ref: 11b631ea870355306c4b1d03458bb3cea8f29188
dir: /lightup.c/
/* * lightup.c: Implementation of the Nikoli game 'Light Up'. * * Possible future solver enhancements: * * - In a situation where two clues are diagonally adjacent, you can * deduce bounds on the number of lights shared between them. For * instance, suppose a 3 clue is diagonally adjacent to a 1 clue: * of the two squares adjacent to both clues, at least one must be * a light (or the 3 would be unsatisfiable) and yet at most one * must be a light (or the 1 would be overcommitted), so in fact * _exactly_ one must be a light, and hence the other two squares * adjacent to the 3 must also be lights and the other two adjacent * to the 1 must not. Likewise if the 3 is replaced with a 2 but * one of its other two squares is known not to be a light, and so * on. * * - In a situation where two clues are orthogonally separated (not * necessarily directly adjacent), you may be able to deduce * something about the squares that align with each other. For * instance, suppose two clues are vertically adjacent. Consider * the pair of squares A,B horizontally adjacent to the top clue, * and the pair C,D horizontally adjacent to the bottom clue. * Assuming no intervening obstacles, A and C align with each other * and hence at most one of them can be a light, and B and D * likewise, so we must have at most two lights between the four * squares. So if the clues indicate that there are at _least_ two * lights in those four squares because the top clue requires at * least one of AB to be a light and the bottom one requires at * least one of CD, then we can in fact deduce that there are * _exactly_ two lights between the four squares, and fill in the * other squares adjacent to each clue accordingly. For instance, * if both clues are 3s, then we instantly deduce that all four of * the squares _vertically_ adjacent to the two clues must be * lights. (For that to happen, of course, there'd also have to be * a black square in between the clues, so the two inner lights * don't light each other.) * * - I haven't thought it through carefully, but there's always the * possibility that both of the above deductions are special cases * of some more general pattern which can be made computationally * feasible... */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <assert.h> #include <ctype.h> #include <limits.h> #include <math.h> #include "puzzles.h" /* * In standalone solver mode, `verbose' is a variable which can be * set by command-line option; in debugging mode it's simply always * true. */ #if defined STANDALONE_SOLVER #define SOLVER_DIAGNOSTICS int verbose = 0; #undef debug #define debug(x) printf x #elif defined SOLVER_DIAGNOSTICS #define verbose 2 #endif /* --- Constants, structure definitions, etc. --- */ #define PREFERRED_TILE_SIZE 32 #define TILE_SIZE (ds->tilesize) #define BORDER (TILE_SIZE / 2) #define TILE_RADIUS (ds->crad) #define COORD(x) ( (x) * TILE_SIZE + BORDER ) #define FROMCOORD(x) ( ((x) - BORDER + TILE_SIZE) / TILE_SIZE - 1 ) #define FLASH_TIME 0.30F enum { COL_BACKGROUND, COL_GRID, COL_BLACK, /* black */ COL_LIGHT, /* white */ COL_LIT, /* yellow */ COL_ERROR, /* red */ COL_CURSOR, NCOLOURS }; enum { SYMM_NONE, SYMM_REF2, SYMM_ROT2, SYMM_REF4, SYMM_ROT4, SYMM_MAX }; #define DIFFCOUNT 2 struct game_params { int w, h; int blackpc; /* %age of black squares */ int symm; int difficulty; /* 0 to DIFFCOUNT */ }; #define F_BLACK 1 /* flags for black squares */ #define F_NUMBERED 2 /* it has a number attached */ #define F_NUMBERUSED 4 /* this number was useful for solving */ /* flags for non-black squares */ #define F_IMPOSSIBLE 8 /* can't put a light here */ #define F_LIGHT 16 #define F_MARK 32 struct game_state { int w, h, nlights; int *lights; /* For black squares, (optionally) the number of surrounding lights. For non-black squares, the number of times it's lit. size h*w*/ unsigned int *flags; /* size h*w */ bool completed, used_solve; }; #define GRID(gs,grid,x,y) (gs->grid[(y)*((gs)->w) + (x)]) /* A ll_data holds information about which lights would be lit by * a particular grid location's light (or conversely, which locations * could light a specific other location). */ /* most things should consider this struct opaque. */ typedef struct { int ox,oy; int minx, maxx, miny, maxy; bool include_origin; } ll_data; /* Macro that executes 'block' once per light in lld, including * the origin if include_origin is specified. 'block' can use * lx and ly as the coords. */ #define FOREACHLIT(lld,block) do { \ int lx,ly; \ ly = (lld)->oy; \ for (lx = (lld)->minx; lx <= (lld)->maxx; lx++) { \ if (lx == (lld)->ox) continue; \ block \ } \ lx = (lld)->ox; \ for (ly = (lld)->miny; ly <= (lld)->maxy; ly++) { \ if (!(lld)->include_origin && ly == (lld)->oy) continue; \ block \ } \ } while(0) typedef struct { struct { int x, y; unsigned int f; } points[4]; int npoints; } surrounds; /* Fills in (doesn't allocate) a surrounds structure with the grid locations * around a given square, taking account of the edges. */ static void get_surrounds(const game_state *state, int ox, int oy, surrounds *s) { assert(ox >= 0 && ox < state->w && oy >= 0 && oy < state->h); s->npoints = 0; #define ADDPOINT(cond,nx,ny) do {\ if (cond) { \ s->points[s->npoints].x = (nx); \ s->points[s->npoints].y = (ny); \ s->points[s->npoints].f = 0; \ s->npoints++; \ } } while(0) ADDPOINT(ox > 0, ox-1, oy); ADDPOINT(ox < (state->w-1), ox+1, oy); ADDPOINT(oy > 0, ox, oy-1); ADDPOINT(oy < (state->h-1), ox, oy+1); } /* --- Game parameter functions --- */ #define DEFAULT_PRESET 0 static const struct game_params lightup_presets[] = { { 7, 7, 20, SYMM_ROT4, 0 }, { 7, 7, 20, SYMM_ROT4, 1 }, { 7, 7, 20, SYMM_ROT4, 2 }, { 10, 10, 20, SYMM_ROT2, 0 }, { 10, 10, 20, SYMM_ROT2, 1 }, #ifdef SLOW_SYSTEM { 12, 12, 20, SYMM_ROT2, 0 }, { 12, 12, 20, SYMM_ROT2, 1 }, #else { 10, 10, 20, SYMM_ROT2, 2 }, { 14, 14, 20, SYMM_ROT2, 0 }, { 14, 14, 20, SYMM_ROT2, 1 }, { 