037 | break; |
2038 | case SYMM_ROT4: |
2039 | ADD(cr - 1 - y, x); |
2040 | ADD(y, cr - 1 - x); |
2041 | ADD(cr - 1 - x, cr - 1 - y); |
2042 | break; |
2043 | case SYMM_REF2: |
2044 | ADD(cr - 1 - x, y); |
2045 | break; |
2046 | case SYMM_REF2D: |
2047 | ADD(y, x); |
2048 | break; |
2049 | case SYMM_REF4: |
2050 | ADD(cr - 1 - x, y); |
2051 | ADD(x, cr - 1 - y); |
2052 | ADD(cr - 1 - x, cr - 1 - y); |
2053 | break; |
2054 | case SYMM_REF4D: |
2055 | ADD(y, x); |
2056 | ADD(cr - 1 - x, cr - 1 - y); |
2057 | ADD(cr - 1 - y, cr - 1 - x); |
2058 | break; |
2059 | case SYMM_REF8: |
2060 | ADD(cr - 1 - x, y); |
2061 | ADD(x, cr - 1 - y); |
2062 | ADD(cr - 1 - x, cr - 1 - y); |
2063 | ADD(y, x); |
2064 | ADD(y, cr - 1 - x); |
2065 | ADD(cr - 1 - y, x); |
2066 | ADD(cr - 1 - y, cr - 1 - x); |
2067 | break; |
ef57b17d |
2068 | } |
2069 | |
154bf9b1 |
2070 | #undef ADD |
2071 | |
ef57b17d |
2072 | return i; |
2073 | } |
2074 | |
c566778e |
2075 | static char *encode_solve_move(int cr, digit *grid) |
2076 | { |
2077 | int i, len; |
2078 | char *ret, *p, *sep; |
2079 | |
2080 | /* |
2081 | * It's surprisingly easy to work out _exactly_ how long this |
2082 | * string needs to be. To decimal-encode all the numbers from 1 |
2083 | * to n: |
2084 | * |
2085 | * - every number has a units digit; total is n. |
2086 | * - all numbers above 9 have a tens digit; total is max(n-9,0). |
2087 | * - all numbers above 99 have a hundreds digit; total is max(n-99,0). |
2088 | * - and so on. |
2089 | */ |
2090 | len = 0; |
2091 | for (i = 1; i <= cr; i *= 10) |
2092 | len += max(cr - i + 1, 0); |
2093 | len += cr; /* don't forget the commas */ |
2094 | len *= cr; /* there are cr rows of these */ |
2095 | |
2096 | /* |
2097 | * Now len is one bigger than the total size of the |
2098 | * comma-separated numbers (because we counted an |
2099 | * additional leading comma). We need to have a leading S |
2100 | * and a trailing NUL, so we're off by one in total. |
2101 | */ |
2102 | len++; |
2103 | |
2104 | ret = snewn(len, char); |
2105 | p = ret; |
2106 | *p++ = 'S'; |
2107 | sep = ""; |
2108 | for (i = 0; i < cr*cr; i++) { |
2109 | p += sprintf(p, "%s%d", sep, grid[i]); |
2110 | sep = ","; |
2111 | } |
2112 | *p++ = '\0'; |
2113 | assert(p - ret == len); |
2114 | |
2115 | return ret; |
2116 | } |
3220eba4 |
2117 | |
1185e3c5 |
2118 | static char *new_game_desc(game_params *params, random_state *rs, |
c566778e |
2119 | char **aux, int interactive) |
1d8e8ad8 |
2120 | { |
2121 | int c = params->c, r = params->r, cr = c*r; |
2122 | int area = cr*cr; |
2123 | digit *grid, *grid2; |
2124 | struct xy { int x, y; } *locs; |
2125 | int nlocs; |
1185e3c5 |
2126 | char *desc; |
ef57b17d |
2127 | int coords[16], ncoords; |
1af60e1e |
2128 | int maxdiff; |
2129 | int x, y, i, j; |
1d8e8ad8 |
2130 | |
2131 | /* |
7c568a48 |
2132 | * Adjust the maximum difficulty level to be consistent with |
2133 | * the puzzle size: all 2x2 puzzles appear to be Trivial |
2134 | * (DIFF_BLOCK) so we cannot hold out for even a Basic |
2135 | * (DIFF_SIMPLE) one. |
1d8e8ad8 |
2136 | */ |
7c568a48 |
2137 | maxdiff = params->diff; |
2138 | if (c == 2 && r == 2) |
2139 | maxdiff = DIFF_BLOCK; |
1d8e8ad8 |
2140 | |
7c568a48 |
2141 | grid = snewn(area, digit); |
ef57b17d |
2142 | locs = snewn(area, struct xy); |
1d8e8ad8 |
2143 | grid2 = snewn(area, digit); |
1d8e8ad8 |
2144 | |
7c568a48 |
2145 | /* |
2146 | * Loop until we get a grid of the required difficulty. This is |
2147 | * nasty, but it seems to be unpleasantly hard to generate |
2148 | * difficult grids otherwise. |
2149 | */ |
2150 | do { |
2151 | /* |
ab362080 |
2152 | * Generate a random solved state. |
7c568a48 |
2153 | */ |
ab362080 |
2154 | gridgen(c, r, grid, rs); |
7c568a48 |
2155 | assert(check_valid(c, r, grid)); |
2156 | |
3220eba4 |
2157 | /* |
c566778e |
2158 | * Save the solved grid in aux. |
3220eba4 |
2159 | */ |
2160 | { |
ab53eb64 |
2161 | /* |
2162 | * We might already have written *aux the last time we |
2163 | * went round this loop, in which case we should free |
c566778e |
2164 | * the old aux before overwriting it with the new one. |
ab53eb64 |
2165 | */ |
2166 | if (*aux) { |
ab53eb64 |
2167 | sfree(*aux); |
2168 | } |
c566778e |
2169 | |
2170 | *aux = encode_solve_move(cr, grid); |
3220eba4 |
2171 | } |
2172 | |
7c568a48 |
2173 | /* |
2174 | * Now we have a solved grid, start removing things from it |
2175 | * while preserving solubility. |
2176 | */ |
7c568a48 |
2177 | |
1af60e1e |
2178 | /* |
2179 | * Find the set of equivalence classes of squares permitted |
2180 | * by the selected symmetry. We do this by enumerating all |
2181 | * the grid squares which have no symmetric companion |
2182 | * sorting lower than themselves. |
