e7414d31 |
1 | /* |
2 | * range.c: implementation of the Nikoli game 'Kurodoko' / 'Kuromasu'. |
3 | */ |
4 | |
5 | /* |
6 | * Puzzle rules: the player is given a WxH grid of white squares, some |
7 | * of which contain numbers. The goal is to paint some of the squares |
8 | * black, such that: |
9 | * |
10 | * - no cell (err, cell = square) with a number is painted black |
11 | * - no black cells have an adjacent (horz/vert) black cell |
12 | * - the white cells are all connected (through other white cells) |
13 | * - if a cell contains a number n, let h and v be the lengths of the |
14 | * maximal horizontal and vertical white sequences containing that |
15 | * cell. Then n must equal h + v - 1. |
16 | */ |
17 | |
18 | /* example instance with its encoding: |
19 | * |
20 | * +--+--+--+--+--+--+--+ |
21 | * | | | | | 7| | | |
22 | * +--+--+--+--+--+--+--+ |
23 | * | 3| | | | | | 8| |
24 | * +--+--+--+--+--+--+--+ |
25 | * | | | | | | 5| | |
26 | * +--+--+--+--+--+--+--+ |
27 | * | | | 7| | 7| | | |
28 | * +--+--+--+--+--+--+--+ |
29 | * | |13| | | | | | |
30 | * +--+--+--+--+--+--+--+ |
31 | * | 4| | | | | | 8| |
32 | * +--+--+--+--+--+--+--+ |
33 | * | | | 4| | | | | |
34 | * +--+--+--+--+--+--+--+ |
35 | * |
36 | * 7x7:d7b3e8e5c7a7c13e4d8b4d |
37 | */ |
38 | |
39 | #include <stdio.h> |
40 | #include <stdlib.h> |
41 | #include <string.h> |
42 | #include <assert.h> |
43 | #include <ctype.h> |
44 | #include <math.h> |
45 | |
46 | #include "puzzles.h" |
47 | |
48 | #include <stdarg.h> |
49 | |
50 | #define setmember(obj, field) ( (obj) . field = field ) |
51 | |
52 | char *nfmtstr(int n, char *fmt, ...) { |
53 | va_list va; |
54 | char *ret = snewn(n+1, char); |
55 | va_start(va, fmt); |
56 | vsprintf(ret, fmt, va); |
57 | va_end(va); |
58 | return ret; |
59 | } |
60 | |
61 | #define SWAP(type, lvar1, lvar2) do { \ |
62 | type tmp = (lvar1); \ |
63 | (lvar1) = (lvar2); \ |
64 | (lvar2) = tmp; \ |
65 | } while (0) |
66 | |
67 | /* ---------------------------------------------------------------------- |
68 | * Game parameters, presets, states |
69 | */ |
70 | |
71 | typedef signed char puzzle_size; |
72 | |
73 | struct game_params { |
74 | puzzle_size w; |
75 | puzzle_size h; |
76 | }; |
77 | |
78 | struct game_state { |
79 | struct game_params params; |
80 | unsigned int has_cheated: 1; |
81 | unsigned int was_solved: 1; |
82 | puzzle_size *grid; |
83 | }; |
84 | |
85 | #define DEFAULT_PRESET 0 |
86 | static struct game_params presets[] = {{9, 6}, {12, 8}, {13, 9}, {16, 11}}; |
87 | /* rationale: I want all four combinations of {odd/even, odd/even}, as |
88 | * they play out differently with respect to two-way symmetry. I also |
89 | * want them to be generated relatively fast yet still be large enough |
90 | * to be entertaining for a decent amount of time, and I want them to |
91 | * make good use of monitor real estate (the typical screen resolution |
92 | * is why I do 13x9 and not 9x13). |
93 | */ |
94 | |
95 | static game_params *default_params(void) |
96 | { |
97 | game_params *ret = snew(game_params); |
98 | *ret = presets[DEFAULT_PRESET]; /* structure copy */ |
99 | return ret; |
100 | } |
101 | |
102 | static game_params *dup_params(game_params *params) |
103 | { |
104 | game_params *ret = snew(game_params); |
105 | *ret = *params; /* structure copy */ |
106 | return ret; |
107 | } |
108 | |
109 | static int game_fetch_preset(int i, char **name, game_params **params) |
110 | { |
111 | if (i < 0 || i >= lenof(presets)) return FALSE; |
112 | |
113 | *name = nfmtstr(40, "%d x %d", presets[i].w, presets[i].h); |
114 | *params = dup_params(&presets[i]); |
115 | |
116 | return TRUE; |
117 | } |
118 | |
119 | static void free_params(game_params *params) |
120 | { |
121 | sfree(params); |
122 | } |
123 | |
124 | static void decode_params(game_params *params, char const *string) |
125 | { |
126 | /* FIXME check for puzzle_size overflow and decoding issues */ |
127 | params->w = params->h = atoi(string); |
128 | while (*string && isdigit((unsigned char) *string)) ++string; |
129 | if (*string == 'x') { |
130 | string++; |
131 | params->h = atoi(string); |
132 | while (*string && isdigit((unsigned char)*string)) string++; |
133 | } |
134 | } |
135 | |
136 | static char *encode_params(game_params *params, int full) |
137 | { |
138 | char str[80]; |
139 | sprintf(str, "%dx%d", params->w, params->h); |
140 | return dupstr(str); |
141 | } |
142 | |
143 | static config_item *game_configure(game_params *params) |
144 | { |
145 | config_item *ret; |
146 | |
147 | ret = snewn(3, config_item); |
148 | |
149 | ret[0].name = "Width"; |
150 | ret[0].type = C_STRING; |
151 | ret[0].sval = nfmtstr(10, "%d", params->w); |
152 | ret[0].ival = 0; |
153 | |
154 | ret[1].name = "Height"; |
155 | ret[1].type = C_STRING; |
156 | ret[1].sval = nfmtstr(10, "%d", params->h); |
157 | ret[1].ival = 0; |
158 | |
159 | ret[2].name = NULL; |
160 | ret[2].type = C_END; |
161 | ret[2].sval = NULL; |
162 | ret[2].ival = 0; |
163 | |
164 | return ret; |
165 | } |
166 | |
167 | static game_params *custom_params(config_item *configuration) |
168 | { |
169 | game_params *ret = snew(game_params); |
170 | ret->w = atoi(configuration[0].sval); |
171 | ret->h = atoi(configuration[1].sval); |
172 | return ret; |
173 | } |
174 | |
175 | #define memdup(dst, src, n, type) do { \ |
176 | dst = snewn(n, type); \ |
177 | memcpy(dst, src, n * sizeof (type)); \ |
178 | } while (0) |
179 | |
180 | static game_state *dup_game(game_state *state) |
181 | { |
182 | game_state *ret = snew(game_state); |
183 | int const n = state->params.w * state->params.h; |
184 | |
185 | *ret = *state; /* structure copy */ |
186 | |
187 | /* copy the poin_tee_, set a new value of the poin_ter_ */ |
188 | memdup(ret->grid, state->grid, n, puzzle_size); |
189 | |
190 | return ret; |
191 | } |
192 | |
193 | static void free_game(game_state *state) |
194 | { |
195 | sfree(state->grid); |
196 | sfree(state); |
197 | } |
198 | |
199 | |
200 | /* ---------------------------------------------------------------------- |
201 | * The solver subsystem. |
202 | * |
203 | * The solver is used for two purposes: |
204 | * - To solve puzzles when the user selects `Solve'. |
205 | * - To test solubility of a grid as clues are being removed from it |
206 | * during the puzzle generation. |
207 | * |
208 | * It supports the following ways of reasoning: |
209 | * |
210 | * - A cell adjacent to a black cell must be white. |
211 | * |
212 | * - If painting a square black would bisect the white regions, that |
213 | * square is white (by finding biconnected components' cut points) |
214 | * |
215 | * - A cell with number n, covering at most k white squares in three |
216 | * directions must white-cover n-k squares in the last direction. |
217 | * |
218 | * - A cell with number n known to cover k squares, if extending the |
219 | * cover by one square in a given direction causes the cell to |
220 | * cover _more_ than n squares, that extension cell must be black. |
221 | * |
222 | * (either if the square already covers n, or if it extends into a |
223 | * chunk of size > n - k) |
224 | * |
225 | * - Recursion. Pick any cell and see if this leads to either a |
226 | * contradiction or a solution (and then act appropriately). |
227 | * |
228 | * |
229 | * TODO: |
230 | * |
231 | * (propagation upper limit) |
232 | * - If one has two numbers on the same line, the smaller limits the |
