2 * lightup.c: Implementation of the Nikoli game 'Light Up'.
15 * In standalone solver mode, `verbose' is a variable which can be
16 * set by command-line option; in debugging mode it's simply always
19 #if defined STANDALONE_SOLVER
20 #define SOLVER_DIAGNOSTICS
23 #define debug(x) printf x
24 #elif defined SOLVER_DIAGNOSTICS
28 /* --- Constants, structure definitions, etc. --- */
30 #define PREFERRED_TILE_SIZE 32
31 #define TILE_SIZE (ds->tilesize)
32 #define BORDER (TILE_SIZE / 2)
33 #define TILE_RADIUS (ds->crad)
35 #define COORD(x) ( (x) * TILE_SIZE + BORDER )
36 #define FROMCOORD(x) ( ((x) - BORDER + TILE_SIZE) / TILE_SIZE - 1 )
38 #define FLASH_TIME 0.30F
43 COL_BLACK, /* black */
44 COL_LIGHT, /* white */
51 enum { SYMM_NONE, SYMM_REF2, SYMM_ROT2, SYMM_REF4, SYMM_ROT4, SYMM_MAX };
57 int blackpc; /* %age of black squares */
59 int difficulty; /* 0 to DIFFCOUNT */
64 /* flags for black squares */
65 #define F_NUMBERED 2 /* it has a number attached */
66 #define F_NUMBERUSED 4 /* this number was useful for solving */
68 /* flags for non-black squares */
69 #define F_IMPOSSIBLE 8 /* can't put a light here */
76 int *lights; /* For black squares, (optionally) the number
77 of surrounding lights. For non-black squares,
78 the number of times it's lit. size h*w*/
79 unsigned int *flags; /* size h*w */
80 int completed, used_solve;
83 #define GRID(gs,grid,x,y) (gs->grid[(y)*((gs)->w) + (x)])
85 /* A ll_data holds information about which lights would be lit by
86 * a particular grid location's light (or conversely, which locations
87 * could light a specific other location). */
88 /* most things should consider this struct opaque. */
91 int minx, maxx, miny, maxy;
95 /* Macro that executes 'block' once per light in lld, including
96 * the origin if include_origin is specified. 'block' can use
97 * lx and ly as the coords. */
98 #define FOREACHLIT(lld,block) do { \
101 for (lx = (lld)->minx; lx <= (lld)->maxx; lx++) { \
102 if (lx == (lld)->ox) continue; \
106 for (ly = (lld)->miny; ly <= (lld)->maxy; ly++) { \
107 if (!(lld)->include_origin && ly == (lld)->oy) continue; \
114 struct { int x, y; unsigned int f; } points[4];
118 /* Fills in (doesn't allocate) a surrounds structure with the grid locations
119 * around a given square, taking account of the edges. */
120 static void get_surrounds(game_state *state, int ox, int oy, surrounds *s)
122 assert(ox >= 0 && ox < state->w && oy >= 0 && oy < state->h);
124 #define ADDPOINT(cond,nx,ny) do {\
126 s->points[s->npoints].x = (nx); \
127 s->points[s->npoints].y = (ny); \
128 s->points[s->npoints].f = 0; \
131 ADDPOINT(ox > 0, ox-1, oy);
132 ADDPOINT(ox < (state->w-1), ox+1, oy);
133 ADDPOINT(oy > 0, ox, oy-1);
134 ADDPOINT(oy < (state->h-1), ox, oy+1);
137 /* --- Game parameter functions --- */
139 #define DEFAULT_PRESET 0
141 const struct game_params lightup_presets[] = {
142 { 7, 7, 20, SYMM_ROT4, 0 },
143 { 7, 7, 20, SYMM_ROT4, 1 },
144 { 7, 7, 20, SYMM_ROT4, 2 },
145 { 10, 10, 20, SYMM_ROT2, 0 },
146 { 10, 10, 20, SYMM_ROT2, 1 },
148 { 12, 12, 20, SYMM_ROT2, 0 },
149 { 12, 12, 20, SYMM_ROT2, 1 },
151 { 10, 10, 20, SYMM_ROT2, 2 },
152 { 14, 14, 20, SYMM_ROT2, 0 },
153 { 14, 14, 20, SYMM_ROT2, 1 },
154 { 14, 14, 20, SYMM_ROT2, 2 }
158 static game_params *default_params(void)
160 game_params *ret = snew(game_params);
161 *ret = lightup_presets[DEFAULT_PRESET];
166 static int game_fetch_preset(int i, char **name, game_params **params)
171 if (i < 0 || i >= lenof(lightup_presets))
174 ret = default_params();
175 *ret = lightup_presets[i];
178 sprintf(buf, "%dx%d %s",
180 ret->difficulty == 2 ? "hard" :
181 ret->difficulty == 1 ? "tricky" : "easy");
187 static void free_params(game_params *params)
192 static game_params *dup_params(game_params *params)
194 game_params *ret = snew(game_params);
195 *ret = *params; /* structure copy */
199 #define EATNUM(x) do { \
200 (x) = atoi(string); \
201 while (*string && isdigit((unsigned char)*string)) string++; \
204 static void decode_params(game_params *params, char const *string)
207 if (*string == 'x') {
211 if (*string == 'b') {
213 EATNUM(params->blackpc);
215 if (*string == 's') {
217 EATNUM(params->symm);
219 params->difficulty = 0;
220 /* cope with old params */
221 if (*string == 'r') {
222 params->difficulty = 2;
225 if (*string == 'd') {
227 EATNUM(params->difficulty);
231 static char *encode_params(game_params *params, int full)
236 sprintf(buf, "%dx%db%ds%dd%d",
237 params->w, params->h, params->blackpc,
241 sprintf(buf, "%dx%d", params->w, params->h);
246 static config_item *game_configure(game_params *params)
251 ret = snewn(6, config_item);
253 ret[0].name = "Width";
254 ret[0].type = C_STRING;
255 sprintf(buf, "%d", params->w);
256 ret[0].sval = dupstr(buf);
259 ret[1].name = "Height";
260 ret[1].type = C_STRING;
261 sprintf(buf, "%d", params->h);
262 ret[1].sval = dupstr(buf);
265 ret[2].name = "%age of black squares";
266 ret[2].type = C_STRING;
267 sprintf(buf, "%d", params->blackpc);
268 ret[2].sval = dupstr(buf);
271 ret[3].name = "Symmetry";
272 ret[3].type = C_CHOICES;
273 ret[3].sval = ":None"
274 ":2-way mirror:2-way rotational"
275 ":4-way mirror:4-way rotational";
276 ret[3].ival = params->symm;
278 ret[4].name = "Difficulty";
279 ret[4].type = C_CHOICES;
280 ret[4].sval = ":Easy:Tricky:Hard";
281 ret[4].ival = params->difficulty;
291 static game_params *custom_params(config_item *cfg)
293 game_params *ret = snew(game_params);
295 ret->w = atoi(cfg[0].sval);
296 ret->h = atoi(cfg[1].sval);
297 ret->blackpc = atoi(cfg[2].sval);
298 ret->symm = cfg[3].ival;
299 ret->difficulty = cfg[4].ival;
304 static char *validate_params(game_params *params, int full)
306 if (params->w < 2 || params->h < 2)
307 return "Width and height must be at least 2";
309 if (params->blackpc < 5 || params->blackpc > 100)
310 return "Percentage of black squares must be between 5% and 100%";
311 if (params->w != params->h) {
312 if (params->symm == SYMM_ROT4)
313 return "4-fold symmetry is only available with square grids";
315 if (params->symm < 0 || params->symm >= SYMM_MAX)
316 return "Unknown symmetry type";
317 if (params->difficulty < 0 || params->difficulty > DIFFCOUNT)
318 return "Unknown difficulty level";
323 /* --- Game state construction/freeing helper functions --- */
325 static game_state *new_state(game_params *params)
327 game_state *ret = snew(game_state);
331 ret->lights = snewn(ret->w * ret->h, int);
333 memset(ret->lights, 0, ret->w * ret->h * sizeof(int));
334 ret->flags = snewn(ret->w * ret->h, unsigned int);
335 memset(ret->flags, 0, ret->w * ret->h * sizeof(unsigned int));
336 ret->completed = ret->used_solve = 0;
340 static game_state *dup_game(game_state *state)
342 game_state *ret = snew(game_state);
347 ret->lights = snewn(ret->w * ret->h, int);
348 memcpy(ret->lights, state->lights, ret->w * ret->h * sizeof(int));
349 ret->nlights = state->nlights;
351 ret->flags = snewn(ret->w * ret->h, unsigned int);
352 memcpy(ret->flags, state->flags, ret->w * ret->h * sizeof(unsigned int));
354 ret->completed = state->completed;
355 ret->used_solve = state->used_solve;
360 static void free_game(game_state *state)
362 sfree(state->lights);
367 static void debug_state(game_state *state)
372 for (y = 0; y < state->h; y++) {
373 for (x = 0; x < state->w; x++) {
375 if (GRID(state, flags, x, y) & F_BLACK) {
376 if (GRID(state, flags, x, y) & F_NUMBERED)
377 c = GRID(state, lights, x, y) + '0';
381 if (GRID(state, flags, x, y) & F_LIGHT)
383 else if (GRID(state, flags, x, y) & F_IMPOSSIBLE)
386 debug(("%c", (int)c));
389 for (x = 0; x < state->w; x++) {
390 if (GRID(state, flags, x, y) & F_BLACK)
393 c = (GRID(state, flags, x, y) & F_LIGHT) ? 'A' : 'a';
394 c += GRID(state, lights, x, y);
396 debug(("%c", (int)c));
402 /* --- Game completion test routines. --- */
404 /* These are split up because occasionally functions are only
405 * interested in one particular aspect. */
407 /* Returns non-zero if all grid spaces are lit. */
408 static int grid_lit(game_state *state)
412 for (x = 0; x < state->w; x++) {
413 for (y = 0; y < state->h; y++) {
414 if (GRID(state,flags,x,y) & F_BLACK) continue;
415 if (GRID(state,lights,x,y) == 0)
422 /* Returns non-zero if any lights are lit by other lights. */
423 static int grid_overlap(game_state *state)
427 for (x = 0; x < state->w; x++) {
428 for (y = 0; y < state->h; y++) {
429 if (!(GRID(state, flags, x, y) & F_LIGHT)) continue;
430 if (GRID(state, lights, x, y) > 1)
437 static int number_wrong(game_state *state, int x, int y)
440 int i, n, empty, lights = GRID(state, lights, x, y);
443 * This function computes the display hint for a number: we
444 * turn the number red if it is definitely wrong. This means
447 * (a) it has too many lights around it, or
448 * (b) it would have too few lights around it even if all the
449 * plausible squares (not black, lit or F_IMPOSSIBLE) were
450 * filled with lights.