2183 | */ |
2184 | nlocs = 0; |
2185 | for (y = 0; y < cr; y++) |
2186 | for (x = 0; x < cr; x++) { |
2187 | int i = y*cr+x; |
2188 | int j; |
7c568a48 |
2189 | |
1af60e1e |
2190 | ncoords = symmetries(params, x, y, coords, params->symm); |
2191 | for (j = 0; j < ncoords; j++) |
2192 | if (coords[2*j+1]*cr+coords[2*j] < i) |
2193 | break; |
2194 | if (j == ncoords) { |
154bf9b1 |
2195 | locs[nlocs].x = x; |
2196 | locs[nlocs].y = y; |
2197 | nlocs++; |
2198 | } |
2199 | } |
7c568a48 |
2200 | |
1af60e1e |
2201 | /* |
2202 | * Now shuffle that list. |
2203 | */ |
2204 | shuffle(locs, nlocs, sizeof(*locs), rs); |
de60d8bd |
2205 | |
1af60e1e |
2206 | /* |
2207 | * Now loop over the shuffled list and, for each element, |
2208 | * see whether removing that element (and its reflections) |
2209 | * from the grid will still leave the grid soluble. |
2210 | */ |
2211 | for (i = 0; i < nlocs; i++) { |
2212 | int ret; |
7c568a48 |
2213 | |
1af60e1e |
2214 | x = locs[i].x; |
2215 | y = locs[i].y; |
7c568a48 |
2216 | |
1af60e1e |
2217 | memcpy(grid2, grid, area); |
2218 | ncoords = symmetries(params, x, y, coords, params->symm); |
2219 | for (j = 0; j < ncoords; j++) |
2220 | grid2[coords[2*j+1]*cr+coords[2*j]] = 0; |
7c568a48 |
2221 | |
1af60e1e |
2222 | ret = solver(c, r, grid2, maxdiff); |
437ed08c |
2223 | if (ret <= maxdiff) { |
1af60e1e |
2224 | for (j = 0; j < ncoords; j++) |
2225 | grid[coords[2*j+1]*cr+coords[2*j]] = 0; |
7c568a48 |
2226 | } |
2227 | } |
1d8e8ad8 |
2228 | |
7c568a48 |
2229 | memcpy(grid2, grid, area); |
947a07d6 |
2230 | } while (solver(c, r, grid2, maxdiff) < maxdiff); |
1d8e8ad8 |
2231 | |
1d8e8ad8 |
2232 | sfree(grid2); |
2233 | sfree(locs); |
2234 | |
1d8e8ad8 |
2235 | /* |
2236 | * Now we have the grid as it will be presented to the user. |
1185e3c5 |
2237 | * Encode it in a game desc. |
1d8e8ad8 |
2238 | */ |
2239 | { |
2240 | char *p; |
2241 | int run, i; |
2242 | |
1185e3c5 |
2243 | desc = snewn(5 * area, char); |
2244 | p = desc; |
1d8e8ad8 |
2245 | run = 0; |
2246 | for (i = 0; i <= area; i++) { |
2247 | int n = (i < area ? grid[i] : -1); |
2248 | |
2249 | if (!n) |
2250 | run++; |
2251 | else { |
2252 | if (run) { |
2253 | while (run > 0) { |
2254 | int c = 'a' - 1 + run; |
2255 | if (run > 26) |
2256 | c = 'z'; |
2257 | *p++ = c; |
2258 | run -= c - ('a' - 1); |
2259 | } |
2260 | } else { |
2261 | /* |
2262 | * If there's a number in the very top left or |
2263 | * bottom right, there's no point putting an |
2264 | * unnecessary _ before or after it. |
2265 | */ |
1185e3c5 |
2266 | if (p > desc && n > 0) |
1d8e8ad8 |
2267 | *p++ = '_'; |
2268 | } |
2269 | if (n > 0) |
2270 | p += sprintf(p, "%d", n); |
2271 | run = 0; |
2272 | } |
2273 | } |
1185e3c5 |
2274 | assert(p - desc < 5 * area); |
1d8e8ad8 |
2275 | *p++ = '\0'; |
1185e3c5 |
2276 | desc = sresize(desc, p - desc, char); |
1d8e8ad8 |
2277 | } |
2278 | |
2279 | sfree(grid); |
2280 | |
1185e3c5 |
2281 | return desc; |
1d8e8ad8 |
2282 | } |
2283 | |
1185e3c5 |
2284 | static char *validate_desc(game_params *params, char *desc) |
1d8e8ad8 |
2285 | { |
2286 | int area = params->r * params->r * params->c * params->c; |
2287 | int squares = 0; |
2288 | |
1185e3c5 |
2289 | while (*desc) { |
2290 | int n = *desc++; |
1d8e8ad8 |
2291 | if (n >= 'a' && n <= 'z') { |
2292 | squares += n - 'a' + 1; |
2293 | } else if (n == '_') { |
2294 | /* do nothing */; |
2295 | } else if (n > '0' && n <= '9') { |
d0ed57cd |
2296 | int val = atoi(desc-1); |
2297 | if (val < 1 || val > params->c * params->r) |
2298 | return "Out-of-range number in game description"; |
1d8e8ad8 |
2299 | squares++; |
1185e3c5 |
2300 | while (*desc >= '0' && *desc <= '9') |
2301 | desc++; |
1d8e8ad8 |
2302 | } else |
1185e3c5 |
2303 | return "Invalid character in game description"; |
1d8e8ad8 |
2304 | } |
2305 | |
2306 | if (squares < area) |
2307 | return "Not enough data to fill grid"; |
2308 | |
2309 | if (squares > area) |
2310 | return "Too much data to fit in grid"; |
2311 | |
2312 | return NULL; |
2313 | } |
2314 | |
dafd6cf6 |
2315 | static game_state *new_game(midend *me, game_params *params, char *desc) |
1d8e8ad8 |
2316 | { |
2317 | game_state *state = snew(game_state); |
2318 | int c = params->c, r = params->r, cr = c*r, area = cr * cr; |
2319 | int i; |
2320 | |
2321 | state->c = params->c; |
2322 | state->r = params->r; |
2323 | |
2324 | state->grid = snewn(area, digit); |
c8266e03 |
2325 | state->pencil = snewn(area * cr, unsigned char); |
2326 | memset(state->pencil, 0, area * cr); |
1d8e8ad8 |
2327 | state->immutable = snewn(area, unsigned char); |
2328 | memset(state->immutable, FALSE, area); |
2329 | |
2ac6d24e |
2330 | state->completed = state->cheated = FALSE; |
1d8e8ad8 |