233 | * larger. Example: in |b|_|_|8|4|_|_|b|, only two _'s can be both |
234 | * white and connected to the "8" cell; so that cell will propagate |
235 | * at least four cells orthogonally to the displayed line (which is |
236 | * better than the current "at least 2"). |
237 | * |
238 | * (propagation upper limit) |
239 | * - cells can't propagate into other cells if doing so exceeds that |
240 | * number. Example: in |b|4|.|.|2|b|, at most one _ can be white; |
241 | * otherwise, the |2| would have too many reaching white cells. |
242 | * |
243 | * (propagation lower and upper limit) |
244 | * - `Full Combo': in each four directions d_1 ... d_4, find a set of |
245 | * possible propagation distances S_1 ... S_4. For each i=1..4, |
246 | * for each x in S_i: if not exists (y, z, w) in the other sets |
247 | * such that (x+y+z+w+1 == clue value): then remove x from S_i. |
248 | * Repeat until this stabilizes. If any cell would contradict |
249 | */ |
250 | |
251 | #define idx(i, j, w) ((i)*(w) + (j)) |
252 | #define out_of_bounds(r, c, w, h) \ |
253 | ((r) < 0 || (r) >= h || (c) < 0 || (c) >= w) |
254 | |
255 | typedef struct square { |
256 | puzzle_size r, c; |
257 | } square; |
258 | |
259 | enum {BLACK = -2, WHITE, EMPTY}; |
260 | /* white is for pencil marks, empty is undecided */ |
261 | |
262 | static int const dr[4] = {+1, 0, -1, 0}; |
263 | static int const dc[4] = { 0, +1, 0, -1}; |
264 | static int const cursors[4] = /* must match dr and dc */ |
265 | {CURSOR_DOWN, CURSOR_RIGHT, CURSOR_UP, CURSOR_LEFT}; |
266 | |
267 | typedef struct move { |
268 | square square; |
269 | unsigned int colour: 1; |
270 | } move; |
271 | enum {M_BLACK = 0, M_WHITE = 1}; |
272 | |
273 | typedef move *(reasoning)(game_state *state, |
274 | int nclues, |
275 | const square *clues, |
276 | move *buf); |
277 | |
278 | static reasoning solver_reasoning_not_too_big; |
279 | static reasoning solver_reasoning_adjacency; |
280 | static reasoning solver_reasoning_connectedness; |
281 | static reasoning solver_reasoning_recursion; |
282 | |
283 | enum { |
284 | DIFF_NOT_TOO_BIG, |
285 | DIFF_ADJACENCY, |
286 | DIFF_CONNECTEDNESS, |
287 | DIFF_RECURSION |
288 | }; |
289 | |
290 | static move *solve_internal(game_state *state, move *base, int diff); |
291 | |
292 | static char *solve_game(game_state *orig, game_state *curpos, |
293 | char *aux, char **error) |
294 | { |
295 | int const n = orig->params.w * orig->params.h; |
296 | move *const base = snewn(n, move); |
297 | move *moves = solve_internal(orig, base, DIFF_RECURSION); |
298 | |
299 | char *ret = NULL; |
300 | |
301 | if (moves != NULL) { |
302 | int const k = moves - base; |
303 | char *str = ret = snewn(15*k + 2, char); |
304 | char colour[2] = "BW"; |
305 | move *it; |
306 | *str++ = 'S'; |
307 | *str = '\0'; |
308 | for (it = base; it < moves; ++it) |
309 | str += sprintf(str, "%c,%d,%d", colour[it->colour], |
310 | it->square.r, it->square.c); |
311 | } else *error = "This puzzle instance contains a contradiction"; |
312 | |
313 | sfree(base); |
314 | return ret; |
315 | } |
316 | |
317 | static square *find_clues(game_state *state, int *ret_nclues); |
318 | static move *do_solve(game_state *state, |
319 | int nclues, |
320 | const square *clues, |
321 | move *move_buffer, |
322 | int difficulty); |
323 | |
324 | /* new_game_desc entry point in the solver subsystem */ |
325 | static move *solve_internal(game_state *state, move *base, int diff) |
326 | { |
327 | int nclues; |
328 | square *const clues = find_clues(state, &nclues); |
329 | game_state *dup = dup_game(state); |
330 | move *const moves = do_solve(dup, nclues, clues, base, diff); |
331 | free_game(dup); |
332 | sfree(clues); |
333 | return moves; |
334 | } |
335 | |
336 | static move *do_solve(game_state *state, |
337 | int nclues, |
338 | const square *clues, |
339 | move *move_buffer, |
340 | int difficulty) |
341 | { |
342 | reasoning *reasonings[] = { |
343 | solver_reasoning_not_too_big, |
344 | solver_reasoning_adjacency, |
345 | solver_reasoning_connectedness, |
346 | solver_reasoning_recursion |
347 | }; |
348 | |
349 | struct move *buf = move_buffer, *oldbuf; |
350 | int i; |
351 | |
352 | do { |
353 | oldbuf = buf; |
354 | for (i = 0; i < lenof(reasonings) && i <= difficulty; ++i) { |
355 | /* only recurse if all else fails */ |
356 | if (i == DIFF_RECURSION && buf > oldbuf) continue; |
357 | buf = (*reasonings[i])(state, nclues, clues, buf); |
358 | if (buf == NULL) return NULL; |
359 | } |
360 | } while (buf > oldbuf); |
361 | |
362 | return buf; |
363 | } |
364 | |
365 | #define MASK(n) (1 << ((n) + 2)) |
366 | |
367 | static int runlength(puzzle_size r, puzzle_size c, |
368 | puzzle_size dr, puzzle_size dc, |
369 | game_state *state, int colourmask) |
370 | { |
371 | int const w = state->params.w, h = state->params.h; |
372 | int sz = 0; |
373 | while (TRUE) { |
374 | int cell = idx(r, c, w); |
375 | if (out_of_bounds(r, c, w, h)) break; |
376 | if (state->grid[cell] > 0) { |
377 | if (!(colourmask & ~(MASK(BLACK) | MASK(WHITE) | MASK(EMPTY)))) |
378 | break; |
379 | } else if (!(MASK(state->grid[cell]) & colourmask)) break; |
380 | ++sz; |
381 | r += dr; |
382 | c += dc; |
383 | } |
384 | return sz; |
385 | } |
386 | |
387 | static void solver_makemove(puzzle_size r, puzzle_size c, int colour, |
388 | game_state *state, move **buffer_ptr) |
389 | { |
390 | int const cell = idx(r, c, state->params.w); |
391 | if (out_of_bounds(r, c, state->params.w, state->params.h)) return; |
392 | if (state->grid[cell] != EMPTY) return; |
393 | setmember((*buffer_ptr)->square, r); |
394 | setmember((*buffer_ptr)->square, c); |
395 | setmember(**buffer_ptr, colour); |
396 | ++*buffer_ptr; |
397 | state->grid[cell] = (colour == M_BLACK ? BLACK : WHITE); |
398 | } |
399 | |
400 | static move *solver_reasoning_adjacency(game_state *state, |
401 | int nclues, |
402 | const square *clues, |
403 | move *buf) |
404 | { |
405 | int r, c, i; |
406 | for (r = 0; r < state->params.h; ++r) |
407 | for (c = 0; c < state->params.w; ++c) { |
408 | int const cell = idx(r, c, state->params.w); |
409 | if (state->grid[cell] != BLACK) continue; |
410 | for (i = 0; i < 4; ++i) |
411 | solver_makemove(r + dr[i], c + dc[i], M_WHITE, state, &buf); |
412 | } |
413 | return buf; |
414 | } |
415 | |
416 | enum {NOT_VISITED = -1}; |
417 | |
418 | static int dfs_biconnect_visit(puzzle_size r, puzzle_size c, |
419 | game_state *state, |
420 | square *dfs_parent, int *dfs_depth, |
421 | move **buf); |
422 | |
423 | static move *solver_reasoning_connectedness(game_state *state, |
424 | int nclues, |
425 | const square *clues, |
426 | move *buf) |
427 | { |
428 | int const w = state->params.w, h = state->params.h, n = w * h; |
429 | |
430 | square *const dfs_parent = snewn(n, square); |
431 | int *const dfs_depth = snewn(n, int); |
432 | |
433 | int i; |
434 | for (i = 0; i < n; ++i) { |
435 | dfs_parent[i].r = NOT_VISITED; |
436 | dfs_depth[i] = -n; |
437 | } |
438 | |
439 | for (i = 0; i < n && state->grid[i] == BLACK; ++i); |
440 | |
441 | dfs_parent[i].r = i / w; |
442 | dfs_parent[i].c = i % w; /* `dfs root`.parent == `dfs root` */ |
443 | dfs_depth[i] = 0; |
444 | |
445 | dfs_biconnect_visit(i / w, i % w, state, dfs_parent, dfs_depth, &buf); |
446 | |
447 | sfree(dfs_parent); |
448 | sfree(dfs_depth); |
449 | |
450 | return buf; |
451 | } |
452 | |
453 | /* returns the `lowpoint` of (r, c) */ |