453 assert(GRID(state, flags, x, y) & F_NUMBERED);
454 get_surrounds(state, x, y, &s);
457 for (i = 0; i < s.npoints; i++) {
458 if (GRID(state,flags,s.points[i].x,s.points[i].y) & F_LIGHT) {
462 if (GRID(state,flags,s.points[i].x,s.points[i].y) & F_BLACK)
464 if (GRID(state,flags,s.points[i].x,s.points[i].y) & F_IMPOSSIBLE)
466 if (GRID(state,lights,s.points[i].x,s.points[i].y))
470 return (n > lights || (n + empty < lights));
473 static int number_correct(game_state *state, int x, int y)
476 int n = 0, i, lights = GRID(state, lights, x, y);
478 assert(GRID(state, flags, x, y) & F_NUMBERED);
479 get_surrounds(state, x, y, &s);
480 for (i = 0; i < s.npoints; i++) {
481 if (GRID(state,flags,s.points[i].x,s.points[i].y) & F_LIGHT)
484 return (n == lights) ? 1 : 0;
487 /* Returns non-zero if any numbers add up incorrectly. */
488 static int grid_addsup(game_state *state)
492 for (x = 0; x < state->w; x++) {
493 for (y = 0; y < state->h; y++) {
494 if (!(GRID(state, flags, x, y) & F_NUMBERED)) continue;
495 if (!number_correct(state, x, y)) return 0;
501 static int grid_correct(game_state *state)
503 if (grid_lit(state) &&
504 !grid_overlap(state) &&
505 grid_addsup(state)) return 1;
509 /* --- Board initial setup (blacks, lights, numbers) --- */
511 static void clean_board(game_state *state, int leave_blacks)
514 for (x = 0; x < state->w; x++) {
515 for (y = 0; y < state->h; y++) {
517 GRID(state, flags, x, y) &= F_BLACK;
519 GRID(state, flags, x, y) = 0;
520 GRID(state, lights, x, y) = 0;
526 static void set_blacks(game_state *state, game_params *params, random_state *rs)
528 int x, y, degree = 0, rotate = 0, nblack;
530 int wodd = (state->w % 2) ? 1 : 0;
531 int hodd = (state->h % 2) ? 1 : 0;
534 switch (params->symm) {
535 case SYMM_NONE: degree = 1; rotate = 0; break;
536 case SYMM_ROT2: degree = 2; rotate = 1; break;
537 case SYMM_REF2: degree = 2; rotate = 0; break;
538 case SYMM_ROT4: degree = 4; rotate = 1; break;
539 case SYMM_REF4: degree = 4; rotate = 0; break;
540 default: assert(!"Unknown symmetry type");
542 if (params->symm == SYMM_ROT4 && (state->h != state->w))
543 assert(!"4-fold symmetry unavailable without square grid");
548 if (!rotate) rw += wodd; /* ... but see below. */
550 } else if (degree == 2) {
559 /* clear, then randomise, required region. */
560 clean_board(state, 0);
561 nblack = (rw * rh * params->blackpc) / 100;
562 for (i = 0; i < nblack; i++) {
564 x = random_upto(rs,rw);
565 y = random_upto(rs,rh);
566 } while (GRID(state,flags,x,y) & F_BLACK);
567 GRID(state, flags, x, y) |= F_BLACK;
570 /* Copy required region. */
571 if (params->symm == SYMM_NONE) return;
573 for (x = 0; x < rw; x++) {
574 for (y = 0; y < rh; y++) {
578 xs[1] = state->w - 1 - (rotate ? y : x);
579 ys[1] = rotate ? x : y;
580 xs[2] = rotate ? (state->w - 1 - x) : x;
581 ys[2] = state->h - 1 - y;
582 xs[3] = rotate ? y : (state->w - 1 - x);
583 ys[3] = state->h - 1 - (rotate ? x : y);
587 xs[1] = rotate ? (state->w - 1 - x) : x;
588 ys[1] = state->h - 1 - y;
590 for (i = 1; i < degree; i++) {
591 GRID(state, flags, xs[i], ys[i]) =
592 GRID(state, flags, xs[0], ys[0]);
596 /* SYMM_ROT4 misses the middle square above; fix that here. */
597 if (degree == 4 && rotate && wodd &&
598 (random_upto(rs,100) <= (unsigned int)params->blackpc))
600 state->w/2 + wodd - 1, state->h/2 + hodd - 1) |= F_BLACK;
602 #ifdef SOLVER_DIAGNOSTICS
603 if (verbose) debug_state(state);
607 /* Fills in (does not allocate) a ll_data with all the tiles that would
608 * be illuminated by a light at point (ox,oy). If origin=1 then the
609 * origin is included in this list. */
610 static void list_lights(game_state *state, int ox, int oy, int origin,
615 memset(lld, 0, sizeof(lld));
616 lld->ox = lld->minx = lld->maxx = ox;
617 lld->oy = lld->miny = lld->maxy = oy;
618 lld->include_origin = origin;
621 for (x = ox-1; x >= 0; x--) {
622 if (GRID(state, flags, x, y) & F_BLACK) break;
623 if (x < lld->minx) lld->minx = x;
625 for (x = ox+1; x < state->w; x++) {
626 if (GRID(state, flags, x, y) & F_BLACK) break;
627 if (x > lld->maxx) lld->maxx = x;
631 for (y = oy-1; y >= 0; y--) {
632 if (GRID(state, flags, x, y) & F_BLACK) break;
633 if (y < lld->miny) lld->miny = y;
635 for (y = oy+1; y < state->h; y++) {
636 if (GRID(state, flags, x, y) & F_BLACK) break;
637 if (y > lld->maxy) lld->maxy = y;
641 /* Makes sure a light is the given state, editing the lights table to suit the
642 * new state if necessary. */
643 static void set_light(game_state *state, int ox, int oy, int on)
648 assert(!(GRID(state,flags,ox,oy) & F_BLACK));
650 if (!on && GRID(state,flags,ox,oy) & F_LIGHT) {
652 GRID(state,flags,ox,oy) &= ~F_LIGHT;
654 } else if (on && !(GRID(state,flags,ox,oy) & F_LIGHT)) {
656 GRID(state,flags,ox,oy) |= F_LIGHT;
661 list_lights(state,ox,oy,1,&lld);
662 FOREACHLIT(&lld, GRID(state,lights,lx,ly) += diff; );
666 /* Returns 1 if removing a light at (x,y) would cause a square to go dark. */
667 static int check_dark(game_state *state, int x, int y)
671 list_lights(state, x, y, 1, &lld);
672 FOREACHLIT(&lld, if (GRID(state,lights,lx,ly) == 1) { return 1; } );
676 /* Sets up an initial random correct position (i.e. every
677 * space lit, and no lights lit by other lights) by filling the
678 * grid with lights and then removing lights one by one at random. */
679 static void place_lights(game_state *state, random_state *rs)
681 int i, x, y, n, *numindices, wh = state->w*state->h;
684 numindices = snewn(wh, int);
685 for (i = 0; i < wh; i++) numindices[i] = i;
686 shuffle(numindices, wh, sizeof(*numindices), rs);
688 /* Place a light on all grid squares without lights. */
689 for (x = 0; x < state->w; x++) {
690 for (y = 0; y < state->h; y++) {
691 GRID(state, flags, x, y) &= ~F_MARK; /* we use this later. */
692 if (GRID(state, flags, x, y) & F_BLACK) continue;
693 set_light(state, x, y, 1);
697 for (i = 0; i < wh; i++) {
698 y = numindices[i] / state->w;
699 x = numindices[i] % state->w;
700 if (!(GRID(state, flags, x, y) & F_LIGHT)) continue;
701 if (GRID(state, flags, x, y) & F_MARK) continue;
702 list_lights(state, x, y, 0, &lld);
704 /* If we're not lighting any lights ourself, don't remove anything. */
706 FOREACHLIT(&lld, if (GRID(state,flags,lx,ly) & F_LIGHT) { n += 1; } );
707 if (n == 0) continue; /* [1] */
709 /* Check whether removing lights we're lighting would cause anything