2331 | |
2332 | i = 0; |
1185e3c5 |
2333 | while (*desc) { |
2334 | int n = *desc++; |
1d8e8ad8 |
2335 | if (n >= 'a' && n <= 'z') { |
2336 | int run = n - 'a' + 1; |
2337 | assert(i + run <= area); |
2338 | while (run-- > 0) |
2339 | state->grid[i++] = 0; |
2340 | } else if (n == '_') { |
2341 | /* do nothing */; |
2342 | } else if (n > '0' && n <= '9') { |
2343 | assert(i < area); |
2344 | state->immutable[i] = TRUE; |
1185e3c5 |
2345 | state->grid[i++] = atoi(desc-1); |
2346 | while (*desc >= '0' && *desc <= '9') |
2347 | desc++; |
1d8e8ad8 |
2348 | } else { |
2349 | assert(!"We can't get here"); |
2350 | } |
2351 | } |
2352 | assert(i == area); |
2353 | |
2354 | return state; |
2355 | } |
2356 | |
2357 | static game_state *dup_game(game_state *state) |
2358 | { |
2359 | game_state *ret = snew(game_state); |
2360 | int c = state->c, r = state->r, cr = c*r, area = cr * cr; |
2361 | |
2362 | ret->c = state->c; |
2363 | ret->r = state->r; |
2364 | |
2365 | ret->grid = snewn(area, digit); |
2366 | memcpy(ret->grid, state->grid, area); |
2367 | |
c8266e03 |
2368 | ret->pencil = snewn(area * cr, unsigned char); |
2369 | memcpy(ret->pencil, state->pencil, area * cr); |
2370 | |
1d8e8ad8 |
2371 | ret->immutable = snewn(area, unsigned char); |
2372 | memcpy(ret->immutable, state->immutable, area); |
2373 | |
2374 | ret->completed = state->completed; |
2ac6d24e |
2375 | ret->cheated = state->cheated; |
1d8e8ad8 |
2376 | |
2377 | return ret; |
2378 | } |
2379 | |
2380 | static void free_game(game_state *state) |
2381 | { |
2382 | sfree(state->immutable); |
c8266e03 |
2383 | sfree(state->pencil); |
1d8e8ad8 |
2384 | sfree(state->grid); |
2385 | sfree(state); |
2386 | } |
2387 | |
df11cd4e |
2388 | static char *solve_game(game_state *state, game_state *currstate, |
c566778e |
2389 | char *ai, char **error) |
2ac6d24e |
2390 | { |
3220eba4 |
2391 | int c = state->c, r = state->r, cr = c*r; |
c566778e |
2392 | char *ret; |
df11cd4e |
2393 | digit *grid; |
ab362080 |
2394 | int solve_ret; |
2ac6d24e |
2395 | |
3220eba4 |
2396 | /* |
c566778e |
2397 | * If we already have the solution in ai, save ourselves some |
2398 | * time. |
3220eba4 |
2399 | */ |
c566778e |
2400 | if (ai) |
2401 | return dupstr(ai); |
3220eba4 |
2402 | |
c566778e |
2403 | grid = snewn(cr*cr, digit); |
2404 | memcpy(grid, state->grid, cr*cr); |
947a07d6 |
2405 | solve_ret = solver(c, r, grid, DIFF_RECURSIVE); |
ab362080 |
2406 | |
2407 | *error = NULL; |
df11cd4e |
2408 | |
ab362080 |
2409 | if (solve_ret == DIFF_IMPOSSIBLE) |
2410 | *error = "No solution exists for this puzzle"; |
2411 | else if (solve_ret == DIFF_AMBIGUOUS) |
2412 | *error = "Multiple solutions exist for this puzzle"; |
2413 | |
2414 | if (*error) { |
c566778e |
2415 | sfree(grid); |
c566778e |
2416 | return NULL; |
df11cd4e |
2417 | } |
2418 | |
c566778e |
2419 | ret = encode_solve_move(cr, grid); |
df11cd4e |
2420 | |
c566778e |
2421 | sfree(grid); |
2ac6d24e |
2422 | |
2423 | return ret; |
2424 | } |
2425 | |
9b4b03d3 |
2426 | static char *grid_text_format(int c, int r, digit *grid) |
2427 | { |
2428 | int cr = c*r; |
2429 | int x, y; |
2430 | int maxlen; |
2431 | char *ret, *p; |
2432 | |
2433 | /* |
2434 | * There are cr lines of digits, plus r-1 lines of block |
2435 | * separators. Each line contains cr digits, cr-1 separating |
2436 | * spaces, and c-1 two-character block separators. Thus, the |
2437 | * total length of a line is 2*cr+2*c-3 (not counting the |
2438 | * newline), and there are cr+r-1 of them. |
2439 | */ |
2440 | maxlen = (cr+r-1) * (2*cr+2*c-2); |
2441 | ret = snewn(maxlen+1, char); |
2442 | p = ret; |
2443 | |
2444 | for (y = 0; y < cr; y++) { |
2445 | for (x = 0; x < cr; x++) { |
2446 | int ch = grid[y * cr + x]; |
2447 | if (ch == 0) |
59b4cf3c |
2448 | ch = '.'; |
9b4b03d3 |
2449 | else if (ch <= 9) |
2450 | ch = '0' + ch; |
2451 | else |
2452 | ch = 'a' + ch-10; |
2453 | *p++ = ch; |
2454 | if (x+1 < cr) { |
2455 | *p++ = ' '; |
2456 | if ((x+1) % r == 0) { |
2457 | *p++ = '|'; |
2458 | *p++ = ' '; |
2459 | } |
2460 | } |
2461 | } |
2462 | *p++ = '\n'; |
2463 | if (y+1 < cr && (y+1) % c == 0) { |
2464 | for (x = 0; x < cr; x++) { |
2465 | *p++ = '-'; |
2466 | if (x+1 < cr) { |
2467 | *p++ = '-'; |
2468 | if ((x+1) % r == 0) { |
2469 | *p++ = '+'; |
2470 | *p++ = '-'; |
2471 | } |
2472 | } |
2473 | } |
2474 | *p++ = '\n'; |
2475 | } |
2476 | } |
2477 | |
2478 | assert(p - ret == maxlen); |
2479 | *p = '\0'; |
2480 | return ret; |
2481 | } |
2482 | |
2483 | static char *game_text_format(game_state *state) |
2484 | { |
2485 | return grid_text_format(state->c, state->r, state->grid); |
2486 | } |
2487 | |
1d8e8ad8 |
2488 | struct game_ui { |
2489 | /* |
2490 | * These are the coordinates of the currently highlighted |