454 | static int dfs_biconnect_visit(puzzle_size r, puzzle_size c, |
455 | game_state *state, |
456 | square *dfs_parent, int *dfs_depth, |
457 | move **buf) |
458 | { |
459 | const puzzle_size w = state->params.w, h = state->params.h; |
460 | int const i = idx(r, c, w), mydepth = dfs_depth[i]; |
461 | int lowpoint = mydepth, j, nchildren = 0; |
462 | |
463 | for (j = 0; j < 4; ++j) { |
464 | const puzzle_size rr = r + dr[j], cc = c + dc[j]; |
465 | int const cell = idx(rr, cc, w); |
466 | |
467 | if (out_of_bounds(rr, cc, w, h)) continue; |
468 | if (state->grid[cell] == BLACK) continue; |
469 | |
470 | if (dfs_parent[cell].r == NOT_VISITED) { |
471 | int child_lowpoint; |
472 | dfs_parent[cell].r = r; |
473 | dfs_parent[cell].c = c; |
474 | dfs_depth[cell] = mydepth + 1; |
475 | child_lowpoint = dfs_biconnect_visit(rr, cc, state, dfs_parent, |
476 | dfs_depth, buf); |
477 | |
478 | if (child_lowpoint >= mydepth && mydepth > 0) |
479 | solver_makemove(r, c, M_WHITE, state, buf); |
480 | |
481 | lowpoint = min(lowpoint, child_lowpoint); |
482 | ++nchildren; |
483 | } else if (rr != dfs_parent[i].r || cc != dfs_parent[i].c) { |
484 | lowpoint = min(lowpoint, dfs_depth[cell]); |
485 | } |
486 | } |
487 | |
488 | if (mydepth == 0 && nchildren >= 2) |
489 | solver_makemove(r, c, M_WHITE, state, buf); |
490 | |
491 | return lowpoint; |
492 | } |
493 | |
494 | static move *solver_reasoning_not_too_big(game_state *state, |
495 | int nclues, |
496 | const square *clues, |
497 | move *buf) |
498 | { |
499 | int const w = state->params.w, runmasks[4] = { |
500 | ~(MASK(BLACK) | MASK(EMPTY)), |
501 | MASK(EMPTY), |
502 | ~(MASK(BLACK) | MASK(EMPTY)), |
503 | ~(MASK(BLACK)) |
504 | }; |
505 | enum {RUN_WHITE, RUN_EMPTY, RUN_BEYOND, RUN_SPACE}; |
506 | |
507 | int i, runlengths[4][4]; |
508 | |
509 | for (i = 0; i < nclues; ++i) { |
510 | int j, k, whites, space; |
511 | |
512 | const puzzle_size row = clues[i].r, col = clues[i].c; |
513 | int const clue = state->grid[idx(row, col, w)]; |
514 | |
515 | for (j = 0; j < 4; ++j) { |
516 | puzzle_size r = row + dr[j], c = col + dc[j]; |
517 | runlengths[RUN_SPACE][j] = 0; |
518 | for (k = 0; k <= RUN_SPACE; ++k) { |
519 | int l = runlength(r, c, dr[j], dc[j], state, runmasks[k]); |
520 | if (k < RUN_SPACE) { |
521 | runlengths[k][j] = l; |
522 | r += dr[j] * l; |
523 | c += dc[j] * l; |
524 | } |
525 | runlengths[RUN_SPACE][j] += l; |
526 | } |
527 | } |
528 | |
529 | whites = 1; |
530 | for (j = 0; j < 4; ++j) whites += runlengths[RUN_WHITE][j]; |
531 | |
532 | for (j = 0; j < 4; ++j) { |
533 | int const delta = 1 + runlengths[RUN_WHITE][j]; |
534 | const puzzle_size r = row + delta * dr[j]; |
535 | const puzzle_size c = col + delta * dc[j]; |
536 | |
537 | if (whites == clue) { |
538 | solver_makemove(r, c, M_BLACK, state, &buf); |
539 | continue; |
540 | } |
541 | |
542 | if (runlengths[RUN_EMPTY][j] == 1 && |
543 | whites |
544 | + runlengths[RUN_EMPTY][j] |
545 | + runlengths[RUN_BEYOND][j] |
546 | > clue) { |
547 | solver_makemove(r, c, M_BLACK, state, &buf); |
548 | continue; |
549 | } |
550 | |
551 | if (whites |
552 | + runlengths[RUN_EMPTY][j] |
553 | + runlengths[RUN_BEYOND][j] |
554 | > clue) { |
555 | runlengths[RUN_SPACE][j] = |
556 | runlengths[RUN_WHITE][j] + |
557 | runlengths[RUN_EMPTY][j] - 1; |
558 | |
559 | if (runlengths[RUN_EMPTY][j] == 1) |
560 | solver_makemove(r, c, M_BLACK, state, &buf); |
561 | } |
562 | } |
563 | |
564 | space = 1; |
565 | for (j = 0; j < 4; ++j) space += runlengths[RUN_SPACE][j]; |
566 | for (j = 0; j < 4; ++j) { |
567 | puzzle_size r = row + dr[j], c = col + dc[j]; |
568 | |
569 | int k = space - runlengths[RUN_SPACE][j]; |
570 | if (k >= clue) continue; |
571 | |
572 | for (; k < clue; ++k, r += dr[j], c += dc[j]) |
573 | solver_makemove(r, c, M_WHITE, state, &buf); |
574 | } |
575 | } |
576 | return buf; |
577 | } |
578 | |
579 | static move *solver_reasoning_recursion(game_state *state, |
580 | int nclues, |
581 | const square *clues, |
582 | move *buf) |
583 | { |
584 | int const w = state->params.w, n = w * state->params.h; |
585 | int cell, colour; |
586 | |
587 | for (cell = 0; cell < n; ++cell) { |
588 | int const r = cell / w, c = cell % w; |
589 | int i; |
590 | game_state *newstate; |
591 | move *recursive_result; |
592 | |
593 | if (state->grid[cell] != EMPTY) continue; |
594 | |
595 | /* FIXME: add enum alias for smallest and largest (or N) */ |
596 | for (colour = M_BLACK; colour <= M_WHITE; ++colour) { |
597 | newstate = dup_game(state); |
598 | newstate->grid[cell] = colour; |
599 | recursive_result = do_solve(newstate, nclues, clues, buf, |
600 | DIFF_RECURSION); |
601 | free_game(newstate); |
602 | if (recursive_result == NULL) { |
603 | solver_makemove(r, c, M_BLACK + M_WHITE - colour, state, &buf); |
604 | return buf; |
605 | } |
606 | for (i = 0; i < n && newstate->grid[i] != EMPTY; ++i); |
607 | if (i == n) return buf; |
608 | } |
609 | } |
610 | return buf; |
611 | } |
612 | |
613 | static square *find_clues(game_state *state, int *ret_nclues) |
614 | { |
615 | int r, c, i, nclues = 0; |
616 | square *ret = snewn(state->params.w * state->params.h, struct square); |
617 | |
618 | for (i = r = 0; r < state->params.h; ++r) |
619 | for (c = 0; c < state->params.w; ++c, ++i) |
620 | if (state->grid[i] > 0) { |
621 | ret[nclues].r = r; |
622 | ret[nclues].c = c; |
623 | ++nclues; |
624 | } |
625 | |
626 | *ret_nclues = nclues; |
627 | return sresize(ret, nclues + (nclues == 0), square); |
628 | } |
629 | |
630 | /* ---------------------------------------------------------------------- |
631 | * Puzzle generation |
632 | * |
633 | * Generating kurodoko instances is rather straightforward: |
634 | * |
635 | * - Start with a white grid and add black squares at randomly chosen |
636 | * locations, unless colouring that square black would violate |
637 | * either the adjacency or connectedness constraints. |
638 | * |
639 | * - For each white square, compute the number it would contain if it |
640 | * were given as a clue. |
641 | * |
642 | * - From a starting point of "give _every_ white square as a clue", |
643 | * for each white square (in a random order), see if the board is |
644 | * solvable when that square is not given as a clue. If not, don't |
645 | * give it as a clue, otherwise do. |
646 | * |
647 | * This never fails, but it's only _almost_ what I do. The real final |
648 | * step is this: |
649 | * |
650 | * - From a starting point of "give _every_ white square as a clue", |
651 | * first remove all clues that are two-way rotationally symmetric |
652 | * to a black square. If this leaves the puzzle unsolvable, throw |
653 | * it out and try again. Otherwise, remove all _pairs_ of clues |
654 | * (that are rotationally symmetric) which can be removed without |
655 | * rendering the puzzle unsolvable. |
656 | * |
657 | * This can fail even if one only removes the black and symmetric |
658 | * clues; indeed it happens often (avg. once or twice per puzzle) when |
659 | * generating 1xN instances. (If you add black cells they must be in |
660 | * the end, and if you only add one, it's ambiguous where). |
661 | */ |
662 | |
663 | /* forward declarations of internal calls */ |
664 | static void newdesc_choose_black_squares(game_state *state, |
665 | const int *shuffle_1toN); |
666 | static void newdesc_compute_clues(game_state *state); |
667 | static int newdesc_strip_clues(game_state *state, int *shuffle_1toN); |