712 FOREACHLIT(&lld, if (GRID(state,flags,lx,ly) & F_LIGHT) { n += check_dark(state,lx,ly); } );
714 /* No, it wouldn't, so we can remove them all. */
715 FOREACHLIT(&lld, set_light(state,lx,ly, 0); );
716 GRID(state,flags,x,y) |= F_MARK;
719 if (!grid_overlap(state)) {
721 return; /* we're done. */
723 assert(grid_lit(state));
725 /* could get here if the line at [1] continue'd out of the loop. */
726 if (grid_overlap(state)) {
728 assert(!"place_lights failed to resolve overlapping lights!");
732 /* Fills in all black squares with numbers of adjacent lights. */
733 static void place_numbers(game_state *state)
738 for (x = 0; x < state->w; x++) {
739 for (y = 0; y < state->h; y++) {
740 if (!(GRID(state,flags,x,y) & F_BLACK)) continue;
741 get_surrounds(state, x, y, &s);
743 for (i = 0; i < s.npoints; i++) {
744 if (GRID(state,flags,s.points[i].x, s.points[i].y) & F_LIGHT)
747 GRID(state,flags,x,y) |= F_NUMBERED;
748 GRID(state,lights,x,y) = n;
753 /* --- Actual solver, with helper subroutines. --- */
755 static void tsl_callback(game_state *state,
756 int lx, int ly, int *x, int *y, int *n)
758 if (GRID(state,flags,lx,ly) & F_IMPOSSIBLE) return;
759 if (GRID(state,lights,lx,ly) > 0) return;
760 *x = lx; *y = ly; (*n)++;
763 static int try_solve_light(game_state *state, int ox, int oy,
764 unsigned int flags, int lights)
769 if (lights > 0) return 0;
770 if (flags & F_BLACK) return 0;
772 /* We have an unlit square; count how many ways there are left to
773 * place a light that lights us (including this square); if only
774 * one, we must put a light there. Squares that could light us
775 * are, of course, the same as the squares we would light... */
776 list_lights(state, ox, oy, 1, &lld);
777 FOREACHLIT(&lld, { tsl_callback(state, lx, ly, &sx, &sy, &n); });
779 set_light(state, sx, sy, 1);
780 #ifdef SOLVER_DIAGNOSTICS
781 debug(("(%d,%d) can only be lit from (%d,%d); setting to LIGHT\n",
783 if (verbose) debug_state(state);
791 static int could_place_light(unsigned int flags, int lights)
793 if (flags & (F_BLACK | F_IMPOSSIBLE)) return 0;
794 return (lights > 0) ? 0 : 1;
797 static int could_place_light_xy(game_state *state, int x, int y)
799 int lights = GRID(state,lights,x,y);
800 unsigned int flags = GRID(state,flags,x,y);
801 return (could_place_light(flags, lights)) ? 1 : 0;
804 /* For a given number square, determine whether we have enough info
805 * to unambiguously place its lights. */
806 static int try_solve_number(game_state *state, int nx, int ny,
807 unsigned int nflags, int nlights)
810 int x, y, nl, ns, i, ret = 0, lights;
813 if (!(nflags & F_NUMBERED)) return 0;
815 get_surrounds(state,nx,ny,&s);
818 /* nl is no. of lights we need to place, ns is no. of spaces we
819 * have to place them in. Try and narrow these down, and mark
820 * points we can ignore later. */
821 for (i = 0; i < s.npoints; i++) {
822 x = s.points[i].x; y = s.points[i].y;
823 flags = GRID(state,flags,x,y);
824 lights = GRID(state,lights,x,y);
825 if (flags & F_LIGHT) {
826 /* light here already; one less light for one less place. */
828 s.points[i].f |= F_MARK;
829 } else if (!could_place_light(flags, lights)) {
831 s.points[i].f |= F_MARK;
834 if (ns == 0) return 0; /* nowhere to put anything. */
836 /* we have placed all lights we need to around here; all remaining
837 * surrounds are therefore IMPOSSIBLE. */
838 GRID(state,flags,nx,ny) |= F_NUMBERUSED;
839 for (i = 0; i < s.npoints; i++) {
840 if (!(s.points[i].f & F_MARK)) {
841 GRID(state,flags,s.points[i].x,s.points[i].y) |= F_IMPOSSIBLE;
845 #ifdef SOLVER_DIAGNOSTICS
846 printf("Clue at (%d,%d) full; setting unlit to IMPOSSIBLE.\n",
848 if (verbose) debug_state(state);
850 } else if (nl == ns) {
851 /* we have as many lights to place as spaces; fill them all. */
852 GRID(state,flags,nx,ny) |= F_NUMBERUSED;
853 for (i = 0; i < s.npoints; i++) {
854 if (!(s.points[i].f & F_MARK)) {
855 set_light(state, s.points[i].x,s.points[i].y, 1);
859 #ifdef SOLVER_DIAGNOSTICS
860 printf("Clue at (%d,%d) trivial; setting unlit to LIGHT.\n",
862 if (verbose) debug_state(state);
873 #define SCRATCHSZ (state->w+state->h)
875 /* New solver algorithm: overlapping sets can add IMPOSSIBLE flags.
876 * Algorithm thanks to Simon:
878 * (a) Any square where you can place a light has a set of squares
879 * which would become non-lights as a result. (This includes
880 * squares lit by the first square, and can also include squares
881 * adjacent to the same clue square if the new light is the last
882 * one around that clue.) Call this MAKESDARK(x,y) with (x,y) being
883 * the square you place a light.
885 * (b) Any unlit square has a set of squares on which you could place
886 * a light to illuminate it. (Possibly including itself, of
887 * course.) This set of squares has the property that _at least
888 * one_ of them must contain a light. Sets of this type also arise
889 * from clue squares. Call this MAKESLIGHT(x,y), again with (x,y)
890 * the square you would place a light.
892 * (c) If there exists (dx,dy) and (lx,ly) such that MAKESDARK(dx,dy) is
893 * a superset of MAKESLIGHT(lx,ly), this implies that placing a light at
894 * (dx,dy) would either leave no remaining way to illuminate a certain
895 * square, or would leave no remaining way to fulfill a certain clue
896 * (at lx,ly). In either case, a light can be ruled out at that position.
898 * So, we construct all possible MAKESLIGHT sets, both from unlit squares
899 * and clue squares, and then we look for plausible MAKESDARK sets that include
900 * our (lx,ly) to see if we can find a (dx,dy) to rule out. By the time we have
901 * constructed the MAKESLIGHT set we don't care about (lx,ly), just the set
904 * Once we have such a set, Simon came up with a Cunning Plan to find
905 * the most sensible MAKESDARK candidate:
907 * (a) for each square S in your set X, find all the squares which _would_
908 * rule it out. That means any square which would light S, plus
909 * any square adjacent to the same clue square as S (provided
910 * that clue square has only one remaining light to be placed).
911 * It's not hard to make this list. Don't do anything with this
912 * data at the moment except _count_ the squares.
914 * (b) Find the square S_min in the original set which has the
915 * _smallest_ number of other squares which would rule it out.