14, 14, 20, SYMM_ROT2, 2 } #endif }; static game_params *default_params(void) { game_params *ret = snew(game_params); *ret = lightup_presets[DEFAULT_PRESET]; return ret; } static bool game_fetch_preset(int i, char **name, game_params **params) { game_params *ret; char buf[80]; if (i < 0 || i >= lenof(lightup_presets)) return false; ret = default_params(); *ret = lightup_presets[i]; *params = ret; sprintf(buf, "%dx%d %s", ret->w, ret->h, ret->difficulty == 2 ? "hard" : ret->difficulty == 1 ? "tricky" : "easy"); *name = dupstr(buf); return true; } static void free_params(game_params *params) { sfree(params); } static game_params *dup_params(const game_params *params) { game_params *ret = snew(game_params); *ret = *params; /* structure copy */ return ret; } #define EATNUM(x) do { \ (x) = atoi(string); \ while (*string && isdigit((unsigned char)*string)) string++; \ } while(0) static void decode_params(game_params *params, char const *string) { EATNUM(params->w); if (*string == 'x') { string++; EATNUM(params->h); } if (*string == 'b') { string++; EATNUM(params->blackpc); } if (*string == 's') { string++; EATNUM(params->symm); } else { /* cope with user input such as '18x10' by ensuring symmetry * is not selected by default to be incompatible with dimensions */ if (params->symm == SYMM_ROT4 && params->w != params->h) params->symm = SYMM_ROT2; } params->difficulty = 0; /* cope with old params */ if (*string == 'r') { params->difficulty = 2; string++; } if (*string == 'd') { string++; EATNUM(params->difficulty); } } static char *encode_params(const game_params *params, bool full) { char buf[80]; if (full) { sprintf(buf, "%dx%db%ds%dd%d", params->w, params->h, params->blackpc, params->symm, params->difficulty); } else { sprintf(buf, "%dx%d", params->w, params->h); } return dupstr(buf); } static config_item *game_configure(const game_params *params) { config_item *ret; char buf[80]; ret = snewn(6, config_item); ret[0].name = "Width"; ret[0].type = C_STRING; sprintf(buf, "%d", params->w); ret[0].u.string.sval = dupstr(buf); ret[1].name = "Height"; ret[1].type = C_STRING; sprintf(buf, "%d", params->h); ret[1].u.string.sval = dupstr(buf); ret[2].name = "%age of black squares"; ret[2].type = C_STRING; sprintf(buf, "%d", params->blackpc); ret[2].u.string.sval = dupstr(buf); ret[3].name = "Symmetry"; ret[3].type = C_CHOICES; ret[3].u.choices.choicenames = ":None" ":2-way mirror:2-way rotational" ":4-way mirror:4-way rotational"; ret[3].u.choices.selected = params->symm; ret[4].name = "Difficulty"; ret[4].type = C_CHOICES; ret[4].u.choices.choicenames = ":Easy:Tricky:Hard"; ret[4].u.choices.selected = params->difficulty; ret[5].name = NULL; ret[5].type = C_END; return ret; } static game_params *custom_params(const config_item *cfg) { game_params *ret = snew(game_params); ret->w = atoi(cfg[0].u.string.sval); ret->h = atoi(cfg[1].u.string.sval); ret->blackpc = atoi(cfg[2].u.string.sval); ret->symm = cfg[3].u.choices.selected; ret->difficulty = cfg[4].u.choices.selected; return ret; } static const char *validate_params(const game_params *params, bool full) { if (params->w < 2 || params->h < 2) return "Width and height must be at least 2"; if (params->w > INT_MAX / params->h) return "Width times height must not be unreasonably large"; if (full) { if (params->blackpc < 5 || params->blackpc > 100) return "Percentage of black squares must be between 5% and 100%"; if (params->w != params->h) { if (params->symm == SYMM_ROT4) return "4-fold symmetry is only available with square grids"; } if ((params->symm == SYMM_ROT4 || params->symm == SYMM_REF4) && params->w < 3 && params->h < 3) return "Width or height must be at least 3 for 4-way symmetry"; if (params->symm < 0 || params->symm >= SYMM_MAX) return "Unknown symmetry type"; if (params->difficulty < 0 || params->difficulty > DIFFCOUNT) return "Unknown difficulty level"; } return NULL; } /* --- Game state construction/freeing helper functions --- */ static game_state *new_state(const game_params *params) { game_state *ret = snew(game_state); ret->w = params->w; ret->h = params->h; ret->lights = snewn(ret->w * ret->h, int); ret->nlights = 0; memset(ret->lights, 0, ret->w * ret->h * sizeof(int)); ret->flags = snewn(ret->w * ret->h, unsigned int); memset(ret->flags, 0, ret->w * ret->h * sizeof(unsigned int)); ret->completed = false; ret->used_solve = false; return ret; } static game_state *dup_game(const game_state *state) { game_state *ret = snew(game_state); ret->w = state->w; ret->h = state->h; ret->lights = snewn(ret->w * ret->h, int); memcpy(ret->lights, state->lights, ret->w * ret->h * sizeof(int)); ret->nlights = state->nlights; ret->flags = snewn(ret->w * ret->h, unsigned int); memcpy(ret->flags, state->flags, ret->w * ret->h * sizeof(unsigned int)); ret->completed = state->completed; ret->used_solve = state->used_solve; return ret; } static void free_game(game_state *state) { sfree(state->lights); sfree(state->flags); sfree(state); } static void debug_state(game_state *state) { int x, y; char c = '?'; for (y = 0; y < state->h; y++) { for (x = 0; x < state->w; x++) { c = '.'; if (GRID(state, flags, x, y) & F_BLACK) { if (GRID(state, flags, x, y) & F_NUMBERED) c = GRID(state, lights, x, y) + '0'; else c = '#'; } else { if (GRID(state, flags, x, y) & F_LIGHT) c = 'O'; else if (GRID(state, flags, x, y) & F_IMPOSSIBLE) c = 'X'; } debug(("%c", (int)c)); } debug((" ")); for (x = 0; x < state->w; x++) { if (GRID(state, flags, x, y) & F_BLACK) c = '#'; else { c = (GRID(state, flags, x, y) & F_LIGHT) ? 'A' : 'a'; c += GRID(state, lights, x, y); } debug(("%c", (int)c)); } debug(("\n")); } } /* --- Game completion test routines. --- */ /* These are split up because occasionally functions are only * interested in one particular aspect. */ /* Returns true if all grid spaces are lit. */ static bool grid_lit(game_state *state) { int x, y; for (x = 0; x < state->w; x++) { for (y = 0; y < state->h; y++) { if (GRID(state,flags,x,y) & F_BLACK) continue; if (GRID(state,lights,x,y) == 0) return false; } } return true; } /* Returns non-zero if any lights are lit by other lights. */ static bool grid_overlap(game_state *state) { int x, y; for (x = 0; x < state->w; x++) { for (y = 0; y < state->h; y++) { if (!