6193da8d |
1 | /* |
7c95608a |
2 | * loopy.c: |
3 | * |
4 | * An implementation of the Nikoli game 'Loop the loop'. |
121aae4b |
5 | * (c) Mike Pinna, 2005, 2006 |
7c95608a |
6 | * Substantially rewritten to allowing for more general types of grid. |
7 | * (c) Lambros Lambrou 2008 |
6193da8d |
8 | * |
9 | * vim: set shiftwidth=4 :set textwidth=80: |
7c95608a |
10 | */ |
6193da8d |
11 | |
12 | /* |
a36a26d7 |
13 | * Possible future solver enhancements: |
14 | * |
15 | * - There's an interesting deductive technique which makes use |
16 | * of topology rather than just graph theory. Each _face_ in |
17 | * the grid is either inside or outside the loop; you can tell |
18 | * that two faces are on the same side of the loop if they're |
19 | * separated by a LINE_NO (or, more generally, by a path |
20 | * crossing no LINE_UNKNOWNs and an even number of LINE_YESes), |
21 | * and on the opposite side of the loop if they're separated by |
22 | * a LINE_YES (or an odd number of LINE_YESes and no |
23 | * LINE_UNKNOWNs). Oh, and any face separated from the outside |
24 | * of the grid by a LINE_YES or a LINE_NO is on the inside or |
25 | * outside respectively. So if you can track this for all |
26 | * faces, you figure out the state of the line between a pair |
27 | * once their relative insideness is known. |
28 | * + The way I envisage this working is simply to keep an edsf |
29 | * of all _faces_, which indicates whether they're on |
30 | * opposite sides of the loop from one another. We also |
31 | * include a special entry in the edsf for the infinite |
32 | * exterior "face". |
33 | * + So, the simple way to do this is to just go through the |
34 | * edges: every time we see an edge in a state other than |
35 | * LINE_UNKNOWN which separates two faces that aren't in the |
36 | * same edsf class, we can rectify that by merging the |
37 | * classes. Then, conversely, an edge in LINE_UNKNOWN state |
38 | * which separates two faces that _are_ in the same edsf |
39 | * class can immediately have its state determined. |
40 | * + But you can go one better, if you're prepared to loop |
41 | * over all _pairs_ of edges. Suppose we have edges A and B, |
42 | * which respectively separate faces A1,A2 and B1,B2. |
43 | * Suppose that A,B are in the same edge-edsf class and that |
44 | * A1,B1 (wlog) are in the same face-edsf class; then we can |
45 | * immediately place A2,B2 into the same face-edsf class (as |
46 | * each other, not as A1 and A2) one way round or the other. |
47 | * And conversely again, if A1,B1 are in the same face-edsf |
48 | * class and so are A2,B2, then we can put A,B into the same |
49 | * face-edsf class. |
50 | * * Of course, this deduction requires a quadratic-time |
51 | * loop over all pairs of edges in the grid, so it should |
52 | * be reserved until there's nothing easier left to be |
53 | * done. |
54 | * |
55 | * - The generalised grid support has made me (SGT) notice a |
56 | * possible extension to the loop-avoidance code. When you have |
57 | * a path of connected edges such that no other edges at all |
58 | * are incident on any vertex in the middle of the path - or, |
59 | * alternatively, such that any such edges are already known to |
60 | * be LINE_NO - then you know those edges are either all |
61 | * LINE_YES or all LINE_NO. Hence you can mentally merge the |
62 | * entire path into a single long curly edge for the purposes |
63 | * of loop avoidance, and look directly at whether or not the |
64 | * extreme endpoints of the path are connected by some other |
65 | * route. I find this coming up fairly often when I play on the |
66 | * octagonal grid setting, so it might be worth implementing in |
67 | * the solver. |
121aae4b |
68 | * |
69 | * - (Just a speed optimisation.) Consider some todo list queue where every |
70 | * time we modify something we mark it for consideration by other bits of |
71 | * the solver, to save iteration over things that have already been done. |
6193da8d |
72 | */ |
73 | |
74 | #include <stdio.h> |
75 | #include <stdlib.h> |
7126ca41 |
76 | #include <stddef.h> |
6193da8d |
77 | #include <string.h> |
78 | #include <assert.h> |
79 | #include <ctype.h> |
80 | #include <math.h> |
81 | |
82 | #include "puzzles.h" |
83 | #include "tree234.h" |
7c95608a |
84 | #include "grid.h" |
6193da8d |
85 | |
121aae4b |
86 | /* Debugging options */ |
7c95608a |
87 | |
88 | /* |
89 | #define DEBUG_CACHES |
90 | #define SHOW_WORKING |
91 | #define DEBUG_DLINES |
92 | */ |
121aae4b |
93 | |
94 | /* ---------------------------------------------------------------------- |
95 | * Struct, enum and function declarations |
96 | */ |
97 | |
98 | enum { |
99 | COL_BACKGROUND, |
100 | COL_FOREGROUND, |
7c95608a |
101 | COL_LINEUNKNOWN, |
121aae4b |
102 | COL_HIGHLIGHT, |
103 | COL_MISTAKE, |
7c95608a |
104 | COL_SATISFIED, |
ec909c7a |
105 | COL_FAINT, |
121aae4b |
106 | NCOLOURS |
107 | }; |
108 | |
109 | struct game_state { |
cebf0b0d |
110 | grid *game_grid; /* ref-counted (internally) */ |
7c95608a |
111 | |
112 | /* Put -1 in a face that doesn't get a clue */ |
aa8ccc55 |
113 | signed char *clues; |
7c95608a |
114 | |
115 | /* Array of line states, to store whether each line is |
116 | * YES, NO or UNKNOWN */ |
117 | char *lines; |
121aae4b |
118 | |
b6bf0adc |
119 | unsigned char *line_errors; |
120 | |
121aae4b |
121 | int solved; |
122 | int cheated; |
123 | |
7c95608a |
124 | /* Used in game_text_format(), so that it knows what type of |
125 | * grid it's trying to render as ASCII text. */ |
126 | int grid_type; |
121aae4b |
127 | }; |
128 | |
129 | enum solver_status { |
130 | SOLVER_SOLVED, /* This is the only solution the solver could find */ |
131 | SOLVER_MISTAKE, /* This is definitely not a solution */ |
132 | SOLVER_AMBIGUOUS, /* This _might_ be an ambiguous solution */ |
133 | SOLVER_INCOMPLETE /* This may be a partial solution */ |
134 | }; |
135 | |
7c95608a |
136 | /* ------ Solver state ------ */ |
121aae4b |
137 | typedef struct solver_state { |
138 | game_state *state; |
121aae4b |
139 | enum solver_status solver_status; |
140 | /* NB looplen is the number of dots that are joined together at a point, ie a |
141 | * looplen of 1 means there are no lines to a particular dot */ |
142 | int *looplen; |
143 | |
315e47b9 |
144 | /* Difficulty level of solver. Used by solver functions that want to |
145 | * vary their behaviour depending on the requested difficulty level. */ |
146 | int diff; |
147 | |
121aae4b |
148 | /* caches */ |
7c95608a |
149 | char *dot_yes_count; |
150 | char *dot_no_count; |
151 | char *face_yes_count; |
152 | char *face_no_count; |
153 | char *dot_solved, *face_solved; |
121aae4b |
154 | int *dotdsf; |
155 | |
315e47b9 |
156 | /* Information for Normal level deductions: |
157 | * For each dline, store a bitmask for whether we know: |
158 | * (bit 0) at least one is YES |
159 | * (bit 1) at most one is YES */ |
160 | char *dlines; |
161 | |
162 | /* Hard level information */ |
163 | int *linedsf; |
121aae4b |
164 | } solver_state; |
165 | |
166 | /* |
167 | * Difficulty levels. I do some macro ickery here to ensure that my |
168 | * enum and the various forms of my name list always match up. |
169 | */ |
170 | |
171 | #define DIFFLIST(A) \ |
315e47b9 |
172 | A(EASY,Easy,e) \ |
173 | A(NORMAL,Normal,n) \ |
174 | A(TRICKY,Tricky,t) \ |
175 | A(HARD,Hard,h) |
176 | #define ENUM(upper,title,lower) DIFF_ ## upper, |
177 | #define TITLE(upper,title,lower) #title, |
178 | #define ENCODE(upper,title,lower) #lower |
179 | #define CONFIG(upper,title,lower) ":" #title |
1a739e2f |
180 | enum { DIFFLIST(ENUM) DIFF_MAX }; |
121aae4b |
181 | static char const *const diffnames[] = { DIFFLIST(TITLE) }; |
182 | static char const diffchars[] = DIFFLIST(ENCODE); |
183 | #define DIFFCONFIG DIFFLIST(CONFIG) |
315e47b9 |
184 | |
185 | /* |
186 | * Solver routines, sorted roughly in order of computational cost. |
187 | * The solver will run the faster deductions first, and slower deductions are |
188 | * only invoked when the faster deductions are unable to make progress. |
189 | * Each function is associated with a difficulty level, so that the generated |
190 | * puzzles are solvable by applying only the functions with the chosen |
191 | * difficulty level or lower. |
192 | */ |
193 | #define SOLVERLIST(A) \ |
194 | A(trivial_deductions, DIFF_EASY) \ |
195 | A(dline_deductions, DIFF_NORMAL) \ |
196 | A(linedsf_deductions, DIFF_HARD) \ |
197 | A(loop_deductions, DIFF_EASY) |
198 | #define SOLVER_FN_DECL(fn,diff) static int fn(solver_state *); |
199 | #define SOLVER_FN(fn,diff) &fn, |
200 | #define SOLVER_DIFF(fn,diff) diff, |
201 | SOLVERLIST(SOLVER_FN_DECL) |
202 | static int (*(solver_fns[]))(solver_state *) = { SOLVERLIST(SOLVER_FN) }; |
203 | static int const solver_diffs[] = { SOLVERLIST(SOLVER_DIFF) }; |
204 | const int NUM_SOLVERS = sizeof(solver_diffs)/sizeof(*solver_diffs); |
121aae4b |
205 | |
206 | struct game_params { |
207 | int w, h; |
1a739e2f |
208 | int diff; |
7c95608a |
209 | int type; |
121aae4b |
210 | }; |
211 | |
b6bf0adc |
212 | /* line_drawstate is the same as line_state, but with the extra ERROR |
213 | * possibility. The drawing code copies line_state to line_drawstate, |
214 | * except in the case that the line is an error. */ |
121aae4b |
215 | enum line_state { LINE_YES, LINE_UNKNOWN, LINE_NO }; |
b6bf0adc |
216 | enum line_drawstate { DS_LINE_YES, DS_LINE_UNKNOWN, |
217 | DS_LINE_NO, DS_LINE_ERROR }; |
121aae4b |
218 | |
7c95608a |
219 | #define OPP(line_state) \ |
220 | (2 - line_state) |
121aae4b |
221 | |
121aae4b |
222 | |
223 | struct game_drawstate { |
224 | int started; |
7c95608a |
225 | int tilesize; |
121aae4b |
226 | int flashing; |
e0936bbd |
227 | int *textx, *texty; |
7c95608a |
228 | char *lines; |
121aae4b |
229 | char *clue_error; |
7c95608a |
230 | char *clue_satisfied; |
121aae4b |
231 | }; |
232 | |
121aae4b |
233 | static char *validate_desc(game_params *params, char *desc); |
7c95608a |
234 | static int dot_order(const game_state* state, int i, char line_type); |
235 | static int face_order(const game_state* state, int i, char line_type); |
315e47b9 |
236 | static solver_state *solve_game_rec(const solver_state *sstate); |
121aae4b |
237 | |
238 | #ifdef DEBUG_CACHES |
239 | static void check_caches(const solver_state* sstate); |
240 | #else |
241 | #define check_caches(s) |
242 | #endif |
243 | |
7c95608a |
244 | /* ------- List of grid generators ------- */ |
245 | #define GRIDLIST(A) \ |
cebf0b0d |
246 | A(Squares,GRID_SQUARE,3,3) \ |
247 | A(Triangular,GRID_TRIANGULAR,3,3) \ |
248 | A(Honeycomb,GRID_HONEYCOMB,3,3) \ |
249 | A(Snub-Square,GRID_SNUBSQUARE,3,3) \ |
250 | A(Cairo,GRID_CAIRO,3,4) \ |
251 | A(Great-Hexagonal,GRID_GREATHEXAGONAL,3,3) \ |
252 | A(Octagonal,GRID_OCTAGONAL,3,3) \ |
253 | A(Kites,GRID_KITE,3,3) \ |
254 | A(Floret,GRID_FLORET,1,2) \ |
255 | A(Dodecagonal,GRID_DODECAGONAL,2,2) \ |
256 | A(Great-Dodecagonal,GRID_GREATDODECAGONAL,2,2) \ |
257 | A(Penrose (kite/dart),GRID_PENROSE_P2,3,3) \ |
258 | A(Penrose (rhombs),GRID_PENROSE_P3,3,3) |
259 | |
260 | #define GRID_NAME(title,type,amin,omin) #title, |
261 | #define GRID_CONFIG(title,type,amin,omin) ":" #title |
262 | #define GRID_TYPE(title,type,amin,omin) type, |
263 | #define GRID_SIZES(title,type,amin,omin) \ |
e3c9e042 |
264 | {amin, omin, \ |
265 | "Width and height for this grid type must both be at least " #amin, \ |
266 | "At least one of width and height for this grid type must be at least " #omin,}, |
7c95608a |
267 | static char const *const gridnames[] = { GRIDLIST(GRID_NAME) }; |
268 | #define GRID_CONFIGS GRIDLIST(GRID_CONFIG) |
cebf0b0d |
269 | static grid_type grid_types[] = { GRIDLIST(GRID_TYPE) }; |
270 | #define NUM_GRID_TYPES (sizeof(grid_types) / sizeof(grid_types[0])) |
e3c9e042 |
271 | static const struct { |
272 | int amin, omin; |
273 | char *aerr, *oerr; |
274 | } grid_size_limits[] = { GRIDLIST(GRID_SIZES) }; |
7c95608a |
275 | |
276 | /* Generates a (dynamically allocated) new grid, according to the |
277 | * type and size requested in params. Does nothing if the grid is already |
cebf0b0d |
278 | * generated. */ |
279 | static grid *loopy_generate_grid(game_params *params, char *grid_desc) |
7c95608a |
280 | { |
cebf0b0d |
281 | return grid_new(grid_types[params->type], params->w, params->h, grid_desc); |
7c95608a |
282 | } |
283 | |
121aae4b |
284 | /* ---------------------------------------------------------------------- |
7c95608a |
285 | * Preprocessor magic |
121aae4b |
286 | */ |
287 | |
288 | /* General constants */ |
6193da8d |
289 | #define PREFERRED_TILE_SIZE 32 |
7c95608a |
290 | #define BORDER(tilesize) ((tilesize) / 2) |
c0eb17ce |
291 | #define FLASH_TIME 0.5F |
6193da8d |
292 | |
121aae4b |
293 | #define BIT_SET(field, bit) ((field) & (1<<(bit))) |
294 | |
295 | #define SET_BIT(field, bit) (BIT_SET(field, bit) ? FALSE : \ |
296 | ((field) |= (1<<(bit)), TRUE)) |
297 | |
298 | #define CLEAR_BIT(field, bit) (BIT_SET(field, bit) ? \ |
299 | ((field) &= ~(1<<(bit)), TRUE) : FALSE) |
300 | |
121aae4b |
301 | #define CLUE2CHAR(c) \ |
918a098a |
302 | ((c < 0) ? ' ' : c < 10 ? c + '0' : c - 10 + 'A') |
121aae4b |
303 | |
121aae4b |
304 | /* ---------------------------------------------------------------------- |
305 | * General struct manipulation and other straightforward code |
306 | */ |
6193da8d |
307 | |
308 | static game_state *dup_game(game_state *state) |
309 | { |
310 | game_state *ret = snew(game_state); |
311 | |
7c95608a |
312 | ret->game_grid = state->game_grid; |
313 | ret->game_grid->refcount++; |
314 | |
6193da8d |
315 | ret->solved = state->solved; |
316 | ret->cheated = state->cheated; |
317 | |
7c95608a |
318 | ret->clues = snewn(state->game_grid->num_faces, signed char); |
319 | memcpy(ret->clues, state->clues, state->game_grid->num_faces); |
6193da8d |
320 | |
7c95608a |
321 | ret->lines = snewn(state->game_grid->num_edges, char); |
322 | memcpy(ret->lines, state->lines, state->game_grid->num_edges); |
6193da8d |
323 | |
b6bf0adc |
324 | ret->line_errors = snewn(state->game_grid->num_edges, unsigned char); |
325 | memcpy(ret->line_errors, state->line_errors, state->game_grid->num_edges); |
326 | |
7c95608a |
327 | ret->grid_type = state->grid_type; |
6193da8d |
328 | return ret; |
329 | } |
330 | |
331 | static void free_game(game_state *state) |
332 | { |
333 | if (state) { |
7c95608a |
334 | grid_free(state->game_grid); |
6193da8d |
335 | sfree(state->clues); |
7c95608a |
336 | sfree(state->lines); |
b6bf0adc |
337 | sfree(state->line_errors); |
6193da8d |
338 | sfree(state); |
339 | } |
340 | } |
341 | |
7c95608a |
342 | static solver_state *new_solver_state(game_state *state, int diff) { |
343 | int i; |
344 | int num_dots = state->game_grid->num_dots; |
345 | int num_faces = state->game_grid->num_faces; |
346 | int num_edges = state->game_grid->num_edges; |
6193da8d |
347 | solver_state *ret = snew(solver_state); |
6193da8d |
348 | |
7c95608a |
349 | ret->state = dup_game(state); |
350 | |
351 | ret->solver_status = SOLVER_INCOMPLETE; |
315e47b9 |
352 | ret->diff = diff; |
6193da8d |
353 | |
7c95608a |
354 | ret->dotdsf = snew_dsf(num_dots); |
355 | ret->looplen = snewn(num_dots, int); |
121aae4b |
356 | |
7c95608a |
357 | for (i = 0; i < num_dots; i++) { |
121aae4b |
358 | ret->looplen[i] = 1; |
359 | } |
360 | |
7c95608a |
361 | ret->dot_solved = snewn(num_dots, char); |
362 | ret->face_solved = snewn(num_faces, char); |
363 | memset(ret->dot_solved, FALSE, num_dots); |
364 | memset(ret->face_solved, FALSE, num_faces); |
121aae4b |
365 | |
7c95608a |
366 | ret->dot_yes_count = snewn(num_dots, char); |
367 | memset(ret->dot_yes_count, 0, num_dots); |
368 | ret->dot_no_count = snewn(num_dots, char); |
369 | memset(ret->dot_no_count, 0, num_dots); |
370 | ret->face_yes_count = snewn(num_faces, char); |
371 | memset(ret->face_yes_count, 0, num_faces); |
372 | ret->face_no_count = snewn(num_faces, char); |
373 | memset(ret->face_no_count, 0, num_faces); |
121aae4b |
374 | |
375 | if (diff < DIFF_NORMAL) { |
315e47b9 |
376 | ret->dlines = NULL; |
121aae4b |
377 | } else { |
315e47b9 |
378 | ret->dlines = snewn(2*num_edges, char); |
379 | memset(ret->dlines, 0, 2*num_edges); |
121aae4b |
380 | } |
381 | |
382 | if (diff < DIFF_HARD) { |
315e47b9 |
383 | ret->linedsf = NULL; |
121aae4b |
384 | } else { |
315e47b9 |
385 | ret->linedsf = snew_dsf(state->game_grid->num_edges); |
6193da8d |
386 | } |
387 | |
388 | return ret; |
389 | } |
390 | |
391 | static void free_solver_state(solver_state *sstate) { |
392 | if (sstate) { |
393 | free_game(sstate->state); |
9cfc03b7 |
394 | sfree(sstate->dotdsf); |
395 | sfree(sstate->looplen); |
121aae4b |
396 | sfree(sstate->dot_solved); |
7c95608a |
397 | sfree(sstate->face_solved); |
398 | sfree(sstate->dot_yes_count); |
399 | sfree(sstate->dot_no_count); |
400 | sfree(sstate->face_yes_count); |
401 | sfree(sstate->face_no_count); |
121aae4b |
402 | |
315e47b9 |
403 | /* OK, because sfree(NULL) is a no-op */ |
404 | sfree(sstate->dlines); |
405 | sfree(sstate->linedsf); |
121aae4b |
406 | |
9cfc03b7 |
407 | sfree(sstate); |
6193da8d |
408 | } |
409 | } |
410 | |
121aae4b |
411 | static solver_state *dup_solver_state(const solver_state *sstate) { |
7c95608a |
412 | game_state *state = sstate->state; |
413 | int num_dots = state->game_grid->num_dots; |
414 | int num_faces = state->game_grid->num_faces; |
415 | int num_edges = state->game_grid->num_edges; |
6193da8d |
416 | solver_state *ret = snew(solver_state); |
417 | |
9cfc03b7 |
418 | ret->state = state = dup_game(sstate->state); |
6193da8d |
419 | |
6193da8d |
420 | ret->solver_status = sstate->solver_status; |
315e47b9 |
421 | ret->diff = sstate->diff; |
6193da8d |
422 | |
7c95608a |
423 | ret->dotdsf = snewn(num_dots, int); |
424 | ret->looplen = snewn(num_dots, int); |
425 | memcpy(ret->dotdsf, sstate->dotdsf, |
426 | num_dots * sizeof(int)); |
427 | memcpy(ret->looplen, sstate->looplen, |
428 | num_dots * sizeof(int)); |
429 | |
430 | ret->dot_solved = snewn(num_dots, char); |
431 | ret->face_solved = snewn(num_faces, char); |
432 | memcpy(ret->dot_solved, sstate->dot_solved, num_dots); |
433 | memcpy(ret->face_solved, sstate->face_solved, num_faces); |
434 | |
435 | ret->dot_yes_count = snewn(num_dots, char); |
436 | memcpy(ret->dot_yes_count, sstate->dot_yes_count, num_dots); |
437 | ret->dot_no_count = snewn(num_dots, char); |
438 | memcpy(ret->dot_no_count, sstate->dot_no_count, num_dots); |
439 | |
440 | ret->face_yes_count = snewn(num_faces, char); |
441 | memcpy(ret->face_yes_count, sstate->face_yes_count, num_faces); |
442 | ret->face_no_count = snewn(num_faces, char); |
443 | memcpy(ret->face_no_count, sstate->face_no_count, num_faces); |
121aae4b |
444 | |
315e47b9 |
445 | if (sstate->dlines) { |
446 | ret->dlines = snewn(2*num_edges, char); |
447 | memcpy(ret->dlines, sstate->dlines, |
7c95608a |
448 | 2*num_edges); |
121aae4b |
449 | } else { |
315e47b9 |
450 | ret->dlines = NULL; |
121aae4b |
451 | } |
452 | |
315e47b9 |
453 | if (sstate->linedsf) { |
454 | ret->linedsf = snewn(num_edges, int); |
455 | memcpy(ret->linedsf, sstate->linedsf, |
7c95608a |
456 | num_edges * sizeof(int)); |
121aae4b |
457 | } else { |
315e47b9 |
458 | ret->linedsf = NULL; |
121aae4b |
459 | } |
6193da8d |
460 | |
461 | return ret; |
462 | } |
463 | |
121aae4b |
464 | static game_params *default_params(void) |
6193da8d |
465 | { |
121aae4b |
466 | game_params *ret = snew(game_params); |
6193da8d |
467 | |
121aae4b |
468 | #ifdef SLOW_SYSTEM |
7c95608a |
469 | ret->h = 7; |
470 | ret->w = 7; |
121aae4b |
471 | #else |
472 | ret->h = 10; |
473 | ret->w = 10; |
474 | #endif |
475 | ret->diff = DIFF_EASY; |
7c95608a |
476 | ret->type = 0; |
477 | |
121aae4b |
478 | return ret; |
6193da8d |