917 * (c) Find all the squares that rule out S_min (it's probably
918 * better to recompute this than to have stored it during step
919 * (a), since the CPU requirement is modest but the storage
920 * cost would get ugly.) For each of these squares, see if it
921 * rules out everything else in the set X. Any which does can
922 * be marked as not-a-light.
926 typedef void (*trl_cb)(game_state *state, int dx, int dy,
927 struct setscratch *scratch, int n, void *ctx);
929 static void try_rule_out(game_state *state, int x, int y,
930 struct setscratch *scratch, int n,
931 trl_cb cb, void *ctx);
933 static void trl_callback_search(game_state *state, int dx, int dy,
934 struct setscratch *scratch, int n, void *ignored)
938 #ifdef SOLVER_DIAGNOSTICS
939 if (verbose) debug(("discount cb: light at (%d,%d)\n", dx, dy));
942 for (i = 0; i < n; i++) {
943 if (dx == scratch[i].x && dy == scratch[i].y) {
950 static void trl_callback_discount(game_state *state, int dx, int dy,
951 struct setscratch *scratch, int n, void *ctx)
953 int *didsth = (int *)ctx;
956 if (GRID(state,flags,dx,dy) & F_IMPOSSIBLE) {
957 #ifdef SOLVER_DIAGNOSTICS
958 debug(("Square at (%d,%d) already impossible.\n", dx,dy));
963 /* Check whether a light at (dx,dy) rules out everything
964 * in scratch, and mark (dx,dy) as IMPOSSIBLE if it does.
965 * We can use try_rule_out for this as well, as the set of
966 * squares which would rule out (x,y) is the same as the
967 * set of squares which (x,y) would rule out. */
969 #ifdef SOLVER_DIAGNOSTICS
970 if (verbose) debug(("Checking whether light at (%d,%d) rules out everything in scratch.\n", dx, dy));
973 for (i = 0; i < n; i++)
975 try_rule_out(state, dx, dy, scratch, n, trl_callback_search, NULL);
976 for (i = 0; i < n; i++) {
977 if (scratch[i].n == 0) return;
979 /* The light ruled out everything in scratch. Yay. */
980 GRID(state,flags,dx,dy) |= F_IMPOSSIBLE;
981 #ifdef SOLVER_DIAGNOSTICS
982 debug(("Set reduction discounted square at (%d,%d):\n", dx,dy));
983 if (verbose) debug_state(state);
989 static void trl_callback_incn(game_state *state, int dx, int dy,
990 struct setscratch *scratch, int n, void *ctx)
992 struct setscratch *s = (struct setscratch *)ctx;
996 static void try_rule_out(game_state *state, int x, int y,
997 struct setscratch *scratch, int n,
998 trl_cb cb, void *ctx)
1000 /* XXX Find all the squares which would rule out (x,y); anything
1001 * that would light it as well as squares adjacent to same clues
1002 * as X assuming that clue only has one remaining light.
1003 * Call the callback with each square. */
1006 int i, j, curr_lights, tot_lights;
1008 /* Find all squares that would rule out a light at (x,y) and call trl_cb
1009 * with them: anything that would light (x,y)... */
1011 list_lights(state, x, y, 0, &lld);
1012 FOREACHLIT(&lld, { if (could_place_light_xy(state, lx, ly)) { cb(state, lx, ly, scratch, n, ctx); } });
1014 /* ... as well as any empty space (that isn't x,y) next to any clue square
1015 * next to (x,y) that only has one light left to place. */
1017 get_surrounds(state, x, y, &s);
1018 for (i = 0; i < s.npoints; i++) {
1019 if (!GRID(state,flags,s.points[i].x,s.points[i].y) & F_NUMBERED)
1021 /* we have an adjacent clue square; find /it's/ surrounds
1022 * and count the remaining lights it needs. */
1023 get_surrounds(state,s.points[i].x,s.points[i].y,&ss);
1025 for (j = 0; j < ss.npoints; j++) {
1026 if (GRID(state,flags,ss.points[j].x,ss.points[j].y) & F_LIGHT)
1029 tot_lights = GRID(state, lights, s.points[i].x, s.points[i].y);
1030 /* We have a clue with tot_lights to fill, and curr_lights currently
1031 * around it. If adding a light at (x,y) fills up the clue (i.e.
1032 * curr_lights + 1 = tot_lights) then we need to discount all other
1033 * unlit squares around the clue. */
1034 if ((curr_lights + 1) == tot_lights) {
1035 for (j = 0; j < ss.npoints; j++) {
1036 int lx = ss.points[j].x, ly = ss.points[j].y;
1037 if (lx == x && ly == y) continue;
1038 if (could_place_light_xy(state, lx, ly))
1039 cb(state, lx, ly, scratch, n, ctx);
1045 #ifdef SOLVER_DIAGNOSTICS
1046 static void debug_scratch(const char *msg, struct setscratch *scratch, int n)
1049 debug(("%s scratch (%d elements):\n", msg, n));
1050 for (i = 0; i < n; i++) {
1051 debug((" (%d,%d) n%d\n", scratch[i].x, scratch[i].y, scratch[i].n));
1056 static int discount_set(game_state *state,
1057 struct setscratch *scratch, int n)
1059 int i, besti, bestn, didsth = 0;
1061 #ifdef SOLVER_DIAGNOSTICS
1062 if (verbose > 1) debug_scratch("discount_set", scratch, n);
1064 if (n == 0) return 0;
1066 for (i = 0; i < n; i++) {
1067 try_rule_out(state, scratch[i].x, scratch[i].y, scratch, n,
1068 trl_callback_incn, (void*)&(scratch[i]));
1070 #ifdef SOLVER_DIAGNOSTICS
1071 if (verbose > 1) debug_scratch("discount_set after count", scratch, n);
1074 besti = -1; bestn = SCRATCHSZ;
1075 for (i = 0; i < n; i++) {
1076 if (scratch[i].n < bestn) {
1077 bestn = scratch[i].n;
1081 #ifdef SOLVER_DIAGNOSTICS
1082 if (verbose > 1) debug(("best square (%d,%d) with n%d.\n",
1083 scratch[besti].x, scratch[besti].y, scratch[besti].n));
1085 try_rule_out(state, scratch[besti].x, scratch[besti].y, scratch, n,
1086 trl_callback_discount, (void*)&didsth);
1087 #ifdef SOLVER_DIAGNOSTICS
1088 if (didsth) debug((" [from square (%d,%d)]\n",
1089 scratch[besti].x, scratch[besti].y));
1095 static void discount_clear(game_state *state, struct setscratch *scratch, int *n)
1098 memset(scratch, 0, SCRATCHSZ * sizeof(struct setscratch));
1101 static void unlit_cb(game_state *state, int lx, int ly,
1102 struct setscratch *scratch, int *n)
1104 if (could_place_light_xy(state, lx, ly)) {
1105 scratch[*n].x = lx; scratch[*n].y = ly; (*n)++;
1109 /* Construct a MAKESLIGHT set from an unlit square. */
1110 static int discount_unlit(game_state *state, int x, int y,
1111 struct setscratch *scratch)
1116 #ifdef SOLVER_DIAGNOSTICS
1117 if (verbose) debug(("Trying to discount for unlit square at (%d,%d).\n", x, y));
1118 if (verbose > 1) debug_state(state);
1121 discount_clear(state, scratch, &n);
1123 list_lights(state, x, y, 1, &lld);
1124 FOREACHLIT(&lld, { unlit_cb(state, lx, ly, scratch, &n); });
1125 didsth = discount_set(state, scratch, n);
1126 #ifdef SOLVER_DIAGNOSTICS
1127 if (didsth) debug((" [from unlit square at (%d,%d)].\n", x, y));
1133 /* Construct a series of MAKESLIGHT sets from a clue square.
1134 * for a clue square with N remaining spaces that must contain M lights, every
1135 * subset of size N-M+1 of those N spaces forms such a set.
1138 static int discount_clue(game_state *state, int x, int y,
1139 struct setscratch *scratch)
1141 int slen, m = GRID(state, lights, x, y), n, i, didsth = 0, lights;
1143 surrounds s, sempty;
1146 if (m == 0) return 0;
1148 #ifdef SOLVER_DIAGNOSTICS
1149 if (verbose) debug(("Trying to discount for sets at clue (%d,%d).\n", x, y));
1150 if (verbose > 1) debug_state(state);
1153 /* m is no. of lights still to place; starts off at the clue value
1154 * and decreases when we find a light already down.