(GRID(state, flags, x, y) & F_LIGHT)) continue; if (GRID(state, lights, x, y) > 1) return true; } } return false; } static bool number_wrong(const game_state *state, int x, int y) { surrounds s; int i, n, empty, lights = GRID(state, lights, x, y); /* * This function computes the display hint for a number: we * turn the number red if it is definitely wrong. This means * that either * * (a) it has too many lights around it, or * (b) it would have too few lights around it even if all the * plausible squares (not black, lit or F_IMPOSSIBLE) were * filled with lights. */ assert(GRID(state, flags, x, y) & F_NUMBERED); get_surrounds(state, x, y, &s); empty = n = 0; for (i = 0; i < s.npoints; i++) { if (GRID(state,flags,s.points[i].x,s.points[i].y) & F_LIGHT) { n++; continue; } if (GRID(state,flags,s.points[i].x,s.points[i].y) & F_BLACK) continue; if (GRID(state,flags,s.points[i].x,s.points[i].y) & F_IMPOSSIBLE) continue; if (GRID(state,lights,s.points[i].x,s.points[i].y)) continue; empty++; } return (n > lights || (n + empty < lights)); } static bool number_correct(game_state *state, int x, int y) { surrounds s; int n = 0, i, lights = GRID(state, lights, x, y); assert(GRID(state, flags, x, y) & F_NUMBERED); get_surrounds(state, x, y, &s); for (i = 0; i < s.npoints; i++) { if (GRID(state,flags,s.points[i].x,s.points[i].y) & F_LIGHT) n++; } return n == lights; } /* Returns true if any numbers add up incorrectly. */ static bool grid_addsup(game_state *state) { int x, y; for (x = 0; x < state->w; x++) { for (y = 0; y < state->h; y++) { if (!(GRID(state, flags, x, y) & F_NUMBERED)) continue; if (!number_correct(state, x, y)) return false; } } return true; } static bool grid_correct(game_state *state) { if (grid_lit(state) && !grid_overlap(state) && grid_addsup(state)) return true; return false; } /* --- Board initial setup (blacks, lights, numbers) --- */ static void clean_board(game_state *state, bool leave_blacks) { int x,y; for (x = 0; x < state->w; x++) { for (y = 0; y < state->h; y++) { if (leave_blacks) GRID(state, flags, x, y) &= F_BLACK; else GRID(state, flags, x, y) = 0; GRID(state, lights, x, y) = 0; } } state->nlights = 0; } static void set_blacks(game_state *state, const game_params *params, random_state *rs) { int x, y, degree = 0, nblack; bool rotate = false; int rh, rw, i; int wodd = (state->w % 2) ? 1 : 0; int hodd = (state->h % 2) ? 1 : 0; int xs[4], ys[4]; switch (params->symm) { case SYMM_NONE: degree = 1; rotate = false; break; case SYMM_ROT2: degree = 2; rotate = true; break; case SYMM_REF2: degree = 2; rotate = false; break; case SYMM_ROT4: degree = 4; rotate = true; break; case SYMM_REF4: degree = 4; rotate = false; break; default: assert(!"Unknown symmetry type"); } if (params->symm == SYMM_ROT4 && (state->h != state->w)) assert(!"4-fold symmetry unavailable without square grid"); if (degree == 4) { rw = state->w/2; rh = state->h/2; if (!rotate) rw += wodd; /* ... but see below. */ rh += hodd; } else if (degree == 2) { rw = state->w; rh = state->h/2; rh += hodd; } else { rw = state->w; rh = state->h; } /* clear, then randomise, required region. */ clean_board(state, false); nblack = (rw * rh * params->blackpc) / 100; for (i = 0; i < nblack; i++) { do { x = random_upto(rs,rw); y = random_upto(rs,rh); } while (GRID(state,flags,x,y) & F_BLACK); GRID(state, flags, x, y) |= F_BLACK; } /* Copy required region. */ if (params->symm == SYMM_NONE) return; for (x = 0; x < rw; x++) { for (y = 0; y < rh; y++) { if (degree == 4) { xs[0] = x; ys[0] = y; xs[1] = state->w - 1 - (rotate ? y : x); ys[1] = rotate ? x : y; xs[2] = rotate ? (state->w - 1 - x) : x; ys[2] = state->h - 1 - y; xs[3] = rotate ? y : (state->w - 1 - x); ys[3] = state->h - 1 - (rotate ? x : y); } else { xs[0] = x; ys[0] = y; xs[1] = rotate ? (state->w - 1 - x) : x; ys[1] = state->h - 1 - y; } for (i = 1; i < degree; i++) { GRID(state, flags, xs[i], ys[i]) = GRID(state, flags, xs[0], ys[0]); } } } /* SYMM_ROT4 misses the middle square above; fix that here. */ if (degree == 4 && rotate && wodd && (random_upto(rs,100) <= (unsigned int)params->blackpc)) GRID(state,flags, state->w/2 + wodd - 1, state->h/2 + hodd - 1) |= F_BLACK; #ifdef SOLVER_DIAGNOSTICS if (verbose) debug_state(state); #endif } /* Fills in (does not allocate) a ll_data with all the tiles that would * be illuminated by a light at point (ox,oy). If origin is true then the * origin is included in this list. */ static void list_lights(game_state *state, int ox, int oy, bool origin, ll_data *lld) { int x,y; lld->ox = lld->minx = lld->maxx = ox; lld->oy = lld->miny = lld->maxy = oy; lld->include_origin = origin; y = oy; for (x = ox-1; x >= 0; x--) { if (GRID(state, flags, x, y) & F_BLACK) break; if (x < lld->minx) lld->minx = x; } for (x = ox+1; x < state->w; x++) { if (GRID(state, flags, x, y) & F_BLACK) break; if (x > lld->maxx) lld->maxx = x; } x = ox; for (y = oy-1; y >= 0; y--) { if (GRID(state, flags, x, y) & F_BLACK) break; if (y < lld->miny) lld->miny = y; } for (y = oy+1; y < state->h; y++) { if (GRID(state, flags, x, y) & F_BLACK) break; if (y > lld->maxy) lld->maxy = y; } } /* Makes sure a light is the given state, editing the lights table to suit the * new state if necessary. */ static void set_light(game_state *state, int ox, int oy, bool on) { ll_data lld; int diff = 0; assert(!(GRID(state,flags,ox,oy) & F_BLACK)); if (!on && GRID(state,flags,ox,oy) & F_LIGHT) { diff = -1; GRID(state,flags,ox,oy) &= ~F_LIGHT; state->nlights--; } else if (on && !