479 | } |
480 | |
121aae4b |
481 | static game_params *dup_params(game_params *params) |
6193da8d |
482 | { |
121aae4b |
483 | game_params *ret = snew(game_params); |
7c95608a |
484 | |
121aae4b |
485 | *ret = *params; /* structure copy */ |
486 | return ret; |
487 | } |
6193da8d |
488 | |
121aae4b |
489 | static const game_params presets[] = { |
b1535c90 |
490 | #ifdef SMALL_SCREEN |
cebf0b0d |
491 | { 7, 7, DIFF_EASY, 0 }, |
492 | { 7, 7, DIFF_NORMAL, 0 }, |
493 | { 7, 7, DIFF_HARD, 0 }, |
494 | { 7, 7, DIFF_HARD, 1 }, |
495 | { 7, 7, DIFF_HARD, 2 }, |
496 | { 5, 5, DIFF_HARD, 3 }, |
497 | { 7, 7, DIFF_HARD, 4 }, |
498 | { 5, 4, DIFF_HARD, 5 }, |
499 | { 5, 5, DIFF_HARD, 6 }, |
500 | { 5, 5, DIFF_HARD, 7 }, |
501 | { 3, 3, DIFF_HARD, 8 }, |
502 | { 3, 3, DIFF_HARD, 9 }, |
503 | { 3, 3, DIFF_HARD, 10 }, |
504 | { 6, 6, DIFF_HARD, 11 }, |
505 | { 6, 6, DIFF_HARD, 12 }, |
b1535c90 |
506 | #else |
cebf0b0d |
507 | { 7, 7, DIFF_EASY, 0 }, |
508 | { 10, 10, DIFF_EASY, 0 }, |
509 | { 7, 7, DIFF_NORMAL, 0 }, |
510 | { 10, 10, DIFF_NORMAL, 0 }, |
511 | { 7, 7, DIFF_HARD, 0 }, |
512 | { 10, 10, DIFF_HARD, 0 }, |
513 | { 10, 10, DIFF_HARD, 1 }, |
514 | { 12, 10, DIFF_HARD, 2 }, |
515 | { 7, 7, DIFF_HARD, 3 }, |
516 | { 9, 9, DIFF_HARD, 4 }, |
517 | { 5, 4, DIFF_HARD, 5 }, |
518 | { 7, 7, DIFF_HARD, 6 }, |
519 | { 5, 5, DIFF_HARD, 7 }, |
520 | { 5, 5, DIFF_HARD, 8 }, |
521 | { 5, 4, DIFF_HARD, 9 }, |
522 | { 5, 4, DIFF_HARD, 10 }, |
523 | { 10, 10, DIFF_HARD, 11 }, |
524 | { 10, 10, DIFF_HARD, 12 } |
b1535c90 |
525 | #endif |
121aae4b |
526 | }; |
6193da8d |
527 | |
121aae4b |
528 | static int game_fetch_preset(int i, char **name, game_params **params) |
6193da8d |
529 | { |
1a739e2f |
530 | game_params *tmppar; |
121aae4b |
531 | char buf[80]; |
6193da8d |
532 | |
121aae4b |
533 | if (i < 0 || i >= lenof(presets)) |
534 | return FALSE; |
6193da8d |
535 | |
1a739e2f |
536 | tmppar = snew(game_params); |
537 | *tmppar = presets[i]; |
538 | *params = tmppar; |
7c95608a |
539 | sprintf(buf, "%dx%d %s - %s", tmppar->h, tmppar->w, |
540 | gridnames[tmppar->type], diffnames[tmppar->diff]); |
121aae4b |
541 | *name = dupstr(buf); |
542 | |
543 | return TRUE; |
6193da8d |
544 | } |
545 | |
546 | static void free_params(game_params *params) |
547 | { |
548 | sfree(params); |
549 | } |
550 | |
551 | static void decode_params(game_params *params, char const *string) |
552 | { |
553 | params->h = params->w = atoi(string); |
c0eb17ce |
554 | params->diff = DIFF_EASY; |
6193da8d |
555 | while (*string && isdigit((unsigned char)*string)) string++; |
556 | if (*string == 'x') { |
557 | string++; |
558 | params->h = atoi(string); |
121aae4b |
559 | while (*string && isdigit((unsigned char)*string)) string++; |
6193da8d |
560 | } |
7c95608a |
561 | if (*string == 't') { |
6193da8d |
562 | string++; |
7c95608a |
563 | params->type = atoi(string); |
121aae4b |
564 | while (*string && isdigit((unsigned char)*string)) string++; |
6193da8d |
565 | } |
c0eb17ce |
566 | if (*string == 'd') { |
567 | int i; |
c0eb17ce |
568 | string++; |
121aae4b |
569 | for (i = 0; i < DIFF_MAX; i++) |
570 | if (*string == diffchars[i]) |
571 | params->diff = i; |
572 | if (*string) string++; |
c0eb17ce |
573 | } |
6193da8d |
574 | } |
575 | |
576 | static char *encode_params(game_params *params, int full) |
577 | { |
578 | char str[80]; |
7c95608a |
579 | sprintf(str, "%dx%dt%d", params->w, params->h, params->type); |
6193da8d |
580 | if (full) |
7c95608a |
581 | sprintf(str + strlen(str), "d%c", diffchars[params->diff]); |
6193da8d |
582 | return dupstr(str); |
583 | } |
584 | |
585 | static config_item *game_configure(game_params *params) |
586 | { |
587 | config_item *ret; |
588 | char buf[80]; |
589 | |
7c95608a |
590 | ret = snewn(5, config_item); |
6193da8d |
591 | |
592 | ret[0].name = "Width"; |
593 | ret[0].type = C_STRING; |
594 | sprintf(buf, "%d", params->w); |
595 | ret[0].sval = dupstr(buf); |
596 | ret[0].ival = 0; |
597 | |
598 | ret[1].name = "Height"; |
599 | ret[1].type = C_STRING; |
600 | sprintf(buf, "%d", params->h); |
601 | ret[1].sval = dupstr(buf); |
602 | ret[1].ival = 0; |
603 | |
7c95608a |
604 | ret[2].name = "Grid type"; |
c0eb17ce |
605 | ret[2].type = C_CHOICES; |
7c95608a |
606 | ret[2].sval = GRID_CONFIGS; |
607 | ret[2].ival = params->type; |
6193da8d |
608 | |
7c95608a |
609 | ret[3].name = "Difficulty"; |
610 | ret[3].type = C_CHOICES; |
611 | ret[3].sval = DIFFCONFIG; |
612 | ret[3].ival = params->diff; |
613 | |
614 | ret[4].name = NULL; |
615 | ret[4].type = C_END; |
616 | ret[4].sval = NULL; |
617 | ret[4].ival = 0; |
6193da8d |
618 | |
619 | return ret; |
620 | } |
621 | |
622 | static game_params *custom_params(config_item *cfg) |
623 | { |
624 | game_params *ret = snew(game_params); |
625 | |
626 | ret->w = atoi(cfg[0].sval); |
627 | ret->h = atoi(cfg[1].sval); |
7c95608a |
628 | ret->type = cfg[2].ival; |
629 | ret->diff = cfg[3].ival; |
6193da8d |
630 | |
631 | return ret; |
632 | } |
633 | |
634 | static char *validate_params(game_params *params, int full) |
635 | { |
7c95608a |
636 | if (params->type < 0 || params->type >= NUM_GRID_TYPES) |
637 | return "Illegal grid type"; |
e3c9e042 |
638 | if (params->w < grid_size_limits[params->type].amin || |
639 | params->h < grid_size_limits[params->type].amin) |
640 | return grid_size_limits[params->type].aerr; |
641 | if (params->w < grid_size_limits[params->type].omin && |
642 | params->h < grid_size_limits[params->type].omin) |
643 | return grid_size_limits[params->type].oerr; |
c0eb17ce |
644 | |
645 | /* |
646 | * This shouldn't be able to happen at all, since decode_params |
647 | * and custom_params will never generate anything that isn't |
648 | * within range. |
649 | */ |
1a739e2f |
650 | assert(params->diff < DIFF_MAX); |
c0eb17ce |
651 | |
6193da8d |
652 | return NULL; |
653 | } |
654 | |
121aae4b |
655 | /* Returns a newly allocated string describing the current puzzle */ |
656 | static char *state_to_text(const game_state *state) |
6193da8d |
657 | { |
7c95608a |
658 | grid *g = state->game_grid; |
121aae4b |
659 | char *retval; |
7c95608a |
660 | int num_faces = g->num_faces; |
661 | char *description = snewn(num_faces + 1, char); |
121aae4b |
662 | char *dp = description; |
663 | int empty_count = 0; |
7c95608a |
664 | int i; |
6193da8d |
665 | |
7c95608a |
666 | for (i = 0; i < num_faces; i++) { |
667 | if (state->clues[i] < 0) { |
121aae4b |
668 | if (empty_count > 25) { |
669 | dp += sprintf(dp, "%c", (int)(empty_count + 'a' - 1)); |
670 | empty_count = 0; |
671 | } |
672 | empty_count++; |
673 | } else { |
674 | if (empty_count) { |
675 | dp += sprintf(dp, "%c", (int)(empty_count + 'a' - 1)); |
676 | empty_count = 0; |
677 | } |
7c95608a |
678 | dp += sprintf(dp, "%c", (int)CLUE2CHAR(state->clues[i])); |
121aae4b |
679 | } |
680 | } |
6193da8d |
681 | |
121aae4b |
682 | if (empty_count) |
1a739e2f |
683 | dp += sprintf(dp, "%c", (int)(empty_count + 'a' - 1)); |
121aae4b |
684 | |
685 | retval = dupstr(description); |
686 | sfree(description); |
687 | |
688 | return retval; |
6193da8d |
689 | } |
690 | |
cebf0b0d |
691 | #define GRID_DESC_SEP '_' |
692 | |
693 | /* Splits up a (optional) grid_desc from the game desc. Returns the |
694 | * grid_desc (which needs freeing) and updates the desc pointer to |
695 | * start of real desc, or returns NULL if no desc. */ |
696 | static char *extract_grid_desc(char **desc) |
697 | { |
698 | char *sep = strchr(*desc, GRID_DESC_SEP), *gd; |
699 | int gd_len; |
700 | |
701 | if (!sep) return NULL; |
702 | |
703 | gd_len = sep - (*desc); |
704 | gd = snewn(gd_len+1, char); |
705 | memcpy(gd, *desc, gd_len); |
706 | gd[gd_len] = '\0'; |
707 | |
708 | *desc = sep+1; |
709 | |
710 | return gd; |
711 | } |
712 | |
121aae4b |
713 | /* We require that the params pass the test in validate_params and that the |
714 | * description fills the entire game area */ |
715 | static char *validate_desc(game_params *params, char *desc) |
6193da8d |
716 | { |
121aae4b |
717 | int count = 0; |
7c95608a |
718 | grid *g; |
cebf0b0d |
719 | char *grid_desc, *ret; |
720 | |
721 | /* It's pretty inefficient to do this just for validation. All we need to |
722 | * know is the precise number of faces. */ |
723 | grid_desc = extract_grid_desc(&desc); |
724 | ret = grid_validate_desc(grid_types[params->type], params->w, params->h, grid_desc); |
725 | if (ret) return ret; |
726 | |
727 | g = loopy_generate_grid(params, grid_desc); |
728 | if (grid_desc) sfree(grid_desc); |
6193da8d |
729 | |
121aae4b |
730 | for (; *desc; ++desc) { |
918a098a |
731 | if ((*desc >= '0' && *desc <= '9') || (*desc >= 'A' && *desc <= 'Z')) { |
121aae4b |
732 | count++; |
733 | continue; |
734 | } |
735 | if (*desc >= 'a') { |
736 | count += *desc - 'a' + 1; |
737 | continue; |
738 | } |
739 | return "Unknown character in description"; |
6193da8d |
740 | } |
741 | |
7c95608a |
742 | if (count < g->num_faces) |
121aae4b |
743 | return "Description too short for board size"; |
7c95608a |
744 | if (count > g->num_faces) |
121aae4b |
745 | return "Description too long for board size"; |
6193da8d |
746 | |
cebf0b0d |
747 | grid_free(g); |
748 | |
121aae4b |
749 | return NULL; |
6193da8d |
750 | } |
751 | |
121aae4b |
752 | /* Sums the lengths of the numbers in range [0,n) */ |
753 | /* See equivalent function in solo.c for justification of this. */ |
754 | static int len_0_to_n(int n) |
6193da8d |
755 | { |
121aae4b |
756 | int len = 1; /* Counting 0 as a bit of a special case */ |
757 | int i; |
758 | |
759 | for (i = 1; i < n; i *= 10) { |
760 | len += max(n - i, 0); |
6193da8d |
761 | } |
121aae4b |
762 | |
763 | return len; |
6193da8d |
764 | } |
765 | |
121aae4b |
766 | static char *encode_solve_move(const game_state *state) |
767 | { |
7c95608a |
768 | int len; |
121aae4b |
769 | char *ret, *p; |
7c95608a |
770 | int i; |
771 | int num_edges = state->game_grid->num_edges; |
772 | |
121aae4b |
773 | /* This is going to return a string representing the moves needed to set |
774 | * every line in a grid to be the same as the ones in 'state'. The exact |
775 | * length of this string is predictable. */ |
6193da8d |
776 | |
121aae4b |
777 | len = 1; /* Count the 'S' prefix */ |
7c95608a |
778 | /* Numbers in all lines */ |
779 | len += len_0_to_n(num_edges); |
780 | /* For each line we also have a letter */ |
781 | len += num_edges; |
6193da8d |
782 | |
121aae4b |
783 | ret = snewn(len + 1, char); |
784 | p = ret; |
6193da8d |
785 | |
121aae4b |
786 | p += sprintf(p, "S"); |
6193da8d |
787 | |
7c95608a |
788 | for (i = 0; i < num_edges; i++) { |
789 | switch (state->lines[i]) { |
790 | case LINE_YES: |
791 | p += sprintf(p, "%dy", i); |
792 | break; |
793 | case LINE_NO: |
794 | p += sprintf(p, "%dn", i); |
795 | break; |
6193da8d |
796 | } |
6193da8d |
797 | } |
121aae4b |
798 | |
799 | /* No point in doing sums like that if they're going to be wrong */ |
800 | assert(strlen(ret) <= (size_t)len); |
801 | return ret; |
6193da8d |
802 | } |
803 | |
121aae4b |
804 | static game_ui *new_ui(game_state *state) |
6193da8d |
805 | { |
121aae4b |
806 | return NULL; |
807 | } |
6193da8d |
808 | |
121aae4b |
809 | static void free_ui(game_ui *ui) |
810 | { |
811 | } |
6193da8d |
812 | |
121aae4b |
813 | static char *encode_ui(game_ui *ui) |
814 | { |
815 | return NULL; |
816 | } |
6193da8d |
817 | |
121aae4b |
818 | static void decode_ui(game_ui *ui, char *encoding) |
819 | { |
820 | } |
6193da8d |
821 | |
121aae4b |
822 | static void game_changed_state(game_ui *ui, game_state *oldstate, |
823 | game_state *newstate) |
824 | { |
825 | } |
6193da8d |
826 | |
121aae4b |
827 | static void game_compute_size(game_params *params, int tilesize, |
828 | int *x, int *y) |
829 | { |
1515b973 |
830 | int grid_width, grid_height, rendered_width, rendered_height; |
cebf0b0d |
831 | int g_tilesize; |
832 | |
833 | grid_compute_size(grid_types[params->type], params->w, params->h, |
834 | &g_tilesize, &grid_width, &grid_height); |
1515b973 |
835 | |
7c95608a |
836 | /* multiply first to minimise rounding error on integer division */ |
cebf0b0d |
837 | rendered_width = grid_width * tilesize / g_tilesize; |
838 | rendered_height = grid_height * tilesize / g_tilesize; |
7c95608a |
839 | *x = rendered_width + 2 * BORDER(tilesize) + 1; |
840 | *y = rendered_height + 2 * BORDER(tilesize) + 1; |
121aae4b |
841 | } |
6193da8d |
842 | |
121aae4b |
843 | static void game_set_size(drawing *dr, game_drawstate *ds, |
7c95608a |
844 | game_params *params, int tilesize) |
121aae4b |
845 | { |
846 | ds->tilesize = tilesize; |
121aae4b |
847 | } |
6193da8d |
848 | |
121aae4b |
849 | static float *game_colours(frontend *fe, int *ncolours) |
850 | { |
851 | float *ret = snewn(4 * NCOLOURS, float); |
6193da8d |
852 | |
121aae4b |
853 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
854 | |
855 | ret[COL_FOREGROUND * 3 + 0] = 0.0F; |
856 | ret[COL_FOREGROUND * 3 + 1] = 0.0F; |
857 | ret[COL_FOREGROUND * 3 + 2] = 0.0F; |
858 | |
32c231bb |
859 | /* |
860 | * We want COL_LINEUNKNOWN to be a yellow which is a bit darker |
861 | * than the background. (I previously set it to 0.8,0.8,0, but |
862 | * found that this went badly with the 0.8,0.8,0.8 favoured as a |
863 | * background by the Java frontend.) |
864 | */ |
865 | ret[COL_LINEUNKNOWN * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] * 0.9F; |
866 | ret[COL_LINEUNKNOWN * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] * 0.9F; |
7c95608a |
867 | ret[COL_LINEUNKNOWN * 3 + 2] = 0.0F; |
868 | |
121aae4b |
869 | ret[COL_HIGHLIGHT * 3 + 0] = 1.0F; |
870 | ret[COL_HIGHLIGHT * 3 + 1] = 1.0F; |
871 | ret[COL_HIGHLIGHT * 3 + 2] = 1.0F; |
872 | |
873 | ret[COL_MISTAKE * 3 + 0] = 1.0F; |
874 | ret[COL_MISTAKE * 3 + 1] = 0.0F; |
875 | ret[COL_MISTAKE * 3 + 2] = 0.0F; |
876 | |
7c95608a |
877 | ret[COL_SATISFIED * 3 + 0] = 0.0F; |
878 | ret[COL_SATISFIED * 3 + 1] = 0.0F; |
879 | ret[COL_SATISFIED * 3 + 2] = 0.0F; |
880 | |
ec909c7a |
881 | /* We want the faint lines to be a bit darker than the background. |
882 | * Except if the background is pretty dark already; then it ought to be a |
883 | * bit lighter. Oy vey. |
884 | */ |
885 | ret[COL_FAINT * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] * 0.9F; |
886 | ret[COL_FAINT * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] * 0.9F; |
887 | ret[COL_FAINT * 3 + 2] = ret[COL_BACKGROUND * 3 + 2] * 0.9F; |
888 | |
121aae4b |
889 | *ncolours = NCOLOURS; |
890 | return ret; |
891 | } |
892 | |
893 | static game_drawstate *game_new_drawstate(drawing *dr, game_state *state) |
894 | { |
895 | struct game_drawstate *ds = snew(struct game_drawstate); |
7c95608a |
896 | int num_faces = state->game_grid->num_faces; |
897 | int num_edges = state->game_grid->num_edges; |
e0936bbd |
898 | int i; |
121aae4b |
899 | |
7c95608a |
900 | ds->tilesize = 0; |
121aae4b |
901 | ds->started = 0; |
7c95608a |
902 | ds->lines = snewn(num_edges, char); |
903 | ds->clue_error = snewn(num_faces, char); |
904 | ds->clue_satisfied = snewn(num_faces, char); |
e0936bbd |
905 | ds->textx = snewn(num_faces, int); |
906 | ds->texty = snewn(num_faces, int); |
121aae4b |
907 | ds->flashing = 0; |
908 | |
7c95608a |
909 | memset(ds->lines, LINE_UNKNOWN, num_edges); |
910 | memset(ds->clue_error, 0, num_faces); |
911 | memset(ds->clue_satisfied, 0, num_faces); |
e0936bbd |
912 | for (i = 0; i < num_faces; i++) |
913 | ds->textx[i] = ds->texty[i] = -1; |
121aae4b |
914 | |
915 | return ds; |
916 | } |
917 | |
918 | static void game_free_drawstate(drawing *dr, game_drawstate *ds) |
919 | { |
920 | sfree(ds->clue_error); |
7c95608a |
921 | sfree(ds->clue_satisfied); |
922 | sfree(ds->lines); |
121aae4b |
923 | sfree(ds); |
924 | } |
925 | |
926 | static int game_timing_state(game_state *state, game_ui *ui) |
927 | { |
928 | return TRUE; |
929 | } |
930 | |
931 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
932 | int dir, game_ui *ui) |
933 | { |
934 | return 0.0F; |
935 | } |
936 | |
7c95608a |
937 | static int game_can_format_as_text_now(game_params *params) |
938 | { |
939 | if (params->type != 0) |
940 | return FALSE; |
941 | return TRUE; |
942 | } |
943 | |
121aae4b |
944 | static char *game_text_format(game_state *state) |
945 | { |
7c95608a |
946 | int w, h, W, H; |
947 | int x, y, i; |
948 | int cell_size; |
949 | char *ret; |
950 | grid *g = state->game_grid; |
951 | grid_face *f; |
952 | |
953 | assert(state->grid_type == 0); |
954 | |
955 | /* Work out the basic size unit */ |
956 | f = g->faces; /* first face */ |
957 | assert(f->order == 4); |
958 | /* The dots are ordered clockwise, so the two opposite |
959 | * corners are guaranteed to span the square */ |
960 | cell_size = abs(f->dots[0]->x - f->dots[2]->x); |
961 | |
962 | w = (g->highest_x - g->lowest_x) / cell_size; |
963 | h = (g->highest_y - g->lowest_y) / cell_size; |
964 | |
965 | /* Create a blank "canvas" to "draw" on */ |
966 | W = 2 * w + 2; |
967 | H = 2 * h + 1; |
968 | ret = snewn(W * H + 1, char); |
969 | for (y = 0; y < H; y++) { |
970 | for (x = 0; x < W-1; x++) { |
971 | ret[y*W + x] = ' '; |
121aae4b |
972 | } |
7c95608a |
973 | ret[y*W + W-1] = '\n'; |
974 | } |
975 | ret[H*W] = '\0'; |
976 | |
977 | /* Fill in edge info */ |
978 | for (i = 0; i < g->num_edges; i++) { |
979 | grid_edge *e = g->edges + i; |
980 | /* Cell coordinates, from (0,0) to (w-1,h-1) */ |
981 | int x1 = (e->dot1->x - g->lowest_x) / cell_size; |
982 | int x2 = (e->dot2->x - g->lowest_x) / cell_size; |
983 | int y1 = (e->dot1->y - g->lowest_y) / cell_size; |
984 | int y2 = (e->dot2->y - g->lowest_y) / cell_size; |
985 | /* Midpoint, in canvas coordinates (canvas coordinates are just twice |
986 | * cell coordinates) */ |
987 | x = x1 + x2; |
988 | y = y1 + y2; |
989 | switch (state->lines[i]) { |
990 | case LINE_YES: |
991 | ret[y*W + x] = (y1 == y2) ? '-' : '|'; |
992 | break; |
993 | case LINE_NO: |
994 | ret[y*W + x] = 'x'; |
995 | break; |
996 | case LINE_UNKNOWN: |
997 | break; /* already a space */ |
998 | default: |
999 | assert(!"Illegal line state"); |
121aae4b |
1000 | } |
121aae4b |
1001 | } |
7c95608a |
1002 | |
1003 | /* Fill in clues */ |
1004 | for (i = 0; i < g->num_faces; i++) { |
1515b973 |
1005 | int x1, x2, y1, y2; |
1006 | |
7c95608a |
1007 | f = g->faces + i; |
1008 | assert(f->order == 4); |
1009 | /* Cell coordinates, from (0,0) to (w-1,h-1) */ |
1515b973 |
1010 | x1 = (f->dots[0]->x - g->lowest_x) / cell_size; |
1011 | x2 = (f->dots[2]->x - g->lowest_x) / cell_size; |
1012 | y1 = (f->dots[0]->y - g->lowest_y) / cell_size; |
1013 | y2 = (f->dots[2]->y - g->lowest_y) / cell_size; |
7c95608a |
1014 | /* Midpoint, in canvas coordinates */ |
1015 | x = x1 + x2; |
1016 | y = y1 + y2; |
1017 | ret[y*W + x] = CLUE2CHAR(state->clues[i]); |
121aae4b |
1018 | } |
121aae4b |
1019 | return ret; |
1020 | } |
1021 | |
1022 | /* ---------------------------------------------------------------------- |
1023 | * Debug code |
1024 | */ |
1025 | |
1026 | #ifdef DEBUG_CACHES |
1027 | static void check_caches(const solver_state* sstate) |
1028 | { |
7c95608a |
1029 | int i; |
121aae4b |
1030 | const game_state *state = sstate->state; |
7c95608a |
1031 | const grid *g = state->game_grid; |
121aae4b |
1032 | |
7c95608a |
1033 | for (i = 0; i < g->num_dots; i++) { |
1034 | assert(dot_order(state, i, LINE_YES) == sstate->dot_yes_count[i]); |
1035 | assert(dot_order(state, i, LINE_NO) == sstate->dot_no_count[i]); |
121aae4b |
1036 | } |
1037 | |
7c95608a |
1038 | for (i = 0; i < g->num_faces; i++) { |
1039 | assert(face_order(state, i, LINE_YES) == sstate->face_yes_count[i]); |
1040 | assert(face_order(state, i, LINE_NO) == sstate->face_no_count[i]); |
121aae4b |
1041 | } |
1042 | } |
1043 | |
1044 | #if 0 |
1045 | #define check_caches(s) \ |
1046 | do { \ |