668 | static char *newdesc_encode_game_description(int n, puzzle_size *grid); |
669 | |
670 | static char *new_game_desc(game_params *params, random_state *rs, |
671 | char **aux, int interactive) |
672 | { |
673 | int const w = params->w, h = params->h, n = w * h; |
674 | |
675 | puzzle_size *const grid = snewn(n, puzzle_size); |
676 | int *const shuffle_1toN = snewn(n, int); |
677 | |
678 | int i, clues_removed; |
679 | |
680 | char *encoding; |
681 | |
682 | game_state state; |
683 | state.params = *params; |
684 | state.grid = grid; |
685 | |
686 | interactive = 0; /* I don't need it, I shouldn't use it*/ |
687 | |
688 | for (i = 0; i < n; ++i) shuffle_1toN[i] = i; |
689 | |
690 | while (TRUE) { |
691 | shuffle(shuffle_1toN, n, sizeof (int), rs); |
692 | newdesc_choose_black_squares(&state, shuffle_1toN); |
693 | |
694 | newdesc_compute_clues(&state); |
695 | |
696 | shuffle(shuffle_1toN, n, sizeof (int), rs); |
697 | clues_removed = newdesc_strip_clues(&state, shuffle_1toN); |
698 | |
699 | if (clues_removed < 0) continue; else break; |
700 | } |
701 | |
702 | encoding = newdesc_encode_game_description(n, grid); |
703 | |
704 | sfree(grid); |
705 | sfree(shuffle_1toN); |
706 | |
707 | return encoding; |
708 | } |
709 | |
710 | static int dfs_count_white(game_state *state, int cell); |
711 | |
712 | static void newdesc_choose_black_squares(game_state *state, |
713 | const int *shuffle_1toN) |
714 | { |
715 | int const w = state->params.w, h = state->params.h, n = w * h; |
716 | |
717 | int k, any_white_cell, n_black_cells; |
718 | |
719 | for (k = 0; k < n; ++k) state->grid[k] = WHITE; |
720 | |
721 | any_white_cell = shuffle_1toN[n - 1]; |
722 | n_black_cells = 0; |
723 | |
724 | /* I like the puzzles that result from n / 3, but maybe this |
725 | * could be made a (generation, i.e. non-full) parameter? */ |
726 | for (k = 0; k < n / 3; ++k) { |
727 | int const i = shuffle_1toN[k], c = i % w, r = i / w; |
728 | |
729 | int j; |
730 | for (j = 0; j < 4; ++j) { |
731 | int const rr = r + dr[j], cc = c + dc[j], cell = idx(rr, cc, w); |
732 | /* if you're out of bounds, we skip you */ |
733 | if (out_of_bounds(rr, cc, w, h)) continue; |
734 | if (state->grid[cell] == BLACK) break; /* I can't be black */ |
735 | } if (j < 4) continue; /* I have black neighbour: I'm white */ |
736 | |
737 | state->grid[i] = BLACK; |
738 | ++n_black_cells; |
739 | |
740 | j = dfs_count_white(state, any_white_cell); |
741 | if (j + n_black_cells < n) { |
742 | state->grid[i] = WHITE; |
743 | --n_black_cells; |
744 | } |
745 | } |
746 | } |
747 | |
748 | static void newdesc_compute_clues(game_state *state) |
749 | { |
750 | int const w = state->params.w, h = state->params.h; |
751 | int r, c; |
752 | |
753 | for (r = 0; r < h; ++r) { |
754 | int run_size = 0, c, cc; |
755 | for (c = 0; c <= w; ++c) { |
756 | if (c == w || state->grid[idx(r, c, w)] == BLACK) { |
757 | for (cc = c - run_size; cc < c; ++cc) |
758 | state->grid[idx(r, cc, w)] += run_size; |
759 | run_size = 0; |
760 | } else ++run_size; |
761 | } |
762 | } |
763 | |
764 | for (c = 0; c < w; ++c) { |
765 | int run_size = 0, r, rr; |
766 | for (r = 0; r <= h; ++r) { |
767 | if (r == h || state->grid[idx(r, c, w)] == BLACK) { |
768 | for (rr = r - run_size; rr < r; ++rr) |
769 | state->grid[idx(rr, c, w)] += run_size; |
770 | run_size = 0; |
771 | } else ++run_size; |
772 | } |
773 | } |
774 | } |
775 | |
776 | #define rotate(x) (n - 1 - (x)) |
777 | |
778 | static int newdesc_strip_clues(game_state *state, int *shuffle_1toN) |
779 | { |
780 | int const w = state->params.w, n = w * state->params.h; |
781 | |
782 | move *const move_buffer = snewn(n, move); |
783 | move *buf; |
784 | game_state *dupstate; |
785 | |
786 | /* |
787 | * do a partition/pivot of shuffle_1toN into three groups: |
788 | * (1) squares rotationally-symmetric to (3) |
789 | * (2) squares not in (1) or (3) |
790 | * (3) black squares |
791 | * |
792 | * They go from [0, left), [left, right) and [right, n) in |
793 | * shuffle_1toN (and from there into state->grid[ ]) |
794 | * |
795 | * Then, remove clues from the grid one by one in shuffle_1toN |
796 | * order, until the solver becomes unhappy. If we didn't remove |
797 | * all of (1), return (-1). Else, we're happy. |
798 | */ |
799 | |
800 | /* do the partition */ |
801 | int clues_removed, k = 0, left = 0, right = n; |
802 | |
803 | for (;; ++k) { |
804 | while (k < right && state->grid[shuffle_1toN[k]] == BLACK) { |
805 | --right; |
806 | SWAP(int, shuffle_1toN[right], shuffle_1toN[k]); |
807 | assert(state->grid[shuffle_1toN[right]] == BLACK); |
808 | } |
809 | if (k >= right) break; |
810 | assert (k >= left); |
811 | if (state->grid[rotate(shuffle_1toN[k])] == BLACK) { |
812 | SWAP(int, shuffle_1toN[k], shuffle_1toN[left]); |
813 | ++left; |
814 | } |
815 | assert (state->grid[rotate(shuffle_1toN[k])] != BLACK |
816 | || k == left - 1); |
817 | } |
818 | |
819 | for (k = 0; k < left; ++k) { |
820 | assert (state->grid[rotate(shuffle_1toN[k])] == BLACK); |
821 | state->grid[shuffle_1toN[k]] = EMPTY; |
822 | } |
823 | for (k = left; k < right; ++k) { |
824 | assert (state->grid[rotate(shuffle_1toN[k])] != BLACK); |
825 | assert (state->grid[shuffle_1toN[k]] != BLACK); |
826 | } |
827 | for (k = right; k < n; ++k) { |
828 | assert (state->grid[shuffle_1toN[k]] == BLACK); |
829 | state->grid[shuffle_1toN[k]] = EMPTY; |
830 | } |
831 | |
832 | clues_removed = (left - 0) + (n - right); |
833 | |
834 | dupstate = dup_game(state); |
835 | buf = solve_internal(dupstate, move_buffer, DIFF_RECURSION - 1); |
836 | free_game(dupstate); |
837 | if (buf - move_buffer < clues_removed) { |
838 | /* branch prediction: I don't think I'll go here */ |
839 | clues_removed = -1; |
840 | goto ret; |
841 | } |
842 | |
843 | for (k = left; k < right; ++k) { |
844 | const int i = shuffle_1toN[k], j = rotate(i); |
845 | int const clue = state->grid[i], clue_rot = state->grid[j]; |
846 | if (clue == BLACK) continue; |
847 | state->grid[i] = state->grid[j] = EMPTY; |
848 | dupstate = dup_game(state); |
849 | buf = solve_internal(dupstate, move_buffer, DIFF_RECURSION - 1); |
850 | free_game(dupstate); |
851 | clues_removed += 2 - (i == j); |
852 | /* if i is the center square, then i == (j = rotate(i)) |
853 | * when i and j are one, removing i and j removes only one */ |
854 | if (buf - move_buffer == clues_removed) continue; |
855 | /* if the solver is sound, refilling all removed clues means |
856 | * we have filled all squares, i.e. solved the puzzle. */ |
857 | state->grid[i] = clue; |
858 | state->grid[j] = clue_rot; |
859 | clues_removed -= 2 - (i == j); |
860 | } |
861 | |
862 | ret: |
863 | sfree(move_buffer); |
864 | return clues_removed; |
865 | } |
866 | |
867 | static int dfs_count_rec(puzzle_size *grid, int r, int c, int w, int h) |
868 | { |
869 | int const cell = idx(r, c, w); |
870 | if (out_of_bounds(r, c, w, h)) return 0; |
871 | if (grid[cell] != WHITE) return 0; |
872 | grid[cell] = EMPTY; |
873 | return 1 + |
874 | dfs_count_rec(grid, r + 0, c + 1, w, h) + |
875 | dfs_count_rec(grid, r + 0, c - 1, w, h) + |
876 | dfs_count_rec(grid, r + 1, c + 0, w, h) + |
877 | dfs_count_rec(grid, r - 1, c + 0, w, h); |
878 | } |
879 | |
880 | static int dfs_count_white(game_state *state, int cell) |
881 | { |
882 | int const w = state->params.w, h = state->params.h, n = w * h; |
883 | int const r = cell / w, c = cell % w; |