(GRID(state,flags,ox,oy) & F_LIGHT)) { diff = 1; GRID(state,flags,ox,oy) |= F_LIGHT; state->nlights++; } if (diff != 0) { list_lights(state,ox,oy,true,&lld); FOREACHLIT(&lld, GRID(state,lights,lx,ly) += diff; ); } } /* Returns 1 if removing a light at (x,y) would cause a square to go dark. */ static int check_dark(game_state *state, int x, int y) { ll_data lld; list_lights(state, x, y, true, &lld); FOREACHLIT(&lld, if (GRID(state,lights,lx,ly) == 1) { return 1; } ); return 0; } /* Sets up an initial random correct position (i.e. every * space lit, and no lights lit by other lights) by filling the * grid with lights and then removing lights one by one at random. */ static void place_lights(game_state *state, random_state *rs) { int i, x, y, n, *numindices, wh = state->w*state->h; ll_data lld; numindices = snewn(wh, int); for (i = 0; i < wh; i++) numindices[i] = i; shuffle(numindices, wh, sizeof(*numindices), rs); /* Place a light on all grid squares without lights. */ for (x = 0; x < state->w; x++) { for (y = 0; y < state->h; y++) { GRID(state, flags, x, y) &= ~F_MARK; /* we use this later. */ if (GRID(state, flags, x, y) & F_BLACK) continue; set_light(state, x, y, true); } } for (i = 0; i < wh; i++) { y = numindices[i] / state->w; x = numindices[i] % state->w; if (!(GRID(state, flags, x, y) & F_LIGHT)) continue; if (GRID(state, flags, x, y) & F_MARK) continue; list_lights(state, x, y, false, &lld); /* If we're not lighting any lights ourself, don't remove anything. */ n = 0; FOREACHLIT(&lld, if (GRID(state,flags,lx,ly) & F_LIGHT) { n += 1; } ); if (n == 0) continue; /* [1] */ /* Check whether removing lights we're lighting would cause anything * to go dark. */ n = 0; FOREACHLIT(&lld, if (GRID(state,flags,lx,ly) & F_LIGHT) { n += check_dark(state,lx,ly); } ); if (n == 0) { /* No, it wouldn't, so we can remove them all. */ FOREACHLIT(&lld, set_light(state,lx,ly, false); ); GRID(state,flags,x,y) |= F_MARK; } if (!grid_overlap(state)) { sfree(numindices); return; /* we're done. */ } assert(grid_lit(state)); } /* could get here if the line at [1] continue'd out of the loop. */ if (grid_overlap(state)) { debug_state(state); assert(!"place_lights failed to resolve overlapping lights!"); } sfree(numindices); } /* Fills in all black squares with numbers of adjacent lights. */ static void place_numbers(game_state *state) { int x, y, i, n; surrounds s; for (x = 0; x < state->w; x++) { for (y = 0; y < state->h; y++) { if (!(GRID(state,flags,x,y) & F_BLACK)) continue; get_surrounds(state, x, y, &s); n = 0; for (i = 0; i < s.npoints; i++) { if (GRID(state,flags,s.points[i].x, s.points[i].y) & F_LIGHT) n++; } GRID(state,flags,x,y) |= F_NUMBERED; GRID(state,lights,x,y) = n; } } } /* --- Actual solver, with helper subroutines. --- */ static void tsl_callback(game_state *state, int lx, int ly, int *x, int *y, int *n) { if (GRID(state,flags,lx,ly) & F_IMPOSSIBLE) return; if (GRID(state,lights,lx,ly) > 0) return; *x = lx; *y = ly; (*n)++; } static bool try_solve_light(game_state *state, int ox, int oy, unsigned int flags, int lights) { ll_data lld; int sx = 0, sy = 0, n = 0; if (lights > 0) return false; if (flags & F_BLACK) return false; /* We have an unlit square; count how many ways there are left to * place a light that lights us (including this square); if only * one, we must put a light there. Squares that could light us * are, of course, the same as the squares we would light... */ list_lights(state, ox, oy, true, &lld); FOREACHLIT(&lld, { tsl_callback(state, lx, ly, &sx, &sy, &n); }); if (n == 1) { set_light(state, sx, sy, true); #ifdef SOLVER_DIAGNOSTICS debug(("(%d,%d) can only be lit from (%d,%d); setting to LIGHT\n", ox,oy,sx,sy)); if (verbose) debug_state(state); #endif return true; } return false; } static bool could_place_light(unsigned int flags, int lights) { if (flags & (F_BLACK | F_IMPOSSIBLE)) return false; return !(lights > 0); } static bool could_place_light_xy(game_state *state, int x, int y) { int lights = GRID(state,lights,x,y); unsigned int flags = GRID(state,flags,x,y); return could_place_light(flags, lights); } /* For a given number square, determine whether we have enough info * to unambiguously place its lights. */ static bool try_solve_number(game_state *state, int nx, int ny, unsigned int nflags, int nlights) { surrounds s; int x, y, nl, ns, i, lights; bool ret = false; unsigned int flags; if (!(nflags & F_NUMBERED)) return false; nl = nlights; get_surrounds(state,nx,ny,&s); ns = s.npoints; /* nl is no. of lights we need to place, ns is no. of spaces we * have to place them in. Try and narrow these down, and mark * points we can ignore later. */ for (i = 0; i < s.npoints; i++) { x = s.points[i].x; y = s.points[i].y; flags = GRID(state,flags,x,y); lights = GRID(state,lights,x,y); if (flags & F_LIGHT) { /* light here already; one less light for one less place. */ nl--; ns--; s.points[i].f |= F_MARK; } else if (!could_place_light(flags, lights)) { ns--; s.points[i].f |= F_MARK; } } if (ns == 0) return false; /* nowhere to put anything. */ if (nl == 0) { /* we have placed all lights we need to around here; all remaining * surrounds are therefore IMPOSSIBLE. */ GRID(state,flags,nx,ny) |= F_NUMBERUSED; for (i = 0; i < s.npoints; i++) { if (!(s.points[i].f & F_MARK)) { GRID(state,flags,s.points[i].x,s.points[i].y) |= F_IMPOSSIBLE; ret = true; } } #ifdef SOLVER_DIAGNOSTICS printf("Clue at (%d,%d) full; setting unlit to IMPOSSIBLE.\n", nx,ny); if (verbose) debug_state(state); #endif } else if (nl == ns) { /* we have as many lights to place as spaces; fill them all. */ GRID(state,flags,nx,ny) |= F_NUMBERUSED; for (i = 0; i < s.npoints; i++) { if (!(s.points[i].f & F_MARK)) { set_light(state, s.points[i].x,s.points[i].y, true); ret = true; } } #ifdef SOLVER_DIAGNOSTICS printf("Clue at (%d,%d) trivial; setting unlit to LIGHT.