1047 | fprintf(stderr, "check_caches at line %d\n", __LINE__); \ |
1048 | check_caches(s); \ |
1049 | } while (0) |
1050 | #endif |
1051 | #endif /* DEBUG_CACHES */ |
1052 | |
1053 | /* ---------------------------------------------------------------------- |
1054 | * Solver utility functions |
1055 | */ |
1056 | |
7c95608a |
1057 | /* Sets the line (with index i) to the new state 'line_new', and updates |
1058 | * the cached counts of any affected faces and dots. |
1059 | * Returns TRUE if this actually changed the line's state. */ |
1060 | static int solver_set_line(solver_state *sstate, int i, |
1061 | enum line_state line_new |
121aae4b |
1062 | #ifdef SHOW_WORKING |
7c95608a |
1063 | , const char *reason |
121aae4b |
1064 | #endif |
7c95608a |
1065 | ) |
121aae4b |
1066 | { |
1067 | game_state *state = sstate->state; |
7c95608a |
1068 | grid *g; |
1069 | grid_edge *e; |
121aae4b |
1070 | |
1071 | assert(line_new != LINE_UNKNOWN); |
1072 | |
1073 | check_caches(sstate); |
1074 | |
7c95608a |
1075 | if (state->lines[i] == line_new) { |
1076 | return FALSE; /* nothing changed */ |
121aae4b |
1077 | } |
7c95608a |
1078 | state->lines[i] = line_new; |
121aae4b |
1079 | |
1080 | #ifdef SHOW_WORKING |
7c95608a |
1081 | fprintf(stderr, "solver: set line [%d] to %s (%s)\n", |
1082 | i, line_new == LINE_YES ? "YES" : "NO", |
121aae4b |
1083 | reason); |
1084 | #endif |
1085 | |
7c95608a |
1086 | g = state->game_grid; |
1087 | e = g->edges + i; |
1088 | |
1089 | /* Update the cache for both dots and both faces affected by this. */ |
121aae4b |
1090 | if (line_new == LINE_YES) { |
7c95608a |
1091 | sstate->dot_yes_count[e->dot1 - g->dots]++; |
1092 | sstate->dot_yes_count[e->dot2 - g->dots]++; |
1093 | if (e->face1) { |
1094 | sstate->face_yes_count[e->face1 - g->faces]++; |
1095 | } |
1096 | if (e->face2) { |
1097 | sstate->face_yes_count[e->face2 - g->faces]++; |
1098 | } |
121aae4b |
1099 | } else { |
7c95608a |
1100 | sstate->dot_no_count[e->dot1 - g->dots]++; |
1101 | sstate->dot_no_count[e->dot2 - g->dots]++; |
1102 | if (e->face1) { |
1103 | sstate->face_no_count[e->face1 - g->faces]++; |
1104 | } |
1105 | if (e->face2) { |
1106 | sstate->face_no_count[e->face2 - g->faces]++; |
1107 | } |
1108 | } |
1109 | |
121aae4b |
1110 | check_caches(sstate); |
7c95608a |
1111 | return TRUE; |
121aae4b |
1112 | } |
1113 | |
1114 | #ifdef SHOW_WORKING |
7c95608a |
1115 | #define solver_set_line(a, b, c) \ |
1116 | solver_set_line(a, b, c, __FUNCTION__) |
121aae4b |
1117 | #endif |
1118 | |
1119 | /* |
1120 | * Merge two dots due to the existence of an edge between them. |
1121 | * Updates the dsf tracking equivalence classes, and keeps track of |
1122 | * the length of path each dot is currently a part of. |
1123 | * Returns TRUE if the dots were already linked, ie if they are part of a |
1124 | * closed loop, and false otherwise. |
1125 | */ |
7c95608a |
1126 | static int merge_dots(solver_state *sstate, int edge_index) |
121aae4b |
1127 | { |
1128 | int i, j, len; |
7c95608a |
1129 | grid *g = sstate->state->game_grid; |
1130 | grid_edge *e = g->edges + edge_index; |
121aae4b |
1131 | |
7c95608a |
1132 | i = e->dot1 - g->dots; |
1133 | j = e->dot2 - g->dots; |
121aae4b |
1134 | |
1135 | i = dsf_canonify(sstate->dotdsf, i); |
1136 | j = dsf_canonify(sstate->dotdsf, j); |
1137 | |
1138 | if (i == j) { |
1139 | return TRUE; |
1140 | } else { |
1141 | len = sstate->looplen[i] + sstate->looplen[j]; |
1142 | dsf_merge(sstate->dotdsf, i, j); |
1143 | i = dsf_canonify(sstate->dotdsf, i); |
1144 | sstate->looplen[i] = len; |
1145 | return FALSE; |
1146 | } |
1147 | } |
1148 | |
121aae4b |
1149 | /* Merge two lines because the solver has deduced that they must be either |
1150 | * identical or opposite. Returns TRUE if this is new information, otherwise |
1151 | * FALSE. */ |
7c95608a |
1152 | static int merge_lines(solver_state *sstate, int i, int j, int inverse |
121aae4b |
1153 | #ifdef SHOW_WORKING |
1154 | , const char *reason |
1155 | #endif |
7c95608a |
1156 | ) |
121aae4b |
1157 | { |
7c95608a |
1158 | int inv_tmp; |
121aae4b |
1159 | |
7c95608a |
1160 | assert(i < sstate->state->game_grid->num_edges); |
1161 | assert(j < sstate->state->game_grid->num_edges); |
121aae4b |
1162 | |
315e47b9 |
1163 | i = edsf_canonify(sstate->linedsf, i, &inv_tmp); |
121aae4b |
1164 | inverse ^= inv_tmp; |
315e47b9 |
1165 | j = edsf_canonify(sstate->linedsf, j, &inv_tmp); |
121aae4b |
1166 | inverse ^= inv_tmp; |
1167 | |
315e47b9 |
1168 | edsf_merge(sstate->linedsf, i, j, inverse); |
121aae4b |
1169 | |
1170 | #ifdef SHOW_WORKING |
1171 | if (i != j) { |
7c95608a |
1172 | fprintf(stderr, "%s [%d] [%d] %s(%s)\n", |
1173 | __FUNCTION__, i, j, |
121aae4b |
1174 | inverse ? "inverse " : "", reason); |
1175 | } |
1176 | #endif |
1177 | return (i != j); |
1178 | } |
1179 | |
1180 | #ifdef SHOW_WORKING |
7c95608a |
1181 | #define merge_lines(a, b, c, d) \ |
1182 | merge_lines(a, b, c, d, __FUNCTION__) |
121aae4b |
1183 | #endif |
1184 | |
1185 | /* Count the number of lines of a particular type currently going into the |
7c95608a |
1186 | * given dot. */ |
1187 | static int dot_order(const game_state* state, int dot, char line_type) |
121aae4b |
1188 | { |
1189 | int n = 0; |
7c95608a |
1190 | grid *g = state->game_grid; |
1191 | grid_dot *d = g->dots + dot; |
1192 | int i; |
121aae4b |
1193 | |
7c95608a |
1194 | for (i = 0; i < d->order; i++) { |
1195 | grid_edge *e = d->edges[i]; |
1196 | if (state->lines[e - g->edges] == line_type) |
121aae4b |
1197 | ++n; |
1198 | } |
121aae4b |
1199 | return n; |
1200 | } |
1201 | |
1202 | /* Count the number of lines of a particular type currently surrounding the |
7c95608a |
1203 | * given face */ |
1204 | static int face_order(const game_state* state, int face, char line_type) |
121aae4b |
1205 | { |
1206 | int n = 0; |
7c95608a |
1207 | grid *g = state->game_grid; |
1208 | grid_face *f = g->faces + face; |
1209 | int i; |
121aae4b |
1210 | |
7c95608a |
1211 | for (i = 0; i < f->order; i++) { |
1212 | grid_edge *e = f->edges[i]; |
1213 | if (state->lines[e - g->edges] == line_type) |
1214 | ++n; |
1215 | } |
121aae4b |
1216 | return n; |
1217 | } |
1218 | |
7c95608a |
1219 | /* Set all lines bordering a dot of type old_type to type new_type |
121aae4b |
1220 | * Return value tells caller whether this function actually did anything */ |
7c95608a |
1221 | static int dot_setall(solver_state *sstate, int dot, |
1222 | char old_type, char new_type) |
121aae4b |
1223 | { |
1224 | int retval = FALSE, r; |
1225 | game_state *state = sstate->state; |
7c95608a |
1226 | grid *g; |
1227 | grid_dot *d; |
1228 | int i; |
1229 | |
121aae4b |
1230 | if (old_type == new_type) |
1231 | return FALSE; |
1232 | |
7c95608a |
1233 | g = state->game_grid; |
1234 | d = g->dots + dot; |
121aae4b |
1235 | |
7c95608a |
1236 | for (i = 0; i < d->order; i++) { |
1237 | int line_index = d->edges[i] - g->edges; |
1238 | if (state->lines[line_index] == old_type) { |
1239 | r = solver_set_line(sstate, line_index, new_type); |
1240 | assert(r == TRUE); |
1241 | retval = TRUE; |
1242 | } |
121aae4b |
1243 | } |
121aae4b |
1244 | return retval; |
1245 | } |
1246 | |
7c95608a |
1247 | /* Set all lines bordering a face of type old_type to type new_type */ |
1248 | static int face_setall(solver_state *sstate, int face, |
1249 | char old_type, char new_type) |
121aae4b |
1250 | { |
7c95608a |
1251 | int retval = FALSE, r; |
121aae4b |
1252 | game_state *state = sstate->state; |
7c95608a |
1253 | grid *g; |
1254 | grid_face *f; |
1255 | int i; |
121aae4b |
1256 | |
7c95608a |
1257 | if (old_type == new_type) |
1258 | return FALSE; |
1259 | |
1260 | g = state->game_grid; |
1261 | f = g->faces + face; |
121aae4b |
1262 | |
7c95608a |
1263 | for (i = 0; i < f->order; i++) { |
1264 | int line_index = f->edges[i] - g->edges; |
1265 | if (state->lines[line_index] == old_type) { |
1266 | r = solver_set_line(sstate, line_index, new_type); |
1267 | assert(r == TRUE); |
1268 | retval = TRUE; |
1269 | } |
1270 | } |
1271 | return retval; |
121aae4b |
1272 | } |
1273 | |
1274 | /* ---------------------------------------------------------------------- |
1275 | * Loop generation and clue removal |
1276 | */ |
1277 | |
7126ca41 |
1278 | /* We're going to store lists of current candidate faces for colouring black |
1279 | * or white. |
7c95608a |
1280 | * Each face gets a 'score', which tells us how adding that face right |
7126ca41 |
1281 | * now would affect the curliness of the solution loop. We're trying to |
7c95608a |
1282 | * maximise that quantity so will bias our random selection of faces to |
7126ca41 |
1283 | * colour those with high scores */ |
1284 | struct face_score { |
1285 | int white_score; |
1286 | int black_score; |
121aae4b |
1287 | unsigned long random; |
7126ca41 |
1288 | /* No need to store a grid_face* here. The 'face_scores' array will |
1289 | * be a list of 'face_score' objects, one for each face of the grid, so |
1290 | * the position (index) within the 'face_scores' array will determine |
1291 | * which face corresponds to a particular face_score. |
1292 | * Having a single 'face_scores' array for all faces simplifies memory |
1293 | * management, and probably improves performance, because we don't have to |
1294 | * malloc/free each individual face_score, and we don't have to maintain |
1295 | * a mapping from grid_face* pointers to face_score* pointers. |
1296 | */ |
121aae4b |
1297 | }; |
1298 | |
7126ca41 |
1299 | static int generic_sort_cmpfn(void *v1, void *v2, size_t offset) |
121aae4b |
1300 | { |
7126ca41 |
1301 | struct face_score *f1 = v1; |
1302 | struct face_score *f2 = v2; |
121aae4b |
1303 | int r; |
1304 | |
7126ca41 |
1305 | r = *(int *)((char *)f2 + offset) - *(int *)((char *)f1 + offset); |
121aae4b |
1306 | if (r) { |
1307 | return r; |
1308 | } |
1309 | |
7c95608a |
1310 | if (f1->random < f2->random) |
121aae4b |
1311 | return -1; |
7c95608a |
1312 | else if (f1->random > f2->random) |
121aae4b |
1313 | return 1; |
1314 | |
1315 | /* |
7c95608a |
1316 | * It's _just_ possible that two faces might have been given |
121aae4b |
1317 | * the same random value. In that situation, fall back to |
7126ca41 |
1318 | * comparing based on the positions within the face_scores list. |
7c95608a |
1319 | * This introduces a tiny directional bias, but not a significant one. |
121aae4b |
1320 | */ |
7126ca41 |
1321 | return f1 - f2; |
1322 | } |
1323 | |
1324 | static int white_sort_cmpfn(void *v1, void *v2) |
1325 | { |
1326 | return generic_sort_cmpfn(v1, v2, offsetof(struct face_score,white_score)); |
1327 | } |
1328 | |
1329 | static int black_sort_cmpfn(void *v1, void *v2) |
1330 | { |
1331 | return generic_sort_cmpfn(v1, v2, offsetof(struct face_score,black_score)); |
121aae4b |
1332 | } |
1333 | |
7126ca41 |
1334 | enum face_colour { FACE_WHITE, FACE_GREY, FACE_BLACK }; |
7c95608a |
1335 | |
1336 | /* face should be of type grid_face* here. */ |
7126ca41 |
1337 | #define FACE_COLOUR(face) \ |
1338 | ( (face) == NULL ? FACE_BLACK : \ |
7c95608a |
1339 | board[(face) - g->faces] ) |
1340 | |
1341 | /* 'board' is an array of these enums, indicating which faces are |
7126ca41 |
1342 | * currently black/white/grey. 'colour' is FACE_WHITE or FACE_BLACK. |
1343 | * Returns whether it's legal to colour the given face with this colour. */ |
1344 | static int can_colour_face(grid *g, char* board, int face_index, |
1345 | enum face_colour colour) |
7c95608a |
1346 | { |
1347 | int i, j; |
1348 | grid_face *test_face = g->faces + face_index; |
1349 | grid_face *starting_face, *current_face; |
24575af2 |
1350 | grid_dot *starting_dot; |
7c95608a |
1351 | int transitions; |
7126ca41 |
1352 | int current_state, s; /* booleans: equal or not-equal to 'colour' */ |
1353 | int found_same_coloured_neighbour = FALSE; |
1354 | assert(board[face_index] != colour); |
7c95608a |
1355 | |
7126ca41 |
1356 | /* Can only consider a face for colouring if it's adjacent to a face |
1357 | * with the same colour. */ |
7c95608a |
1358 | for (i = 0; i < test_face->order; i++) { |
1359 | grid_edge *e = test_face->edges[i]; |
1360 | grid_face *f = (e->face1 == test_face) ? e->face2 : e->face1; |
7126ca41 |
1361 | if (FACE_COLOUR(f) == colour) { |
1362 | found_same_coloured_neighbour = TRUE; |
7c95608a |
1363 | break; |
1364 | } |
1365 | } |
7126ca41 |
1366 | if (!found_same_coloured_neighbour) |
7c95608a |
1367 | return FALSE; |
1368 | |
7126ca41 |
1369 | /* Need to avoid creating a loop of faces of this colour around some |
1370 | * differently-coloured faces. |
1371 | * Also need to avoid meeting a same-coloured face at a corner, with |
1372 | * other-coloured faces in between. Here's a simple test that (I believe) |
1373 | * takes care of both these conditions: |
7c95608a |
1374 | * |
1375 | * Take the circular path formed by this face's edges, and inflate it |
1376 | * slightly outwards. Imagine walking around this path and consider |
1377 | * the faces that you visit in sequence. This will include all faces |
1378 | * touching the given face, either along an edge or just at a corner. |
7126ca41 |
1379 | * Count the number of 'colour'/not-'colour' transitions you encounter, as |
1380 | * you walk along the complete loop. This will obviously turn out to be |
1381 | * an even number. |
1382 | * If 0, we're either in the middle of an "island" of this colour (should |
1383 | * be impossible as we're not supposed to create black or white loops), |
1384 | * or we're about to start a new island - also not allowed. |
1385 | * If 4 or greater, there are too many separate coloured regions touching |
1386 | * this face, and colouring it would create a loop or a corner-violation. |
7c95608a |
1387 | * The only allowed case is when the count is exactly 2. */ |
1388 | |
1389 | /* i points to a dot around the test face. |
1390 | * j points to a face around the i^th dot. |
1391 | * The current face will always be: |
1392 | * test_face->dots[i]->faces[j] |
1393 | * We assume dots go clockwise around the test face, |
1394 | * and faces go clockwise around dots. */ |
24575af2 |
1395 | |
1396 | /* |
1397 | * The end condition is slightly fiddly. In sufficiently strange |
1398 | * degenerate grids, our test face may be adjacent to the same |
1399 | * other face multiple times (typically if it's the exterior |
1400 | * face). Consider this, in particular: |
1401 | * |
1402 | * +--+ |
1403 | * | | |
1404 | * +--+--+ |
1405 | * | | | |
1406 | * +--+--+ |
1407 | * |
1408 | * The bottom left face there is adjacent to the exterior face |
1409 | * twice, so we can't just terminate our iteration when we reach |
1410 | * the same _face_ we started at. Furthermore, we can't |
1411 | * condition on having the same (i,j) pair either, because |
1412 | * several (i,j) pairs identify the bottom left contiguity with |
1413 | * the exterior face! We canonicalise the (i,j) pair by taking |
1414 | * one step around before we set the termination tracking. |
1415 | */ |
1416 | |
7c95608a |
1417 | i = j = 0; |
24575af2 |
1418 | current_face = test_face->dots[0]->faces[0]; |
1419 | if (current_face == test_face) { |
7c95608a |
1420 | j = 1; |
24575af2 |
1421 | current_face = test_face->dots[0]->faces[1]; |
7c95608a |
1422 | } |
7c95608a |
1423 | transitions = 0; |
7126ca41 |
1424 | current_state = (FACE_COLOUR(current_face) == colour); |
24575af2 |
1425 | starting_dot = NULL; |
1426 | starting_face = NULL; |
1427 | while (TRUE) { |
7c95608a |
1428 | /* Advance to next face. |
1429 | * Need to loop here because it might take several goes to |
1430 | * find it. */ |
1431 | while (TRUE) { |
1432 | j++; |
1433 | if (j == test_face->dots[i]->order) |
1434 | j = 0; |
1435 | |
1436 | if (test_face->dots[i]->faces[j] == test_face) { |
1437 | /* Advance to next dot round test_face, then |
1438 | * find current_face around new dot |
1439 | * and advance to the next face clockwise */ |
1440 | i++; |
1441 | if (i == test_face->order) |
1442 | i = 0; |
1443 | for (j = 0; j < test_face->dots[i]->order; j++) { |
1444 | if (test_face->dots[i]->faces[j] == current_face) |
1445 | break; |
1446 | } |
1447 | /* Must actually find current_face around new dot, |
1448 | * or else something's wrong with the grid. */ |
1449 | assert(j != test_face->dots[i]->order); |
1450 | /* Found, so advance to next face and try again */ |
1451 | } else { |
1452 | break; |
1453 | } |
1454 | } |
1455 | /* (i,j) are now advanced to next face */ |
1456 | current_face = test_face->dots[i]->faces[j]; |
7126ca41 |
1457 | s = (FACE_COLOUR(current_face) == colour); |
24575af2 |
1458 | if (!starting_dot) { |
1459 | starting_dot = test_face->dots[i]; |
1460 | starting_face = current_face; |
1461 | current_state = s; |
1462 | } else { |
1463 | if (s != current_state) { |
1464 | ++transitions; |
1465 | current_state = s; |
1466 | if (transitions > 2) |
1467 | break; |
1468 | } |
1469 | if (test_face->dots[i] == starting_dot && |
1470 | current_face == starting_face) |
1471 | break; |
7c95608a |
1472 | } |
24575af2 |
1473 | } |
121aae4b |
1474 | |
7c95608a |
1475 | return (transitions == 2) ? TRUE : FALSE; |
1476 | } |
121aae4b |
1477 | |
7126ca41 |
1478 | /* Count the number of neighbours of 'face', having colour 'colour' */ |
1479 | static int face_num_neighbours(grid *g, char *board, grid_face *face, |
1480 | enum face_colour colour) |
7c95608a |
1481 | { |
7126ca41 |
1482 | int colour_count = 0; |
7c95608a |
1483 | int i; |
1484 | grid_face *f; |
1485 | grid_edge *e; |
1486 | for (i = 0; i < face->order; i++) { |
1487 | e = face->edges[i]; |
1488 | f = (e->face1 == face) ? e->face2 : e->face1; |
7126ca41 |
1489 | if (FACE_COLOUR(f) == colour) |
1490 | ++colour_count; |
7c95608a |
1491 | } |
7126ca41 |
1492 | return colour_count; |
7c95608a |
1493 | } |
121aae4b |
1494 | |
7126ca41 |
1495 | /* The 'score' of a face reflects its current desirability for selection |
1496 | * as the next face to colour white or black. We want to encourage moving |
1497 | * into grey areas and increasing loopiness, so we give scores according to |
1498 | * how many of the face's neighbours are currently coloured the same as the |
1499 | * proposed colour. */ |
1500 | static int face_score(grid *g, char *board, grid_face *face, |
1501 | enum face_colour colour) |
1502 | { |
1503 | /* Simple formula: score = 0 - num. same-coloured neighbours, |
1504 | * so a higher score means fewer same-coloured neighbours. */ |
1505 | return -face_num_neighbours(g, board, face, colour); |
1506 | } |
1507 | |
1508 | /* Generate a new complete set of clues for the given game_state. |
1509 | * The method is to generate a WHITE/BLACK colouring of all the faces, |
1510 | * such that the WHITE faces will define the inside of the path, and the |
1511 | * BLACK faces define the outside. |
1512 | * To do this, we initially colour all faces GREY. The infinite space outside |
1513 | * the grid is coloured BLACK, and we choose a random face to colour WHITE. |
1514 | * Then we gradually grow the BLACK and the WHITE regions, eliminating GREY |
1515 | * faces, until the grid is filled with BLACK/WHITE. As we grow the regions, |
1516 | * we avoid creating loops of a single colour, to preserve the topological |
1517 | * shape of the WHITE and BLACK regions. |
1518 | * We also try to make the boundary as loopy and twisty as possible, to avoid |
1519 | * generating paths that are uninteresting. |
1520 | * The algorithm works by choosing a BLACK/WHITE colour, then choosing a GREY |
1521 | * face that can be coloured with that colour (without violating the |
1522 | * topological shape of that region). It's not obvious, but I think this |
1523 | * algorithm is guaranteed to terminate without leaving any GREY faces behind. |
1524 | * Indeed, if there are any GREY faces at all, both the WHITE and BLACK |