2491 | * square on the grid, or -1,-1 if there isn't one. When there |
2492 | * is, pressing a valid number or letter key or Space will |
2493 | * enter that number or letter in the grid. |
2494 | */ |
2495 | int hx, hy; |
c8266e03 |
2496 | /* |
2497 | * This indicates whether the current highlight is a |
2498 | * pencil-mark one or a real one. |
2499 | */ |
2500 | int hpencil; |
1d8e8ad8 |
2501 | }; |
2502 | |
2503 | static game_ui *new_ui(game_state *state) |
2504 | { |
2505 | game_ui *ui = snew(game_ui); |
2506 | |
2507 | ui->hx = ui->hy = -1; |
c8266e03 |
2508 | ui->hpencil = 0; |
1d8e8ad8 |
2509 | |
2510 | return ui; |
2511 | } |
2512 | |
2513 | static void free_ui(game_ui *ui) |
2514 | { |
2515 | sfree(ui); |
2516 | } |
2517 | |
844f605f |
2518 | static char *encode_ui(game_ui *ui) |
ae8290c6 |
2519 | { |
2520 | return NULL; |
2521 | } |
2522 | |
844f605f |
2523 | static void decode_ui(game_ui *ui, char *encoding) |
ae8290c6 |
2524 | { |
2525 | } |
2526 | |
07dfb697 |
2527 | static void game_changed_state(game_ui *ui, game_state *oldstate, |
2528 | game_state *newstate) |
2529 | { |
2530 | int c = newstate->c, r = newstate->r, cr = c*r; |
2531 | /* |
2532 | * We prevent pencil-mode highlighting of a filled square. So |
2533 | * if the user has just filled in a square which we had a |
2534 | * pencil-mode highlight in (by Undo, or by Redo, or by Solve), |
2535 | * then we cancel the highlight. |
2536 | */ |
2537 | if (ui->hx >= 0 && ui->hy >= 0 && ui->hpencil && |
2538 | newstate->grid[ui->hy * cr + ui->hx] != 0) { |
2539 | ui->hx = ui->hy = -1; |
2540 | } |
2541 | } |
2542 | |
1e3e152d |
2543 | struct game_drawstate { |
2544 | int started; |
2545 | int c, r, cr; |
2546 | int tilesize; |
2547 | digit *grid; |
2548 | unsigned char *pencil; |
2549 | unsigned char *hl; |
2550 | /* This is scratch space used within a single call to game_redraw. */ |
2551 | int *entered_items; |
2552 | }; |
2553 | |
df11cd4e |
2554 | static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, |
2555 | int x, int y, int button) |
1d8e8ad8 |
2556 | { |
df11cd4e |
2557 | int c = state->c, r = state->r, cr = c*r; |
1d8e8ad8 |
2558 | int tx, ty; |
df11cd4e |
2559 | char buf[80]; |
1d8e8ad8 |
2560 | |
f0ee053c |
2561 | button &= ~MOD_MASK; |
3c833d45 |
2562 | |
ae812854 |
2563 | tx = (x + TILE_SIZE - BORDER) / TILE_SIZE - 1; |
2564 | ty = (y + TILE_SIZE - BORDER) / TILE_SIZE - 1; |
1d8e8ad8 |
2565 | |
39d682c9 |
2566 | if (tx >= 0 && tx < cr && ty >= 0 && ty < cr) { |
2567 | if (button == LEFT_BUTTON) { |
df11cd4e |
2568 | if (state->immutable[ty*cr+tx]) { |
39d682c9 |
2569 | ui->hx = ui->hy = -1; |
2570 | } else if (tx == ui->hx && ty == ui->hy && ui->hpencil == 0) { |
2571 | ui->hx = ui->hy = -1; |
2572 | } else { |
2573 | ui->hx = tx; |
2574 | ui->hy = ty; |
2575 | ui->hpencil = 0; |
2576 | } |
df11cd4e |
2577 | return ""; /* UI activity occurred */ |
39d682c9 |
2578 | } |
2579 | if (button == RIGHT_BUTTON) { |
2580 | /* |
2581 | * Pencil-mode highlighting for non filled squares. |
2582 | */ |
df11cd4e |
2583 | if (state->grid[ty*cr+tx] == 0) { |
39d682c9 |
2584 | if (tx == ui->hx && ty == ui->hy && ui->hpencil) { |
2585 | ui->hx = ui->hy = -1; |
2586 | } else { |
2587 | ui->hpencil = 1; |
2588 | ui->hx = tx; |
2589 | ui->hy = ty; |
2590 | } |
2591 | } else { |
2592 | ui->hx = ui->hy = -1; |
2593 | } |
df11cd4e |
2594 | return ""; /* UI activity occurred */ |
39d682c9 |
2595 | } |
1d8e8ad8 |
2596 | } |
2597 | |
2598 | if (ui->hx != -1 && ui->hy != -1 && |
2599 | ((button >= '1' && button <= '9' && button - '0' <= cr) || |
2600 | (button >= 'a' && button <= 'z' && button - 'a' + 10 <= cr) || |
2601 | (button >= 'A' && button <= 'Z' && button - 'A' + 10 <= cr) || |
0eb4d76e |
2602 | button == ' ' || button == '\010' || button == '\177')) { |
1d8e8ad8 |
2603 | int n = button - '0'; |
2604 | if (button >= 'A' && button <= 'Z') |
2605 | n = button - 'A' + 10; |
2606 | if (button >= 'a' && button <= 'z') |
2607 | n = button - 'a' + 10; |
0eb4d76e |
2608 | if (button == ' ' || button == '\010' || button == '\177') |
1d8e8ad8 |
2609 | n = 0; |
2610 | |
39d682c9 |
2611 | /* |
2612 | * Can't overwrite this square. In principle this shouldn't |
2613 | * happen anyway because we should never have even been |
2614 | * able to highlight the square, but it never hurts to be |
2615 | * careful. |
2616 | */ |
df11cd4e |
2617 | if (state->immutable[ui->hy*cr+ui->hx]) |
39d682c9 |
2618 | return NULL; |
1d8e8ad8 |
2619 | |
c8266e03 |
2620 | /* |
2621 | * Can't make pencil marks in a filled square. In principle |
2622 | * this shouldn't happen anyway because we should never |
2623 | * have even been able to pencil-highlight the square, but |