1155 * n is no. of spaces left; starts off at 0 and goes up when we find
1156 * a plausible space. */
1158 get_surrounds(state, x, y, &s);
1159 memset(&sempty, 0, sizeof(surrounds));
1160 for (i = 0; i < s.npoints; i++) {
1161 int lx = s.points[i].x, ly = s.points[i].y;
1162 flags = GRID(state,flags,lx,ly);
1163 lights = GRID(state,lights,lx,ly);
1165 if (flags & F_LIGHT) m--;
1167 if (could_place_light(flags, lights)) {
1168 sempty.points[sempty.npoints].x = lx;
1169 sempty.points[sempty.npoints].y = ly;
1173 n = sempty.npoints; /* sempty is now a surrounds of only blank squares. */
1174 if (n == 0) return 0; /* clue is full already. */
1176 if (m < 0 || m > n) return 0; /* become impossible. */
1178 combi = new_combi(n - m + 1, n);
1179 while (next_combi(combi)) {
1180 discount_clear(state, scratch, &slen);
1181 for (i = 0; i < combi->r; i++) {
1182 scratch[slen].x = sempty.points[combi->a[i]].x;
1183 scratch[slen].y = sempty.points[combi->a[i]].y;
1186 if (discount_set(state, scratch, slen)) didsth = 1;
1189 #ifdef SOLVER_DIAGNOSTICS
1190 if (didsth) debug((" [from clue at (%d,%d)].\n", x, y));
1195 #define F_SOLVE_FORCEUNIQUE 1
1196 #define F_SOLVE_DISCOUNTSETS 2
1197 #define F_SOLVE_ALLOWRECURSE 4
1199 static unsigned int flags_from_difficulty(int difficulty)
1201 unsigned int sflags = F_SOLVE_FORCEUNIQUE;
1202 assert(difficulty <= DIFFCOUNT);
1203 if (difficulty >= 1) sflags |= F_SOLVE_DISCOUNTSETS;
1204 if (difficulty >= 2) sflags |= F_SOLVE_ALLOWRECURSE;
1208 #define MAXRECURSE 5
1210 static int solve_sub(game_state *state,
1211 unsigned int solve_flags, int depth,
1215 int x, y, didstuff, ncanplace, lights;
1216 int bestx, besty, n, bestn, copy_soluble, self_soluble, ret, maxrecurse = 0;
1219 struct setscratch *sscratch = NULL;
1221 #ifdef SOLVER_DIAGNOSTICS
1222 printf("solve_sub: depth = %d\n", depth);
1224 if (maxdepth && *maxdepth < depth) *maxdepth = depth;
1225 if (solve_flags & F_SOLVE_ALLOWRECURSE) maxrecurse = MAXRECURSE;
1228 if (grid_overlap(state)) {
1229 /* Our own solver, from scratch, should never cause this to happen
1230 * (assuming a soluble grid). However, if we're trying to solve
1231 * from a half-completed *incorrect* grid this might occur; we
1232 * just return the 'no solutions' code in this case. */
1236 if (grid_correct(state)) { ret = 1; goto done; }
1240 /* These 2 loops, and the functions they call, are the critical loops
1241 * for timing; any optimisations should look here first. */
1242 for (x = 0; x < state->w; x++) {
1243 for (y = 0; y < state->h; y++) {
1244 flags = GRID(state,flags,x,y);
1245 lights = GRID(state,lights,x,y);
1246 ncanplace += could_place_light(flags, lights);
1248 if (try_solve_light(state, x, y, flags, lights)) didstuff = 1;
1249 if (try_solve_number(state, x, y, flags, lights)) didstuff = 1;
1252 if (didstuff) continue;
1254 /* nowhere to put a light, puzzle is unsoluble. */
1258 if (solve_flags & F_SOLVE_DISCOUNTSETS) {
1259 if (!sscratch) sscratch = snewn(SCRATCHSZ, struct setscratch);
1260 /* Try a more cunning (and more involved) way... more details above. */
1261 for (x = 0; x < state->w; x++) {
1262 for (y = 0; y < state->h; y++) {
1263 flags = GRID(state,flags,x,y);
1264 lights = GRID(state,lights,x,y);
1266 if (!(flags & F_BLACK) && lights == 0) {
1267 if (discount_unlit(state, x, y, sscratch)) {
1269 goto reduction_success;
1271 } else if (flags & F_NUMBERED) {
1272 if (discount_clue(state, x, y, sscratch)) {
1274 goto reduction_success;
1281 if (didstuff) continue;
1283 /* We now have to make a guess; we have places to put lights but
1284 * no definite idea about where they can go. */
1285 if (depth >= maxrecurse) {
1286 /* mustn't delve any deeper. */
1287 ret = -1; goto done;
1289 /* Of all the squares that we could place a light, pick the one
1290 * that would light the most currently unlit squares. */
1291 /* This heuristic was just plucked from the air; there may well be
1292 * a more efficient way of choosing a square to flip to minimise
1295 bestx = besty = -1; /* suyb */
1296 for (x = 0; x < state->w; x++) {
1297 for (y = 0; y < state->h; y++) {
1298 flags = GRID(state,flags,x,y);
1299 lights = GRID(state,lights,x,y);
1300 if (!could_place_light(flags, lights)) continue;
1303 list_lights(state, x, y, 1, &lld);
1304 FOREACHLIT(&lld, { if (GRID(state,lights,lx,ly) == 0) n++; });
1306 bestn = n; bestx = x; besty = y;
1311 assert(bestx >= 0 && besty >= 0);
1313 /* Now we've chosen a plausible (x,y), try to solve it once as 'lit'
1314 * and once as 'impossible'; we need to make one copy to do this. */
1316 scopy = dup_game(state);
1317 #ifdef SOLVER_DIAGNOSTICS
1318 debug(("Recursing #1: trying (%d,%d) as IMPOSSIBLE\n", bestx, besty));
1320 GRID(state,flags,bestx,besty) |= F_IMPOSSIBLE;
1321 self_soluble = solve_sub(state, solve_flags, depth+1, maxdepth);
1323 if (!(solve_flags & F_SOLVE_FORCEUNIQUE) && self_soluble > 0) {
1324 /* we didn't care about finding all solutions, and we just
1325 * found one; return with it immediately. */
1331 #ifdef SOLVER_DIAGNOSTICS
1332 debug(("Recursing #2: trying (%d,%d) as LIGHT\n", bestx, besty));
1334 set_light(scopy, bestx, besty, 1);
1335 copy_soluble = solve_sub(scopy, solve_flags, depth+1, maxdepth);
1337 /* If we wanted a unique solution but we hit our recursion limit
1338 * (on either branch) then we have to assume we didn't find possible
1339 * extra solutions, and return 'not soluble'. */
1340 if ((solve_flags & F_SOLVE_FORCEUNIQUE) &&
1341 ((copy_soluble < 0) || (self_soluble < 0))) {
1343 /* Make sure that whether or not it was self or copy (or both) that
1344 * were soluble, that we return a solved state in self. */
1345 } else if (copy_soluble <= 0) {
1346 /* copy wasn't soluble; keep self state and return that result. */
1348 } else if (self_soluble <= 0) {
1349 /* copy solved and we didn't, so copy in copy's (now solved)
1350 * flags and light state. */
1351 memcpy(state->lights, scopy->lights,
1352 scopy->w * scopy->h * sizeof(int));
1353 memcpy(state->flags, scopy->flags,
1354 scopy->w * scopy->h * sizeof(unsigned int));
1357 ret = copy_soluble + self_soluble;
1363 if (sscratch) sfree(sscratch);
1364 #ifdef SOLVER_DIAGNOSTICS
1366 debug(("solve_sub: depth = %d returning, ran out of recursion.\n",
1369 debug(("solve_sub: depth = %d returning, %d solutions.\n",
1375 /* Fills in the (possibly partially-complete) game_state as far as it can,
1376 * returning the number of possible solutions. If it returns >0 then the
1377 * game_state will be in a solved state, but you won't know which one. */
1378 static int dosolve(game_state *state, int solve_flags, int *maxdepth)
1382 for (x = 0; x < state->w; x++) {
1383 for (y = 0; y < state->h; y++) {
1384 GRID(state,flags,x,y) &= ~F_NUMBERUSED;
1387 nsol = solve_sub(state, solve_flags, 0, maxdepth);
1391 static int strip_unused_nums(game_state *state)
1394 for (x = 0; x < state->w; x++) {
1395 for (y = 0; y < state->h; y++) {
1396 if ((GRID(state,flags,x,y) & F_NUMBERED) &&
1397 !(GRID(state,flags,x,y) & F_NUMBERUSED)) {
1398 GRID(state,flags,x,y) &= ~F_NUMBERED;
1399 GRID(state,lights,x,y) = 0;
1407 static void unplace_lights(game_state *state)
1410 for (x = 0; x < state->w; x++) {
1411 for (y = 0; y < state->h; y++) {
1412 if (GRID(state,flags,x,y) & F_LIGHT)
1413 set_light(state,x,y,0);
1414 GRID(state,flags,x,y) &= ~F_IMPOSSIBLE;
1415 GRID(state,flags,x,y) &= ~F_NUMBERUSED;
1420 static int puzzle_is_good(game_state *state, int difficulty)
1422 int nsol, mdepth = 0;
1423 unsigned int sflags = flags_from_difficulty(difficulty);
1425 unplace_lights(state);
1427 #ifdef SOLVER_DIAGNOSTICS
1428 debug(("Trying to solve with difficulty %d (0x%x):\n",
1429 difficulty, sflags));
1430 if (verbose) debug_state(state);
1433 nsol = dosolve(state, sflags, &mdepth);
1434 /* if we wanted an easy puzzle, make sure we didn't need recursion. */
1435 if (!(sflags & F_SOLVE_ALLOWRECURSE) && mdepth > 0) {
1436 debug(("Ignoring recursive puzzle.\n"));
1440 debug(("%d solutions found.\n", nsol));
1441 if (nsol <= 0) return 0;
1442 if (nsol > 1) return 0;
1446 /* --- New game creation and user input code. --- */
1448 /* The basic algorithm here is to generate the most complex grid possible
1449 * while honouring two restrictions:
1451 * * we require a unique solution, and
1452 * * either we require solubility with no recursion (!params->recurse)
1453 * * or we require some recursion. (params->recurse).