\n", nx,ny); if (verbose) debug_state(state); #endif } return ret; } struct setscratch { int x, y; int n; }; #define SCRATCHSZ (state->w+state->h) /* New solver algorithm: overlapping sets can add IMPOSSIBLE flags. * Algorithm thanks to Simon: * * (a) Any square where you can place a light has a set of squares * which would become non-lights as a result. (This includes * squares lit by the first square, and can also include squares * adjacent to the same clue square if the new light is the last * one around that clue.) Call this MAKESDARK(x,y) with (x,y) being * the square you place a light. * (b) Any unlit square has a set of squares on which you could place * a light to illuminate it. (Possibly including itself, of * course.) This set of squares has the property that _at least * one_ of them must contain a light. Sets of this type also arise * from clue squares. Call this MAKESLIGHT(x,y), again with (x,y) * the square you would place a light. * (c) If there exists (dx,dy) and (lx,ly) such that MAKESDARK(dx,dy) is * a superset of MAKESLIGHT(lx,ly), this implies that placing a light at * (dx,dy) would either leave no remaining way to illuminate a certain * square, or would leave no remaining way to fulfill a certain clue * (at lx,ly). In either case, a light can be ruled out at that position. * * So, we construct all possible MAKESLIGHT sets, both from unlit squares * and clue squares, and then we look for plausible MAKESDARK sets that include * our (lx,ly) to see if we can find a (dx,dy) to rule out. By the time we have * constructed the MAKESLIGHT set we don't care about (lx,ly), just the set * members. * * Once we have such a set, Simon came up with a Cunning Plan to find * the most sensible MAKESDARK candidate: * * (a) for each square S in your set X, find all the squares which _would_ * rule it out. That means any square which would light S, plus * any square adjacent to the same clue square as S (provided * that clue square has only one remaining light to be placed). * It's not hard to make this list. Don't do anything with this * data at the moment except _count_ the squares. * (b) Find the square S_min in the original set which has the * _smallest_ number of other squares which would rule it out. * (c) Find all the squares that rule out S_min (it's probably * better to recompute this than to have stored it during step * (a), since the CPU requirement is modest but the storage * cost would get ugly.) For each of these squares, see if it * rules out everything else in the set X. Any which does can * be marked as not-a-light. * */ typedef void (*trl_cb)(game_state *state, int dx, int dy, struct setscratch *scratch, int n, void *ctx); static void try_rule_out(game_state *state, int x, int y, struct setscratch *scratch, int n, trl_cb cb, void *ctx); static void trl_callback_search(game_state *state, int dx, int dy, struct setscratch *scratch, int n, void *ignored) { int i; #ifdef SOLVER_DIAGNOSTICS if (verbose) debug(("discount cb: light at (%d,%d)\n", dx, dy)); #endif for (i = 0; i < n; i++) { if (dx == scratch[i].x && dy == scratch[i].y) { scratch[i].n = 1; return; } } } static void trl_callback_discount(game_state *state, int dx, int dy, struct setscratch *scratch, int n, void *ctx) { bool *didsth = (bool *)ctx; int i; if (GRID(state,flags,dx,dy) & F_IMPOSSIBLE) { #ifdef SOLVER_DIAGNOSTICS debug(("Square at (%d,%d) already impossible.\n", dx,dy)); #endif return; } /* Check whether a light at (dx,dy) rules out everything * in scratch, and mark (dx,dy) as IMPOSSIBLE if it does. * We can use try_rule_out for this as well, as the set of * squares which would rule out (x,y) is the same as the * set of squares which (x,y) would rule out. */ #ifdef SOLVER_DIAGNOSTICS if (verbose) debug(("Checking whether light at (%d,%d) rules out everything in scratch.\n", dx, dy)); #endif for (i = 0; i < n; i++) scratch[i].n = 0; try_rule_out(state, dx, dy, scratch, n, trl_callback_search, NULL); for (i = 0; i < n; i++) { if (scratch[i].n == 0) return; } /* The light ruled out everything in scratch. Yay. */ GRID(state,flags,dx,dy) |= F_IMPOSSIBLE; #ifdef SOLVER_DIAGNOSTICS debug(("Set reduction discounted square at (%d,%d):\n", dx,dy)); if (verbose) debug_state(state); #endif *didsth = true; } static void trl_callback_incn(game_state *state, int dx, int dy, struct setscratch *scratch, int n, void *ctx) { struct setscratch *s = (struct setscratch *)ctx; s->n++; } static void try_rule_out(game_state *state, int x, int y, struct setscratch *scratch, int n, trl_cb cb, void *ctx) { /* XXX Find all the squares which would rule out (x,y); anything * that would light it as well as squares adjacent to same clues * as X assuming that clue only has one remaining light. * Call the callback with each square. */ ll_data lld; surrounds s, ss; int i, j, curr_lights, tot_lights; /* Find all squares that would rule out a light at (x,y) and call trl_cb * with them: anything that would light (x,y)... */ list_lights(state, x, y, false, &lld); FOREACHLIT(&lld, { if (could_place_light_xy(state, lx, ly)) { cb(state, lx, ly, scratch, n, ctx); } }); /* ... as well as any empty space (that isn't x,y) next to any clue square * next to (x,y) that only has one light left to place. */ get_surrounds(state, x, y, &s); for (i = 0; i < s.npoints; i++) { if (!(GRID(state,flags,s.points[i].x,s.points[i].y) & F_NUMBERED)) continue; /* we have an adjacent clue square; find /its/ surrounds * and count the remaining lights it needs. */ get_surrounds(state,s.points[i].x,s.points[i].y,&ss); curr_lights = 0; for (j = 0; j < ss.npoints; j++) { if (GRID(state,flags,ss.points[j].x,ss.points[j].y) & F_LIGHT) curr_lights++; } tot_lights = GRID(state, lights, s.points[i].x, s.points[i].y); /* We have a clue with tot_lights to fill, and curr_lights currently * around it. If adding a light at (x,y) fills up the clue (i.e. * curr_lights + 1 = tot_lights) then we need to discount all other * unlit squares around the clue. */ if ((curr_lights + 1) == tot_lights) { for (j = 0; j < ss.npoints; j++) { int lx = ss.points[j].x, ly = ss.points[j].y; if (lx == x && ly == y) continue; if (could_place_light_xy(state, lx, ly)) cb(state, lx, ly, scratch, n, ctx); } } } } #ifdef SOLVER_DIAGNOSTICS static void debug_scratch(const char *msg, struct setscratch *scratch, int n) { int i; debug(("%s scratch (%d elements):\n", msg, n)); for (i = 0; i < n; i++) { debug((" (%d,%d) n%d\n", scratch[i].x, scratch[i].y, scratch[i].n)); } } #endif static bool discount_set(game_state *state, struct setscratch *scratch, int n) { int i, besti, bestn; bool didsth = false; #ifdef SOLVER_DIAGNOSTICS if (verbose > 1) debug_scratch("discount_set", scratch, n); #endif if (n == 0) return false; for (i = 0; i < n; i++) { try_rule_out(state, scratch[i].x, scratch[i].y, scratch, n, trl_callback_incn, (void*)&(scratch[i])); } #ifdef SOLVER_DIAGNOSTICS if (verbose > 1) debug_scratch("discount_set after count", scratch, n); #endif besti = -1; bestn = SCRATCHSZ; for (i = 0; i < n; i++) { if (scratch[i].n < bestn) { bestn = scratch[i].n; besti = i; } } #ifdef SOLVER_DIAGNOSTICS if (verbose > 1) debug(("best square (%d,%d) with n%d.