1525 | * regions can be grown. |
1526 | * This is checked using assert()ions, and I haven't seen any failures yet. |
1527 | * |
1528 | * Hand-wavy proof: imagine what can go wrong... |
1529 | * |
1530 | * Could the white faces get completely cut off by the black faces, and still |
1531 | * leave some grey faces remaining? |
1532 | * No, because then the black faces would form a loop around both the white |
1533 | * faces and the grey faces, which is disallowed because we continually |
1534 | * maintain the correct topological shape of the black region. |
1535 | * Similarly, the black faces can never get cut off by the white faces. That |
1536 | * means both the WHITE and BLACK regions always have some room to grow into |
1537 | * the GREY regions. |
1538 | * Could it be that we can't colour some GREY face, because there are too many |
1539 | * WHITE/BLACK transitions as we walk round the face? (see the |
1540 | * can_colour_face() function for details) |
1541 | * No. Imagine otherwise, and we see WHITE/BLACK/WHITE/BLACK as we walk |
1542 | * around the face. The two WHITE faces would be connected by a WHITE path, |
1543 | * and the BLACK faces would be connected by a BLACK path. These paths would |
1544 | * have to cross, which is impossible. |
1545 | * Another thing that could go wrong: perhaps we can't find any GREY face to |
1546 | * colour WHITE, because it would create a loop-violation or a corner-violation |
1547 | * with the other WHITE faces? |
1548 | * This is a little bit tricky to prove impossible. Imagine you have such a |
1549 | * GREY face (that is, if you coloured it WHITE, you would create a WHITE loop |
1550 | * or corner violation). |
1551 | * That would cut all the non-white area into two blobs. One of those blobs |
1552 | * must be free of BLACK faces (because the BLACK stuff is a connected blob). |
1553 | * So we have a connected GREY area, completely surrounded by WHITE |
1554 | * (including the GREY face we've tentatively coloured WHITE). |
1555 | * A well-known result in graph theory says that you can always find a GREY |
1556 | * face whose removal leaves the remaining GREY area connected. And it says |
1557 | * there are at least two such faces, so we can always choose the one that |
1558 | * isn't the "tentative" GREY face. Colouring that face WHITE leaves |
1559 | * everything nice and connected, including that "tentative" GREY face which |
1560 | * acts as a gateway to the rest of the non-WHITE grid. |
1561 | */ |
121aae4b |
1562 | static void add_full_clues(game_state *state, random_state *rs) |
1563 | { |
7c95608a |
1564 | signed char *clues = state->clues; |
121aae4b |
1565 | char *board; |
7c95608a |
1566 | grid *g = state->game_grid; |
7126ca41 |
1567 | int i, j; |
7c95608a |
1568 | int num_faces = g->num_faces; |
7126ca41 |
1569 | struct face_score *face_scores; /* Array of face_score objects */ |
1570 | struct face_score *fs; /* Points somewhere in the above list */ |
1571 | struct grid_face *cur_face; |
1572 | tree234 *lightable_faces_sorted; |
1573 | tree234 *darkable_faces_sorted; |
1574 | int *face_list; |
1575 | int do_random_pass; |
7c95608a |
1576 | |
1577 | board = snewn(num_faces, char); |
121aae4b |
1578 | |
1579 | /* Make a board */ |
7126ca41 |
1580 | memset(board, FACE_GREY, num_faces); |
1581 | |
1582 | /* Create and initialise the list of face_scores */ |
1583 | face_scores = snewn(num_faces, struct face_score); |
1584 | for (i = 0; i < num_faces; i++) { |
1585 | face_scores[i].random = random_bits(rs, 31); |
8719c2e7 |
1586 | face_scores[i].black_score = face_scores[i].white_score = 0; |
7126ca41 |
1587 | } |
1588 | |
1589 | /* Colour a random, finite face white. The infinite face is implicitly |
1590 | * coloured black. Together, they will seed the random growth process |
1591 | * for the black and white areas. */ |
1592 | i = random_upto(rs, num_faces); |
1593 | board[i] = FACE_WHITE; |
7c95608a |
1594 | |
1595 | /* We need a way of favouring faces that will increase our loopiness. |
1596 | * We do this by maintaining a list of all candidate faces sorted by |
1597 | * their score and choose randomly from that with appropriate skew. |
1598 | * In order to avoid consistently biasing towards particular faces, we |
121aae4b |
1599 | * need the sort order _within_ each group of scores to be completely |
1600 | * random. But it would be abusing the hospitality of the tree234 data |
1601 | * structure if our comparison function were nondeterministic :-). So with |
7c95608a |
1602 | * each face we associate a random number that does not change during a |
121aae4b |
1603 | * particular run of the generator, and use that as a secondary sort key. |
7c95608a |
1604 | * Yes, this means we will be biased towards particular random faces in |
121aae4b |
1605 | * any one run but that doesn't actually matter. */ |
7c95608a |
1606 | |
7126ca41 |
1607 | lightable_faces_sorted = newtree234(white_sort_cmpfn); |
1608 | darkable_faces_sorted = newtree234(black_sort_cmpfn); |
121aae4b |
1609 | |
7126ca41 |
1610 | /* Initialise the lists of lightable and darkable faces. This is |
1611 | * slightly different from the code inside the while-loop, because we need |
1612 | * to check every face of the board (the grid structure does not keep a |
1613 | * list of the infinite face's neighbours). */ |
1614 | for (i = 0; i < num_faces; i++) { |
1615 | grid_face *f = g->faces + i; |
1616 | struct face_score *fs = face_scores + i; |
1617 | if (board[i] != FACE_GREY) continue; |
1618 | /* We need the full colourability check here, it's not enough simply |
1619 | * to check neighbourhood. On some grids, a neighbour of the infinite |
1620 | * face is not necessarily darkable. */ |
1621 | if (can_colour_face(g, board, i, FACE_BLACK)) { |
1622 | fs->black_score = face_score(g, board, f, FACE_BLACK); |
1623 | add234(darkable_faces_sorted, fs); |
1624 | } |
1625 | if (can_colour_face(g, board, i, FACE_WHITE)) { |
1626 | fs->white_score = face_score(g, board, f, FACE_WHITE); |
1627 | add234(lightable_faces_sorted, fs); |
1628 | } |
1629 | } |
7c95608a |
1630 | |
7126ca41 |
1631 | /* Colour faces one at a time until no more faces are colourable. */ |
121aae4b |
1632 | while (TRUE) |
1633 | { |
7126ca41 |
1634 | enum face_colour colour; |
1635 | struct face_score *fs_white, *fs_black; |
1636 | int c_lightable = count234(lightable_faces_sorted); |
1637 | int c_darkable = count234(darkable_faces_sorted); |
24575af2 |
1638 | if (c_lightable == 0 && c_darkable == 0) { |
1639 | /* No more faces we can use at all. */ |
7126ca41 |
1640 | break; |
1641 | } |
24575af2 |
1642 | assert(c_lightable != 0 && c_darkable != 0); |
121aae4b |
1643 | |
7126ca41 |
1644 | fs_white = (struct face_score *)index234(lightable_faces_sorted, 0); |
1645 | fs_black = (struct face_score *)index234(darkable_faces_sorted, 0); |
121aae4b |
1646 | |
7126ca41 |
1647 | /* Choose a colour, and colour the best available face |
1648 | * with that colour. */ |
1649 | colour = random_upto(rs, 2) ? FACE_WHITE : FACE_BLACK; |
121aae4b |
1650 | |
7126ca41 |
1651 | if (colour == FACE_WHITE) |
1652 | fs = fs_white; |
1653 | else |
1654 | fs = fs_black; |
1655 | assert(fs); |
1656 | i = fs - face_scores; |
1657 | assert(board[i] == FACE_GREY); |
1658 | board[i] = colour; |
1659 | |
1660 | /* Remove this newly-coloured face from the lists. These lists should |
1661 | * only contain grey faces. */ |
1662 | del234(lightable_faces_sorted, fs); |
1663 | del234(darkable_faces_sorted, fs); |
1664 | |
1665 | /* Remember which face we've just coloured */ |
1666 | cur_face = g->faces + i; |
1667 | |
1668 | /* The face we've just coloured potentially affects the colourability |
1669 | * and the scores of any neighbouring faces (touching at a corner or |
1670 | * edge). So the search needs to be conducted around all faces |
1671 | * touching the one we've just lit. Iterate over its corners, then |
1672 | * over each corner's faces. For each such face, we remove it from |
1673 | * the lists, recalculate any scores, then add it back to the lists |
1674 | * (depending on whether it is lightable, darkable or both). */ |
1675 | for (i = 0; i < cur_face->order; i++) { |
1676 | grid_dot *d = cur_face->dots[i]; |
7c95608a |
1677 | for (j = 0; j < d->order; j++) { |
7126ca41 |
1678 | grid_face *f = d->faces[j]; |
1679 | int fi; /* face index of f */ |
1680 | |
1681 | if (f == NULL) |
121aae4b |
1682 | continue; |
7126ca41 |
1683 | if (f == cur_face) |
7c95608a |
1684 | continue; |
7126ca41 |
1685 | |
1686 | /* If the face is already coloured, it won't be on our |
1687 | * lightable/darkable lists anyway, so we can skip it without |
1688 | * bothering with the removal step. */ |
1689 | if (FACE_COLOUR(f) != FACE_GREY) continue; |
1690 | |
1691 | /* Find the face index and face_score* corresponding to f */ |
1692 | fi = f - g->faces; |
1693 | fs = face_scores + fi; |
1694 | |
1695 | /* Remove from lightable list if it's in there. We do this, |
1696 | * even if it is still lightable, because the score might |
1697 | * be different, and we need to remove-then-add to maintain |
1698 | * correct sort order. */ |
1699 | del234(lightable_faces_sorted, fs); |
1700 | if (can_colour_face(g, board, fi, FACE_WHITE)) { |
1701 | fs->white_score = face_score(g, board, f, FACE_WHITE); |
1702 | add234(lightable_faces_sorted, fs); |
121aae4b |
1703 | } |
7126ca41 |
1704 | /* Do the same for darkable list. */ |
1705 | del234(darkable_faces_sorted, fs); |
1706 | if (can_colour_face(g, board, fi, FACE_BLACK)) { |
1707 | fs->black_score = face_score(g, board, f, FACE_BLACK); |
1708 | add234(darkable_faces_sorted, fs); |
121aae4b |
1709 | } |
1710 | } |
1711 | } |
121aae4b |
1712 | } |
1713 | |
1714 | /* Clean up */ |
7c95608a |
1715 | freetree234(lightable_faces_sorted); |
7126ca41 |
1716 | freetree234(darkable_faces_sorted); |
1717 | sfree(face_scores); |
1718 | |
1719 | /* The next step requires a shuffled list of all faces */ |
1720 | face_list = snewn(num_faces, int); |
1721 | for (i = 0; i < num_faces; ++i) { |
1722 | face_list[i] = i; |
1723 | } |
1724 | shuffle(face_list, num_faces, sizeof(int), rs); |
1725 | |
1726 | /* The above loop-generation algorithm can often leave large clumps |
1727 | * of faces of one colour. In extreme cases, the resulting path can be |
1728 | * degenerate and not very satisfying to solve. |
1729 | * This next step alleviates this problem: |
1730 | * Go through the shuffled list, and flip the colour of any face we can |
1731 | * legally flip, and which is adjacent to only one face of the opposite |
1732 | * colour - this tends to grow 'tendrils' into any clumps. |
1733 | * Repeat until we can find no more faces to flip. This will |
1734 | * eventually terminate, because each flip increases the loop's |
1735 | * perimeter, which cannot increase for ever. |
1736 | * The resulting path will have maximal loopiness (in the sense that it |
1737 | * cannot be improved "locally". Unfortunately, this allows a player to |
1738 | * make some illicit deductions. To combat this (and make the path more |
1739 | * interesting), we do one final pass making random flips. */ |
1740 | |
1741 | /* Set to TRUE for final pass */ |
1742 | do_random_pass = FALSE; |
1743 | |
1744 | while (TRUE) { |
1745 | /* Remember whether a flip occurred during this pass */ |
1746 | int flipped = FALSE; |
1747 | |
1748 | for (i = 0; i < num_faces; ++i) { |
1749 | int j = face_list[i]; |
1750 | enum face_colour opp = |
1751 | (board[j] == FACE_WHITE) ? FACE_BLACK : FACE_WHITE; |
1752 | if (can_colour_face(g, board, j, opp)) { |
1753 | grid_face *face = g->faces +j; |
1754 | if (do_random_pass) { |
1755 | /* final random pass */ |
1756 | if (!random_upto(rs, 10)) |
1757 | board[j] = opp; |
1758 | } else { |
1759 | /* normal pass - flip when neighbour count is 1 */ |
1760 | if (face_num_neighbours(g, board, face, opp) == 1) { |
1761 | board[j] = opp; |
1762 | flipped = TRUE; |
1763 | } |
1764 | } |
1765 | } |
1766 | } |
1767 | |
1768 | if (do_random_pass) break; |
1769 | if (!flipped) do_random_pass = TRUE; |
1770 | } |
1771 | |
1772 | sfree(face_list); |
7c95608a |
1773 | |
1774 | /* Fill out all the clues by initialising to 0, then iterating over |
1775 | * all edges and incrementing each clue as we find edges that border |
7126ca41 |
1776 | * between BLACK/WHITE faces. While we're at it, we verify that the |
1777 | * algorithm does work, and there aren't any GREY faces still there. */ |
7c95608a |
1778 | memset(clues, 0, num_faces); |
1779 | for (i = 0; i < g->num_edges; i++) { |
1780 | grid_edge *e = g->edges + i; |
1781 | grid_face *f1 = e->face1; |
1782 | grid_face *f2 = e->face2; |
7126ca41 |
1783 | enum face_colour c1 = FACE_COLOUR(f1); |
1784 | enum face_colour c2 = FACE_COLOUR(f2); |
1785 | assert(c1 != FACE_GREY); |
1786 | assert(c2 != FACE_GREY); |
1787 | if (c1 != c2) { |
7c95608a |
1788 | if (f1) clues[f1 - g->faces]++; |
1789 | if (f2) clues[f2 - g->faces]++; |
1790 | } |
121aae4b |
1791 | } |
1792 | |
1793 | sfree(board); |
1794 | } |
1795 | |
7c95608a |
1796 | |
1a739e2f |
1797 | static int game_has_unique_soln(const game_state *state, int diff) |
121aae4b |
1798 | { |
1799 | int ret; |
1800 | solver_state *sstate_new; |
1801 | solver_state *sstate = new_solver_state((game_state *)state, diff); |
7c95608a |
1802 | |
315e47b9 |
1803 | sstate_new = solve_game_rec(sstate); |
121aae4b |
1804 | |
1805 | assert(sstate_new->solver_status != SOLVER_MISTAKE); |
1806 | ret = (sstate_new->solver_status == SOLVER_SOLVED); |
1807 | |
1808 | free_solver_state(sstate_new); |
1809 | free_solver_state(sstate); |
1810 | |
1811 | return ret; |
1812 | } |
1813 | |
7c95608a |
1814 | |
121aae4b |
1815 | /* Remove clues one at a time at random. */ |
7c95608a |
1816 | static game_state *remove_clues(game_state *state, random_state *rs, |
1a739e2f |
1817 | int diff) |
121aae4b |
1818 | { |
7c95608a |
1819 | int *face_list; |
1820 | int num_faces = state->game_grid->num_faces; |
121aae4b |
1821 | game_state *ret = dup_game(state), *saved_ret; |
1822 | int n; |
121aae4b |
1823 | |
1824 | /* We need to remove some clues. We'll do this by forming a list of all |
1825 | * available clues, shuffling it, then going along one at a |
1826 | * time clearing each clue in turn for which doing so doesn't render the |
1827 | * board unsolvable. */ |
7c95608a |
1828 | face_list = snewn(num_faces, int); |
1829 | for (n = 0; n < num_faces; ++n) { |
1830 | face_list[n] = n; |
121aae4b |
1831 | } |
1832 | |
7c95608a |
1833 | shuffle(face_list, num_faces, sizeof(int), rs); |
121aae4b |
1834 | |
7c95608a |
1835 | for (n = 0; n < num_faces; ++n) { |
1836 | saved_ret = dup_game(ret); |
1837 | ret->clues[face_list[n]] = -1; |
121aae4b |
1838 | |
1839 | if (game_has_unique_soln(ret, diff)) { |
1840 | free_game(saved_ret); |
1841 | } else { |
1842 | free_game(ret); |
1843 | ret = saved_ret; |
1844 | } |
1845 | } |
7c95608a |
1846 | sfree(face_list); |
121aae4b |
1847 | |
1848 | return ret; |
1849 | } |
1850 | |
7c95608a |
1851 | |
121aae4b |
1852 | static char *new_game_desc(game_params *params, random_state *rs, |
1853 | char **aux, int interactive) |
1854 | { |
1855 | /* solution and description both use run-length encoding in obvious ways */ |
cebf0b0d |
1856 | char *retval, *game_desc, *grid_desc; |
7c95608a |
1857 | grid *g; |
1858 | game_state *state = snew(game_state); |
1859 | game_state *state_new; |
cebf0b0d |
1860 | |
1861 | grid_desc = grid_new_desc(grid_types[params->type], params->w, params->h, rs); |
1862 | state->game_grid = g = loopy_generate_grid(params, grid_desc); |
1863 | |
7c95608a |
1864 | state->clues = snewn(g->num_faces, signed char); |
1865 | state->lines = snewn(g->num_edges, char); |
b6bf0adc |
1866 | state->line_errors = snewn(g->num_edges, unsigned char); |
121aae4b |
1867 | |
7c95608a |
1868 | state->grid_type = params->type; |
121aae4b |
1869 | |
7c95608a |
1870 | newboard_please: |
121aae4b |
1871 | |
7c95608a |
1872 | memset(state->lines, LINE_UNKNOWN, g->num_edges); |
b6bf0adc |
1873 | memset(state->line_errors, 0, g->num_edges); |
121aae4b |
1874 | |
1875 | state->solved = state->cheated = FALSE; |
121aae4b |
1876 | |
1877 | /* Get a new random solvable board with all its clues filled in. Yes, this |
1878 | * can loop for ever if the params are suitably unfavourable, but |
1879 | * preventing games smaller than 4x4 seems to stop this happening */ |
121aae4b |
1880 | do { |
1881 | add_full_clues(state, rs); |
1882 | } while (!game_has_unique_soln(state, params->diff)); |
1883 | |
1884 | state_new = remove_clues(state, rs, params->diff); |
1885 | free_game(state); |
1886 | state = state_new; |
1887 | |
7c95608a |
1888 | |
121aae4b |
1889 | if (params->diff > 0 && game_has_unique_soln(state, params->diff-1)) { |
1a739e2f |
1890 | #ifdef SHOW_WORKING |
121aae4b |
1891 | fprintf(stderr, "Rejecting board, it is too easy\n"); |
1a739e2f |
1892 | #endif |
121aae4b |
1893 | goto newboard_please; |
1894 | } |
1895 | |
cebf0b0d |
1896 | game_desc = state_to_text(state); |
121aae4b |
1897 | |
1898 | free_game(state); |
7c95608a |
1899 | |
cebf0b0d |
1900 | if (grid_desc) { |
1901 | retval = snewn(strlen(grid_desc) + 1 + strlen(game_desc) + 1, char); |
1902 | sprintf(retval, "%s%c%s", grid_desc, GRID_DESC_SEP, game_desc); |
1903 | sfree(grid_desc); |
1904 | sfree(game_desc); |
1905 | } else { |
1906 | retval = game_desc; |
1907 | } |
1908 | |
121aae4b |
1909 | assert(!validate_desc(params, retval)); |
1910 | |
1911 | return retval; |
1912 | } |
1913 | |
1914 | static game_state *new_game(midend *me, game_params *params, char *desc) |
1915 | { |
7c95608a |
1916 | int i; |
121aae4b |
1917 | game_state *state = snew(game_state); |
1918 | int empties_to_make = 0; |
918a098a |
1919 | int n,n2; |
cebf0b0d |
1920 | const char *dp; |
1921 | char *grid_desc; |
7c95608a |
1922 | grid *g; |
1515b973 |
1923 | int num_faces, num_edges; |
1924 | |
cebf0b0d |
1925 | grid_desc = extract_grid_desc(&desc); |
1926 | state->game_grid = g = loopy_generate_grid(params, grid_desc); |
1927 | if (grid_desc) sfree(grid_desc); |
1928 | |
1929 | dp = desc; |
1930 | |
1515b973 |
1931 | num_faces = g->num_faces; |
1932 | num_edges = g->num_edges; |
121aae4b |
1933 | |
7c95608a |
1934 | state->clues = snewn(num_faces, signed char); |
1935 | state->lines = snewn(num_edges, char); |
b6bf0adc |
1936 | state->line_errors = snewn(num_edges, unsigned char); |
121aae4b |
1937 | |
1938 | state->solved = state->cheated = FALSE; |
1939 | |
7c95608a |
1940 | state->grid_type = params->type; |
1941 | |
1942 | for (i = 0; i < num_faces; i++) { |
121aae4b |
1943 | if (empties_to_make) { |
1944 | empties_to_make--; |
7c95608a |
1945 | state->clues[i] = -1; |
121aae4b |
1946 | continue; |
1947 | } |
1948 | |
1949 | assert(*dp); |
1950 | n = *dp - '0'; |
918a098a |
1951 | n2 = *dp - 'A' + 10; |
121aae4b |
1952 | if (n >= 0 && n < 10) { |
7c95608a |
1953 | state->clues[i] = n; |
918a098a |
1954 | } else if (n2 >= 10 && n2 < 36) { |
1955 | state->clues[i] = n2; |
121aae4b |
1956 | } else { |
1957 | n = *dp - 'a' + 1; |
1958 | assert(n > 0); |
7c95608a |
1959 | state->clues[i] = -1; |
121aae4b |
1960 | empties_to_make = n - 1; |
1961 | } |
1962 | ++dp; |
1963 | } |
1964 | |
7c95608a |
1965 | memset(state->lines, LINE_UNKNOWN, num_edges); |
b6bf0adc |
1966 | memset(state->line_errors, 0, num_edges); |
121aae4b |
1967 | return state; |
1968 | } |
1969 | |
b6bf0adc |
1970 | /* Calculates the line_errors data, and checks if the current state is a |
1971 | * solution */ |
1972 | static int check_completion(game_state *state) |
1973 | { |
1974 | grid *g = state->game_grid; |
1975 | int *dsf; |
1976 | int num_faces = g->num_faces; |
1977 | int i; |
1978 | int infinite_area, finite_area; |
1979 | int loops_found = 0; |
1980 | int found_edge_not_in_loop = FALSE; |