1455 * The solver helpfully keeps track of the numbers it needed to use to
1456 * get its solution, so we use that to remove an initial set of numbers
1457 * and check we still satsify our requirements (on uniqueness and
1458 * non-recursiveness, if applicable; we don't check explicit recursiveness
1461 * Then we try to remove all numbers in a random order, and see if we
1462 * still satisfy requirements (putting them back if we didn't).
1464 * Removing numbers will always, in general terms, make a puzzle require
1465 * more recursion but it may also mean a puzzle becomes non-unique.
1467 * Once we're done, if we wanted a recursive puzzle but the most difficult
1468 * puzzle we could come up with was non-recursive, we give up and try a new
1471 #define MAX_GRIDGEN_TRIES 20
1473 static char *new_game_desc(game_params *params, random_state *rs,
1474 char **aux, int interactive)
1476 game_state *news = new_state(params), *copys;
1477 int nsol, i, j, run, x, y, wh = params->w*params->h, num;
1481 /* Construct a shuffled list of grid positions; we only
1482 * do this once, because if it gets used more than once it'll
1483 * be on a different grid layout. */
1484 numindices = snewn(wh, int);
1485 for (j = 0; j < wh; j++) numindices[j] = j;
1486 shuffle(numindices, wh, sizeof(*numindices), rs);
1489 for (i = 0; i < MAX_GRIDGEN_TRIES; i++) {
1490 set_blacks(news, params, rs); /* also cleans board. */
1492 /* set up lights and then the numbers, and remove the lights */
1493 place_lights(news, rs);
1494 debug(("Generating initial grid.\n"));
1495 place_numbers(news);
1496 if (!puzzle_is_good(news, params->difficulty)) continue;
1498 /* Take a copy, remove numbers we didn't use and check there's
1499 * still a unique solution; if so, use the copy subsequently. */
1500 copys = dup_game(news);
1501 nsol = strip_unused_nums(copys);
1502 debug(("Stripped %d unused numbers.\n", nsol));
1503 if (!puzzle_is_good(copys, params->difficulty)) {
1504 debug(("Stripped grid is not good, reverting.\n"));
1511 /* Go through grid removing numbers at random one-by-one and
1512 * trying to solve again; if it ceases to be good put the number back. */
1513 for (j = 0; j < wh; j++) {
1514 y = numindices[j] / params->w;
1515 x = numindices[j] % params->w;
1516 if (!(GRID(news, flags, x, y) & F_NUMBERED)) continue;
1517 num = GRID(news, lights, x, y);
1518 GRID(news, lights, x, y) = 0;
1519 GRID(news, flags, x, y) &= ~F_NUMBERED;
1520 if (!puzzle_is_good(news, params->difficulty)) {
1521 GRID(news, lights, x, y) = num;
1522 GRID(news, flags, x, y) |= F_NUMBERED;
1524 debug(("Removed (%d,%d) still soluble.\n", x, y));
1526 if (params->difficulty > 0) {
1527 /* Was the maximally-difficult puzzle difficult enough?
1528 * Check we can't solve it with a more simplistic solver. */
1529 if (puzzle_is_good(news, params->difficulty-1)) {
1530 debug(("Maximally-hard puzzle still not hard enough, skipping.\n"));
1537 /* Couldn't generate a good puzzle in however many goes. Ramp up the
1538 * %age of black squares (if we didn't already have lots; in which case
1539 * why couldn't we generate a puzzle?) and try again. */
1540 if (params->blackpc < 90) params->blackpc += 5;
1541 debug(("New black layout %d%%.\n", params->blackpc));
1544 /* Game is encoded as a long string one character per square;
1546 * 'B' is a black square with no number
1547 * '0', '1', '2', '3', '4' is a black square with a number. */
1548 ret = snewn((params->w * params->h) + 1, char);
1551 for (y = 0; y < params->h; y++) {
1552 for (x = 0; x < params->w; x++) {
1553 if (GRID(news,flags,x,y) & F_BLACK) {
1555 *p++ = ('a'-1) + run;
1558 if (GRID(news,flags,x,y) & F_NUMBERED)
1559 *p++ = '0' + GRID(news,lights,x,y);
1564 *p++ = ('a'-1) + run;
1572 *p++ = ('a'-1) + run;
1576 assert(p - ret <= params->w * params->h);
1583 static char *validate_desc(game_params *params, char *desc)
1586 for (i = 0; i < params->w*params->h; i++) {
1587 if (*desc >= '0' && *desc <= '4')
1589 else if (*desc == 'B')
1591 else if (*desc >= 'a' && *desc <= 'z')
1592 i += *desc - 'a'; /* and the i++ will add another one */
1594 return "Game description shorter than expected";
1596 return "Game description contained unexpected character";
1599 if (*desc || i > params->w*params->h)
1600 return "Game description longer than expected";
1605 static game_state *new_game(midend *me, game_params *params, char *desc)
1607 game_state *ret = new_state(params);
1611 for (y = 0; y < params->h; y++) {
1612 for (x = 0; x < params->w; x++) {
1618 if (c >= 'a' && c <= 'z')
1628 case '0': case '1': case '2': case '3': case '4':
1629 GRID(ret,flags,x,y) |= F_NUMBERED;
1630 GRID(ret,lights,x,y) = (c - '0');
1634 GRID(ret,flags,x,y) |= F_BLACK;
1642 assert(!"Malformed desc.");
1647 if (*desc) assert(!"Over-long desc.");
1652 static char *solve_game(game_state *state, game_state *currstate,
1653 char *aux, char **error)
1656 char *move = NULL, buf[80];
1657 int movelen, movesize, x, y, len;
1658 unsigned int oldflags, solvedflags, sflags;
1660 /* We don't care here about non-unique puzzles; if the
1661 * user entered one themself then I doubt they care. */
1663 sflags = F_SOLVE_ALLOWRECURSE | F_SOLVE_DISCOUNTSETS;
1665 /* Try and solve from where we are now (for non-unique
1666 * puzzles this may produce a different answer). */
1667 solved = dup_game(currstate);
1668 if (dosolve(solved, sflags, NULL) > 0) goto solved;
1671 /* That didn't work; try solving from the clean puzzle. */
1672 solved = dup_game(state);
1673 if (dosolve(solved, sflags, NULL) > 0) goto solved;
1674 *error = "Puzzle is not self-consistent.";
1679 move = snewn(movesize, char);
1681 move[movelen++] = 'S';
1682 move[movelen] = '\0';
1683 for (x = 0; x < currstate->w; x++) {
1684 for (y = 0; y < currstate->h; y++) {
1686 oldflags = GRID(currstate, flags, x, y);
1687 solvedflags = GRID(solved, flags, x, y);
1688 if ((oldflags & F_LIGHT) != (solvedflags & F_LIGHT))
1689 len = sprintf(buf, ";L%d,%d", x, y);
1690 else if ((oldflags & F_IMPOSSIBLE) != (solvedflags & F_IMPOSSIBLE))
1691 len = sprintf(buf, ";I%d,%d", x, y);
1693 if (movelen + len >= movesize) {
1694 movesize = movelen + len + 256;
1695 move = sresize(move, movesize, char);
1697 strcpy(move + movelen, buf);
1708 /* 'borrowed' from slant.c, mainly. I could have printed it one
1709 * character per cell (like debug_state) but that comes out tiny.