2624 | * it never hurts to be careful. |
2625 | */ |
df11cd4e |
2626 | if (ui->hpencil && state->grid[ui->hy*cr+ui->hx]) |
c8266e03 |
2627 | return NULL; |
2628 | |
df11cd4e |
2629 | sprintf(buf, "%c%d,%d,%d", |
871bf294 |
2630 | (char)(ui->hpencil && n > 0 ? 'P' : 'R'), ui->hx, ui->hy, n); |
df11cd4e |
2631 | |
2632 | ui->hx = ui->hy = -1; |
2633 | |
2634 | return dupstr(buf); |
2635 | } |
2636 | |
2637 | return NULL; |
2638 | } |
2639 | |
2640 | static game_state *execute_move(game_state *from, char *move) |
2641 | { |
2642 | int c = from->c, r = from->r, cr = c*r; |
2643 | game_state *ret; |
2644 | int x, y, n; |
2645 | |
2646 | if (move[0] == 'S') { |
2647 | char *p; |
2648 | |
1d8e8ad8 |
2649 | ret = dup_game(from); |
df11cd4e |
2650 | ret->completed = ret->cheated = TRUE; |
2651 | |
2652 | p = move+1; |
2653 | for (n = 0; n < cr*cr; n++) { |
2654 | ret->grid[n] = atoi(p); |
2655 | |
2656 | if (!*p || ret->grid[n] < 1 || ret->grid[n] > cr) { |
2657 | free_game(ret); |
2658 | return NULL; |
2659 | } |
2660 | |
2661 | while (*p && isdigit((unsigned char)*p)) p++; |
2662 | if (*p == ',') p++; |
2663 | } |
2664 | |
2665 | return ret; |
2666 | } else if ((move[0] == 'P' || move[0] == 'R') && |
2667 | sscanf(move+1, "%d,%d,%d", &x, &y, &n) == 3 && |
2668 | x >= 0 && x < cr && y >= 0 && y < cr && n >= 0 && n <= cr) { |
2669 | |
2670 | ret = dup_game(from); |
2671 | if (move[0] == 'P' && n > 0) { |
2672 | int index = (y*cr+x) * cr + (n-1); |
c8266e03 |
2673 | ret->pencil[index] = !ret->pencil[index]; |
2674 | } else { |
df11cd4e |
2675 | ret->grid[y*cr+x] = n; |
2676 | memset(ret->pencil + (y*cr+x)*cr, 0, cr); |
1d8e8ad8 |
2677 | |
c8266e03 |
2678 | /* |
2679 | * We've made a real change to the grid. Check to see |
2680 | * if the game has been completed. |
2681 | */ |
2682 | if (!ret->completed && check_valid(c, r, ret->grid)) { |
2683 | ret->completed = TRUE; |
2684 | } |
2685 | } |
df11cd4e |
2686 | return ret; |
2687 | } else |
2688 | return NULL; /* couldn't parse move string */ |
1d8e8ad8 |
2689 | } |
2690 | |
2691 | /* ---------------------------------------------------------------------- |
2692 | * Drawing routines. |
2693 | */ |
2694 | |
1e3e152d |
2695 | #define SIZE(cr) ((cr) * TILE_SIZE + 2*BORDER + 1) |
871bf294 |
2696 | #define GETTILESIZE(cr, w) ( (double)(w-1) / (double)(cr+1) ) |
1d8e8ad8 |
2697 | |
1f3ee4ee |
2698 | static void game_compute_size(game_params *params, int tilesize, |
2699 | int *x, int *y) |
1d8e8ad8 |
2700 | { |
1f3ee4ee |
2701 | /* Ick: fake up `ds->tilesize' for macro expansion purposes */ |
2702 | struct { int tilesize; } ads, *ds = &ads; |
2703 | ads.tilesize = tilesize; |
1e3e152d |
2704 | |
1f3ee4ee |
2705 | *x = SIZE(params->c * params->r); |
2706 | *y = SIZE(params->c * params->r); |
2707 | } |
1d8e8ad8 |
2708 | |
dafd6cf6 |
2709 | static void game_set_size(drawing *dr, game_drawstate *ds, |
2710 | game_params *params, int tilesize) |
1f3ee4ee |
2711 | { |
2712 | ds->tilesize = tilesize; |
1d8e8ad8 |
2713 | } |
2714 | |
8266f3fc |
2715 | static float *game_colours(frontend *fe, int *ncolours) |
1d8e8ad8 |
2716 | { |
2717 | float *ret = snewn(3 * NCOLOURS, float); |
2718 | |
2719 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
2720 | |
2721 | ret[COL_GRID * 3 + 0] = 0.0F; |
2722 | ret[COL_GRID * 3 + 1] = 0.0F; |
2723 | ret[COL_GRID * 3 + 2] = 0.0F; |
2724 | |
2725 | ret[COL_CLUE * 3 + 0] = 0.0F; |
2726 | ret[COL_CLUE * 3 + 1] = 0.0F; |
2727 | ret[COL_CLUE * 3 + 2] = 0.0F; |
2728 | |
2729 | ret[COL_USER * 3 + 0] = 0.0F; |
2730 | ret[COL_USER * 3 + 1] = 0.6F * ret[COL_BACKGROUND * 3 + 1]; |
2731 | ret[COL_USER * 3 + 2] = 0.0F; |
2732 | |
2733 | ret[COL_HIGHLIGHT * 3 + 0] = 0.85F * ret[COL_BACKGROUND * 3 + 0]; |
2734 | ret[COL_HIGHLIGHT * 3 + 1] = 0.85F * ret[COL_BACKGROUND * 3 + 1]; |
2735 | ret[COL_HIGHLIGHT * 3 + 2] = 0.85F * ret[COL_BACKGROUND * 3 + 2]; |
2736 | |
7b14a9ec |
2737 | ret[COL_ERROR * 3 + 0] = 1.0F; |
2738 | ret[COL_ERROR * 3 + 1] = 0.0F; |
2739 | ret[COL_ERROR * 3 + 2] = 0.0F; |
2740 | |
c8266e03 |
2741 | ret[COL_PENCIL * 3 + 0] = 0.5F * ret[COL_BACKGROUND * 3 + 0]; |
2742 | ret[COL_PENCIL * 3 + 1] = 0.5F * ret[COL_BACKGROUND * 3 + 1]; |
2743 | ret[COL_PENCIL * 3 + 2] = ret[COL_BACKGROUND * 3 + 2]; |
2744 | |
1d8e8ad8 |
2745 | *ncolours = NCOLOURS; |
2746 | return ret; |
2747 | } |
2748 | |
dafd6cf6 |
2749 | static game_drawstate *game_new_drawstate(drawing *dr, game_state *state) |
1d8e8ad8 |
2750 | { |
2751 | struct game_drawstate *ds = snew(struct game_drawstate); |
2752 | int c = state->c, r = state->r, cr = c*r; |
2753 | |
2754 | ds->started = FALSE; |
2755 | ds->c = c; |
2756 | ds->r = r; |
2757 | ds->cr = cr; |
2758 | ds->grid = snewn(cr*cr, digit); |
2759 | memset(ds->grid, 0, cr*cr); |