\n", scratch[besti].x, scratch[besti].y, scratch[besti].n)); #endif try_rule_out(state, scratch[besti].x, scratch[besti].y, scratch, n, trl_callback_discount, (void*)&didsth); #ifdef SOLVER_DIAGNOSTICS if (didsth) debug((" [from square (%d,%d)]\n", scratch[besti].x, scratch[besti].y)); #endif return didsth; } static void discount_clear(game_state *state, struct setscratch *scratch, int *n) { *n = 0; memset(scratch, 0, SCRATCHSZ * sizeof(struct setscratch)); } static void unlit_cb(game_state *state, int lx, int ly, struct setscratch *scratch, int *n) { if (could_place_light_xy(state, lx, ly)) { scratch[*n].x = lx; scratch[*n].y = ly; (*n)++; } } /* Construct a MAKESLIGHT set from an unlit square. */ static bool discount_unlit(game_state *state, int x, int y, struct setscratch *scratch) { ll_data lld; int n; bool didsth; #ifdef SOLVER_DIAGNOSTICS if (verbose) debug(("Trying to discount for unlit square at (%d,%d).\n", x, y)); if (verbose > 1) debug_state(state); #endif discount_clear(state, scratch, &n); list_lights(state, x, y, true, &lld); FOREACHLIT(&lld, { unlit_cb(state, lx, ly, scratch, &n); }); didsth = discount_set(state, scratch, n); #ifdef SOLVER_DIAGNOSTICS if (didsth) debug((" [from unlit square at (%d,%d)].\n", x, y)); #endif return didsth; } /* Construct a series of MAKESLIGHT sets from a clue square. * for a clue square with N remaining spaces that must contain M lights, every * subset of size N-M+1 of those N spaces forms such a set. */ static bool discount_clue(game_state *state, int x, int y, struct setscratch *scratch) { int slen, m = GRID(state, lights, x, y), n, i, lights; bool didsth = false; unsigned int flags; surrounds s, sempty; combi_ctx *combi; if (m == 0) return false; #ifdef SOLVER_DIAGNOSTICS if (verbose) debug(("Trying to discount for sets at clue (%d,%d).\n", x, y)); if (verbose > 1) debug_state(state); #endif /* m is no. of lights still to place; starts off at the clue value * and decreases when we find a light already down. * n is no. of spaces left; starts off at 0 and goes up when we find * a plausible space. */ get_surrounds(state, x, y, &s); memset(&sempty, 0, sizeof(surrounds)); for (i = 0; i < s.npoints; i++) { int lx = s.points[i].x, ly = s.points[i].y; flags = GRID(state,flags,lx,ly); lights = GRID(state,lights,lx,ly); if (flags & F_LIGHT) m--; if (could_place_light(flags, lights)) { sempty.points[sempty.npoints].x = lx; sempty.points[sempty.npoints].y = ly; sempty.npoints++; } } n = sempty.npoints; /* sempty is now a surrounds of only blank squares. */ if (n == 0) return false; /* clue is full already. */ if (m < 0 || m > n) return false; /* become impossible. */ combi = new_combi(n - m + 1, n); while (next_combi(combi)) { discount_clear(state, scratch, &slen); for (i = 0; i < combi->r; i++) { scratch[slen].x = sempty.points[combi->a[i]].x; scratch[slen].y = sempty.points[combi->a[i]].y; slen++; } if (discount_set(state, scratch, slen)) didsth = true; } free_combi(combi); #ifdef SOLVER_DIAGNOSTICS if (didsth) debug((" [from clue at (%d,%d)].\n", x, y)); #endif return didsth; } #define F_SOLVE_FORCEUNIQUE 1 #define F_SOLVE_DISCOUNTSETS 2 #define F_SOLVE_ALLOWRECURSE 4 static unsigned int flags_from_difficulty(int difficulty) { unsigned int sflags = F_SOLVE_FORCEUNIQUE; assert(difficulty <= DIFFCOUNT); if (difficulty >= 1) sflags |= F_SOLVE_DISCOUNTSETS; if (difficulty >= 2) sflags |= F_SOLVE_ALLOWRECURSE; return sflags; } #define MAXRECURSE 5 static int solve_sub(game_state *state, unsigned int solve_flags, int depth, int *maxdepth) { unsigned int flags; int x, y, ncanplace, lights; bool didstuff; int bestx, besty, n, bestn, copy_soluble, self_soluble, ret, maxrecurse = 0; game_state *scopy; ll_data lld; struct setscratch *sscratch = NULL; #ifdef SOLVER_DIAGNOSTICS printf("solve_sub: depth = %d\n", depth); #endif if (maxdepth && *maxdepth < depth) *maxdepth = depth; if (solve_flags & F_SOLVE_ALLOWRECURSE) maxrecurse = MAXRECURSE; while (1) { if (grid_overlap(state)) { /* Our own solver, from scratch, should never cause this to happen * (assuming a soluble grid). However, if we're trying to solve * from a half-completed *incorrect* grid this might occur; we * just return the 'no solutions' code in this case. */ ret = 0; goto done; } if (grid_correct(state)) { ret = 1; goto done; } ncanplace = 0; didstuff = false; /* These 2 loops, and the functions they call, are the critical loops * for timing; any optimisations should look here first. */ for (x = 0; x < state->w; x++) { for (y = 0; y < state->h; y++) { flags = GRID(state,flags,x,y); lights = GRID(state,lights,x,y); ncanplace += could_place_light(flags, lights); if (try_solve_light(state, x, y, flags, lights)) didstuff = true; if (try_solve_number(state, x, y, flags, lights)) didstuff = true; } } if (didstuff) continue; if (!ncanplace) { /* nowhere to put a light, puzzle is unsoluble. */ ret = 0; goto done; } if (solve_flags & F_SOLVE_DISCOUNTSETS) { if (!sscratch) sscratch = snewn(SCRATCHSZ, struct setscratch); /* Try a more cunning (and more involved) way... more details above. */ for (x = 0; x < state->w; x++) { for (y = 0; y < state->h; y++) { flags = GRID(state,flags,x,y); lights = GRID(state,lights,x,y); if (!