884 | int i, k = dfs_count_rec(state->grid, r, c, w, h); |
885 | for (i = 0; i < n; ++i) |
886 | if (state->grid[i] == EMPTY) |
887 | state->grid[i] = WHITE; |
888 | return k; |
889 | } |
890 | |
891 | static char *validate_params(game_params *params, int full) |
892 | { |
893 | int const w = params->w, h = params->h; |
894 | if (w < 1) return "Error: width is less than 1"; |
895 | if (h < 1) return "Error: height is less than 1"; |
896 | if (w * h < 1) return "Error: size is less than 1"; |
897 | if (w + h - 1 > SCHAR_MAX) return "Error: w + h is too big"; |
898 | /* I might be unable to store clues in my puzzle_size *grid; */ |
899 | if (full) { |
900 | if (w == 2 && h == 2) return "Error: can't create 2x2 puzzles"; |
901 | if (w == 1 && h == 2) return "Error: can't create 1x2 puzzles"; |
902 | if (w == 2 && h == 1) return "Error: can't create 2x1 puzzles"; |
903 | if (w == 1 && h == 1) return "Error: can't create 1x1 puzzles"; |
904 | } |
905 | return NULL; |
906 | } |
907 | |
908 | /* Definition: a puzzle instance is _good_ if: |
909 | * - it has a unique solution |
910 | * - the solver can find this solution without using recursion |
911 | * - the solution contains at least one black square |
912 | * - the clues are 2-way rotationally symmetric |
913 | * |
914 | * (the idea being: the generator can not output any _bad_ puzzles) |
915 | * |
916 | * Theorem: validate_params, when full != 0, discards exactly the set |
917 | * of parameters for which there are _no_ good puzzle instances. |
918 | * |
919 | * Proof: it's an immediate consequence of the five lemmas below. |
920 | * |
921 | * Observation: not only do puzzles on non-tiny grids exist, the |
922 | * generator is pretty fast about coming up with them. On my pre-2004 |
923 | * desktop box, it generates 100 puzzles on the highest preset (16x11) |
924 | * in 8.383 seconds, or <= 0.1 second per puzzle. |
925 | * |
926 | * ---------------------------------------------------------------------- |
927 | * |
928 | * Lemma: On a 1x1 grid, there are no good puzzles. |
929 | * |
930 | * Proof: the one square can't be a clue because at least one square |
931 | * is black. But both a white square and a black square satisfy the |
932 | * solution criteria, so the puzzle is ambiguous (and hence bad). |
933 | * |
934 | * Lemma: On a 1x2 grid, there are no good puzzles. |
935 | * |
936 | * Proof: let's name the squares l and r. Note that there can be at |
937 | * most one black square, or adjacency is violated. By assumption at |
938 | * least one square is black, so let's call that one l. By clue |
939 | * symmetry, neither l nor r can be given as a clue, so the puzzle |
940 | * instance is blank and thus ambiguous. |
941 | * |
942 | * Corollary: On a 2x1 grid, there are no good puzzles. |
943 | * Proof: rotate the above proof 90 degrees ;-) |
944 | * |
945 | * ---------------------------------------------------------------------- |
946 | * |
947 | * Lemma: On a 2x2 grid, there are no soluble puzzles with 2-way |
948 | * rotational symmetric clues and at least one black square. |
949 | * |
950 | * Proof: Let's name the squares a, b, c, and d, with a and b on the |
951 | * top row, a and c in the left column. Let's consider the case where |
952 | * a is black. Then no other square can be black: b and c would both |
953 | * violate the adjacency constraint; d would disconnect b from c. |
954 | * |
955 | * So exactly one square is black (and by 4-way rotation symmetry of |
956 | * the 2x2 square, it doesn't matter which one, so let's stick to a). |
957 | * By 2-way rotational symmetry of the clues and the rule about not |
958 | * painting numbers black, neither a nor d can be clues. A blank |
959 | * puzzle would be ambiguous, so one of {b, c} is a clue; by symmetry, |
960 | * so is the other one. |
961 | * |
962 | * It is readily seen that their clue value is 2. But "a is black" |
963 | * and "d is black" are both valid solutions in this case, so the |
964 | * puzzle is ambiguous (and hence bad). |
965 | * |
966 | * ---------------------------------------------------------------------- |
967 | * |
968 | * Lemma: On a wxh grid with w, h >= 1 and (w > 2 or h > 2), there is |
969 | * at least one good puzzle. |
970 | * |
971 | * Proof: assume that w > h (otherwise rotate the proof again). Paint |
972 | * the top left and bottom right corners black, and fill a clue into |
973 | * all the other squares. Present this board to the solver code (or |
974 | * player, hypothetically), except with the two black squares as blank |
975 | * squares. |
976 | * |
977 | * For an Nx1 puzzle, observe that every clue is N - 2, and there are |
978 | * N - 2 of them in one connected sequence, so the remaining two |
979 | * squares can be deduced to be black, which solves the puzzle. |
980 | * |
981 | * For any other puzzle, let j be a cell in the same row as a black |
982 | * cell, but not in the same column (such a cell doesn't exist in 2x3 |
983 | * puzzles, but we assume w > h and such cells exist in 3x2 puzzles). |
984 | * |
985 | * Note that the number of cells in axis parallel `rays' going out |
986 | * from j exceeds j's clue value by one. Only one such cell is a |
987 | * non-clue, so it must be black. Similarly for the other corner (let |
988 | * j' be a cell in the same row as the _other_ black cell, but not in |
989 | * the same column as _any_ black cell; repeat this argument at j'). |
990 | * |
991 | * This fills the grid and satisfies all clues and the adjacency |
992 | * constraint and doesn't paint on top of any clues. All that is left |
993 | * to see is connectedness. |
994 | * |
995 | * Observe that the white cells in each column form a single connected |
996 | * `run', and each column contains a white cell adjacent to a white |
997 | * cell in the column to the right, if that column exists. |
998 | * |
999 | * Thus, any cell in the left-most column can reach any other cell: |
1000 | * first go to the target column (by repeatedly going to the cell in |
1001 | * your current column that lets you go right, then going right), then |
1002 | * go up or down to the desired cell. |
1003 | * |
1004 | * As reachability is symmetric (in undirected graphs) and transitive, |
1005 | * any cell can reach any left-column cell, and from there any other |
1006 | * cell. |
1007 | */ |
1008 | |
1009 | /* ---------------------------------------------------------------------- |
1010 | * Game encoding and decoding |
1011 | */ |
1012 | |
1013 | #define NDIGITS_BASE '!' |
1014 | |
1015 | static char *newdesc_encode_game_description(int area, puzzle_size *grid) |
1016 | { |
1017 | char *desc = NULL; |
1018 | int desclen = 0, descsize = 0; |
1019 | int run, i; |
1020 | |
1021 | run = 0; |
1022 | for (i = 0; i <= area; i++) { |
1023 | int n = (i < area ? grid[i] : -1); |
1024 | |
1025 | if (!n) |
1026 | run++; |
1027 | else { |
1028 | if (descsize < desclen + 40) { |
1029 | descsize = desclen * 3 / 2 + 40; |
1030 | desc = sresize(desc, descsize, char); |
1031 | } |
1032 | if (run) { |
1033 | while (run > 0) { |
1034 | int c = 'a' - 1 + run; |
1035 | if (run > 26) |
1036 | c = 'z'; |
1037 | desc[desclen++] = c; |
1038 | run -= c - ('a' - 1); |
1039 | } |
1040 | } else { |
1041 | /* |
1042 | * If there's a number in the very top left or |
1043 | * bottom right, there's no point putting an |
1044 | * unnecessary _ before or after it. |
1045 | */ |
1046 | if (desclen > 0 && n > 0) |