1981 | |
1982 | memset(state->line_errors, 0, g->num_edges); |
1983 | |
1984 | /* LL implementation of SGT's idea: |
1985 | * A loop will partition the grid into an inside and an outside. |
1986 | * If there is more than one loop, the grid will be partitioned into |
1987 | * even more distinct regions. We can therefore track equivalence of |
1988 | * faces, by saying that two faces are equivalent when there is a non-YES |
1989 | * edge between them. |
1990 | * We could keep track of the number of connected components, by counting |
1991 | * the number of dsf-merges that aren't no-ops. |
1992 | * But we're only interested in 3 separate cases: |
1993 | * no loops, one loop, more than one loop. |
1994 | * |
1995 | * No loops: all faces are equivalent to the infinite face. |
1996 | * One loop: only two equivalence classes - finite and infinite. |
1997 | * >= 2 loops: there are 2 distinct finite regions. |
1998 | * |
1999 | * So we simply make two passes through all the edges. |
2000 | * In the first pass, we dsf-merge the two faces bordering each non-YES |
2001 | * edge. |
2002 | * In the second pass, we look for YES-edges bordering: |
2003 | * a) two non-equivalent faces. |
2004 | * b) two non-equivalent faces, and one of them is part of a different |
2005 | * finite area from the first finite area we've seen. |
2006 | * |
2007 | * An occurrence of a) means there is at least one loop. |
2008 | * An occurrence of b) means there is more than one loop. |
2009 | * Edges satisfying a) are marked as errors. |
2010 | * |
2011 | * While we're at it, we set a flag if we find a YES edge that is not |
2012 | * part of a loop. |
2013 | * This information will help decide, if there's a single loop, whether it |
2014 | * is a candidate for being a solution (that is, all YES edges are part of |
2015 | * this loop). |
2016 | * |
2017 | * If there is a candidate loop, we then go through all clues and check |
2018 | * they are all satisfied. If so, we have found a solution and we can |
2019 | * unmark all line_errors. |
2020 | */ |
2021 | |
2022 | /* Infinite face is at the end - its index is num_faces. |
2023 | * This macro is just to make this obvious! */ |
2024 | #define INF_FACE num_faces |
2025 | dsf = snewn(num_faces + 1, int); |
2026 | dsf_init(dsf, num_faces + 1); |
2027 | |
2028 | /* First pass */ |
2029 | for (i = 0; i < g->num_edges; i++) { |
2030 | grid_edge *e = g->edges + i; |
2031 | int f1 = e->face1 ? e->face1 - g->faces : INF_FACE; |
2032 | int f2 = e->face2 ? e->face2 - g->faces : INF_FACE; |
2033 | if (state->lines[i] != LINE_YES) |
2034 | dsf_merge(dsf, f1, f2); |
2035 | } |
2036 | |
2037 | /* Second pass */ |
2038 | infinite_area = dsf_canonify(dsf, INF_FACE); |
2039 | finite_area = -1; |
2040 | for (i = 0; i < g->num_edges; i++) { |
2041 | grid_edge *e = g->edges + i; |
2042 | int f1 = e->face1 ? e->face1 - g->faces : INF_FACE; |
2043 | int can1 = dsf_canonify(dsf, f1); |
2044 | int f2 = e->face2 ? e->face2 - g->faces : INF_FACE; |
2045 | int can2 = dsf_canonify(dsf, f2); |
2046 | if (state->lines[i] != LINE_YES) continue; |
2047 | |
2048 | if (can1 == can2) { |
2049 | /* Faces are equivalent, so this edge not part of a loop */ |
2050 | found_edge_not_in_loop = TRUE; |
2051 | continue; |
2052 | } |
2053 | state->line_errors[i] = TRUE; |
2054 | if (loops_found == 0) loops_found = 1; |
2055 | |
2056 | /* Don't bother with further checks if we've already found 2 loops */ |
2057 | if (loops_found == 2) continue; |
2058 | |
2059 | if (finite_area == -1) { |
2060 | /* Found our first finite area */ |
2061 | if (can1 != infinite_area) |
2062 | finite_area = can1; |
2063 | else |
2064 | finite_area = can2; |
2065 | } |
2066 | |
2067 | /* Have we found a second area? */ |
2068 | if (finite_area != -1) { |
2069 | if (can1 != infinite_area && can1 != finite_area) { |
2070 | loops_found = 2; |
2071 | continue; |
2072 | } |
2073 | if (can2 != infinite_area && can2 != finite_area) { |
2074 | loops_found = 2; |
2075 | } |
2076 | } |
2077 | } |
2078 | |
2079 | /* |
2080 | printf("loops_found = %d\n", loops_found); |
2081 | printf("found_edge_not_in_loop = %s\n", |
2082 | found_edge_not_in_loop ? "TRUE" : "FALSE"); |
2083 | */ |
2084 | |
2085 | sfree(dsf); /* No longer need the dsf */ |
2086 | |
2087 | /* Have we found a candidate loop? */ |
2088 | if (loops_found == 1 && !found_edge_not_in_loop) { |
2089 | /* Yes, so check all clues are satisfied */ |
2090 | int found_clue_violation = FALSE; |
2091 | for (i = 0; i < num_faces; i++) { |
2092 | int c = state->clues[i]; |
2093 | if (c >= 0) { |
2094 | if (face_order(state, i, LINE_YES) != c) { |
2095 | found_clue_violation = TRUE; |
2096 | break; |
2097 | } |
2098 | } |
2099 | } |
2100 | |
2101 | if (!found_clue_violation) { |
2102 | /* The loop is good */ |
2103 | memset(state->line_errors, 0, g->num_edges); |
2104 | return TRUE; /* No need to bother checking for dot violations */ |
2105 | } |
2106 | } |
2107 | |
2108 | /* Check for dot violations */ |
2109 | for (i = 0; i < g->num_dots; i++) { |
2110 | int yes = dot_order(state, i, LINE_YES); |
2111 | int unknown = dot_order(state, i, LINE_UNKNOWN); |
2112 | if ((yes == 1 && unknown == 0) || (yes >= 3)) { |
2113 | /* violation, so mark all YES edges as errors */ |
2114 | grid_dot *d = g->dots + i; |
2115 | int j; |
2116 | for (j = 0; j < d->order; j++) { |
2117 | int e = d->edges[j] - g->edges; |
2118 | if (state->lines[e] == LINE_YES) |
2119 | state->line_errors[e] = TRUE; |
2120 | } |
2121 | } |
2122 | } |
2123 | return FALSE; |
2124 | } |
121aae4b |
2125 | |
2126 | /* ---------------------------------------------------------------------- |
2127 | * Solver logic |
2128 | * |
2129 | * Our solver modes operate as follows. Each mode also uses the modes above it. |
2130 | * |
2131 | * Easy Mode |
2132 | * Just implement the rules of the game. |
2133 | * |
315e47b9 |
2134 | * Normal and Tricky Modes |
7c95608a |
2135 | * For each (adjacent) pair of lines through each dot we store a bit for |
2136 | * whether at least one of them is on and whether at most one is on. (If we |
2137 | * know both or neither is on that's already stored more directly.) |
121aae4b |
2138 | * |
2139 | * Advanced Mode |
2140 | * Use edsf data structure to make equivalence classes of lines that are |
2141 | * known identical to or opposite to one another. |
2142 | */ |
2143 | |
121aae4b |
2144 | |
7c95608a |
2145 | /* DLines: |
2146 | * For general grids, we consider "dlines" to be pairs of lines joined |
2147 | * at a dot. The lines must be adjacent around the dot, so we can think of |
2148 | * a dline as being a dot+face combination. Or, a dot+edge combination where |
2149 | * the second edge is taken to be the next clockwise edge from the dot. |
2150 | * Original loopy code didn't have this extra restriction of the lines being |
2151 | * adjacent. From my tests with square grids, this extra restriction seems to |
2152 | * take little, if anything, away from the quality of the puzzles. |
2153 | * A dline can be uniquely identified by an edge/dot combination, given that |
2154 | * a dline-pair always goes clockwise around its common dot. The edge/dot |
2155 | * combination can be represented by an edge/bool combination - if bool is |
2156 | * TRUE, use edge->dot1 else use edge->dot2. So the total number of dlines is |
2157 | * exactly twice the number of edges in the grid - although the dlines |
2158 | * spanning the infinite face are not all that useful to the solver. |
2159 | * Note that, by convention, a dline goes clockwise around its common dot, |
2160 | * which means the dline goes anti-clockwise around its common face. |
2161 | */ |
121aae4b |
2162 | |
7c95608a |
2163 | /* Helper functions for obtaining an index into an array of dlines, given |
2164 | * various information. We assume the grid layout conventions about how |
2165 | * the various lists are interleaved - see grid_make_consistent() for |
2166 | * details. */ |
121aae4b |
2167 | |
7c95608a |
2168 | /* i points to the first edge of the dline pair, reading clockwise around |
2169 | * the dot. */ |
2170 | static int dline_index_from_dot(grid *g, grid_dot *d, int i) |
121aae4b |
2171 | { |
7c95608a |
2172 | grid_edge *e = d->edges[i]; |
121aae4b |
2173 | int ret; |
7c95608a |
2174 | #ifdef DEBUG_DLINES |
2175 | grid_edge *e2; |
2176 | int i2 = i+1; |
2177 | if (i2 == d->order) i2 = 0; |
2178 | e2 = d->edges[i2]; |
2179 | #endif |
2180 | ret = 2 * (e - g->edges) + ((e->dot1 == d) ? 1 : 0); |
2181 | #ifdef DEBUG_DLINES |
2182 | printf("dline_index_from_dot: d=%d,i=%d, edges [%d,%d] - %d\n", |
2183 | (int)(d - g->dots), i, (int)(e - g->edges), |
2184 | (int)(e2 - g->edges), ret); |
121aae4b |
2185 | #endif |
2186 | return ret; |
2187 | } |
7c95608a |
2188 | /* i points to the second edge of the dline pair, reading clockwise around |
2189 | * the face. That is, the edges of the dline, starting at edge{i}, read |
2190 | * anti-clockwise around the face. By layout conventions, the common dot |
2191 | * of the dline will be f->dots[i] */ |
2192 | static int dline_index_from_face(grid *g, grid_face *f, int i) |
121aae4b |
2193 | { |
7c95608a |
2194 | grid_edge *e = f->edges[i]; |
2195 | grid_dot *d = f->dots[i]; |
121aae4b |
2196 | int ret; |
7c95608a |
2197 | #ifdef DEBUG_DLINES |
2198 | grid_edge *e2; |
2199 | int i2 = i - 1; |
2200 | if (i2 < 0) i2 += f->order; |
2201 | e2 = f->edges[i2]; |
2202 | #endif |
2203 | ret = 2 * (e - g->edges) + ((e->dot1 == d) ? 1 : 0); |
2204 | #ifdef DEBUG_DLINES |
2205 | printf("dline_index_from_face: f=%d,i=%d, edges [%d,%d] - %d\n", |
2206 | (int)(f - g->faces), i, (int)(e - g->edges), |
2207 | (int)(e2 - g->edges), ret); |
121aae4b |
2208 | #endif |
2209 | return ret; |
2210 | } |
7c95608a |
2211 | static int is_atleastone(const char *dline_array, int index) |
121aae4b |
2212 | { |
7c95608a |
2213 | return BIT_SET(dline_array[index], 0); |
121aae4b |
2214 | } |
7c95608a |
2215 | static int set_atleastone(char *dline_array, int index) |
121aae4b |
2216 | { |
7c95608a |
2217 | return SET_BIT(dline_array[index], 0); |
121aae4b |
2218 | } |
7c95608a |
2219 | static int is_atmostone(const char *dline_array, int index) |
121aae4b |
2220 | { |
7c95608a |
2221 | return BIT_SET(dline_array[index], 1); |
2222 | } |
2223 | static int set_atmostone(char *dline_array, int index) |
2224 | { |
2225 | return SET_BIT(dline_array[index], 1); |
121aae4b |
2226 | } |
121aae4b |
2227 | |
2228 | static void array_setall(char *array, char from, char to, int len) |
2229 | { |
2230 | char *p = array, *p_old = p; |
2231 | int len_remaining = len; |
2232 | |
2233 | while ((p = memchr(p, from, len_remaining))) { |
2234 | *p = to; |
2235 | len_remaining -= p - p_old; |
2236 | p_old = p; |
2237 | } |
2238 | } |
6193da8d |
2239 | |
7c95608a |
2240 | /* Helper, called when doing dline dot deductions, in the case where we |
2241 | * have 4 UNKNOWNs, and two of them (adjacent) have *exactly* one YES between |
2242 | * them (because of dline atmostone/atleastone). |
2243 | * On entry, edge points to the first of these two UNKNOWNs. This function |
2244 | * will find the opposite UNKNOWNS (if they are adjacent to one another) |
2245 | * and set their corresponding dline to atleastone. (Setting atmostone |
2246 | * already happens in earlier dline deductions) */ |
2247 | static int dline_set_opp_atleastone(solver_state *sstate, |
2248 | grid_dot *d, int edge) |
121aae4b |
2249 | { |
7c95608a |
2250 | game_state *state = sstate->state; |
2251 | grid *g = state->game_grid; |
2252 | int N = d->order; |
2253 | int opp, opp2; |
2254 | for (opp = 0; opp < N; opp++) { |
2255 | int opp_dline_index; |
2256 | if (opp == edge || opp == edge+1 || opp == edge-1) |
2257 | continue; |
2258 | if (opp == 0 && edge == N-1) |
2259 | continue; |
2260 | if (opp == N-1 && edge == 0) |
2261 | continue; |
2262 | opp2 = opp + 1; |
2263 | if (opp2 == N) opp2 = 0; |
2264 | /* Check if opp, opp2 point to LINE_UNKNOWNs */ |
2265 | if (state->lines[d->edges[opp] - g->edges] != LINE_UNKNOWN) |
2266 | continue; |
2267 | if (state->lines[d->edges[opp2] - g->edges] != LINE_UNKNOWN) |
2268 | continue; |
2269 | /* Found opposite UNKNOWNS and they're next to each other */ |
2270 | opp_dline_index = dline_index_from_dot(g, d, opp); |
315e47b9 |
2271 | return set_atleastone(sstate->dlines, opp_dline_index); |
121aae4b |
2272 | } |
7c95608a |
2273 | return FALSE; |
121aae4b |
2274 | } |
6193da8d |
2275 | |
121aae4b |
2276 | |
7c95608a |
2277 | /* Set pairs of lines around this face which are known to be identical, to |
121aae4b |
2278 | * the given line_state */ |
7c95608a |
2279 | static int face_setall_identical(solver_state *sstate, int face_index, |
2280 | enum line_state line_new) |
121aae4b |
2281 | { |
2282 | /* can[dir] contains the canonical line associated with the line in |
2283 | * direction dir from the square in question. Similarly inv[dir] is |
2284 | * whether or not the line in question is inverse to its canonical |
2285 | * element. */ |
121aae4b |
2286 | int retval = FALSE; |
7c95608a |
2287 | game_state *state = sstate->state; |
2288 | grid *g = state->game_grid; |
2289 | grid_face *f = g->faces + face_index; |
2290 | int N = f->order; |
2291 | int i, j; |
2292 | int can1, can2, inv1, inv2; |
6193da8d |
2293 | |
7c95608a |
2294 | for (i = 0; i < N; i++) { |
2295 | int line1_index = f->edges[i] - g->edges; |
2296 | if (state->lines[line1_index] != LINE_UNKNOWN) |
2297 | continue; |
2298 | for (j = i + 1; j < N; j++) { |
2299 | int line2_index = f->edges[j] - g->edges; |
2300 | if (state->lines[line2_index] != LINE_UNKNOWN) |
121aae4b |
2301 | continue; |
6193da8d |
2302 | |
7c95608a |
2303 | /* Found two UNKNOWNS */ |
315e47b9 |
2304 | can1 = edsf_canonify(sstate->linedsf, line1_index, &inv1); |
2305 | can2 = edsf_canonify(sstate->linedsf, line2_index, &inv2); |
7c95608a |
2306 | if (can1 == can2 && inv1 == inv2) { |
2307 | solver_set_line(sstate, line1_index, line_new); |
2308 | solver_set_line(sstate, line2_index, line_new); |
6193da8d |
2309 | } |
2310 | } |
6193da8d |
2311 | } |
121aae4b |
2312 | return retval; |
2313 | } |
2314 | |
7c95608a |
2315 | /* Given a dot or face, and a count of LINE_UNKNOWNs, find them and |
2316 | * return the edge indices into e. */ |
2317 | static void find_unknowns(game_state *state, |
2318 | grid_edge **edge_list, /* Edge list to search (from a face or a dot) */ |
2319 | int expected_count, /* Number of UNKNOWNs (comes from solver's cache) */ |
2320 | int *e /* Returned edge indices */) |
2321 | { |
2322 | int c = 0; |
2323 | grid *g = state->game_grid; |
2324 | while (c < expected_count) { |
2325 | int line_index = *edge_list - g->edges; |
2326 | if (state->lines[line_index] == LINE_UNKNOWN) { |
2327 | e[c] = line_index; |
2328 | c++; |
6193da8d |
2329 | } |
7c95608a |
2330 | ++edge_list; |
6193da8d |
2331 | } |
6193da8d |
2332 | } |
2333 | |
7c95608a |
2334 | /* If we have a list of edges, and we know whether the number of YESs should |
2335 | * be odd or even, and there are only a few UNKNOWNs, we can do some simple |
2336 | * linedsf deductions. This can be used for both face and dot deductions. |
2337 | * Returns the difficulty level of the next solver that should be used, |
2338 | * or DIFF_MAX if no progress was made. */ |
2339 | static int parity_deductions(solver_state *sstate, |
2340 | grid_edge **edge_list, /* Edge list (from a face or a dot) */ |
2341 | int total_parity, /* Expected number of YESs modulo 2 (either 0 or 1) */ |
2342 | int unknown_count) |
6193da8d |
2343 | { |
121aae4b |
2344 | game_state *state = sstate->state; |
7c95608a |
2345 | int diff = DIFF_MAX; |
315e47b9 |
2346 | int *linedsf = sstate->linedsf; |
7c95608a |
2347 | |
2348 | if (unknown_count == 2) { |
2349 | /* Lines are known alike/opposite, depending on inv. */ |
2350 | int e[2]; |
2351 | find_unknowns(state, edge_list, 2, e); |
2352 | if (merge_lines(sstate, e[0], e[1], total_parity)) |
2353 | diff = min(diff, DIFF_HARD); |
2354 | } else if (unknown_count == 3) { |
2355 | int e[3]; |
2356 | int can[3]; /* canonical edges */ |
2357 | int inv[3]; /* whether can[x] is inverse to e[x] */ |
2358 | find_unknowns(state, edge_list, 3, e); |
2359 | can[0] = edsf_canonify(linedsf, e[0], inv); |
2360 | can[1] = edsf_canonify(linedsf, e[1], inv+1); |
2361 | can[2] = edsf_canonify(linedsf, e[2], inv+2); |
2362 | if (can[0] == can[1]) { |
2363 | if (solver_set_line(sstate, e[2], (total_parity^inv[0]^inv[1]) ? |
2364 | LINE_YES : LINE_NO)) |
2365 | diff = min(diff, DIFF_EASY); |
2366 | } |
2367 | if (can[0] == can[2]) { |
2368 | if (solver_set_line(sstate, e[1], (total_parity^inv[0]^inv[2]) ? |
2369 | LINE_YES : LINE_NO)) |
2370 | diff = min(diff, DIFF_EASY); |
2371 | } |
2372 | if (can[1] == can[2]) { |
2373 | if (solver_set_line(sstate, e[0], (total_parity^inv[1]^inv[2]) ? |
2374 | LINE_YES : LINE_NO)) |
2375 | diff = min(diff, DIFF_EASY); |
2376 | } |
2377 | } else if (unknown_count == 4) { |
2378 | int e[4]; |
2379 | int can[4]; /* canonical edges */ |
2380 | int inv[4]; /* whether can[x] is inverse to e[x] */ |
2381 | find_unknowns(state, edge_list, 4, e); |
2382 | can[0] = edsf_canonify(linedsf, e[0], inv); |
2383 | can[1] = edsf_canonify(linedsf, e[1], inv+1); |
2384 | can[2] = edsf_canonify(linedsf, e[2], inv+2); |
2385 | can[3] = edsf_canonify(linedsf, e[3], inv+3); |
2386 | if (can[0] == can[1]) { |
2387 | if (merge_lines(sstate, e[2], e[3], total_parity^inv[0]^inv[1])) |
2388 | diff = min(diff, DIFF_HARD); |
2389 | } else if (can[0] == can[2]) { |
2390 | if (merge_lines(sstate, e[1], e[3], total_parity^inv[0]^inv[2])) |
2391 | diff = min(diff, DIFF_HARD); |
2392 | } else if (can[0] == can[3]) { |
2393 | if (merge_lines(sstate, e[1], e[2], total_parity^inv[0]^inv[3])) |
2394 | diff = min(diff, DIFF_HARD); |
2395 | } else if (can[1] == can[2]) { |
2396 | if (merge_lines(sstate, e[0], e[3], total_parity^inv[1]^inv[2])) |
2397 | diff = min(diff, DIFF_HARD); |
2398 | } else if (can[1] == can[3]) { |
2399 | if (merge_lines(sstate, e[0], e[2], total_parity^inv[1]^inv[3])) |
2400 | diff = min(diff, DIFF_HARD); |
2401 | } else if (can[2] == can[3]) { |
2402 | if (merge_lines(sstate, e[0], e[1], total_parity^inv[2]^inv[3])) |
2403 | diff = min(diff, DIFF_HARD); |
6193da8d |
2404 | } |
2405 | } |
7c95608a |
2406 | return diff; |
6193da8d |
2407 | } |
2408 | |
7c95608a |
2409 | |
121aae4b |
2410 | /* |
7c95608a |
2411 | * These are the main solver functions. |
121aae4b |
2412 | * |
2413 | * Their return values are diff values corresponding to the lowest mode solver |
2414 | * that would notice the work that they have done. For example if the normal |
2415 | * mode solver adds actual lines or crosses, it will return DIFF_EASY as the |
2416 | * easy mode solver might be able to make progress using that. It doesn't make |
2417 | * sense for one of them to return a diff value higher than that of the |
7c95608a |
2418 | * function itself. |
121aae4b |
2419 | * |
2420 | * Each function returns the lowest value it can, as early as possible, in |
2421 | * order to try and pass as much work as possible back to the lower level |
2422 | * solvers which progress more quickly. |
2423 | */ |
6193da8d |
2424 | |
121aae4b |
2425 | /* PROPOSED NEW DESIGN: |
2426 | * We have a work queue consisting of 'events' notifying us that something has |
2427 | * happened that a particular solver mode might be interested in. For example |
2428 | * the hard mode solver might do something that helps the normal mode solver at |
2429 | * dot [x,y] in which case it will enqueue an event recording this fact. Then |
2430 | * we pull events off the work queue, and hand each in turn to the solver that |
2431 | * is interested in them. If a solver reports that it failed we pass the same |
2432 | * event on to progressively more advanced solvers and the loop detector. Once |