(flags & F_BLACK) && lights == 0) { if (discount_unlit(state, x, y, sscratch)) { didstuff = true; goto reduction_success; } } else if (flags & F_NUMBERED) { if (discount_clue(state, x, y, sscratch)) { didstuff = true; goto reduction_success; } } } } } reduction_success: if (didstuff) continue; /* We now have to make a guess; we have places to put lights but * no definite idea about where they can go. */ if (depth >= maxrecurse) { /* mustn't delve any deeper. */ ret = -1; goto done; } /* Of all the squares that we could place a light, pick the one * that would light the most currently unlit squares. */ /* This heuristic was just plucked from the air; there may well be * a more efficient way of choosing a square to flip to minimise * recursion. */ bestn = 0; bestx = besty = -1; /* suyb */ for (x = 0; x < state->w; x++) { for (y = 0; y < state->h; y++) { flags = GRID(state,flags,x,y); lights = GRID(state,lights,x,y); if (!could_place_light(flags, lights)) continue; n = 0; list_lights(state, x, y, true, &lld); FOREACHLIT(&lld, { if (GRID(state,lights,lx,ly) == 0) n++; }); if (n > bestn) { bestn = n; bestx = x; besty = y; } } } assert(bestn > 0); assert(bestx >= 0 && besty >= 0); /* Now we've chosen a plausible (x,y), try to solve it once as 'lit' * and once as 'impossible'; we need to make one copy to do this. */ scopy = dup_game(state); #ifdef SOLVER_DIAGNOSTICS debug(("Recursing #1: trying (%d,%d) as IMPOSSIBLE\n", bestx, besty)); #endif GRID(state,flags,bestx,besty) |= F_IMPOSSIBLE; self_soluble = solve_sub(state, solve_flags, depth+1, maxdepth); if (!(solve_flags & F_SOLVE_FORCEUNIQUE) && self_soluble > 0) { /* we didn't care about finding all solutions, and we just * found one; return with it immediately. */ free_game(scopy); ret = self_soluble; goto done; } #ifdef SOLVER_DIAGNOSTICS debug(("Recursing #2: trying (%d,%d) as LIGHT\n", bestx, besty)); #endif set_light(scopy, bestx, besty, true); copy_soluble = solve_sub(scopy, solve_flags, depth+1, maxdepth); /* If we wanted a unique solution but we hit our recursion limit * (on either branch) then we have to assume we didn't find possible * extra solutions, and return 'not soluble'. */ if ((solve_flags & F_SOLVE_FORCEUNIQUE) && ((copy_soluble < 0) || (self_soluble < 0))) { ret = -1; /* Make sure that whether or not it was self or copy (or both) that * were soluble, that we return a solved state in self. */ } else if (copy_soluble <= 0) { /* copy wasn't soluble; keep self state and return that result. */ ret = self_soluble; } else if (self_soluble <= 0) { /* copy solved and we didn't, so copy in copy's (now solved) * flags and light state. */ memcpy(state->lights, scopy->lights, scopy->w * scopy->h * sizeof(int)); memcpy(state->flags, scopy->flags, scopy->w * scopy->h * sizeof(unsigned int)); ret = copy_soluble; } else { ret = copy_soluble + self_soluble; } free_game(scopy); goto done; } done: if (sscratch) sfree(sscratch); #ifdef SOLVER_DIAGNOSTICS if (ret < 0) debug(("solve_sub: depth = %d returning, ran out of recursion.\n", depth)); else debug(("solve_sub: depth = %d returning, %d solutions.\n", depth, ret)); #endif return ret; } /* Fills in the (possibly partially-complete) game_state as far as it can, * returning the number of possible solutions. If it returns >0 then the * game_state will be in a solved state, but you won't know which one. */ static int dosolve(game_state *state, int solve_flags, int *maxdepth) { int x, y, nsol; for (x = 0; x < state->w; x++) { for (y = 0; y < state->h; y++) { GRID(state,flags,x,y) &= ~F_NUMBERUSED; } } nsol = solve_sub(state, solve_flags, 0, maxdepth); return nsol; } static int strip_unused_nums(game_state *state) { int x,y,n=0; for (x = 0; x < state->w; x++) { for (y = 0; y < state->h; y++) { if ((GRID(state,flags,x,y) & F_NUMBERED) && !(GRID(state,flags,x,y) & F_NUMBERUSED)) { GRID(state,flags,x,y) &= ~F_NUMBERED; GRID(state,lights,x,y) = 0; n++; } } } debug(("Stripped %d unused numbers.\n", n)); return n; } static void unplace_lights(game_state *state) { int x,y; for (x = 0; x < state->w; x++) { for (y = 0; y < state->h; y++) { if (GRID(state,flags,x,y) & F_LIGHT) set_light(state,x,y,false); GRID(state,flags,x,y) &= ~F_IMPOSSIBLE; GRID(state,flags,x,y) &= ~F_NUMBERUSED; } } } static bool puzzle_is_good(game_state *state, int difficulty) { int nsol, mdepth = 0; unsigned int sflags = flags_from_difficulty(difficulty); unplace_lights(state); #ifdef SOLVER_DIAGNOSTICS debug(("Trying to solve with difficulty %d (0x%x):\n", difficulty, sflags)); if (verbose) debug_state(state); #endif nsol = dosolve(state, sflags, &mdepth); /* if we wanted an easy puzzle, make sure we didn't need recursion. */ if (!(sflags & F_SOLVE_ALLOWRECURSE) && mdepth > 0) { debug(("Ignoring recursive puzzle.\n")); return false; } debug(("%d solutions found.\n", nsol)); if (nsol <= 0) return false; if (nsol > 1) return false; return true; } /* --- New game creation and user input code. --- */ /* The basic algorithm here is to generate the most complex grid possible * while honouring two restrictions: * * * we require a unique solution, and * * either we require solubility with no recursion (!params->recurse) * * or we require some recursion. (params->recurse). * * The solver helpfully keeps track of the numbers it needed to use to * get its solution, so we use that to remove an initial set of numbers * and check we still satsify our requirements (on uniqueness and * non-recursiveness, if applicable; we don't check explicit recursiveness * until the end). * * Then we try to remove all numbers in a random order, and see if we * still satisfy requirements (putting them back if we didn't). * * Removing numbers will always, in general terms, make a puzzle require * more recursion but it may also mean a puzzle becomes non-unique. * * Once we're done, if