1047 | desc[desclen++] = '_'; |
1048 | } |
1049 | if (n > 0) |
1050 | desclen += sprintf(desc+desclen, "%d", n); |
1051 | run = 0; |
1052 | } |
1053 | } |
1054 | desc[desclen] = '\0'; |
1055 | return desc; |
1056 | } |
1057 | |
1058 | static char *validate_desc(game_params *params, char *desc) |
1059 | { |
1060 | int const n = params->w * params->h; |
1061 | int squares = 0; |
1062 | int range = params->w + params->h - 1; /* maximum cell value */ |
1063 | |
1064 | while (*desc && *desc != ',') { |
1065 | int c = *desc++; |
1066 | if (c >= 'a' && c <= 'z') { |
1067 | squares += c - 'a' + 1; |
1068 | } else if (c == '_') { |
1069 | /* do nothing */; |
1070 | } else if (c > '0' && c <= '9') { |
1071 | int val = atoi(desc-1); |
1072 | if (val < 1 || val > range) |
1073 | return "Out-of-range number in game description"; |
1074 | squares++; |
1075 | while (*desc >= '0' && *desc <= '9') |
1076 | desc++; |
1077 | } else |
1078 | return "Invalid character in game description"; |
1079 | } |
1080 | |
1081 | if (squares < n) |
1082 | return "Not enough data to fill grid"; |
1083 | |
1084 | if (squares > n) |
1085 | return "Too much data to fit in grid"; |
1086 | |
1087 | return NULL; |
1088 | } |
1089 | |
1090 | static game_state *new_game(midend *me, game_params *params, char *desc) |
1091 | { |
1092 | int i; |
1093 | char *p; |
1094 | |
1095 | int const n = params->w * params->h; |
1096 | game_state *state = snew(game_state); |
1097 | |
1098 | me = NULL; /* I don't need it, I shouldn't use it */ |
1099 | |
1100 | state->params = *params; /* structure copy */ |
1101 | state->grid = snewn(n, puzzle_size); |
1102 | |
1103 | p = desc; |
1104 | i = 0; |
1105 | while (i < n && *p) { |
1106 | int c = *p++; |
1107 | if (c >= 'a' && c <= 'z') { |
1108 | int squares = c - 'a' + 1; |
1109 | while (squares--) |
1110 | state->grid[i++] = 0; |
1111 | } else if (c == '_') { |
1112 | /* do nothing */; |
1113 | } else if (c > '0' && c <= '9') { |
1114 | int val = atoi(p-1); |
1115 | assert(val >= 1 && val <= params->w+params->h-1); |
1116 | state->grid[i++] = val; |
1117 | while (*p >= '0' && *p <= '9') |
1118 | p++; |
1119 | } |
1120 | } |
1121 | assert(i == n); |
1122 | state->has_cheated = FALSE; |
1123 | state->was_solved = FALSE; |
1124 | |
1125 | return state; |
1126 | } |
1127 | |
1128 | /* ---------------------------------------------------------------------- |
1129 | * User interface: ascii |
1130 | */ |
1131 | |
1132 | static int game_can_format_as_text_now(game_params *params) |
1133 | { |
1134 | return TRUE; |
1135 | } |
1136 | |
1137 | static char *game_text_format(game_state *state) |
1138 | { |
1139 | int cellsize, r, c, i, w_string, h_string, n_string; |
1140 | char *ret, *buf, *gridline; |
1141 | |
1142 | int const w = state->params.w, h = state->params.h; |
1143 | |
1144 | cellsize = 0; /* or may be used uninitialized */ |
1145 | |
1146 | for (c = 0; c < w; ++c) { |
1147 | for (r = 1; r < h; ++r) { |
1148 | puzzle_size k = state->grid[idx(r, c, w)]; |
1149 | int d; |
1150 | for (d = 0; k; k /= 10, ++d); |
1151 | cellsize = max(cellsize, d); |
1152 | } |
1153 | } |
1154 | |
1155 | ++cellsize; |
1156 | |
1157 | w_string = w * cellsize + 2; /* "|%d|%d|...|\n" */ |
1158 | h_string = 2 * h + 1; /* "+--+--+...+\n%s\n+--+--+...+\n" */ |
1159 | n_string = w_string * h_string; |
1160 | |
1161 | gridline = snewn(w_string + 1, char); /* +1: NUL terminator */ |
1162 | memset(gridline, '-', w_string); |
1163 | for (c = 0; c <= w; ++c) gridline[c * cellsize] = '+'; |
1164 | gridline[w_string - 1] = '\n'; |
1165 | gridline[w_string - 0] = '\0'; |
1166 | |
1167 | buf = ret = snewn(n_string + 1, char); /* +1: NUL terminator */ |
1168 | for (i = r = 0; r < h; ++r) { |
1169 | memcpy(buf, gridline, w_string); |
1170 | buf += w_string; |
1171 | for (c = 0; c < w; ++c, ++i) { |
1172 | char ch; |
1173 | switch (state->grid[i]) { |
1174 | case BLACK: ch = '#'; break; |
1175 | case WHITE: ch = '.'; break; |
1176 | case EMPTY: ch = ' '; break; |
1177 | default: |
1178 | buf += sprintf(buf, "|%*d", cellsize - 1, state->grid[i]); |
1179 | continue; |
1180 | } |
1181 | *buf++ = '|'; |
1182 | memset(buf, ch, cellsize - 1); |
1183 | buf += cellsize - 1; |
1184 | } |
1185 | buf += sprintf(buf, "|\n"); |
1186 | } |
1187 | memcpy(buf, gridline, w_string); |
1188 | buf += w_string; |
1189 | assert (buf - ret == n_string); |
1190 | *buf = '\0'; |
1191 | |
1192 | sfree(gridline); |
1193 | |
1194 | return ret; |
1195 | } |
1196 | |
1197 | /* ---------------------------------------------------------------------- |
1198 | * User interfaces: interactive |
1199 | */ |
1200 | |
1201 | struct game_ui { |
1202 | puzzle_size r, c; /* cursor position */ |
1203 | unsigned int cursor_show: 1; |
1204 | unsigned int cheated: 1; |
1205 | }; |
1206 | |
1207 | static game_ui *new_ui(game_state *state) |
1208 | { |
1209 | struct game_ui *ui = snew(game_ui); |
1210 | ui->r = ui->c = 0; |
1211 | ui->cursor_show = ui->cheated = FALSE; |
1212 | return ui; |
1213 | } |
1214 | |
1215 | static void free_ui(game_ui *ui) |
1216 | { |
1217 | sfree(ui); |
1218 | } |
1219 | |
1220 | static char *encode_ui(game_ui *ui) |
1221 | { |
1222 | return dupstr(ui->cheated ? "1" : "0"); |
1223 | } |
1224 | |
1225 | static void decode_ui(game_ui *ui, char *encoding) |
1226 | { |
1227 | ui->cheated = (*encoding == '1'); |
1228 | } |
1229 | |
1230 | typedef struct drawcell { |
1231 | puzzle_size value; |
1232 | unsigned int error: 1; |
1233 | unsigned int cursor: 1; |
1234 | unsigned int flash: 1; |
1235 | } drawcell; |
1236 | |
1237 | struct game_drawstate { |
1238 | int tilesize; |
1239 | drawcell *grid; |
1240 | unsigned int started: 1; |
1241 | }; |
1242 | |
1243 | #define TILESIZE (ds->tilesize) |
1244 | #define BORDER (TILESIZE / 2) |
1245 | #define COORD(x) ((x) * TILESIZE + BORDER) |
1246 | #define FROMCOORD(x) (((x) - BORDER) / TILESIZE) |
1247 | |
1248 | static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, |
1249 | int x, int y, int button) |
1250 | { |
1251 | enum {none, forwards, backwards, hint}; |
1252 | int const w = state->params.w, h = state->params.h; |
1253 | int r = ui->r, c = ui->c, action = none, cell; |
1254 | |
1255 | if (IS_CURSOR_SELECT(button) && !ui->cursor_show) return NULL; |
1256 | |
1257 | if (IS_MOUSE_DOWN(button)) { |
1258 | r = FROMCOORD(y + TILESIZE) - 1; /* or (x, y) < TILESIZE) */ |
1259 | c = FROMCOORD(x + TILESIZE) - 1; /* are considered inside */ |
1260 | if (out_of_bounds(r, c, w, h)) return NULL; |
1261 | ui->r = r; |
1262 | ui->c = c; |
1263 | ui->cursor_show = FALSE; |
1264 | } |
1265 | |
1266 | if (button == LEFT_BUTTON || button == RIGHT_BUTTON) { |
1267 | /* |
1268 | * Utterly awful hack, exactly analogous to the one in Slant, |
1269 | * to configure the left and right mouse buttons the opposite |
1270 | * way round. |
1271 | * |
1272 | * The original puzzle submitter thought it would be more |
1273 | * useful to have the left button turn an empty square into a |
1274 | * dotted one, on the grounds that that was what you did most |
1275 | * often; I (SGT) felt instinctively that the left button |
1276 | * ought to place black squares and the right button place |
1277 | * dots, on the grounds that that was consistent with many |
1278 | * other puzzles in which the left button fills in the data |
1279 | * used by the solution checker while the right button places |
1280 | * pencil marks for the user's convenience. |