1710 * 'L' is used for 'light here' because 'O' looks too much like '0'
1711 * (black square with no surrounding lights). */
1712 static char *game_text_format(game_state *state)
1714 int w = state->w, h = state->h, W = w+1, H = h+1;
1715 int x, y, len, lights;
1719 len = (h+H) * (w+W+1) + 1;
1720 ret = snewn(len, char);
1723 for (y = 0; y < H; y++) {
1724 for (x = 0; x < W; x++) {
1731 for (x = 0; x < W; x++) {
1734 /* actual interesting bit. */
1735 flags = GRID(state, flags, x, y);
1736 lights = GRID(state, lights, x, y);
1737 if (flags & F_BLACK) {
1738 if (flags & F_NUMBERED)
1739 *p++ = '0' + lights;
1743 if (flags & F_LIGHT)
1745 else if (flags & F_IMPOSSIBLE)
1747 else if (lights > 0)
1759 assert(p - ret == len);
1764 int cur_x, cur_y, cur_visible;
1767 static game_ui *new_ui(game_state *state)
1769 game_ui *ui = snew(game_ui);
1770 ui->cur_x = ui->cur_y = ui->cur_visible = 0;
1774 static void free_ui(game_ui *ui)
1779 static char *encode_ui(game_ui *ui)
1781 /* nothing to encode. */
1785 static void decode_ui(game_ui *ui, char *encoding)
1787 /* nothing to decode. */
1790 static void game_changed_state(game_ui *ui, game_state *oldstate,
1791 game_state *newstate)
1793 if (newstate->completed)
1794 ui->cur_visible = 0;
1797 #define DF_BLACK 1 /* black square */
1798 #define DF_NUMBERED 2 /* black square with number */
1799 #define DF_LIT 4 /* display (white) square lit up */
1800 #define DF_LIGHT 8 /* display light in square */
1801 #define DF_OVERLAP 16 /* display light as overlapped */
1802 #define DF_CURSOR 32 /* display cursor */
1803 #define DF_NUMBERWRONG 64 /* display black numbered square as error. */
1804 #define DF_FLASH 128 /* background flash is on. */
1805 #define DF_IMPOSSIBLE 256 /* display non-light little square */
1807 struct game_drawstate {
1810 unsigned int *flags; /* width * height */
1815 /* Believe it or not, this empty = "" hack is needed to get around a bug in
1816 * the prc-tools gcc when optimisation is turned on; before, it produced:
1817 lightup-sect.c: In function `interpret_move':
1818 lightup-sect.c:1416: internal error--unrecognizable insn:
1819 (insn 582 580 583 (set (reg:SI 134)
1823 static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
1824 int x, int y, int button)
1826 enum { NONE, FLIP_LIGHT, FLIP_IMPOSSIBLE } action = NONE;
1827 int cx = -1, cy = -1;
1829 char buf[80], *nullret = NULL, *empty = "", c;
1831 if (button == LEFT_BUTTON || button == RIGHT_BUTTON) {
1832 if (ui->cur_visible)
1834 ui->cur_visible = 0;
1837 action = (button == LEFT_BUTTON) ? FLIP_LIGHT : FLIP_IMPOSSIBLE;
1838 } else if (button == CURSOR_SELECT ||
1839 button == 'i' || button == 'I' ||
1840 button == ' ' || button == '\r' || button == '\n') {
1841 ui->cur_visible = 1;
1844 action = (button == 'i' || button == 'I') ?
1845 FLIP_IMPOSSIBLE : FLIP_LIGHT;
1846 } else if (button == CURSOR_UP || button == CURSOR_DOWN ||
1847 button == CURSOR_RIGHT || button == CURSOR_LEFT) {
1850 case CURSOR_UP: dy = -1; break;
1851 case CURSOR_DOWN: dy = 1; break;
1852 case CURSOR_RIGHT: dx = 1; break;
1853 case CURSOR_LEFT: dx = -1; break;
1854 default: assert(!"shouldn't get here");
1856 ui->cur_x += dx; ui->cur_y += dy;
1857 ui->cur_x = min(max(ui->cur_x, 0), state->w - 1);
1858 ui->cur_y = min(max(ui->cur_y, 0), state->h - 1);
1859 ui->cur_visible = 1;
1866 case FLIP_IMPOSSIBLE:
1867 if (cx < 0 || cy < 0 || cx >= state->w || cy >= state->h)
1869 flags = GRID(state, flags, cx, cy);
1870 if (flags & F_BLACK)
1872 if (action == FLIP_LIGHT) {
1873 if (flags & F_IMPOSSIBLE) return nullret;
1876 if (flags & F_LIGHT) return nullret;
1879 sprintf(buf, "%c%d,%d", (int)c, cx, cy);
1886 assert(!"Shouldn't get here!");
1891 static game_state *execute_move(game_state *state, char *move)
1893 game_state *ret = dup_game(state);
1897 if (!*move) goto badmove;
1902 ret->used_solve = TRUE;
1904 } else if (c == 'L' || c == 'I') {
1906 if (sscanf(move, "%d,%d%n", &x, &y, &n) != 2 ||
1907 x < 0 || y < 0 || x >= ret->w || y >= ret->h)
1910 flags = GRID(ret, flags, x, y);
1911 if (flags & F_BLACK) goto badmove;
1913 /* LIGHT and IMPOSSIBLE are mutually exclusive. */
1915 GRID(ret, flags, x, y) &= ~F_IMPOSSIBLE;
1916 set_light(ret, x, y, (flags & F_LIGHT) ? 0 : 1);
1918 set_light(ret, x, y, 0);
1919 GRID(ret, flags, x, y) ^= F_IMPOSSIBLE;
1922 } else goto badmove;
1926 else if (*move) goto badmove;
1928 if (grid_correct(ret)) ret->completed = 1;
1936 /* ----------------------------------------------------------------------
1940 /* XXX entirely cloned from fifteen.c; separate out? */
1941 static void game_compute_size(game_params *params, int tilesize,
1944 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
1945 struct { int tilesize; } ads, *ds = &ads;
1946 ads.tilesize = tilesize;
1948 *x = TILE_SIZE * params->w + 2 * BORDER;
1949 *y = TILE_SIZE * params->h + 2 * BORDER;
1952 static void game_set_size(drawing *dr, game_drawstate *ds,
1953 game_params *params, int tilesize)
1955 ds->tilesize = tilesize;
1956 ds->crad = 3*(tilesize-1)/8;
1959 static float *game_colours(frontend *fe, game_state *state, int *ncolours)
1961 float *ret = snewn(3 * NCOLOURS, float);
1964 frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
1966 for (i = 0; i < 3; i++) {
1967 ret[COL_BLACK * 3 + i] = 0.0F;
1968 ret[COL_LIGHT * 3 + i] = 1.0F;
1969 ret[COL_CURSOR * 3 + i] = ret[COL_BACKGROUND * 3 + i] / 2.0F;
1970 ret[COL_GRID * 3 + i] = ret[COL_BACKGROUND * 3 + i] / 1.5F;
1974 ret[COL_ERROR * 3 + 0] = 1.0F;
1975 ret[COL_ERROR * 3 + 1] = 0.25F;
1976 ret[COL_ERROR * 3 + 2] = 0.25F;
1978 ret[COL_LIT * 3 + 0] = 1.0F;
1979 ret[COL_LIT * 3 + 1] = 1.0F;
1980 ret[COL_LIT * 3 + 2] = 0.0F;
1982 *ncolours = NCOLOURS;
1986 static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
1988 struct game_drawstate *ds = snew(struct game_drawstate);
1991 ds->tilesize = ds->crad = 0;
1992 ds->w = state->w; ds->h = state->h;
1994 ds->flags = snewn(ds->w*ds->h, unsigned int);
1995 for (i = 0; i < ds->w*ds->h; i++)
2003 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
2009 /* At some stage we should put these into a real options struct.