2433 | * we've exhausted an event, or it has helped us progress, we drop it and |
2434 | * continue to the next one. The events are sorted first in order of solver |
2435 | * complexity (easy first) then order of insertion (oldest first). |
2436 | * Once we run out of events we loop over each permitted solver in turn |
2437 | * (easiest first) until either a deduction is made (and an event therefore |
2438 | * emerges) or no further deductions can be made (in which case we've failed). |
2439 | * |
7c95608a |
2440 | * QUESTIONS: |
121aae4b |
2441 | * * How do we 'loop over' a solver when both dots and squares are concerned. |
2442 | * Answer: first all squares then all dots. |
2443 | */ |
2444 | |
315e47b9 |
2445 | static int trivial_deductions(solver_state *sstate) |
6193da8d |
2446 | { |
7c95608a |
2447 | int i, current_yes, current_no; |
2448 | game_state *state = sstate->state; |
2449 | grid *g = state->game_grid; |
1a739e2f |
2450 | int diff = DIFF_MAX; |
6193da8d |
2451 | |
7c95608a |
2452 | /* Per-face deductions */ |
2453 | for (i = 0; i < g->num_faces; i++) { |
2454 | grid_face *f = g->faces + i; |
2455 | |
2456 | if (sstate->face_solved[i]) |
121aae4b |
2457 | continue; |
6193da8d |
2458 | |
7c95608a |
2459 | current_yes = sstate->face_yes_count[i]; |
2460 | current_no = sstate->face_no_count[i]; |
c0eb17ce |
2461 | |
7c95608a |
2462 | if (current_yes + current_no == f->order) { |
2463 | sstate->face_solved[i] = TRUE; |
121aae4b |
2464 | continue; |
2465 | } |
6193da8d |
2466 | |
7c95608a |
2467 | if (state->clues[i] < 0) |
121aae4b |
2468 | continue; |
6193da8d |
2469 | |
dba1fdaf |
2470 | /* |
2471 | * This code checks whether the numeric clue on a face is so |
2472 | * large as to permit all its remaining LINE_UNKNOWNs to be |
2473 | * filled in as LINE_YES, or alternatively so small as to |
2474 | * permit them all to be filled in as LINE_NO. |
2475 | */ |
2476 | |
7c95608a |
2477 | if (state->clues[i] < current_yes) { |
121aae4b |
2478 | sstate->solver_status = SOLVER_MISTAKE; |
2479 | return DIFF_EASY; |
2480 | } |
7c95608a |
2481 | if (state->clues[i] == current_yes) { |
2482 | if (face_setall(sstate, i, LINE_UNKNOWN, LINE_NO)) |
121aae4b |
2483 | diff = min(diff, DIFF_EASY); |
7c95608a |
2484 | sstate->face_solved[i] = TRUE; |
121aae4b |
2485 | continue; |
2486 | } |
c0eb17ce |
2487 | |
7c95608a |
2488 | if (f->order - state->clues[i] < current_no) { |
121aae4b |
2489 | sstate->solver_status = SOLVER_MISTAKE; |
2490 | return DIFF_EASY; |
2491 | } |
7c95608a |
2492 | if (f->order - state->clues[i] == current_no) { |
2493 | if (face_setall(sstate, i, LINE_UNKNOWN, LINE_YES)) |
121aae4b |
2494 | diff = min(diff, DIFF_EASY); |
7c95608a |
2495 | sstate->face_solved[i] = TRUE; |
121aae4b |
2496 | continue; |
2497 | } |
dba1fdaf |
2498 | |
2499 | if (f->order - state->clues[i] == current_no + 1 && |
2500 | f->order - current_yes - current_no > 2) { |
2501 | /* |
2502 | * One small refinement to the above: we also look for any |
2503 | * adjacent pair of LINE_UNKNOWNs around the face with |
2504 | * some LINE_YES incident on it from elsewhere. If we find |
2505 | * one, then we know that pair of LINE_UNKNOWNs can't |
2506 | * _both_ be LINE_YES, and hence that pushes us one line |
2507 | * closer to being able to determine all the rest. |
2508 | */ |
2509 | int j, k, e1, e2, e, d; |
2510 | |
2511 | for (j = 0; j < f->order; j++) { |
2512 | e1 = f->edges[j] - g->edges; |
2513 | e2 = f->edges[j+1 < f->order ? j+1 : 0] - g->edges; |
2514 | |
2515 | if (g->edges[e1].dot1 == g->edges[e2].dot1 || |
2516 | g->edges[e1].dot1 == g->edges[e2].dot2) { |
2517 | d = g->edges[e1].dot1 - g->dots; |
2518 | } else { |
2519 | assert(g->edges[e1].dot2 == g->edges[e2].dot1 || |
2520 | g->edges[e1].dot2 == g->edges[e2].dot2); |
2521 | d = g->edges[e1].dot2 - g->dots; |
2522 | } |
2523 | |
2524 | if (state->lines[e1] == LINE_UNKNOWN && |
2525 | state->lines[e2] == LINE_UNKNOWN) { |
2526 | for (k = 0; k < g->dots[d].order; k++) { |
2527 | int e = g->dots[d].edges[k] - g->edges; |
2528 | if (state->lines[e] == LINE_YES) |
2529 | goto found; /* multi-level break */ |
2530 | } |
2531 | } |
2532 | } |
2533 | continue; |
2534 | |
2535 | found: |
2536 | /* |
2537 | * If we get here, we've found such a pair of edges, and |
2538 | * they're e1 and e2. |
2539 | */ |
2540 | for (j = 0; j < f->order; j++) { |
2541 | e = f->edges[j] - g->edges; |
2542 | if (state->lines[e] == LINE_UNKNOWN && e != e1 && e != e2) { |
2543 | int r = solver_set_line(sstate, e, LINE_YES); |
2544 | assert(r); |
2545 | diff = min(diff, DIFF_EASY); |
2546 | } |
2547 | } |
2548 | } |
121aae4b |
2549 | } |
6193da8d |
2550 | |
121aae4b |
2551 | check_caches(sstate); |
6193da8d |
2552 | |
121aae4b |
2553 | /* Per-dot deductions */ |
7c95608a |
2554 | for (i = 0; i < g->num_dots; i++) { |
2555 | grid_dot *d = g->dots + i; |
2556 | int yes, no, unknown; |
2557 | |
2558 | if (sstate->dot_solved[i]) |
121aae4b |
2559 | continue; |
c0eb17ce |
2560 | |
7c95608a |
2561 | yes = sstate->dot_yes_count[i]; |
2562 | no = sstate->dot_no_count[i]; |
2563 | unknown = d->order - yes - no; |
2564 | |
2565 | if (yes == 0) { |
2566 | if (unknown == 0) { |
2567 | sstate->dot_solved[i] = TRUE; |
2568 | } else if (unknown == 1) { |
2569 | dot_setall(sstate, i, LINE_UNKNOWN, LINE_NO); |
121aae4b |
2570 | diff = min(diff, DIFF_EASY); |
7c95608a |
2571 | sstate->dot_solved[i] = TRUE; |
2572 | } |
2573 | } else if (yes == 1) { |
2574 | if (unknown == 0) { |
121aae4b |
2575 | sstate->solver_status = SOLVER_MISTAKE; |
2576 | return DIFF_EASY; |
7c95608a |
2577 | } else if (unknown == 1) { |
2578 | dot_setall(sstate, i, LINE_UNKNOWN, LINE_YES); |
2579 | diff = min(diff, DIFF_EASY); |
2580 | } |
2581 | } else if (yes == 2) { |
2582 | if (unknown > 0) { |
2583 | dot_setall(sstate, i, LINE_UNKNOWN, LINE_NO); |
2584 | diff = min(diff, DIFF_EASY); |
2585 | } |
2586 | sstate->dot_solved[i] = TRUE; |
2587 | } else { |
2588 | sstate->solver_status = SOLVER_MISTAKE; |
2589 | return DIFF_EASY; |
6193da8d |
2590 | } |
2591 | } |
6193da8d |
2592 | |
121aae4b |
2593 | check_caches(sstate); |
6193da8d |
2594 | |
121aae4b |
2595 | return diff; |
6193da8d |
2596 | } |
2597 | |
315e47b9 |
2598 | static int dline_deductions(solver_state *sstate) |
6193da8d |
2599 | { |
121aae4b |
2600 | game_state *state = sstate->state; |
7c95608a |
2601 | grid *g = state->game_grid; |
315e47b9 |
2602 | char *dlines = sstate->dlines; |
7c95608a |
2603 | int i; |
1a739e2f |
2604 | int diff = DIFF_MAX; |
6193da8d |
2605 | |
7c95608a |
2606 | /* ------ Face deductions ------ */ |
2607 | |
2608 | /* Given a set of dline atmostone/atleastone constraints, need to figure |
2609 | * out if we can deduce any further info. For more general faces than |
2610 | * squares, this turns out to be a tricky problem. |
2611 | * The approach taken here is to define (per face) NxN matrices: |
2612 | * "maxs" and "mins". |
2613 | * The entries maxs(j,k) and mins(j,k) define the upper and lower limits |
2614 | * for the possible number of edges that are YES between positions j and k |
2615 | * going clockwise around the face. Can think of j and k as marking dots |
2616 | * around the face (recall the labelling scheme: edge0 joins dot0 to dot1, |
2617 | * edge1 joins dot1 to dot2 etc). |
2618 | * Trivially, mins(j,j) = maxs(j,j) = 0, and we don't even bother storing |
2619 | * these. mins(j,j+1) and maxs(j,j+1) are determined by whether edge{j} |
2620 | * is YES, NO or UNKNOWN. mins(j,j+2) and maxs(j,j+2) are related to |
2621 | * the dline atmostone/atleastone status for edges j and j+1. |
2622 | * |
2623 | * Then we calculate the remaining entries recursively. We definitely |
2624 | * know that |
2625 | * mins(j,k) >= { mins(j,u) + mins(u,k) } for any u between j and k. |
2626 | * This is because any valid placement of YESs between j and k must give |
2627 | * a valid placement between j and u, and also between u and k. |
2628 | * I believe it's sufficient to use just the two values of u: |
2629 | * j+1 and j+2. Seems to work well in practice - the bounds we compute |
2630 | * are rigorous, even if they might not be best-possible. |
2631 | * |
2632 | * Once we have maxs and mins calculated, we can make inferences about |
2633 | * each dline{j,j+1} by looking at the possible complementary edge-counts |
2634 | * mins(j+2,j) and maxs(j+2,j) and comparing these with the face clue. |
2635 | * As well as dlines, we can make similar inferences about single edges. |
2636 | * For example, consider a pentagon with clue 3, and we know at most one |
2637 | * of (edge0, edge1) is YES, and at most one of (edge2, edge3) is YES. |
2638 | * We could then deduce edge4 is YES, because maxs(0,4) would be 2, so |
2639 | * that final edge would have to be YES to make the count up to 3. |
2640 | */ |
121aae4b |
2641 | |
7c95608a |
2642 | /* Much quicker to allocate arrays on the stack than the heap, so |
2643 | * define the largest possible face size, and base our array allocations |
2644 | * on that. We check this with an assertion, in case someone decides to |
2645 | * make a grid which has larger faces than this. Note, this algorithm |
2646 | * could get quite expensive if there are many large faces. */ |
918a098a |
2647 | #define MAX_FACE_SIZE 12 |
7c95608a |
2648 | |
2649 | for (i = 0; i < g->num_faces; i++) { |
2650 | int maxs[MAX_FACE_SIZE][MAX_FACE_SIZE]; |
2651 | int mins[MAX_FACE_SIZE][MAX_FACE_SIZE]; |
2652 | grid_face *f = g->faces + i; |
2653 | int N = f->order; |
2654 | int j,m; |
2655 | int clue = state->clues[i]; |
2656 | assert(N <= MAX_FACE_SIZE); |
2657 | if (sstate->face_solved[i]) |
6193da8d |
2658 | continue; |
7c95608a |
2659 | if (clue < 0) continue; |
2660 | |
2661 | /* Calculate the (j,j+1) entries */ |
2662 | for (j = 0; j < N; j++) { |
2663 | int edge_index = f->edges[j] - g->edges; |
2664 | int dline_index; |
2665 | enum line_state line1 = state->lines[edge_index]; |
2666 | enum line_state line2; |
2667 | int tmp; |
2668 | int k = j + 1; |
2669 | if (k >= N) k = 0; |
2670 | maxs[j][k] = (line1 == LINE_NO) ? 0 : 1; |
2671 | mins[j][k] = (line1 == LINE_YES) ? 1 : 0; |
2672 | /* Calculate the (j,j+2) entries */ |
2673 | dline_index = dline_index_from_face(g, f, k); |
2674 | edge_index = f->edges[k] - g->edges; |
2675 | line2 = state->lines[edge_index]; |
2676 | k++; |
2677 | if (k >= N) k = 0; |
2678 | |
2679 | /* max */ |
2680 | tmp = 2; |
2681 | if (line1 == LINE_NO) tmp--; |
2682 | if (line2 == LINE_NO) tmp--; |
2683 | if (tmp == 2 && is_atmostone(dlines, dline_index)) |
2684 | tmp = 1; |
2685 | maxs[j][k] = tmp; |
2686 | |
2687 | /* min */ |
2688 | tmp = 0; |
2689 | if (line1 == LINE_YES) tmp++; |
2690 | if (line2 == LINE_YES) tmp++; |
2691 | if (tmp == 0 && is_atleastone(dlines, dline_index)) |
2692 | tmp = 1; |
2693 | mins[j][k] = tmp; |
2694 | } |
121aae4b |
2695 | |
7c95608a |
2696 | /* Calculate the (j,j+m) entries for m between 3 and N-1 */ |
2697 | for (m = 3; m < N; m++) { |
2698 | for (j = 0; j < N; j++) { |
2699 | int k = j + m; |
2700 | int u = j + 1; |
2701 | int v = j + 2; |
2702 | int tmp; |
2703 | if (k >= N) k -= N; |
2704 | if (u >= N) u -= N; |
2705 | if (v >= N) v -= N; |
2706 | maxs[j][k] = maxs[j][u] + maxs[u][k]; |
2707 | mins[j][k] = mins[j][u] + mins[u][k]; |
2708 | tmp = maxs[j][v] + maxs[v][k]; |
2709 | maxs[j][k] = min(maxs[j][k], tmp); |
2710 | tmp = mins[j][v] + mins[v][k]; |
2711 | mins[j][k] = max(mins[j][k], tmp); |
2712 | } |
2713 | } |
121aae4b |
2714 | |
7c95608a |
2715 | /* See if we can make any deductions */ |
2716 | for (j = 0; j < N; j++) { |
2717 | int k; |
2718 | grid_edge *e = f->edges[j]; |
2719 | int line_index = e - g->edges; |
2720 | int dline_index; |
121aae4b |
2721 | |
7c95608a |
2722 | if (state->lines[line_index] != LINE_UNKNOWN) |
2723 | continue; |
2724 | k = j + 1; |
2725 | if (k >= N) k = 0; |
121aae4b |
2726 | |
7c95608a |
2727 | /* minimum YESs in the complement of this edge */ |
2728 | if (mins[k][j] > clue) { |
2729 | sstate->solver_status = SOLVER_MISTAKE; |
2730 | return DIFF_EASY; |
2731 | } |
2732 | if (mins[k][j] == clue) { |
2733 | /* setting this edge to YES would make at least |
2734 | * (clue+1) edges - contradiction */ |
2735 | solver_set_line(sstate, line_index, LINE_NO); |
2736 | diff = min(diff, DIFF_EASY); |
2737 | } |
2738 | if (maxs[k][j] < clue - 1) { |
2739 | sstate->solver_status = SOLVER_MISTAKE; |
2740 | return DIFF_EASY; |
2741 | } |
2742 | if (maxs[k][j] == clue - 1) { |
2743 | /* Only way to satisfy the clue is to set edge{j} as YES */ |
2744 | solver_set_line(sstate, line_index, LINE_YES); |
2745 | diff = min(diff, DIFF_EASY); |
2746 | } |
2747 | |
315e47b9 |
2748 | /* More advanced deduction that allows propagation along diagonal |
2749 | * chains of faces connected by dots, for example, 3-2-...-2-3 |
2750 | * in square grids. */ |
2751 | if (sstate->diff >= DIFF_TRICKY) { |
2752 | /* Now see if we can make dline deduction for edges{j,j+1} */ |
2753 | e = f->edges[k]; |
2754 | if (state->lines[e - g->edges] != LINE_UNKNOWN) |
2755 | /* Only worth doing this for an UNKNOWN,UNKNOWN pair. |
2756 | * Dlines where one of the edges is known, are handled in the |
2757 | * dot-deductions */ |
2758 | continue; |
2759 | |
2760 | dline_index = dline_index_from_face(g, f, k); |
2761 | k++; |
2762 | if (k >= N) k = 0; |
2763 | |
2764 | /* minimum YESs in the complement of this dline */ |
2765 | if (mins[k][j] > clue - 2) { |
2766 | /* Adding 2 YESs would break the clue */ |
2767 | if (set_atmostone(dlines, dline_index)) |
2768 | diff = min(diff, DIFF_NORMAL); |
2769 | } |
2770 | /* maximum YESs in the complement of this dline */ |
2771 | if (maxs[k][j] < clue) { |
2772 | /* Adding 2 NOs would mean not enough YESs */ |
2773 | if (set_atleastone(dlines, dline_index)) |
2774 | diff = min(diff, DIFF_NORMAL); |
2775 | } |
7c95608a |
2776 | } |
6193da8d |
2777 | } |
6193da8d |
2778 | } |
2779 | |
121aae4b |
2780 | if (diff < DIFF_NORMAL) |
2781 | return diff; |
6193da8d |
2782 | |
7c95608a |
2783 | /* ------ Dot deductions ------ */ |
6193da8d |
2784 | |
7c95608a |
2785 | for (i = 0; i < g->num_dots; i++) { |
2786 | grid_dot *d = g->dots + i; |
2787 | int N = d->order; |
2788 | int yes, no, unknown; |
2789 | int j; |
2790 | if (sstate->dot_solved[i]) |
2791 | continue; |
2792 | yes = sstate->dot_yes_count[i]; |
2793 | no = sstate->dot_no_count[i]; |
2794 | unknown = N - yes - no; |
2795 | |
2796 | for (j = 0; j < N; j++) { |
2797 | int k; |
2798 | int dline_index; |
2799 | int line1_index, line2_index; |
2800 | enum line_state line1, line2; |
2801 | k = j + 1; |
2802 | if (k >= N) k = 0; |
2803 | dline_index = dline_index_from_dot(g, d, j); |
2804 | line1_index = d->edges[j] - g->edges; |
2805 | line2_index = d->edges[k] - g->edges; |
2806 | line1 = state->lines[line1_index]; |
2807 | line2 = state->lines[line2_index]; |
2808 | |
2809 | /* Infer dline state from line state */ |
2810 | if (line1 == LINE_NO || line2 == LINE_NO) { |
2811 | if (set_atmostone(dlines, dline_index)) |
2812 | diff = min(diff, DIFF_NORMAL); |
2813 | } |
2814 | if (line1 == LINE_YES || line2 == LINE_YES) { |
2815 | if (set_atleastone(dlines, dline_index)) |
2816 | diff = min(diff, DIFF_NORMAL); |
2817 | } |
2818 | /* Infer line state from dline state */ |
2819 | if (is_atmostone(dlines, dline_index)) { |
2820 | if (line1 == LINE_YES && line2 == LINE_UNKNOWN) { |
2821 | solver_set_line(sstate, line2_index, LINE_NO); |
2822 | diff = min(diff, DIFF_EASY); |
2823 | } |
2824 | if (line2 == LINE_YES && line1 == LINE_UNKNOWN) { |
2825 | solver_set_line(sstate, line1_index, LINE_NO); |
2826 | diff = min(diff, DIFF_EASY); |
2827 | } |
2828 | } |
2829 | if (is_atleastone(dlines, dline_index)) { |
2830 | if (line1 == LINE_NO && line2 == LINE_UNKNOWN) { |
2831 | solver_set_line(sstate, line2_index, LINE_YES); |
2832 | diff = min(diff, DIFF_EASY); |
2833 | } |
2834 | if (line2 == LINE_NO && line1 == LINE_UNKNOWN) { |
2835 | solver_set_line(sstate, line1_index, LINE_YES); |
2836 | diff = min(diff, DIFF_EASY); |
2837 | } |
2838 | } |
2839 | /* Deductions that depend on the numbers of lines. |
2840 | * Only bother if both lines are UNKNOWN, otherwise the |
2841 | * easy-mode solver (or deductions above) would have taken |
2842 | * care of it. */ |
2843 | if (line1 != LINE_UNKNOWN || line2 != LINE_UNKNOWN) |
2844 | continue; |
6193da8d |
2845 | |
7c95608a |
2846 | if (yes == 0 && unknown == 2) { |
2847 | /* Both these unknowns must be identical. If we know |
2848 | * atmostone or atleastone, we can make progress. */ |
2849 | if (is_atmostone(dlines, dline_index)) { |
2850 | solver_set_line(sstate, line1_index, LINE_NO); |
2851 | solver_set_line(sstate, line2_index, LINE_NO); |
2852 | diff = min(diff, DIFF_EASY); |
2853 | } |
2854 | if (is_atleastone(dlines, dline_index)) { |
2855 | solver_set_line(sstate, line1_index, LINE_YES); |
2856 | solver_set_line(sstate, line2_index, LINE_YES); |
2857 | diff = min(diff, DIFF_EASY); |
2858 | } |
2859 | } |
2860 | if (yes == 1) { |
2861 | if (set_atmostone(dlines, dline_index)) |
2862 | diff = min(diff, DIFF_NORMAL); |
2863 | if (unknown == 2) { |
2864 | if (set_atleastone(dlines, dline_index)) |
2865 | diff = min(diff, DIFF_NORMAL); |
2866 | } |
121aae4b |
2867 | } |
6193da8d |
2868 | |
315e47b9 |
2869 | /* More advanced deduction that allows propagation along diagonal |
2870 | * chains of faces connected by dots, for example: 3-2-...-2-3 |
2871 | * in square grids. */ |
2872 | if (sstate->diff >= DIFF_TRICKY) { |
2873 | /* If we have atleastone set for this dline, infer |
2874 | * atmostone for each "opposite" dline (that is, each |
2875 | * dline without edges in common with this one). |
2876 | * Again, this test is only worth doing if both these |
2877 | * lines are UNKNOWN. For if one of these lines were YES, |
2878 | * the (yes == 1) test above would kick in instead. */ |
2879 | if (is_atleastone(dlines, dline_index)) { |
2880 | int opp; |
2881 | for (opp = 0; opp < N; opp++) { |
2882 | int opp_dline_index; |
2883 | if (opp == j || opp == j+1 || opp == j-1) |
2884 | continue; |
2885 | if (j == 0 && opp == N-1) |
2886 | continue; |
2887 | if (j == N-1 && opp == 0) |
2888 | continue; |
2889 | opp_dline_index = dline_index_from_dot(g, d, opp); |
2890 | if (set_atmostone(dlines, opp_dline_index)) |
2891 | diff = min(diff, DIFF_NORMAL); |
2892 | } |
2893 | if (yes == 0 && is_atmostone(dlines, dline_index)) { |
2894 | /* This dline has *exactly* one YES and there are no |
2895 | * other YESs. This allows more deductions. */ |
2896 | if (unknown == 3) { |
2897 | /* Third unknown must be YES */ |
2898 | for (opp = 0; opp < N; opp++) { |
2899 | int opp_index; |
2900 | if (opp == j || opp == k) |
2901 | continue; |
2902 | opp_index = d->edges[opp] - g->edges; |
2903 | if (state->lines[opp_index] == LINE_UNKNOWN) { |
2904 | solver_set_line(sstate, opp_index, |
2905 | LINE_YES); |
2906 | diff = min(diff, DIFF_EASY); |
2907 | } |
121aae4b |
2908 | } |
315e47b9 |
2909 | } else if (unknown == 4) { |
2910 | /* Exactly one of opposite UNKNOWNS is YES. We've |
2911 | * already set atmostone, so set atleastone as |
2912 | * well. |
2913 | */ |
2914 | if (dline_set_opp_atleastone(sstate, d, j)) |
2915 | diff = min(diff, DIFF_NORMAL); |
121aae4b |
2916 | } |
2917 | } |
121aae4b |
2918 | } |
6193da8d |
2919 | } |
6193da8d |
2920 | } |
121aae4b |
2921 | } |
121aae4b |
2922 | return diff; |
6193da8d |
2923 | } |
2924 | |
315e47b9 |
2925 | static int linedsf_deductions(solver_state *sstate) |
6193da8d |
2926 | { |
121aae4b |
2927 | game_state *state = sstate->state; |
7c95608a |
2928 | grid *g = state->game_grid; |
315e47b9 |
2929 | char *dlines = sstate->dlines; |
7c95608a |
2930 | int i; |
1a739e2f |
2931 | int diff = DIFF_MAX; |
7c95608a |