1281 | * |
1282 | * My first beta-player wasn't sure either, so I thought I'd |
1283 | * pre-emptively put in a 'configuration' mechanism just in |
1284 | * case. |
1285 | */ |
1286 | { |
1287 | static int swap_buttons = -1; |
1288 | if (swap_buttons < 0) { |
1289 | char *env = getenv("RANGE_SWAP_BUTTONS"); |
1290 | swap_buttons = (env && (env[0] == 'y' || env[0] == 'Y')); |
1291 | } |
1292 | if (swap_buttons) { |
1293 | if (button == LEFT_BUTTON) |
1294 | button = RIGHT_BUTTON; |
1295 | else |
1296 | button = LEFT_BUTTON; |
1297 | } |
1298 | } |
1299 | } |
1300 | |
1301 | switch (button) { |
1302 | case CURSOR_SELECT : case LEFT_BUTTON: action = backwards; break; |
1303 | case CURSOR_SELECT2: case RIGHT_BUTTON: action = forwards; break; |
1304 | case 'h': case 'H' : action = hint; break; |
1305 | case CURSOR_UP: case CURSOR_DOWN: |
1306 | case CURSOR_LEFT: case CURSOR_RIGHT: |
1307 | if (ui->cursor_show) { |
1308 | int i; |
1309 | for (i = 0; i < 4 && cursors[i] != button; ++i); |
1310 | assert (i < 4); |
1311 | if (!out_of_bounds(ui->r + dr[i], ui->c + dc[i], w, h)) { |
1312 | ui->r += dr[i]; |
1313 | ui->c += dc[i]; |
1314 | } |
1315 | } else ui->cursor_show = TRUE; |
1316 | return ""; |
1317 | } |
1318 | |
1319 | if (action == hint) { |
1320 | move *end, *buf = snewn(state->params.w * state->params.h, |
1321 | struct move); |
1322 | char *ret = NULL; |
1323 | end = solve_internal(state, buf, DIFF_RECURSION); |
1324 | if (end != NULL && end > buf) { |
1325 | ret = nfmtstr(40, "%c,%d,%d", |
1326 | buf->colour == M_BLACK ? 'B' : 'W', |
1327 | buf->square.r, buf->square.c); |
1328 | ui->cheated = TRUE; /* you are being naughty ;-) */ |
1329 | } |
1330 | sfree(buf); |
1331 | return ret; |
1332 | } |
1333 | |
1334 | cell = state->grid[idx(r, c, state->params.w)]; |
1335 | if (cell > 0) return NULL; |
1336 | |
1337 | if (action == forwards) switch (cell) { |
1338 | case EMPTY: return nfmtstr(40, "W,%d,%d", r, c); |
1339 | case WHITE: return nfmtstr(40, "B,%d,%d", r, c); |
1340 | case BLACK: return nfmtstr(40, "E,%d,%d", r, c); |
1341 | } |
1342 | |
1343 | else if (action == backwards) switch (cell) { |
1344 | case BLACK: return nfmtstr(40, "W,%d,%d", r, c); |
1345 | case WHITE: return nfmtstr(40, "E,%d,%d", r, c); |
1346 | case EMPTY: return nfmtstr(40, "B,%d,%d", r, c); |
1347 | } |
1348 | |
1349 | return NULL; |
1350 | } |
1351 | |
1352 | static int find_errors(game_state *state, int *report) |
1353 | { |
1354 | int const w = state->params.w, h = state->params.h, n = w * h; |
1355 | |
1356 | int r, c, i; |
1357 | |
1358 | int nblack = 0, any_white_cell = -1; |
1359 | game_state *dup = dup_game(state); |
1360 | |
1361 | for (i = r = 0; r < h; ++r) |
1362 | for (c = 0; c < w; ++c, ++i) { |
1363 | switch (state->grid[i]) { |
1364 | |
1365 | case BLACK: |
1366 | { |
1367 | int j; |
1368 | ++nblack; |
1369 | for (j = 0; j < 4; ++j) { |
1370 | int const rr = r + dr[j], cc = c + dc[j]; |
1371 | if (out_of_bounds(rr, cc, w, h)) continue; |
1372 | if (state->grid[idx(rr, cc, w)] != BLACK) continue; |
1373 | if (!report) goto found_error; |
1374 | report[i] = TRUE; |
1375 | break; |
1376 | } |
1377 | } |
1378 | break; |
1379 | default: |
1380 | { |
1381 | int j, runs; |
1382 | for (runs = 1, j = 0; j < 4; ++j) { |
1383 | int const rr = r + dr[j], cc = c + dc[j]; |
1384 | runs += runlength(rr, cc, dr[j], dc[j], state, |
1385 | ~MASK(BLACK)); |
1386 | } |
1387 | if (!report) { |
1388 | if (runs != state->grid[i]) goto found_error; |
1389 | } else if (runs < state->grid[i]) report[i] = TRUE; |
1390 | else { |
1391 | for (runs = 1, j = 0; j < 4; ++j) { |
1392 | int const rr = r + dr[j], cc = c + dc[j]; |
1393 | runs += runlength(rr, cc, dr[j], dc[j], state, |
1394 | ~(MASK(BLACK) | MASK(EMPTY))); |
1395 | } |
1396 | if (runs > state->grid[i]) report[i] = TRUE; |
1397 | } |
1398 | } |
1399 | |
1400 | /* note: fallthrough _into_ these cases */ |
1401 | case EMPTY: |
1402 | case WHITE: any_white_cell = i; |
1403 | } |
1404 | } |
1405 | |
1406 | for (i = 0; i < n; ++i) if (dup->grid[i] != BLACK) dup->grid[i] = WHITE; |
1407 | if (nblack + dfs_count_white(dup, any_white_cell) < n) { |
1408 | if (!report) { |
1409 | printf("dfs fail at %d\n", any_white_cell); |
1410 | goto found_error; |
1411 | } |
1412 | for (i = 0; i < n; ++i) if (state->grid[i] != BLACK) report[i] = TRUE; |
1413 | } |
1414 | |
1415 | free_game(dup); |
1416 | return FALSE; /* if report != NULL, this is ignored */ |
1417 | |
1418 | found_error: |
1419 | free_game(dup); |
1420 | return TRUE; |
1421 | } |
1422 | |
1423 | static game_state *execute_move(game_state *state, char *move) |
1424 | { |
1425 | signed int r, c, value, nchars, ntok; |
1426 | signed char what_to_do; |
1427 | game_state *ret; |
1428 | |
1429 | assert (move); |
1430 | |
1431 | ret = dup_game(state); |
1432 | |
1433 | if (*move == 'S') { |
1434 | ++move; |
1435 | ret->has_cheated = ret->was_solved = TRUE; |
1436 | } |
1437 | |
1438 | for (; *move; move += nchars) { |
1439 | ntok = sscanf(move, "%c,%d,%d%n", &what_to_do, &r, &c, &nchars); |
1440 | if (ntok < 3) goto failure; |
1441 | switch (what_to_do) { |
1442 | case 'W': value = WHITE; break; |
1443 | case 'E': value = EMPTY; break; |
1444 | case 'B': value = BLACK; break; |
1445 | default: goto failure; |
1446 | } |
1447 | if (out_of_bounds(r, c, ret->params.w, ret->params.h)) goto failure; |
1448 | ret->grid[idx(r, c, ret->params.w)] = value; |
1449 | } |
1450 | |
1451 | if (ret->was_solved == FALSE) |
1452 | ret->was_solved = !find_errors(ret, NULL); |
1453 | |
1454 | return ret; |
1455 | |
1456 | failure: |
1457 | free_game(ret); |
1458 | return NULL; |
1459 | } |
1460 | |
1461 | static void game_changed_state(game_ui *ui, game_state *oldstate, |
1462 | game_state *newstate) |
1463 | { |
1464 | if (newstate->has_cheated) ui->cheated = TRUE; |
1465 | } |
1466 | |
1467 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
1468 | int dir, game_ui *ui) |
1469 | { |
1470 | return 0.0F; |
1471 | } |
1472 | |
1473 | #define FLASH_TIME 0.7F |
1474 | |
1475 | static float game_flash_length(game_state *from, game_state *to, |
1476 | int dir, game_ui *ui) |
1477 | { |
1478 | if (!from->was_solved && to->was_solved && !ui->cheated) |
1479 | return FLASH_TIME; |
1480 | return 0.0F; |
1481 | } |
1482 | |
4496362f |
1483 | static int game_is_solved(game_state *state) |
1484 | { |
1485 | return state->was_solved; |
1486 | } |
1487 | |
e7414d31 |
1488 | /* ---------------------------------------------------------------------- |
1489 | * Drawing routines. |
1490 | */ |
1491 | |
1492 | #define PREFERRED_TILE_SIZE 32 |
1493 | |
1494 | enum { |
1495 | COL_BACKGROUND = 0, |
1496 | COL_GRID, |
1497 | COL_BLACK = COL_GRID, |
1498 | COL_TEXT = COL_GRID, |
1499 | COL_USER = COL_GRID, |
1500 | COL_ERROR, |
1501 | COL_LOWLIGHT, |
1502 | COL_HIGHLIGHT = COL_ERROR, /* mkhighlight needs it, I don't */ |
1503 | COL_CURSOR = COL_LOWLIGHT, |
1504 | NCOLOURS |
1505 | }; |
1506 | |
1507 | static void game_compute_size(game_params *params, int tilesize, |
1508 | int *x, int *y) |
1509 | { |
1510 | *x = (1 + params->w) * tilesize; |
1511 | *y = (1 + params->h) * tilesize; |
1512 | } |
1513 | |
1514 | static void game_set_size(drawing *dr, game_drawstate *ds, |
1515 | game_params *params, int tilesize) |
1516 | { |
1517 | ds->tilesize = tilesize; |
1518 | } |
1519 | |
1520 | #define COLOUR(ret, i, r, g, b) \ |