c8266e03 |
2760 | ds->pencil = snewn(cr*cr*cr, digit); |
2761 | memset(ds->pencil, 0, cr*cr*cr); |
1d8e8ad8 |
2762 | ds->hl = snewn(cr*cr, unsigned char); |
2763 | memset(ds->hl, 0, cr*cr); |
b71dd7fc |
2764 | ds->entered_items = snewn(cr*cr, int); |
1e3e152d |
2765 | ds->tilesize = 0; /* not decided yet */ |
1d8e8ad8 |
2766 | return ds; |
2767 | } |
2768 | |
dafd6cf6 |
2769 | static void game_free_drawstate(drawing *dr, game_drawstate *ds) |
1d8e8ad8 |
2770 | { |
2771 | sfree(ds->hl); |
c8266e03 |
2772 | sfree(ds->pencil); |
1d8e8ad8 |
2773 | sfree(ds->grid); |
b71dd7fc |
2774 | sfree(ds->entered_items); |
1d8e8ad8 |
2775 | sfree(ds); |
2776 | } |
2777 | |
dafd6cf6 |
2778 | static void draw_number(drawing *dr, game_drawstate *ds, game_state *state, |
1d8e8ad8 |
2779 | int x, int y, int hl) |
2780 | { |
2781 | int c = state->c, r = state->r, cr = c*r; |
2782 | int tx, ty; |
2783 | int cx, cy, cw, ch; |
2784 | char str[2]; |
2785 | |
c8266e03 |
2786 | if (ds->grid[y*cr+x] == state->grid[y*cr+x] && |
2787 | ds->hl[y*cr+x] == hl && |
2788 | !memcmp(ds->pencil+(y*cr+x)*cr, state->pencil+(y*cr+x)*cr, cr)) |
1d8e8ad8 |
2789 | return; /* no change required */ |
2790 | |
2791 | tx = BORDER + x * TILE_SIZE + 2; |
2792 | ty = BORDER + y * TILE_SIZE + 2; |
2793 | |
2794 | cx = tx; |
2795 | cy = ty; |
2796 | cw = TILE_SIZE-3; |
2797 | ch = TILE_SIZE-3; |
2798 | |
2799 | if (x % r) |
2800 | cx--, cw++; |
2801 | if ((x+1) % r) |
2802 | cw++; |
2803 | if (y % c) |
2804 | cy--, ch++; |
2805 | if ((y+1) % c) |
2806 | ch++; |
2807 | |
dafd6cf6 |
2808 | clip(dr, cx, cy, cw, ch); |
1d8e8ad8 |
2809 | |
c8266e03 |
2810 | /* background needs erasing */ |
dafd6cf6 |
2811 | draw_rect(dr, cx, cy, cw, ch, (hl & 15) == 1 ? COL_HIGHLIGHT : COL_BACKGROUND); |
c8266e03 |
2812 | |
2813 | /* pencil-mode highlight */ |
7b14a9ec |
2814 | if ((hl & 15) == 2) { |
c8266e03 |
2815 | int coords[6]; |
2816 | coords[0] = cx; |
2817 | coords[1] = cy; |
2818 | coords[2] = cx+cw/2; |
2819 | coords[3] = cy; |
2820 | coords[4] = cx; |
2821 | coords[5] = cy+ch/2; |
dafd6cf6 |
2822 | draw_polygon(dr, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT); |
c8266e03 |
2823 | } |
1d8e8ad8 |
2824 | |
2825 | /* new number needs drawing? */ |
2826 | if (state->grid[y*cr+x]) { |
2827 | str[1] = '\0'; |
2828 | str[0] = state->grid[y*cr+x] + '0'; |
2829 | if (str[0] > '9') |
2830 | str[0] += 'a' - ('9'+1); |
dafd6cf6 |
2831 | draw_text(dr, tx + TILE_SIZE/2, ty + TILE_SIZE/2, |
1d8e8ad8 |
2832 | FONT_VARIABLE, TILE_SIZE/2, ALIGN_VCENTRE | ALIGN_HCENTRE, |
7b14a9ec |
2833 | state->immutable[y*cr+x] ? COL_CLUE : (hl & 16) ? COL_ERROR : COL_USER, str); |
c8266e03 |
2834 | } else { |
edf63745 |
2835 | int i, j, npencil; |
2836 | int pw, ph, pmax, fontsize; |
2837 | |
2838 | /* count the pencil marks required */ |
2839 | for (i = npencil = 0; i < cr; i++) |
2840 | if (state->pencil[(y*cr+x)*cr+i]) |
2841 | npencil++; |
2842 | |
2843 | /* |
2844 | * It's not sensible to arrange pencil marks in the same |
2845 | * layout as the squares within a block, because this leads |
2846 | * to the font being too small. Instead, we arrange pencil |
2847 | * marks in the nearest thing we can to a square layout, |
2848 | * and we adjust the square layout depending on the number |
2849 | * of pencil marks in the square. |
2850 | */ |
2851 | for (pw = 1; pw * pw < npencil; pw++); |
2852 | if (pw < 3) pw = 3; /* otherwise it just looks _silly_ */ |
2853 | ph = (npencil + pw - 1) / pw; |
2854 | if (ph < 2) ph = 2; /* likewise */ |
2855 | pmax = max(pw, ph); |
2856 | fontsize = TILE_SIZE/(pmax*(11-pmax)/8); |
c8266e03 |
2857 | |
2858 | for (i = j = 0; i < cr; i++) |
2859 | if (state->pencil[(y*cr+x)*cr+i]) { |
edf63745 |
2860 | int dx = j % pw, dy = j / pw; |
2861 | |
c8266e03 |
2862 | str[1] = '\0'; |
2863 | str[0] = i + '1'; |
2864 | if (str[0] > '9') |
2865 | str[0] += 'a' - ('9'+1); |
dafd6cf6 |
2866 | draw_text(dr, tx + (4*dx+3) * TILE_SIZE / (4*pw+2), |
edf63745 |
2867 | ty + (4*dy+3) * TILE_SIZE / (4*ph+2), |
2868 | FONT_VARIABLE, fontsize, |
c8266e03 |
2869 | ALIGN_VCENTRE | ALIGN_HCENTRE, COL_PENCIL, str); |
2870 | j++; |
2871 | } |
1d8e8ad8 |
2872 | } |
2873 | |
dafd6cf6 |
2874 | unclip(dr); |
1d8e8ad8 |
2875 | |
dafd6cf6 |
2876 | draw_update(dr, cx, cy, cw, ch); |
1d8e8ad8 |
2877 | |
2878 | ds->grid[y*cr+x] = state->grid[y*cr+x]; |
c8266e03 |
2879 | memcpy(ds->pencil+(y*cr+x)*cr, state->pencil+(y*cr+x)*cr, cr); |
1d8e8ad8 |
2880 | ds->hl[y*cr+x] = hl; |
2881 | } |
2882 | |
dafd6cf6 |
2883 | static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate, |
1d8e8ad8 |
2884 | game_state *state, int dir, game_ui *ui, |
2885 | float animtime, float flashtime) |
2886 | { |
2887 | int c = state->c, r = state->r, cr = c*r; |