2010 * Note that tile_redraw has no #ifdeffery; it relies on tile_flags not
2011 * to put those flags in. */
2013 #define HINT_OVERLAPS
2014 #define HINT_NUMBERS
2016 static unsigned int tile_flags(game_drawstate *ds, game_state *state, game_ui *ui,
2017 int x, int y, int flashing)
2019 unsigned int flags = GRID(state, flags, x, y);
2020 int lights = GRID(state, lights, x, y);
2021 unsigned int ret = 0;
2023 if (flashing) ret |= DF_FLASH;
2024 if (ui && ui->cur_visible && x == ui->cur_x && y == ui->cur_y)
2027 if (flags & F_BLACK) {
2029 if (flags & F_NUMBERED) {
2031 if (number_wrong(state, x, y))
2032 ret |= DF_NUMBERWRONG;
2038 if (lights > 0) ret |= DF_LIT;
2040 if (flags & F_LIGHT) {
2042 #ifdef HINT_OVERLAPS
2043 if (lights > 1) ret |= DF_OVERLAP;
2046 if (flags & F_IMPOSSIBLE) ret |= DF_IMPOSSIBLE;
2051 static void tile_redraw(drawing *dr, game_drawstate *ds, game_state *state,
2054 unsigned int ds_flags = GRID(ds, flags, x, y);
2055 int dx = COORD(x), dy = COORD(y);
2056 int lit = (ds_flags & DF_FLASH) ? COL_GRID : COL_LIT;
2058 if (ds_flags & DF_BLACK) {
2059 draw_rect(dr, dx, dy, TILE_SIZE, TILE_SIZE, COL_BLACK);
2060 if (ds_flags & DF_NUMBERED) {
2061 int ccol = (ds_flags & DF_NUMBERWRONG) ? COL_ERROR : COL_LIGHT;
2064 /* We know that this won't change over the course of the game
2065 * so it's OK to ignore this when calculating whether or not
2066 * to redraw the tile. */
2067 sprintf(str, "%d", GRID(state, lights, x, y));
2068 draw_text(dr, dx + TILE_SIZE/2, dy + TILE_SIZE/2,
2069 FONT_VARIABLE, TILE_SIZE*3/5,
2070 ALIGN_VCENTRE | ALIGN_HCENTRE, ccol, str);
2073 draw_rect(dr, dx, dy, TILE_SIZE, TILE_SIZE,
2074 (ds_flags & DF_LIT) ? lit : COL_BACKGROUND);
2075 draw_rect_outline(dr, dx, dy, TILE_SIZE, TILE_SIZE, COL_GRID);
2076 if (ds_flags & DF_LIGHT) {
2077 int lcol = (ds_flags & DF_OVERLAP) ? COL_ERROR : COL_LIGHT;
2078 draw_circle(dr, dx + TILE_SIZE/2, dy + TILE_SIZE/2, TILE_RADIUS,
2080 } else if (ds_flags & DF_IMPOSSIBLE) {
2081 int rlen = TILE_SIZE / 4;
2082 draw_rect(dr, dx + TILE_SIZE/2 - rlen/2, dy + TILE_SIZE/2 - rlen/2,
2083 rlen, rlen, COL_BLACK);
2087 if (ds_flags & DF_CURSOR) {
2088 int coff = TILE_SIZE/8;
2089 draw_rect_outline(dr, dx + coff, dy + coff,
2090 TILE_SIZE - coff*2, TILE_SIZE - coff*2, COL_CURSOR);
2093 draw_update(dr, dx, dy, TILE_SIZE, TILE_SIZE);
2096 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
2097 game_state *state, int dir, game_ui *ui,
2098 float animtime, float flashtime)
2100 int flashing = FALSE;
2103 if (flashtime) flashing = (int)(flashtime * 3 / FLASH_TIME) != 1;
2107 TILE_SIZE * ds->w + 2 * BORDER,
2108 TILE_SIZE * ds->h + 2 * BORDER, COL_BACKGROUND);
2110 draw_rect_outline(dr, COORD(0)-1, COORD(0)-1,
2111 TILE_SIZE * ds->w + 2,
2112 TILE_SIZE * ds->h + 2,
2115 draw_update(dr, 0, 0,
2116 TILE_SIZE * ds->w + 2 * BORDER,
2117 TILE_SIZE * ds->h + 2 * BORDER);
2121 for (x = 0; x < ds->w; x++) {
2122 for (y = 0; y < ds->h; y++) {
2123 unsigned int ds_flags = tile_flags(ds, state, ui, x, y, flashing);
2124 if (ds_flags != GRID(ds, flags, x, y)) {
2125 GRID(ds, flags, x, y) = ds_flags;
2126 tile_redraw(dr, ds, state, x, y);
2132 static float game_anim_length(game_state *oldstate, game_state *newstate,
2133 int dir, game_ui *ui)
2138 static float game_flash_length(game_state *oldstate, game_state *newstate,
2139 int dir, game_ui *ui)
2141 if (!oldstate->completed && newstate->completed &&
2142 !oldstate->used_solve && !newstate->used_solve)
2147 static int game_wants_statusbar(void)
2152 static int game_timing_state(game_state *state, game_ui *ui)
2157 static void game_print_size(game_params *params, float *x, float *y)
2162 * I'll use 6mm squares by default.
2164 game_compute_size(params, 600, &pw, &ph);
2169 static void game_print(drawing *dr, game_state *state, int tilesize)
2171 int w = state->w, h = state->h;
2172 int ink = print_mono_colour(dr, 0);
2173 int paper = print_mono_colour(dr, 1);
2176 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2177 game_drawstate ads, *ds = &ads;
2178 ads.tilesize = tilesize;
2179 ds->crad = 3*(tilesize-1)/8;
2184 print_line_width(dr, TILE_SIZE / 16);
2185 draw_rect_outline(dr, COORD(0), COORD(0),
2186 TILE_SIZE * w, TILE_SIZE * h, ink);
2191 print_line_width(dr, TILE_SIZE / 24);
2192 for (x = 1; x < w; x++)
2193 draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h), ink);
2194 for (y = 1; y < h; y++)
2195 draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y), ink);
2200 for (y = 0; y < h; y++)
2201 for (x = 0; x < w; x++) {
2202 unsigned int ds_flags = tile_flags(ds, state, NULL, x, y, FALSE);
2203 int dx = COORD(x), dy = COORD(y);
2204 if (ds_flags & DF_BLACK) {
2205 draw_rect(dr, dx, dy, TILE_SIZE, TILE_SIZE, ink);
2206 if (ds_flags & DF_NUMBERED) {
2208 sprintf(str, "%d", GRID(state, lights, x, y));
2209 draw_text(dr, dx + TILE_SIZE/2, dy + TILE_SIZE/2,
2210 FONT_VARIABLE, TILE_SIZE*3/5,
2211 ALIGN_VCENTRE | ALIGN_HCENTRE, paper, str);
2213 } else if (ds_flags & DF_LIGHT) {
2214 draw_circle(dr, dx + TILE_SIZE/2, dy + TILE_SIZE/2,
2215 TILE_RADIUS, -1, ink);
2221 #define thegame lightup
2224 const struct game thegame = {
2225 "Light Up", "games.lightup",
2232 TRUE, game_configure, custom_params,
2240 TRUE, game_text_format,
2248 PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
2251 game_free_drawstate,
2255 TRUE, FALSE, game_print_size, game_print,
2256 game_wants_statusbar,
2257 FALSE, game_timing_state,
2258 0, /* mouse_priorities */
2261 #ifdef STANDALONE_SOLVER
2263 int main(int argc, char **argv)
2267 char *id = NULL, *desc, *err, *result;
2268 int nsol, diff, really_verbose = 0;
2269 unsigned int sflags;
2271 while (--argc > 0) {
2273 if (!strcmp(p, "-v")) {
2275 } else if (*p == '-') {
2276 fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p);
2284 fprintf(stderr, "usage: %s [-v] <game_id>\n", argv[0]);
2288 desc = strchr(id, ':');
2290 fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]);
2295 p = default_params();
2296 decode_params(p, id);
2297 err = validate_desc(p, desc);
2299 fprintf(stderr, "%s: %s\n", argv[0], err);
2302 s = new_game(NULL, p, desc);
2304 /* Run the solvers easiest to hardest until we find one that
2305 * can solve our puzzle. If it's soluble we know that the
2306 * hardest (recursive) solver will always find the solution. */
2308 for (diff = 0; diff <= DIFFCOUNT; diff++) {
2309 printf("\nSolving with difficulty %d.\n", diff);
2310 sflags = flags_from_difficulty(diff);
2312 nsol = dosolve(s, sflags, NULL);
2313 if (nsol == 1) break;
2318 printf("Puzzle has no solution.\n");
2319 } else if (nsol < 0) {
2320 printf("Unable to find a unique solution.\n");
2321 } else if (nsol > 1) {
2322 printf("Puzzle has multiple solutions.\n");
2324 verbose = really_verbose;
2326 printf("Puzzle has difficulty %d: solving...\n", diff);
2327 dosolve(s, sflags, NULL); /* sflags from last successful solve */
2328 result = game_text_format(s);
2329 printf("%s", result);
2338 /* vim: set shiftwidth=4 tabstop=8: */