2932 | int diff_tmp; |
121aae4b |
2933 | |
7c95608a |
2934 | /* ------ Face deductions ------ */ |
6193da8d |
2935 | |
7c95608a |
2936 | /* A fully-general linedsf deduction seems overly complicated |
2937 | * (I suspect the problem is NP-complete, though in practice it might just |
2938 | * be doable because faces are limited in size). |
2939 | * For simplicity, we only consider *pairs* of LINE_UNKNOWNS that are |
2940 | * known to be identical. If setting them both to YES (or NO) would break |
2941 | * the clue, set them to NO (or YES). */ |
121aae4b |
2942 | |
7c95608a |
2943 | for (i = 0; i < g->num_faces; i++) { |
2944 | int N, yes, no, unknown; |
2945 | int clue; |
6193da8d |
2946 | |
7c95608a |
2947 | if (sstate->face_solved[i]) |
121aae4b |
2948 | continue; |
7c95608a |
2949 | clue = state->clues[i]; |
2950 | if (clue < 0) |
121aae4b |
2951 | continue; |
6193da8d |
2952 | |
7c95608a |
2953 | N = g->faces[i].order; |
2954 | yes = sstate->face_yes_count[i]; |
2955 | if (yes + 1 == clue) { |
2956 | if (face_setall_identical(sstate, i, LINE_NO)) |
2957 | diff = min(diff, DIFF_EASY); |
121aae4b |
2958 | } |
7c95608a |
2959 | no = sstate->face_no_count[i]; |
2960 | if (no + 1 == N - clue) { |
2961 | if (face_setall_identical(sstate, i, LINE_YES)) |
2962 | diff = min(diff, DIFF_EASY); |
6193da8d |
2963 | } |
6193da8d |
2964 | |
7c95608a |
2965 | /* Reload YES count, it might have changed */ |
2966 | yes = sstate->face_yes_count[i]; |
2967 | unknown = N - no - yes; |
2968 | |
2969 | /* Deductions with small number of LINE_UNKNOWNs, based on overall |
2970 | * parity of lines. */ |
2971 | diff_tmp = parity_deductions(sstate, g->faces[i].edges, |
2972 | (clue - yes) % 2, unknown); |
2973 | diff = min(diff, diff_tmp); |
2974 | } |
2975 | |
2976 | /* ------ Dot deductions ------ */ |
2977 | for (i = 0; i < g->num_dots; i++) { |
2978 | grid_dot *d = g->dots + i; |
2979 | int N = d->order; |
2980 | int j; |
2981 | int yes, no, unknown; |
2982 | /* Go through dlines, and do any dline<->linedsf deductions wherever |
2983 | * we find two UNKNOWNS. */ |
2984 | for (j = 0; j < N; j++) { |
2985 | int dline_index = dline_index_from_dot(g, d, j); |
2986 | int line1_index; |
2987 | int line2_index; |
2988 | int can1, can2, inv1, inv2; |
2989 | int j2; |
2990 | line1_index = d->edges[j] - g->edges; |
2991 | if (state->lines[line1_index] != LINE_UNKNOWN) |
121aae4b |
2992 | continue; |
7c95608a |
2993 | j2 = j + 1; |
2994 | if (j2 == N) j2 = 0; |
2995 | line2_index = d->edges[j2] - g->edges; |
2996 | if (state->lines[line2_index] != LINE_UNKNOWN) |
121aae4b |
2997 | continue; |
7c95608a |
2998 | /* Infer dline flags from linedsf */ |
315e47b9 |
2999 | can1 = edsf_canonify(sstate->linedsf, line1_index, &inv1); |
3000 | can2 = edsf_canonify(sstate->linedsf, line2_index, &inv2); |
7c95608a |
3001 | if (can1 == can2 && inv1 != inv2) { |
3002 | /* These are opposites, so set dline atmostone/atleastone */ |
3003 | if (set_atmostone(dlines, dline_index)) |
3004 | diff = min(diff, DIFF_NORMAL); |
3005 | if (set_atleastone(dlines, dline_index)) |
3006 | diff = min(diff, DIFF_NORMAL); |
121aae4b |
3007 | continue; |
7c95608a |
3008 | } |
3009 | /* Infer linedsf from dline flags */ |
3010 | if (is_atmostone(dlines, dline_index) |
3011 | && is_atleastone(dlines, dline_index)) { |
3012 | if (merge_lines(sstate, line1_index, line2_index, 1)) |
121aae4b |
3013 | diff = min(diff, DIFF_HARD); |
121aae4b |
3014 | } |
3015 | } |
7c95608a |
3016 | |
3017 | /* Deductions with small number of LINE_UNKNOWNs, based on overall |
3018 | * parity of lines. */ |
3019 | yes = sstate->dot_yes_count[i]; |
3020 | no = sstate->dot_no_count[i]; |
3021 | unknown = N - yes - no; |
3022 | diff_tmp = parity_deductions(sstate, d->edges, |
3023 | yes % 2, unknown); |
3024 | diff = min(diff, diff_tmp); |
121aae4b |
3025 | } |
6193da8d |
3026 | |
7c95608a |
3027 | /* ------ Edge dsf deductions ------ */ |
3028 | |
3029 | /* If the state of a line is known, deduce the state of its canonical line |
3030 | * too, and vice versa. */ |
3031 | for (i = 0; i < g->num_edges; i++) { |
3032 | int can, inv; |
3033 | enum line_state s; |
315e47b9 |
3034 | can = edsf_canonify(sstate->linedsf, i, &inv); |
7c95608a |
3035 | if (can == i) |
3036 | continue; |
3037 | s = sstate->state->lines[can]; |
3038 | if (s != LINE_UNKNOWN) { |
3039 | if (solver_set_line(sstate, i, inv ? OPP(s) : s)) |
3040 | diff = min(diff, DIFF_EASY); |
3041 | } else { |
3042 | s = sstate->state->lines[i]; |
3043 | if (s != LINE_UNKNOWN) { |
3044 | if (solver_set_line(sstate, can, inv ? OPP(s) : s)) |
121aae4b |
3045 | diff = min(diff, DIFF_EASY); |
3046 | } |
3047 | } |
3048 | } |
6193da8d |
3049 | |
121aae4b |
3050 | return diff; |
3051 | } |
6193da8d |
3052 | |
121aae4b |
3053 | static int loop_deductions(solver_state *sstate) |
3054 | { |
3055 | int edgecount = 0, clues = 0, satclues = 0, sm1clues = 0; |
3056 | game_state *state = sstate->state; |
7c95608a |
3057 | grid *g = state->game_grid; |
3058 | int shortest_chainlen = g->num_dots; |
121aae4b |
3059 | int loop_found = FALSE; |
121aae4b |
3060 | int dots_connected; |
3061 | int progress = FALSE; |
7c95608a |
3062 | int i; |
6193da8d |
3063 | |
121aae4b |
3064 | /* |
3065 | * Go through the grid and update for all the new edges. |
3066 | * Since merge_dots() is idempotent, the simplest way to |
3067 | * do this is just to update for _all_ the edges. |
7c95608a |
3068 | * Also, while we're here, we count the edges. |
121aae4b |
3069 | */ |
7c95608a |
3070 | for (i = 0; i < g->num_edges; i++) { |
3071 | if (state->lines[i] == LINE_YES) { |
3072 | loop_found |= merge_dots(sstate, i); |
121aae4b |
3073 | edgecount++; |
3074 | } |
7c95608a |
3075 | } |
6193da8d |
3076 | |
7c95608a |
3077 | /* |
3078 | * Count the clues, count the satisfied clues, and count the |
3079 | * satisfied-minus-one clues. |
3080 | */ |
3081 | for (i = 0; i < g->num_faces; i++) { |
3082 | int c = state->clues[i]; |
3083 | if (c >= 0) { |
3084 | int o = sstate->face_yes_count[i]; |
121aae4b |
3085 | if (o == c) |
3086 | satclues++; |
3087 | else if (o == c-1) |
3088 | sm1clues++; |
3089 | clues++; |
3090 | } |
3091 | } |
6193da8d |
3092 | |
7c95608a |
3093 | for (i = 0; i < g->num_dots; ++i) { |
3094 | dots_connected = |
121aae4b |
3095 | sstate->looplen[dsf_canonify(sstate->dotdsf, i)]; |
3096 | if (dots_connected > 1) |
3097 | shortest_chainlen = min(shortest_chainlen, dots_connected); |
6193da8d |
3098 | } |
6193da8d |
3099 | |
121aae4b |
3100 | assert(sstate->solver_status == SOLVER_INCOMPLETE); |
6c42c563 |
3101 | |
121aae4b |
3102 | if (satclues == clues && shortest_chainlen == edgecount) { |
3103 | sstate->solver_status = SOLVER_SOLVED; |
3104 | /* This discovery clearly counts as progress, even if we haven't |
3105 | * just added any lines or anything */ |
7c95608a |
3106 | progress = TRUE; |
121aae4b |
3107 | goto finished_loop_deductionsing; |
3108 | } |
6193da8d |
3109 | |
121aae4b |
3110 | /* |
3111 | * Now go through looking for LINE_UNKNOWN edges which |
3112 | * connect two dots that are already in the same |
3113 | * equivalence class. If we find one, test to see if the |
3114 | * loop it would create is a solution. |
3115 | */ |
7c95608a |
3116 | for (i = 0; i < g->num_edges; i++) { |
3117 | grid_edge *e = g->edges + i; |
3118 | int d1 = e->dot1 - g->dots; |
3119 | int d2 = e->dot2 - g->dots; |
3120 | int eqclass, val; |
3121 | if (state->lines[i] != LINE_UNKNOWN) |
3122 | continue; |
121aae4b |
3123 | |
7c95608a |
3124 | eqclass = dsf_canonify(sstate->dotdsf, d1); |
3125 | if (eqclass != dsf_canonify(sstate->dotdsf, d2)) |
3126 | continue; |
121aae4b |
3127 | |
7c95608a |
3128 | val = LINE_NO; /* loop is bad until proven otherwise */ |
6193da8d |
3129 | |
7c95608a |
3130 | /* |
3131 | * This edge would form a loop. Next |
3132 | * question: how long would the loop be? |
3133 | * Would it equal the total number of edges |
3134 | * (plus the one we'd be adding if we added |
3135 | * it)? |
3136 | */ |
3137 | if (sstate->looplen[eqclass] == edgecount + 1) { |
3138 | int sm1_nearby; |
121aae4b |
3139 | |
3140 | /* |
7c95608a |
3141 | * This edge would form a loop which |
3142 | * took in all the edges in the entire |
3143 | * grid. So now we need to work out |
3144 | * whether it would be a valid solution |
3145 | * to the puzzle, which means we have to |
3146 | * check if it satisfies all the clues. |
3147 | * This means that every clue must be |
3148 | * either satisfied or satisfied-minus- |
3149 | * 1, and also that the number of |
3150 | * satisfied-minus-1 clues must be at |
3151 | * most two and they must lie on either |
3152 | * side of this edge. |
121aae4b |
3153 | */ |
7c95608a |
3154 | sm1_nearby = 0; |
3155 | if (e->face1) { |
3156 | int f = e->face1 - g->faces; |
3157 | int c = state->clues[f]; |
3158 | if (c >= 0 && sstate->face_yes_count[f] == c - 1) |
121aae4b |
3159 | sm1_nearby++; |
6c42c563 |
3160 | } |
7c95608a |
3161 | if (e->face2) { |
3162 | int f = e->face2 - g->faces; |
3163 | int c = state->clues[f]; |
3164 | if (c >= 0 && sstate->face_yes_count[f] == c - 1) |
3165 | sm1_nearby++; |
6c42c563 |
3166 | } |
7c95608a |
3167 | if (sm1clues == sm1_nearby && |
3168 | sm1clues + satclues == clues) { |
3169 | val = LINE_YES; /* loop is good! */ |
6c42c563 |
3170 | } |
121aae4b |
3171 | } |
7c95608a |
3172 | |
3173 | /* |
3174 | * Right. Now we know that adding this edge |
3175 | * would form a loop, and we know whether |
3176 | * that loop would be a viable solution or |
3177 | * not. |
3178 | * |
3179 | * If adding this edge produces a solution, |
3180 | * then we know we've found _a_ solution but |
3181 | * we don't know that it's _the_ solution - |
3182 | * if it were provably the solution then |
3183 | * we'd have deduced this edge some time ago |
3184 | * without the need to do loop detection. So |
3185 | * in this state we return SOLVER_AMBIGUOUS, |
3186 | * which has the effect that hitting Solve |
3187 | * on a user-provided puzzle will fill in a |
3188 | * solution but using the solver to |
3189 | * construct new puzzles won't consider this |
3190 | * a reasonable deduction for the user to |
3191 | * make. |
3192 | */ |
3193 | progress = solver_set_line(sstate, i, val); |
3194 | assert(progress == TRUE); |
3195 | if (val == LINE_YES) { |
3196 | sstate->solver_status = SOLVER_AMBIGUOUS; |
3197 | goto finished_loop_deductionsing; |
3198 | } |
6193da8d |
3199 | } |
6193da8d |
3200 | |
7c95608a |
3201 | finished_loop_deductionsing: |
121aae4b |
3202 | return progress ? DIFF_EASY : DIFF_MAX; |
c0eb17ce |
3203 | } |
6193da8d |
3204 | |
3205 | /* This will return a dynamically allocated solver_state containing the (more) |
3206 | * solved grid */ |
315e47b9 |
3207 | static solver_state *solve_game_rec(const solver_state *sstate_start) |
121aae4b |
3208 | { |
315e47b9 |
3209 | solver_state *sstate; |
6193da8d |
3210 | |
315e47b9 |
3211 | /* Index of the solver we should call next. */ |
3212 | int i = 0; |
3213 | |
3214 | /* As a speed-optimisation, we avoid re-running solvers that we know |
3215 | * won't make any progress. This happens when a high-difficulty |
3216 | * solver makes a deduction that can only help other high-difficulty |
3217 | * solvers. |
3218 | * For example: if a new 'dline' flag is set by dline_deductions, the |
3219 | * trivial_deductions solver cannot do anything with this information. |
3220 | * If we've already run the trivial_deductions solver (because it's |
3221 | * earlier in the list), there's no point running it again. |
3222 | * |
3223 | * Therefore: if a solver is earlier in the list than "threshold_index", |
3224 | * we don't bother running it if it's difficulty level is less than |
3225 | * "threshold_diff". |
3226 | */ |
3227 | int threshold_diff = 0; |
3228 | int threshold_index = 0; |
3229 | |
121aae4b |
3230 | sstate = dup_solver_state(sstate_start); |
7c95608a |
3231 | |
121aae4b |
3232 | check_caches(sstate); |
6193da8d |
3233 | |
315e47b9 |
3234 | while (i < NUM_SOLVERS) { |
121aae4b |
3235 | if (sstate->solver_status == SOLVER_MISTAKE) |
3236 | return sstate; |
7c95608a |
3237 | if (sstate->solver_status == SOLVER_SOLVED || |
121aae4b |
3238 | sstate->solver_status == SOLVER_AMBIGUOUS) { |
315e47b9 |
3239 | /* solver finished */ |
121aae4b |
3240 | break; |
3241 | } |
99dd160e |
3242 | |
315e47b9 |
3243 | if ((solver_diffs[i] >= threshold_diff || i >= threshold_index) |
3244 | && solver_diffs[i] <= sstate->diff) { |
3245 | /* current_solver is eligible, so use it */ |
3246 | int next_diff = solver_fns[i](sstate); |
3247 | if (next_diff != DIFF_MAX) { |
3248 | /* solver made progress, so use new thresholds and |
3249 | * start again at top of list. */ |
3250 | threshold_diff = next_diff; |
3251 | threshold_index = i; |
3252 | i = 0; |
3253 | continue; |
3254 | } |
3255 | } |
3256 | /* current_solver is ineligible, or failed to make progress, so |
3257 | * go to the next solver in the list */ |
3258 | i++; |
3259 | } |
121aae4b |
3260 | |
3261 | if (sstate->solver_status == SOLVER_SOLVED || |
3262 | sstate->solver_status == SOLVER_AMBIGUOUS) { |
3263 | /* s/LINE_UNKNOWN/LINE_NO/g */ |
7c95608a |
3264 | array_setall(sstate->state->lines, LINE_UNKNOWN, LINE_NO, |
3265 | sstate->state->game_grid->num_edges); |
121aae4b |
3266 | return sstate; |
3267 | } |
6193da8d |
3268 | |
121aae4b |
3269 | return sstate; |
6193da8d |
3270 | } |
3271 | |
6193da8d |
3272 | static char *solve_game(game_state *state, game_state *currstate, |
3273 | char *aux, char **error) |
3274 | { |
3275 | char *soln = NULL; |
3276 | solver_state *sstate, *new_sstate; |
3277 | |
121aae4b |
3278 | sstate = new_solver_state(state, DIFF_MAX); |
315e47b9 |
3279 | new_sstate = solve_game_rec(sstate); |
6193da8d |
3280 | |
3281 | if (new_sstate->solver_status == SOLVER_SOLVED) { |
3282 | soln = encode_solve_move(new_sstate->state); |
3283 | } else if (new_sstate->solver_status == SOLVER_AMBIGUOUS) { |
3284 | soln = encode_solve_move(new_sstate->state); |
3285 | /**error = "Solver found ambiguous solutions"; */ |
3286 | } else { |
3287 | soln = encode_solve_move(new_sstate->state); |
3288 | /**error = "Solver failed"; */ |
3289 | } |
3290 | |
3291 | free_solver_state(new_sstate); |
3292 | free_solver_state(sstate); |
3293 | |
3294 | return soln; |
3295 | } |
3296 | |
121aae4b |
3297 | /* ---------------------------------------------------------------------- |
3298 | * Drawing and mouse-handling |
3299 | */ |
6193da8d |
3300 | |
3301 | static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, |
3302 | int x, int y, int button) |
3303 | { |
7c95608a |
3304 | grid *g = state->game_grid; |
3305 | grid_edge *e; |
3306 | int i; |
6193da8d |
3307 | char *ret, buf[80]; |
3308 | char button_char = ' '; |
3309 | enum line_state old_state; |
3310 | |
3311 | button &= ~MOD_MASK; |
3312 | |
7c95608a |
3313 | /* Convert mouse-click (x,y) to grid coordinates */ |
3314 | x -= BORDER(ds->tilesize); |
3315 | y -= BORDER(ds->tilesize); |
3316 | x = x * g->tilesize / ds->tilesize; |
3317 | y = y * g->tilesize / ds->tilesize; |
3318 | x += g->lowest_x; |
3319 | y += g->lowest_y; |
6193da8d |
3320 | |
7c95608a |
3321 | e = grid_nearest_edge(g, x, y); |
3322 | if (e == NULL) |
6193da8d |
3323 | return NULL; |
3324 | |
7c95608a |
3325 | i = e - g->edges; |
6193da8d |
3326 | |
3327 | /* I think it's only possible to play this game with mouse clicks, sorry */ |
3328 | /* Maybe will add mouse drag support some time */ |
7c95608a |
3329 | old_state = state->lines[i]; |
6193da8d |
3330 | |
3331 | switch (button) { |
7c95608a |
3332 | case LEFT_BUTTON: |
3333 | switch (old_state) { |
3334 | case LINE_UNKNOWN: |
3335 | button_char = 'y'; |
3336 | break; |
3337 | case LINE_YES: |
80e7e37c |
3338 | #ifdef STYLUS_BASED |
3339 | button_char = 'n'; |
3340 | break; |
3341 | #endif |
7c95608a |
3342 | case LINE_NO: |
3343 | button_char = 'u'; |
3344 | break; |
3345 | } |
3346 | break; |
3347 | case MIDDLE_BUTTON: |
3348 | button_char = 'u'; |
3349 | break; |
3350 | case RIGHT_BUTTON: |
3351 | switch (old_state) { |
3352 | case LINE_UNKNOWN: |
3353 | button_char = 'n'; |
3354 | break; |
3355 | case LINE_NO: |
80e7e37c |
3356 | #ifdef STYLUS_BASED |
3357 | button_char = 'y'; |
3358 | break; |
3359 | #endif |
7c95608a |
3360 | case LINE_YES: |
3361 | button_char = 'u'; |
3362 | break; |
3363 | } |
3364 | break; |
3365 | default: |
3366 | return NULL; |
3367 | } |
3368 | |
3369 | |
3370 | sprintf(buf, "%d%c", i, (int)button_char); |
6193da8d |
3371 | ret = dupstr(buf); |
3372 | |
3373 | return ret; |
3374 | } |
3375 | |
3376 | static game_state *execute_move(game_state *state, char *move) |
3377 | { |
7c95608a |
3378 | int i; |
6193da8d |
3379 | game_state *newstate = dup_game(state); |
3380 | |
3381 | if (move[0] == 'S') { |
3382 | move++; |
3383 | newstate->cheated = TRUE; |
3384 | } |
3385 | |
3386 | while (*move) { |
3387 | i = atoi(move); |
8719c2e7 |
3388 | if (i < 0 || i >= newstate->game_grid->num_edges) |
3389 | goto fail; |
6193da8d |
3390 | move += strspn(move, "1234567890"); |
3391 | switch (*(move++)) { |
7c95608a |
3392 | case 'y': |
3393 | newstate->lines[i] = LINE_YES; |
3394 | break; |
3395 | case 'n': |
3396 | newstate->lines[i] = LINE_NO; |
3397 | break; |
3398 | case 'u': |
3399 | newstate->lines[i] = LINE_UNKNOWN; |
3400 | break; |
3401 | default: |
3402 | goto fail; |
6193da8d |
3403 | } |
3404 | } |
3405 | |
3406 | /* |
3407 | * Check for completion. |
3408 | */ |
b6bf0adc |
3409 | if (check_completion(newstate)) |
121aae4b |
3410 | newstate->solved = TRUE; |
6193da8d |
3411 | |
6193da8d |
3412 | return newstate; |
3413 | |
7c95608a |
3414 | fail: |
6193da8d |
3415 | free_game(newstate); |
3416 | return NULL; |
3417 | } |
3418 | |
3419 | /* ---------------------------------------------------------------------- |
3420 | * Drawing routines. |
3421 | */ |
7c95608a |
3422 | |
3423 | /* Convert from grid coordinates to screen coordinates */ |
3424 | static void grid_to_screen(const game_drawstate *ds, const grid *g, |
3425 | int grid_x, int grid_y, int *x, int *y) |
3426 | { |
3427 | *x = grid_x - g->lowest_x; |
3428 | *y = grid_y - g->lowest_y; |
3429 | *x = *x * ds->tilesize / g->tilesize; |
3430 | *y = *y * ds->tilesize / g->tilesize; |
3431 | *x += BORDER(ds->tilesize); |
3432 | *y += BORDER(ds->tilesize); |
3433 | } |
3434 | |
3435 | /* Returns (into x,y) position of centre of face for rendering the text clue. |
3436 | */ |
3437 | static void face_text_pos(const game_drawstate *ds, const grid *g, |
e64991db |
3438 | grid_face *f, int *xret, int *yret) |
7c95608a |
3439 | { |
e0936bbd |
3440 | int faceindex = f - g->faces; |
7c95608a |
3441 | |
e0936bbd |
3442 | /* |
3443 | * Return the cached position for this face, if we've already |
3444 | * worked it out. |
3445 | */ |
3446 | if (ds->textx[faceindex] >= 0) { |
3447 | *xret = ds->textx[faceindex]; |
3448 | *yret = ds->texty[faceindex]; |
3449 | return; |
3450 | } |
7c95608a |
3451 | |
e0936bbd |
3452 | /* |
e64991db |
3453 | * Otherwise, use the incentre computed by grid.c and convert it |
3454 | * to screen coordinates. |
e0936bbd |
3455 | */ |
e64991db |
3456 | grid_find_incentre(f); |
3457 | grid_to_screen(ds, g, f->ix, f->iy, |
e0936bbd |
3458 | &ds->textx[faceindex], &ds->texty[faceindex]); |
3459 | |
3460 | *xret = ds->textx[faceindex]; |
3461 | *yret = ds->texty[faceindex]; |
7c95608a |
3462 | } |
3463 | |
1463f9f1 |
3464 | static void face_text_bbox(game_drawstate *ds, grid *g, grid_face *f, |
3465 | int *x, int *y, int *w, int *h) |
3466 | { |
3467 | int xx, yy; |
3468 | face_text_pos(ds, g, f, &xx, &yy); |
3469 | |
3470 | /* There seems to be a certain amount of trial-and-error involved |
3471 | * in working out the correct bounding-box for the text. */ |
3472 | |
3473 | *x = xx - ds->tilesize/4 - 1; |