2888 | int x, y; |
2889 | |
2890 | if (!ds->started) { |
2891 | /* |
2892 | * The initial contents of the window are not guaranteed |
2893 | * and can vary with front ends. To be on the safe side, |
2894 | * all games should start by drawing a big |
2895 | * background-colour rectangle covering the whole window. |
2896 | */ |
dafd6cf6 |
2897 | draw_rect(dr, 0, 0, SIZE(cr), SIZE(cr), COL_BACKGROUND); |
1d8e8ad8 |
2898 | |
2899 | /* |
2900 | * Draw the grid. |
2901 | */ |
2902 | for (x = 0; x <= cr; x++) { |
2903 | int thick = (x % r ? 0 : 1); |
dafd6cf6 |
2904 | draw_rect(dr, BORDER + x*TILE_SIZE - thick, BORDER-1, |
1d8e8ad8 |
2905 | 1+2*thick, cr*TILE_SIZE+3, COL_GRID); |
2906 | } |
2907 | for (y = 0; y <= cr; y++) { |
2908 | int thick = (y % c ? 0 : 1); |
dafd6cf6 |
2909 | draw_rect(dr, BORDER-1, BORDER + y*TILE_SIZE - thick, |
1d8e8ad8 |
2910 | cr*TILE_SIZE+3, 1+2*thick, COL_GRID); |
2911 | } |
2912 | } |
2913 | |
2914 | /* |
7b14a9ec |
2915 | * This array is used to keep track of rows, columns and boxes |
2916 | * which contain a number more than once. |
2917 | */ |
2918 | for (x = 0; x < cr * cr; x++) |
b71dd7fc |
2919 | ds->entered_items[x] = 0; |
7b14a9ec |
2920 | for (x = 0; x < cr; x++) |
2921 | for (y = 0; y < cr; y++) { |
2922 | digit d = state->grid[y*cr+x]; |
2923 | if (d) { |
2924 | int box = (x/r)+(y/c)*c; |
b71dd7fc |
2925 | ds->entered_items[x*cr+d-1] |= ((ds->entered_items[x*cr+d-1] & 1) << 1) | 1; |
2926 | ds->entered_items[y*cr+d-1] |= ((ds->entered_items[y*cr+d-1] & 4) << 1) | 4; |
2927 | ds->entered_items[box*cr+d-1] |= ((ds->entered_items[box*cr+d-1] & 16) << 1) | 16; |
7b14a9ec |
2928 | } |
2929 | } |
2930 | |
2931 | /* |
1d8e8ad8 |
2932 | * Draw any numbers which need redrawing. |
2933 | */ |
2934 | for (x = 0; x < cr; x++) { |
2935 | for (y = 0; y < cr; y++) { |
c8266e03 |
2936 | int highlight = 0; |
7b14a9ec |
2937 | digit d = state->grid[y*cr+x]; |
2938 | |
c8266e03 |
2939 | if (flashtime > 0 && |
2940 | (flashtime <= FLASH_TIME/3 || |
2941 | flashtime >= FLASH_TIME*2/3)) |
2942 | highlight = 1; |
7b14a9ec |
2943 | |
2944 | /* Highlight active input areas. */ |
c8266e03 |
2945 | if (x == ui->hx && y == ui->hy) |
2946 | highlight = ui->hpencil ? 2 : 1; |
7b14a9ec |
2947 | |
2948 | /* Mark obvious errors (ie, numbers which occur more than once |
2949 | * in a single row, column, or box). */ |
5d744557 |
2950 | if (d && ((ds->entered_items[x*cr+d-1] & 2) || |
2951 | (ds->entered_items[y*cr+d-1] & 8) || |
2952 | (ds->entered_items[((x/r)+(y/c)*c)*cr+d-1] & 32))) |
7b14a9ec |
2953 | highlight |= 16; |
2954 | |
dafd6cf6 |
2955 | draw_number(dr, ds, state, x, y, highlight); |
1d8e8ad8 |
2956 | } |
2957 | } |
2958 | |
2959 | /* |
2960 | * Update the _entire_ grid if necessary. |
2961 | */ |
2962 | if (!ds->started) { |
dafd6cf6 |
2963 | draw_update(dr, 0, 0, SIZE(cr), SIZE(cr)); |
1d8e8ad8 |
2964 | ds->started = TRUE; |
2965 | } |
2966 | } |
2967 | |
2968 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
e3f21163 |
2969 | int dir, game_ui *ui) |
1d8e8ad8 |
2970 | { |
2971 | return 0.0F; |
2972 | } |
2973 | |
2974 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
e3f21163 |
2975 | int dir, game_ui *ui) |
1d8e8ad8 |
2976 | { |
2ac6d24e |
2977 | if (!oldstate->completed && newstate->completed && |
2978 | !oldstate->cheated && !newstate->cheated) |
1d8e8ad8 |
2979 | return FLASH_TIME; |
2980 | return 0.0F; |
2981 | } |
2982 | |
4d08de49 |
2983 | static int game_timing_state(game_state *state, game_ui *ui) |
48dcdd62 |
2984 | { |
2985 | return TRUE; |
2986 | } |
2987 | |
dafd6cf6 |
2988 | static void game_print_size(game_params *params, float *x, float *y) |
2989 | { |
2990 | int pw, ph; |
2991 | |
2992 | /* |
2993 | * I'll use 9mm squares by default. They should be quite big |
2994 | * for this game, because players will want to jot down no end |
2995 | * of pencil marks in the squares. |
2996 | */ |
2997 | game_compute_size(params, 900, &pw, &ph); |
2998 | *x = pw / 100.0; |
2999 | *y = ph / 100.0; |
3000 | } |
3001 | |
3002 | static void game_print(drawing *dr, game_state *state, int tilesize) |
3003 | { |
3004 | int c = state->c, r = state->r, cr = c*r; |
3005 | int ink = print_mono_colour(dr, 0); |
3006 | int x, y; |
3007 | |
3008 | /* Ick: fake up `ds->tilesize' for macro expansion purposes */ |
3009 | game_drawstate ads, *ds = &ads; |
4413ef0f |
3010 | game_set_size(dr, ds, NULL, tilesize); |
dafd6cf6 |
3011 | |
3012 | /* |
3013 | * Border. |
3014 | */ |
3015 | print_line_width(dr, 3 * TILE_SIZE / 40); |
3016 | draw_rect_outline(dr, BORDER, BORDER, cr*TILE_SIZE, cr*TILE_SIZE, ink); |
3017 | |
3018 | /* |
3019 | * Grid. |
3020 | */ |
3021 | for (x = 1; x < cr; x++) { |