1521 | ((ret[3*(i)+0] = (r)), (ret[3*(i)+1] = (g)), (ret[3*(i)+2] = (b))) |
1522 | |
1523 | static float *game_colours(frontend *fe, int *ncolours) |
1524 | { |
1525 | float *ret = snewn(3 * NCOLOURS, float); |
1526 | |
1527 | game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT); |
1528 | COLOUR(ret, COL_GRID, 0.0F, 0.0F, 0.0F); |
1529 | COLOUR(ret, COL_ERROR, 1.0F, 0.0F, 0.0F); |
1530 | |
1531 | *ncolours = NCOLOURS; |
1532 | return ret; |
1533 | } |
1534 | |
1535 | static drawcell makecell(puzzle_size value, int error, int cursor, int flash) |
1536 | { |
1537 | drawcell ret; |
1538 | setmember(ret, value); |
1539 | setmember(ret, error); |
1540 | setmember(ret, cursor); |
1541 | setmember(ret, flash); |
1542 | return ret; |
1543 | } |
1544 | |
1545 | static game_drawstate *game_new_drawstate(drawing *dr, game_state *state) |
1546 | { |
1547 | int const w = state->params.w, h = state->params.h, n = w * h; |
1548 | struct game_drawstate *ds = snew(struct game_drawstate); |
1549 | int i; |
1550 | |
1551 | ds->tilesize = 0; |
1552 | ds->started = FALSE; |
1553 | |
1554 | ds->grid = snewn(n, drawcell); |
1555 | for (i = 0; i < n; ++i) |
1556 | ds->grid[i] = makecell(w + h, FALSE, FALSE, FALSE); |
1557 | |
1558 | return ds; |
1559 | } |
1560 | |
1561 | static void game_free_drawstate(drawing *dr, game_drawstate *ds) |
1562 | { |
1563 | sfree(ds->grid); |
1564 | sfree(ds); |
1565 | } |
1566 | |
1567 | #define cmpmember(a, b, field) ((a) . field == (b) . field) |
1568 | |
1569 | static int cell_eq(drawcell a, drawcell b) |
1570 | { |
1571 | return |
1572 | cmpmember(a, b, value) && |
1573 | cmpmember(a, b, error) && |
1574 | cmpmember(a, b, cursor) && |
1575 | cmpmember(a, b, flash); |
1576 | } |
1577 | |
1578 | static void draw_cell(drawing *dr, game_drawstate *ds, int r, int c, |
1579 | drawcell cell); |
1580 | |
1581 | static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate, |
1582 | game_state *state, int dir, game_ui *ui, |
1583 | float animtime, float flashtime) |
1584 | { |
1585 | int const w = state->params.w, h = state->params.h, n = w * h; |
1586 | int const wpx = (w+1) * ds->tilesize, hpx = (h+1) * ds->tilesize; |
1587 | int const flash = ((int) (flashtime * 5 / FLASH_TIME)) % 2; |
1588 | |
1589 | int r, c, i; |
1590 | |
1591 | int *errors = snewn(n, int); |
1592 | memset(errors, FALSE, n * sizeof (int)); |
1593 | find_errors(state, errors); |
1594 | |
1595 | assert (oldstate == NULL); /* only happens if animating moves */ |
1596 | |
1597 | if (!ds->started) { |
1598 | ds->started = TRUE; |
1599 | draw_rect(dr, 0, 0, wpx, hpx, COL_BACKGROUND); |
1600 | draw_rect(dr, BORDER-1, BORDER-1, |
1601 | ds->tilesize*w+2, ds->tilesize*h+2, COL_GRID); |
1602 | draw_update(dr, 0, 0, wpx, hpx); |
1603 | } |
1604 | |
1605 | for (i = r = 0; r < h; ++r) { |
1606 | for (c = 0; c < w; ++c, ++i) { |
1607 | drawcell cell = makecell(state->grid[i], errors[i], FALSE, flash); |
1608 | if (r == ui->r && c == ui->c && ui->cursor_show) |
1609 | cell.cursor = TRUE; |
1610 | if (!cell_eq(cell, ds->grid[i])) { |
1611 | draw_cell(dr, ds, r, c, cell); |
1612 | ds->grid[i] = cell; |
1613 | } |
1614 | } |
1615 | } |
1616 | |
1617 | sfree(errors); |
1618 | } |
1619 | |
1620 | static void draw_cell(drawing *draw, game_drawstate *ds, int r, int c, |
1621 | drawcell cell) |
1622 | { |
1623 | int const ts = ds->tilesize; |
1624 | int const y = BORDER + ts * r, x = BORDER + ts * c; |
1625 | int const tx = x + (ts / 2), ty = y + (ts / 2); |
1626 | int const dotsz = (ds->tilesize + 9) / 10; |
1627 | |
1628 | int const colour = (cell.value == BLACK ? |
1629 | cell.error ? COL_ERROR : COL_BLACK : |
1630 | cell.flash || cell.cursor ? |
1631 | COL_LOWLIGHT : COL_BACKGROUND); |
1632 | |
1633 | draw_rect (draw, x, y, ts, ts, colour); |
1634 | draw_rect_outline(draw, x, y, ts, ts, COL_GRID); |
1635 | |
1636 | switch (cell.value) { |
1637 | case WHITE: draw_rect(draw, tx - dotsz / 2, ty - dotsz / 2, dotsz, dotsz, |
1638 | cell.error ? COL_ERROR : COL_USER); |
1639 | case BLACK: break; |
1640 | case EMPTY: |
1641 | if (cell.error) |
1642 | draw_circle(draw, tx, ty, dotsz / 2, COL_ERROR, COL_GRID); |
1643 | break; |
1644 | default: |
1645 | { |
1646 | int const colour = (cell.error ? COL_ERROR : COL_GRID); |
1647 | char *msg = nfmtstr(10, "%d", cell.value); |
1648 | draw_text(draw, tx, ty, FONT_VARIABLE, ts * 3 / 5, |
1649 | ALIGN_VCENTRE | ALIGN_HCENTRE, colour, msg); |
1650 | sfree(msg); |
1651 | } |
1652 | } |
1653 | |
1654 | draw_update(draw, x, y, ts, ts); |
1655 | } |
1656 | |
1657 | static int game_timing_state(game_state *state, game_ui *ui) |
1658 | { |
1659 | puts("warning: game_timing_state was called (this shouldn't happen)"); |
1660 | return FALSE; /* the (non-existing) timer should not be running */ |
1661 | } |
1662 | |
1663 | /* ---------------------------------------------------------------------- |
1664 | * User interface: print |
1665 | */ |
1666 | |
1667 | static void game_print_size(game_params *params, float *x, float *y) |
1668 | { |
1669 | int print_width, print_height; |
1670 | game_compute_size(params, 800, &print_width, &print_height); |
1671 | *x = print_width / 100.0F; |
1672 | *y = print_height / 100.0F; |
1673 | } |
1674 | |
1675 | static void game_print(drawing *dr, game_state *state, int tilesize) |
1676 | { |
1677 | int const w = state->params.w, h = state->params.h; |
1678 | game_drawstate ds_obj, *ds = &ds_obj; |
1679 | int r, c, i, colour; |
1680 | |
1681 | ds->tilesize = tilesize; |
1682 | |
1683 | colour = print_mono_colour(dr, 1); assert(colour == COL_BACKGROUND); |
1684 | colour = print_mono_colour(dr, 0); assert(colour == COL_GRID); |
1685 | colour = print_mono_colour(dr, 1); assert(colour == COL_ERROR); |
1686 | colour = print_mono_colour(dr, 0); assert(colour == COL_LOWLIGHT); |
1687 | colour = print_mono_colour(dr, 0); assert(colour == NCOLOURS); |
1688 | |
1689 | for (i = r = 0; r < h; ++r) |
1690 | for (c = 0; c < w; ++c, ++i) |
1691 | draw_cell(dr, ds, r, c, |
1692 | makecell(state->grid[i], FALSE, FALSE, FALSE)); |
1693 | |
1694 | print_line_width(dr, 3 * tilesize / 40); |
1695 | draw_rect_outline(dr, BORDER, BORDER, w*TILESIZE, h*TILESIZE, COL_GRID); |
1696 | } |
1697 | |
1698 | /* And that's about it ;-) **************************************************/ |
1699 | |
1700 | #ifdef COMBINED |
1701 | #define thegame range |
1702 | #endif |
1703 | |
1704 | struct game const thegame = { |
1705 | "Range", "games.range", "range", |
1706 | default_params, |
1707 | game_fetch_preset, |
1708 | decode_params, |
1709 | encode_params, |
1710 | free_params, |
1711 | dup_params, |
1712 | TRUE, game_configure, custom_params, |
1713 | validate_params, |
1714 | new_game_desc, |
1715 | validate_desc, |
1716 | new_game, |
1717 | dup_game, |
1718 | free_game, |
1719 | TRUE, solve_game, |
1720 | TRUE, game_can_format_as_text_now, game_text_format, |
1721 | new_ui, |
1722 | free_ui, |
1723 | encode_ui, |
1724 | decode_ui, |
1725 | game_changed_state, |
1726 | interpret_move, |
1727 | execute_move, |
1728 | PREFERRED_TILE_SIZE, game_compute_size, game_set_size, |
1729 | game_colours, |
1730 | game_new_drawstate, |
1731 | game_free_drawstate, |
1732 | game_redraw, |
1733 | game_anim_length, |
1734 | game_flash_length, |
4496362f |
1735 | game_is_solved, |
e7414d31 |
1736 | TRUE, FALSE, game_print_size, game_print, |
1737 | FALSE, /* wants_statusbar */ |
1738 | FALSE, game_timing_state, |
1739 | 0, /* flags */ |
1740 | }; |