3474 | *y = yy - ds->tilesize/4 - 3; |
3475 | *w = ds->tilesize/2 + 2; |
3476 | *h = ds->tilesize/2 + 5; |
3477 | } |
3478 | |
d68b2c10 |
3479 | static void game_redraw_clue(drawing *dr, game_drawstate *ds, |
3480 | game_state *state, int i) |
3481 | { |
3482 | grid *g = state->game_grid; |
3483 | grid_face *f = g->faces + i; |
3484 | int x, y; |
918a098a |
3485 | char c[3]; |
d68b2c10 |
3486 | |
918a098a |
3487 | if (state->clues[i] < 10) { |
3488 | c[0] = CLUE2CHAR(state->clues[i]); |
3489 | c[1] = '\0'; |
3490 | } else { |
3491 | sprintf(c, "%d", state->clues[i]); |
3492 | } |
d68b2c10 |
3493 | |
3494 | face_text_pos(ds, g, f, &x, &y); |
3495 | draw_text(dr, x, y, |
3496 | FONT_VARIABLE, ds->tilesize/2, |
3497 | ALIGN_VCENTRE | ALIGN_HCENTRE, |
3498 | ds->clue_error[i] ? COL_MISTAKE : |
3499 | ds->clue_satisfied[i] ? COL_SATISFIED : COL_FOREGROUND, c); |
3500 | } |
3501 | |
1463f9f1 |
3502 | static void edge_bbox(game_drawstate *ds, grid *g, grid_edge *e, |
3503 | int *x, int *y, int *w, int *h) |
3504 | { |
3505 | int x1 = e->dot1->x; |
3506 | int y1 = e->dot1->y; |
3507 | int x2 = e->dot2->x; |
3508 | int y2 = e->dot2->y; |
3509 | int xmin, xmax, ymin, ymax; |
3510 | |
3511 | grid_to_screen(ds, g, x1, y1, &x1, &y1); |
3512 | grid_to_screen(ds, g, x2, y2, &x2, &y2); |
3513 | /* Allow extra margin for dots, and thickness of lines */ |
3514 | xmin = min(x1, x2) - 2; |
3515 | xmax = max(x1, x2) + 2; |
3516 | ymin = min(y1, y2) - 2; |
3517 | ymax = max(y1, y2) + 2; |
3518 | |
3519 | *x = xmin; |
3520 | *y = ymin; |
3521 | *w = xmax - xmin + 1; |
3522 | *h = ymax - ymin + 1; |
3523 | } |
3524 | |
3525 | static void dot_bbox(game_drawstate *ds, grid *g, grid_dot *d, |
3526 | int *x, int *y, int *w, int *h) |
3527 | { |
3528 | int x1, y1; |
3529 | |
3530 | grid_to_screen(ds, g, d->x, d->y, &x1, &y1); |
3531 | |
3532 | *x = x1 - 2; |
3533 | *y = y1 - 2; |
3534 | *w = 5; |
3535 | *h = 5; |
3536 | } |
3537 | |
b0a2ee96 |
3538 | static const int loopy_line_redraw_phases[] = { |
3539 | COL_FAINT, COL_LINEUNKNOWN, COL_FOREGROUND, COL_HIGHLIGHT, COL_MISTAKE |
3540 | }; |
3541 | #define NPHASES lenof(loopy_line_redraw_phases) |
3542 | |
d68b2c10 |
3543 | static void game_redraw_line(drawing *dr, game_drawstate *ds, |
b0a2ee96 |
3544 | game_state *state, int i, int phase) |
d68b2c10 |
3545 | { |
3546 | grid *g = state->game_grid; |
3547 | grid_edge *e = g->edges + i; |
3548 | int x1, x2, y1, y2; |
3549 | int xmin, ymin, xmax, ymax; |
3550 | int line_colour; |
3551 | |
3552 | if (state->line_errors[i]) |
3553 | line_colour = COL_MISTAKE; |
3554 | else if (state->lines[i] == LINE_UNKNOWN) |
3555 | line_colour = COL_LINEUNKNOWN; |
3556 | else if (state->lines[i] == LINE_NO) |
3557 | line_colour = COL_FAINT; |
3558 | else if (ds->flashing) |
3559 | line_colour = COL_HIGHLIGHT; |
3560 | else |
3561 | line_colour = COL_FOREGROUND; |
b0a2ee96 |
3562 | if (line_colour != loopy_line_redraw_phases[phase]) |
3563 | return; |
d68b2c10 |
3564 | |
3565 | /* Convert from grid to screen coordinates */ |
3566 | grid_to_screen(ds, g, e->dot1->x, e->dot1->y, &x1, &y1); |
3567 | grid_to_screen(ds, g, e->dot2->x, e->dot2->y, &x2, &y2); |
3568 | |
3569 | xmin = min(x1, x2); |
3570 | xmax = max(x1, x2); |
3571 | ymin = min(y1, y2); |
3572 | ymax = max(y1, y2); |
3573 | |
3574 | if (line_colour == COL_FAINT) { |
3575 | static int draw_faint_lines = -1; |
3576 | if (draw_faint_lines < 0) { |
3577 | char *env = getenv("LOOPY_FAINT_LINES"); |
3578 | draw_faint_lines = (!env || (env[0] == 'y' || |
3579 | env[0] == 'Y')); |
3580 | } |
3581 | if (draw_faint_lines) |
3582 | draw_line(dr, x1, y1, x2, y2, line_colour); |
3583 | } else { |
3584 | draw_thick_line(dr, 3.0, |
3585 | x1 + 0.5, y1 + 0.5, |
3586 | x2 + 0.5, y2 + 0.5, |
3587 | line_colour); |
3588 | } |
3589 | } |
3590 | |
3591 | static void game_redraw_dot(drawing *dr, game_drawstate *ds, |
3592 | game_state *state, int i) |
3593 | { |
3594 | grid *g = state->game_grid; |
3595 | grid_dot *d = g->dots + i; |
3596 | int x, y; |
3597 | |
3598 | grid_to_screen(ds, g, d->x, d->y, &x, &y); |
3599 | draw_circle(dr, x, y, 2, COL_FOREGROUND, COL_FOREGROUND); |
3600 | } |
3601 | |
1463f9f1 |
3602 | static int boxes_intersect(int x0, int y0, int w0, int h0, |
3603 | int x1, int y1, int w1, int h1) |
3604 | { |
3605 | /* |
3606 | * Two intervals intersect iff neither is wholly on one side of |
3607 | * the other. Two boxes intersect iff their horizontal and |
3608 | * vertical intervals both intersect. |
3609 | */ |
3610 | return (x0 < x1+w1 && x1 < x0+w0 && y0 < y1+h1 && y1 < y0+h0); |
3611 | } |
3612 | |
3613 | static void game_redraw_in_rect(drawing *dr, game_drawstate *ds, |
3614 | game_state *state, int x, int y, int w, int h) |
3615 | { |
3616 | grid *g = state->game_grid; |
3617 | int i, phase; |
3618 | int bx, by, bw, bh; |
3619 | |
3620 | clip(dr, x, y, w, h); |
3621 | draw_rect(dr, x, y, w, h, COL_BACKGROUND); |
3622 | |
3623 | for (i = 0; i < g->num_faces; i++) { |
75a52b16 |
3624 | if (state->clues[i] >= 0) { |
3625 | face_text_bbox(ds, g, &g->faces[i], &bx, &by, &bw, &bh); |
3626 | if (boxes_intersect(x, y, w, h, bx, by, bw, bh)) |
3627 | game_redraw_clue(dr, ds, state, i); |
3628 | } |
1463f9f1 |
3629 | } |
3630 | for (phase = 0; phase < NPHASES; phase++) { |
3631 | for (i = 0; i < g->num_edges; i++) { |
3632 | edge_bbox(ds, g, &g->edges[i], &bx, &by, &bw, &bh); |
3633 | if (boxes_intersect(x, y, w, h, bx, by, bw, bh)) |
3634 | game_redraw_line(dr, ds, state, i, phase); |
3635 | } |
3636 | } |
3637 | for (i = 0; i < g->num_dots; i++) { |
3638 | dot_bbox(ds, g, &g->dots[i], &bx, &by, &bw, &bh); |
3639 | if (boxes_intersect(x, y, w, h, bx, by, bw, bh)) |
3640 | game_redraw_dot(dr, ds, state, i); |
3641 | } |
3642 | |
3643 | unclip(dr); |
3644 | draw_update(dr, x, y, w, h); |
3645 | } |
3646 | |
6193da8d |
3647 | static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate, |
3648 | game_state *state, int dir, game_ui *ui, |
3649 | float animtime, float flashtime) |
3650 | { |
d68b2c10 |
3651 | #define REDRAW_OBJECTS_LIMIT 16 /* Somewhat arbitrary tradeoff */ |
3652 | |
7c95608a |
3653 | grid *g = state->game_grid; |
3654 | int border = BORDER(ds->tilesize); |
1463f9f1 |
3655 | int i; |
d68b2c10 |
3656 | int flash_changed; |
3657 | int redraw_everything = FALSE; |
3658 | |
3659 | int edges[REDRAW_OBJECTS_LIMIT], nedges = 0; |
3660 | int faces[REDRAW_OBJECTS_LIMIT], nfaces = 0; |
3661 | |
3662 | /* Redrawing is somewhat involved. |
3663 | * |
3664 | * An update can theoretically affect an arbitrary number of edges |
3665 | * (consider, for example, completing or breaking a cycle which doesn't |
3666 | * satisfy all the clues -- we'll switch many edges between error and |
3667 | * normal states). On the other hand, redrawing the whole grid takes a |
3668 | * while, making the game feel sluggish, and many updates are actually |
3669 | * quite well localized. |
3670 | * |
3671 | * This redraw algorithm attempts to cope with both situations gracefully |
3672 | * and correctly. For localized changes, we set a clip rectangle, fill |
3673 | * it with background, and then redraw (a plausible but conservative |
3674 | * guess at) the objects which intersect the rectangle; if several |
3675 | * objects need redrawing, we'll do them individually. However, if lots |
3676 | * of objects are affected, we'll just redraw everything. |
3677 | * |
3678 | * The reason for all of this is that it's just not safe to do the redraw |
3679 | * piecemeal. If you try to draw an antialiased diagonal line over |
3680 | * itself, you get a slightly thicker antialiased diagonal line, which |
3681 | * looks rather ugly after a while. |
3682 | * |
3683 | * So, we take two passes over the grid. The first attempts to work out |
3684 | * what needs doing, and the second actually does it. |
3685 | */ |
3686 | |
3687 | if (!ds->started) |
3688 | redraw_everything = TRUE; |
3689 | else { |
3690 | |
3691 | /* First, trundle through the faces. */ |
3692 | for (i = 0; i < g->num_faces; i++) { |
3693 | grid_face *f = g->faces + i; |
3694 | int sides = f->order; |
3695 | int clue_mistake; |
3696 | int clue_satisfied; |
3697 | int n = state->clues[i]; |
3698 | if (n < 0) |
3699 | continue; |
3700 | |
3701 | clue_mistake = (face_order(state, i, LINE_YES) > n || |
3702 | face_order(state, i, LINE_NO ) > (sides-n)); |
3703 | clue_satisfied = (face_order(state, i, LINE_YES) == n && |
3704 | face_order(state, i, LINE_NO ) == (sides-n)); |
3705 | |
3706 | if (clue_mistake != ds->clue_error[i] || |
3707 | clue_satisfied != ds->clue_satisfied[i]) { |
3708 | ds->clue_error[i] = clue_mistake; |
3709 | ds->clue_satisfied[i] = clue_satisfied; |
3710 | if (nfaces == REDRAW_OBJECTS_LIMIT) |
3711 | redraw_everything = TRUE; |
3712 | else |
3713 | faces[nfaces++] = i; |
3714 | } |
3715 | } |
3716 | |
3717 | /* Work out what the flash state needs to be. */ |
3718 | if (flashtime > 0 && |
3719 | (flashtime <= FLASH_TIME/3 || |
3720 | flashtime >= FLASH_TIME*2/3)) { |
3721 | flash_changed = !ds->flashing; |
3722 | ds->flashing = TRUE; |
3723 | } else { |
3724 | flash_changed = ds->flashing; |
3725 | ds->flashing = FALSE; |
3726 | } |
3727 | |
3728 | /* Now, trundle through the edges. */ |
3729 | for (i = 0; i < g->num_edges; i++) { |
3730 | char new_ds = |
3731 | state->line_errors[i] ? DS_LINE_ERROR : state->lines[i]; |
3732 | if (new_ds != ds->lines[i] || |
3733 | (flash_changed && state->lines[i] == LINE_YES)) { |
3734 | ds->lines[i] = new_ds; |
3735 | if (nedges == REDRAW_OBJECTS_LIMIT) |
3736 | redraw_everything = TRUE; |
3737 | else |
3738 | edges[nedges++] = i; |
3739 | } |
3740 | } |
3741 | } |
3742 | |
3743 | /* Pass one is now done. Now we do the actual drawing. */ |
3744 | if (redraw_everything) { |
7c95608a |
3745 | int grid_width = g->highest_x - g->lowest_x; |
3746 | int grid_height = g->highest_y - g->lowest_y; |
3747 | int w = grid_width * ds->tilesize / g->tilesize; |
3748 | int h = grid_height * ds->tilesize / g->tilesize; |
6193da8d |
3749 | |
1463f9f1 |
3750 | game_redraw_in_rect(dr, ds, state, |
3751 | 0, 0, w + 2*border + 1, h + 2*border + 1); |
d68b2c10 |
3752 | } else { |
c0eb17ce |
3753 | |
d68b2c10 |
3754 | /* Right. Now we roll up our sleeves. */ |
3755 | |
3756 | for (i = 0; i < nfaces; i++) { |
3757 | grid_face *f = g->faces + faces[i]; |
d68b2c10 |
3758 | int x, y, w, h; |
1463f9f1 |
3759 | |
3760 | face_text_bbox(ds, g, f, &x, &y, &w, &h); |
3761 | game_redraw_in_rect(dr, ds, state, x, y, w, h); |
d68b2c10 |
3762 | } |
c0eb17ce |
3763 | |
d68b2c10 |
3764 | for (i = 0; i < nedges; i++) { |
1463f9f1 |
3765 | grid_edge *e = g->edges + edges[i]; |
3766 | int x, y, w, h; |
6193da8d |
3767 | |
1463f9f1 |
3768 | edge_bbox(ds, g, e, &x, &y, &w, &h); |
3769 | game_redraw_in_rect(dr, ds, state, x, y, w, h); |
d68b2c10 |
3770 | } |
6193da8d |
3771 | } |
d68b2c10 |
3772 | |
7c95608a |
3773 | ds->started = TRUE; |
6193da8d |
3774 | } |
3775 | |
6193da8d |
3776 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
3777 | int dir, game_ui *ui) |
3778 | { |
3779 | if (!oldstate->solved && newstate->solved && |
3780 | !oldstate->cheated && !newstate->cheated) { |
3781 | return FLASH_TIME; |
3782 | } |
3783 | |
3784 | return 0.0F; |
3785 | } |
3786 | |
4496362f |
3787 | static int game_is_solved(game_state *state) |
3788 | { |
3789 | return state->solved; |
3790 | } |
3791 | |
6193da8d |
3792 | static void game_print_size(game_params *params, float *x, float *y) |
3793 | { |
3794 | int pw, ph; |
3795 | |
3796 | /* |
7c95608a |
3797 | * I'll use 7mm "squares" by default. |
6193da8d |
3798 | */ |
3799 | game_compute_size(params, 700, &pw, &ph); |
3800 | *x = pw / 100.0F; |
3801 | *y = ph / 100.0F; |
3802 | } |
3803 | |
3804 | static void game_print(drawing *dr, game_state *state, int tilesize) |
3805 | { |
6193da8d |
3806 | int ink = print_mono_colour(dr, 0); |
7c95608a |
3807 | int i; |
6193da8d |
3808 | game_drawstate ads, *ds = &ads; |
7c95608a |
3809 | grid *g = state->game_grid; |
4413ef0f |
3810 | |
092e9395 |
3811 | ds->tilesize = tilesize; |
6193da8d |
3812 | |
7c95608a |
3813 | for (i = 0; i < g->num_dots; i++) { |
3814 | int x, y; |
3815 | grid_to_screen(ds, g, g->dots[i].x, g->dots[i].y, &x, &y); |
3816 | draw_circle(dr, x, y, ds->tilesize / 15, ink, ink); |
121aae4b |
3817 | } |
6193da8d |
3818 | |
3819 | /* |
3820 | * Clues. |
3821 | */ |
7c95608a |
3822 | for (i = 0; i < g->num_faces; i++) { |
3823 | grid_face *f = g->faces + i; |
3824 | int clue = state->clues[i]; |
3825 | if (clue >= 0) { |
121aae4b |
3826 | char c[2]; |
7c95608a |
3827 | int x, y; |
3828 | c[0] = CLUE2CHAR(clue); |
121aae4b |
3829 | c[1] = '\0'; |
7c95608a |
3830 | face_text_pos(ds, g, f, &x, &y); |
3831 | draw_text(dr, x, y, |
3832 | FONT_VARIABLE, ds->tilesize / 2, |
121aae4b |
3833 | ALIGN_VCENTRE | ALIGN_HCENTRE, ink, c); |
3834 | } |
3835 | } |
6193da8d |
3836 | |
3837 | /* |
7c95608a |
3838 | * Lines. |
6193da8d |
3839 | */ |
7c95608a |
3840 | for (i = 0; i < g->num_edges; i++) { |
3841 | int thickness = (state->lines[i] == LINE_YES) ? 30 : 150; |
3842 | grid_edge *e = g->edges + i; |
3843 | int x1, y1, x2, y2; |
3844 | grid_to_screen(ds, g, e->dot1->x, e->dot1->y, &x1, &y1); |
3845 | grid_to_screen(ds, g, e->dot2->x, e->dot2->y, &x2, &y2); |
3846 | if (state->lines[i] == LINE_YES) |
3847 | { |
3848 | /* (dx, dy) points from (x1, y1) to (x2, y2). |
3849 | * The line is then "fattened" in a perpendicular |
3850 | * direction to create a thin rectangle. */ |
3851 | double d = sqrt(SQ((double)x1 - x2) + SQ((double)y1 - y2)); |
3852 | double dx = (x2 - x1) / d; |
3853 | double dy = (y2 - y1) / d; |
1515b973 |
3854 | int points[8]; |
3855 | |
7c95608a |
3856 | dx = (dx * ds->tilesize) / thickness; |
3857 | dy = (dy * ds->tilesize) / thickness; |
b1535c90 |
3858 | points[0] = x1 + (int)dy; |
3859 | points[1] = y1 - (int)dx; |
3860 | points[2] = x1 - (int)dy; |
3861 | points[3] = y1 + (int)dx; |
3862 | points[4] = x2 - (int)dy; |
3863 | points[5] = y2 + (int)dx; |
3864 | points[6] = x2 + (int)dy; |
3865 | points[7] = y2 - (int)dx; |
7c95608a |
3866 | draw_polygon(dr, points, 4, ink, ink); |
3867 | } |
3868 | else |
3869 | { |
3870 | /* Draw a dotted line */ |
3871 | int divisions = 6; |
3872 | int j; |
3873 | for (j = 1; j < divisions; j++) { |
3874 | /* Weighted average */ |
3875 | int x = (x1 * (divisions -j) + x2 * j) / divisions; |
3876 | int y = (y1 * (divisions -j) + y2 * j) / divisions; |
3877 | draw_circle(dr, x, y, ds->tilesize / thickness, ink, ink); |
3878 | } |
3879 | } |
121aae4b |
3880 | } |
6193da8d |
3881 | } |
3882 | |
3883 | #ifdef COMBINED |
3884 | #define thegame loopy |
3885 | #endif |
3886 | |
3887 | const struct game thegame = { |
750037d7 |
3888 | "Loopy", "games.loopy", "loopy", |
6193da8d |
3889 | default_params, |
3890 | game_fetch_preset, |
3891 | decode_params, |
3892 | encode_params, |
3893 | free_params, |
3894 | dup_params, |
3895 | TRUE, game_configure, custom_params, |
3896 | validate_params, |
3897 | new_game_desc, |
3898 | validate_desc, |
3899 | new_game, |
3900 | dup_game, |
3901 | free_game, |
3902 | 1, solve_game, |
fa3abef5 |
3903 | TRUE, game_can_format_as_text_now, game_text_format, |
6193da8d |
3904 | new_ui, |
3905 | free_ui, |
3906 | encode_ui, |
3907 | decode_ui, |
3908 | game_changed_state, |
3909 | interpret_move, |
3910 | execute_move, |
3911 | PREFERRED_TILE_SIZE, game_compute_size, game_set_size, |
3912 | game_colours, |
3913 | game_new_drawstate, |
3914 | game_free_drawstate, |
3915 | game_redraw, |
3916 | game_anim_length, |
3917 | game_flash_length, |
4496362f |
3918 | game_is_solved, |
6193da8d |
3919 | TRUE, FALSE, game_print_size, game_print, |
121aae4b |
3920 | FALSE /* wants_statusbar */, |
6193da8d |
3921 | FALSE, game_timing_state, |
121aae4b |
3922 | 0, /* mouse_priorities */ |
6193da8d |
3923 | }; |
5ca89681 |
3924 | |
3925 | #ifdef STANDALONE_SOLVER |
3926 | |
3927 | /* |
3928 | * Half-hearted standalone solver. It can't output the solution to |
3929 | * anything but a square puzzle, and it can't log the deductions |
3930 | * it makes either. But it can solve square puzzles, and more |
3931 | * importantly it can use its solver to grade the difficulty of |
3932 | * any puzzle you give it. |
3933 | */ |
3934 | |
3935 | #include <stdarg.h> |
3936 | |
3937 | int main(int argc, char **argv) |
3938 | { |
3939 | game_params *p; |
3940 | game_state *s; |
3941 | char *id = NULL, *desc, *err; |
3942 | int grade = FALSE; |
3943 | int ret, diff; |
3944 | #if 0 /* verbose solver not supported here (yet) */ |
3945 | int really_verbose = FALSE; |
3946 | #endif |
3947 | |
3948 | while (--argc > 0) { |
3949 | char *p = *++argv; |
3950 | #if 0 /* verbose solver not supported here (yet) */ |
3951 | if (!strcmp(p, "-v")) { |
3952 | really_verbose = TRUE; |
3953 | } else |
3954 | #endif |
3955 | if (!strcmp(p, "-g")) { |
3956 | grade = TRUE; |
3957 | } else if (*p == '-') { |
3958 | fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p); |
3959 | return 1; |
3960 | } else { |
3961 | id = p; |
3962 | } |
3963 | } |
3964 | |
3965 | if (!id) { |
3966 | fprintf(stderr, "usage: %s [-g | -v] <game_id>\n", argv[0]); |
3967 | return 1; |
3968 | } |
3969 | |
3970 | desc = strchr(id, ':'); |
3971 | if (!desc) { |
3972 | fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]); |
3973 | return 1; |
3974 | } |
3975 | *desc++ = '\0'; |
3976 | |
3977 | p = default_params(); |
3978 | decode_params(p, id); |
3979 | err = validate_desc(p, desc); |
3980 | if (err) { |
3981 | fprintf(stderr, "%s: %s\n", argv[0], err); |
3982 | return 1; |
3983 | } |
3984 | s = new_game(NULL, p, desc); |
3985 | |
3986 | /* |
3987 | * When solving an Easy puzzle, we don't want to bother the |
3988 | * user with Hard-level deductions. For this reason, we grade |
3989 | * the puzzle internally before doing anything else. |
3990 | */ |
3991 | ret = -1; /* placate optimiser */ |
3992 | for (diff = 0; diff < DIFF_MAX; diff++) { |
3993 | solver_state *sstate_new; |
3994 | solver_state *sstate = new_solver_state((game_state *)s, diff); |
3995 | |
315e47b9 |
3996 | sstate_new = solve_game_rec(sstate); |
5ca89681 |
3997 | |
3998 | if (sstate_new->solver_status == SOLVER_MISTAKE) |
3999 | ret = 0; |
4000 | else if (sstate_new->solver_status == SOLVER_SOLVED) |
4001 | ret = 1; |
4002 | else |
4003 | ret = 2; |
4004 | |
4005 | free_solver_state(sstate_new); |
4006 | free_solver_state(sstate); |
4007 | |
4008 | if (ret < 2) |
4009 | break; |
4010 | } |
4011 | |
4012 | if (diff == DIFF_MAX) { |
4013 | if (grade) |
4014 | printf("Difficulty rating: harder than Hard, or ambiguous\n"); |
4015 | else |
4016 | printf("Unable to find a unique solution\n"); |
4017 | } else { |
4018 | if (grade) { |
4019 | if (ret == 0) |
4020 | printf("Difficulty rating: impossible (no solution exists)\n"); |
4021 | else if (ret == 1) |
4022 | printf("Difficulty rating: %s\n", diffnames[diff]); |
4023 | } else { |
4024 | solver_state *sstate_new; |
4025 | solver_state *sstate = new_solver_state((game_state *)s, diff); |
4026 | |
4027 | /* If we supported a verbose solver, we'd set verbosity here */ |
4028 | |
315e47b9 |
4029 | sstate_new = solve_game_rec(sstate); |
5ca89681 |
4030 | |
4031 | if (sstate_new->solver_status == SOLVER_MISTAKE) |
4032 | printf("Puzzle is inconsistent\n"); |
4033 | else { |
4034 | assert(sstate_new->solver_status == SOLVER_SOLVED); |
4035 | if (s->grid_type == 0) { |
4036 | fputs(game_text_format(sstate_new->state), stdout); |
4037 | } else { |
4038 | printf("Unable to output non-square grids\n"); |
4039 | } |
4040 | } |
4041 | |
4042 | free_solver_state(sstate_new); |
4043 | free_solver_state(sstate); |
4044 | } |
4045 | } |
4046 | |
4047 | return 0; |
4048 | } |
4049 | |
4050 | #endif |
cebf0b0d |
4051 | |
4052 | /* vim: set shiftwidth=4 tabstop=8: */ |