3022 | print_line_width(dr, (x % r ? 1 : 3) * TILE_SIZE / 40); |
3023 | draw_line(dr, BORDER+x*TILE_SIZE, BORDER, |
3024 | BORDER+x*TILE_SIZE, BORDER+cr*TILE_SIZE, ink); |
3025 | } |
3026 | for (y = 1; y < cr; y++) { |
3027 | print_line_width(dr, (y % c ? 1 : 3) * TILE_SIZE / 40); |
3028 | draw_line(dr, BORDER, BORDER+y*TILE_SIZE, |
3029 | BORDER+cr*TILE_SIZE, BORDER+y*TILE_SIZE, ink); |
3030 | } |
3031 | |
3032 | /* |
3033 | * Numbers. |
3034 | */ |
3035 | for (y = 0; y < cr; y++) |
3036 | for (x = 0; x < cr; x++) |
3037 | if (state->grid[y*cr+x]) { |
3038 | char str[2]; |
3039 | str[1] = '\0'; |
3040 | str[0] = state->grid[y*cr+x] + '0'; |
3041 | if (str[0] > '9') |
3042 | str[0] += 'a' - ('9'+1); |
3043 | draw_text(dr, BORDER + x*TILE_SIZE + TILE_SIZE/2, |
3044 | BORDER + y*TILE_SIZE + TILE_SIZE/2, |
3045 | FONT_VARIABLE, TILE_SIZE/2, |
3046 | ALIGN_VCENTRE | ALIGN_HCENTRE, ink, str); |
3047 | } |
3048 | } |
3049 | |
1d8e8ad8 |
3050 | #ifdef COMBINED |
3051 | #define thegame solo |
3052 | #endif |
3053 | |
3054 | const struct game thegame = { |
750037d7 |
3055 | "Solo", "games.solo", "solo", |
1d8e8ad8 |
3056 | default_params, |
3057 | game_fetch_preset, |
3058 | decode_params, |
3059 | encode_params, |
3060 | free_params, |
3061 | dup_params, |
1d228b10 |
3062 | TRUE, game_configure, custom_params, |
1d8e8ad8 |
3063 | validate_params, |
1185e3c5 |
3064 | new_game_desc, |
1185e3c5 |
3065 | validate_desc, |
1d8e8ad8 |
3066 | new_game, |
3067 | dup_game, |
3068 | free_game, |
2ac6d24e |
3069 | TRUE, solve_game, |
9b4b03d3 |
3070 | TRUE, game_text_format, |
1d8e8ad8 |
3071 | new_ui, |
3072 | free_ui, |
ae8290c6 |
3073 | encode_ui, |
3074 | decode_ui, |
07dfb697 |
3075 | game_changed_state, |
df11cd4e |
3076 | interpret_move, |
3077 | execute_move, |
1f3ee4ee |
3078 | PREFERRED_TILE_SIZE, game_compute_size, game_set_size, |
1d8e8ad8 |
3079 | game_colours, |
3080 | game_new_drawstate, |
3081 | game_free_drawstate, |
3082 | game_redraw, |
3083 | game_anim_length, |
3084 | game_flash_length, |
dafd6cf6 |
3085 | TRUE, FALSE, game_print_size, game_print, |
ac9f41c4 |
3086 | FALSE, /* wants_statusbar */ |
48dcdd62 |
3087 | FALSE, game_timing_state, |
cb0c7d4a |
3088 | REQUIRE_RBUTTON | REQUIRE_NUMPAD, /* flags */ |
1d8e8ad8 |
3089 | }; |
3ddae0ff |
3090 | |
3091 | #ifdef STANDALONE_SOLVER |
3092 | |
3ddae0ff |
3093 | int main(int argc, char **argv) |
3094 | { |
3095 | game_params *p; |
3096 | game_state *s; |
1185e3c5 |
3097 | char *id = NULL, *desc, *err; |
7c568a48 |
3098 | int grade = FALSE; |
ab362080 |
3099 | int ret; |
3ddae0ff |
3100 | |
3101 | while (--argc > 0) { |
3102 | char *p = *++argv; |
ab362080 |
3103 | if (!strcmp(p, "-v")) { |
7c568a48 |
3104 | solver_show_working = TRUE; |
7c568a48 |
3105 | } else if (!strcmp(p, "-g")) { |
3106 | grade = TRUE; |
3ddae0ff |
3107 | } else if (*p == '-') { |
8317499a |
3108 | fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p); |
3ddae0ff |
3109 | return 1; |
3110 | } else { |
3111 | id = p; |
3112 | } |
3113 | } |
3114 | |
3115 | if (!id) { |
ab362080 |
3116 | fprintf(stderr, "usage: %s [-g | -v] <game_id>\n", argv[0]); |
3ddae0ff |
3117 | return 1; |
3118 | } |
3119 | |
1185e3c5 |
3120 | desc = strchr(id, ':'); |
3121 | if (!desc) { |
3ddae0ff |
3122 | fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]); |
3123 | return 1; |
3124 | } |
1185e3c5 |
3125 | *desc++ = '\0'; |
3ddae0ff |
3126 | |
1733f4ca |
3127 | p = default_params(); |
3128 | decode_params(p, id); |
1185e3c5 |
3129 | err = validate_desc(p, desc); |
3ddae0ff |
3130 | if (err) { |
3131 | fprintf(stderr, "%s: %s\n", argv[0], err); |
3132 | return 1; |
3133 | } |
39d682c9 |
3134 | s = new_game(NULL, p, desc); |
3ddae0ff |
3135 | |
947a07d6 |
3136 | ret = solver(p->c, p->r, s->grid, DIFF_RECURSIVE); |
ab362080 |
3137 | if (grade) { |
3138 | printf("Difficulty rating: %s\n", |
3139 | ret==DIFF_BLOCK ? "Trivial (blockwise positional elimination only)": |
3140 | ret==DIFF_SIMPLE ? "Basic (row/column/number elimination required)": |
3141 | ret==DIFF_INTERSECT ? "Intermediate (intersectional analysis required)": |
3142 | ret==DIFF_SET ? "Advanced (set elimination required)": |
44bf5f6f |
3143 | ret==DIFF_EXTREME ? "Extreme (complex non-recursive techniques required)": |
ab362080 |
3144 | ret==DIFF_RECURSIVE ? "Unreasonable (guesswork and backtracking required)": |
3145 | ret==DIFF_AMBIGUOUS ? "Ambiguous (multiple solutions exist)": |
3146 | ret==DIFF_IMPOSSIBLE ? "Impossible (no solution exists)": |
3147 | "INTERNAL ERROR: unrecognised difficulty code"); |
3ddae0ff |
3148 | } else { |
ab362080 |
3149 | printf("%s\n", grid_text_format(p->c, p->r, s->grid)); |
3ddae0ff |
3150 | } |
3151 | |
3ddae0ff |
3152 | return 0; |
3153 | } |
3154 | |
3155 | #endif |