we wanted a recursive puzzle but the most difficult * puzzle we could come up with was non-recursive, we give up and try a new * grid. */ #define MAX_GRIDGEN_TRIES 20 static char *new_game_desc(const game_params *params_in, random_state *rs, char **aux, bool interactive) { game_params params_copy = *params_in; /* structure copy */ game_params *params = ¶ms_copy; game_state *news = new_state(params), *copys; int i, j, run, x, y, wh = params->w*params->h, num; char *ret, *p; int *numindices; /* Construct a shuffled list of grid positions; we only * do this once, because if it gets used more than once it'll * be on a different grid layout. */ numindices = snewn(wh, int); for (j = 0; j < wh; j++) numindices[j] = j; shuffle(numindices, wh, sizeof(*numindices), rs); while (1) { for (i = 0; i < MAX_GRIDGEN_TRIES; i++) { set_blacks(news, params, rs); /* also cleans board. */ /* set up lights and then the numbers, and remove the lights */ place_lights(news, rs); debug(("Generating initial grid.\n")); place_numbers(news); if (!puzzle_is_good(news, params->difficulty)) continue; /* Take a copy, remove numbers we didn't use and check there's * still a unique solution; if so, use the copy subsequently. */ copys = dup_game(news); strip_unused_nums(copys); if (!puzzle_is_good(copys, params->difficulty)) { debug(("Stripped grid is not good, reverting.\n")); free_game(copys); } else { free_game(news); news = copys; } /* Go through grid removing numbers at random one-by-one and * trying to solve again; if it ceases to be good put the number back. */ for (j = 0; j < wh; j++) { y = numindices[j] / params->w; x = numindices[j] % params->w; if (!(GRID(news, flags, x, y) & F_NUMBERED)) continue; num = GRID(news, lights, x, y); GRID(news, lights, x, y) = 0; GRID(news, flags, x, y) &= ~F_NUMBERED; if (!puzzle_is_good(news, params->difficulty)) { GRID(news, lights, x, y) = num; GRID(news, flags, x, y) |= F_NUMBERED; } else debug(("Removed (%d,%d) still soluble.\n", x, y)); } if (params->difficulty > 0) { /* Was the maximally-difficult puzzle difficult enough? * Check we can't solve it with a more simplistic solver. */ if (puzzle_is_good(news, params->difficulty-1)) { debug(("Maximally-hard puzzle still not hard enough, skipping.\n")); continue; } } goto goodpuzzle; } /* Couldn't generate a good puzzle in however many goes. Ramp up the * %age of black squares (if we didn't already have lots; in which case * why couldn't we generate a puzzle?) and try again. */ if (params->blackpc < 90) params->blackpc += 5; debug(("New black layout %d%%.\n", params->blackpc)); } goodpuzzle: /* Game is encoded as a long string one character per square; * 'S' is a space * 'B' is a black square with no number * '0', '1', '2', '3', '4' is a black square with a number. */ ret = snewn((params->w * params->h) + 1, char); p = ret; run = 0; for (y = 0; y < params->h; y++) { for (x = 0; x < params->w; x++) { if (GRID(news,flags,x,y) & F_BLACK) { if (run) { *p++ = ('a'-1) + run; run = 0; } if (GRID(news,flags,x,y) & F_NUMBERED) *p++ = '0' + GRID(news,lights,x,y); else *p++ = 'B'; } else { if (run == 26) { *p++ = ('a'-1) + run; run = 0; } run++; } } } if (run) { *p++ = ('a'-1) + run; run = 0; } *p = '\0'; assert(p - ret <= params->w * params->h); free_game(news); sfree(numindices); return ret; } static const char *validate_desc(const game_params *params, const char *desc) { int i; for (i = 0; i < params->w*params->h; i++) { if (*desc >= '0' && *desc <= '4') /* OK */; else if (*desc == 'B') /* OK */; else if (*desc >= 'a' && *desc <= 'z') i += *desc - 'a'; /* and the i++ will add another one */ else if (!*desc) return "Game description shorter than expected"; else return "Game description contained unexpected character"; desc++; } if (*desc || i > params->w*params->h) return "Game description longer than expected"; return NULL; } static game_state *new_game(midend *me, const game_params *params, const char *desc) { game_state *ret = new_state(params); int x,y; int run = 0; for (y = 0; y < params->h; y++) { for (x = 0; x < params->w; x++) { char c = '\0'; if (run == 0) { c = *desc++; assert(c != 'S'); if (c >= 'a' && c <= 'z') run = c - 'a' + 1; } if (run > 0) { c = 'S'; run--; } switch (c) { case '0': case '1': case '2': case '3': case '4': GRID(ret,flags,x,y) |= F_NUMBERED; GRID(ret,lights,x,y) = (c - '0'); /* run-on... */ case 'B': GRID(ret,flags,x,y) |= F_BLACK; break; case 'S': /* empty square */ break; default: assert(!"Malformed desc."); break; } } } if (*desc) assert(!"Over-long desc."); return ret; } static char *solve_game(const game_state *state, const game_state *currstate, const char *aux, const char **error) { game_state *solved; char *move = NULL, buf[80]; int movelen, movesize, x, y, len; unsigned int oldflags, solvedflags, sflags; /* We don't care here about non-unique puzzles; if the * user entered one themself then I doubt they care. */ sflags = F_SOLVE_ALLOWRECURSE | F_SOLVE_DISCOUNTSETS; /* Try and solve from where we are now (for non-unique * puzzles this may produce a different answer). */ solved = dup_game(currstate); if (dosolve(solved, sflags, NULL) > 0) goto solved; free_game(solved); /* That didn't work; try solving from the clean puzzle. */ solved = dup_game(state); if (dosolve(solved, sflags, NULL) > 0) goto solved; *error = "Unable to find a solution to this puzzle."; goto done; solved: movesize = 256; move = snewn(movesize, char); movelen = 0; move[movelen++] = 'S'; move[movelen] = '\0'; for (x = 0; x < currstate->w; x++) { for (y = 0; y < currstate->h; y++) { len = 0; oldflags = GRID(currstate, flags, x, y); solvedflags = GRID(solved, flags, x, y); if ((oldflags & F_LIGHT) != (solvedflags & F_LIGHT)) len = sprintf(buf, ";L%d,%d", x, y); else if ((oldflags & F_IMPOSSIBLE) != (solvedflags & F_IMPOSSIBLE)) len = sprintf(buf, ";I%d,%d", x, y); if (len) { if (movelen + len >= movesize) { movesize = movelen + len + 256; move = sresize(move, movesize, char); } strcpy(move + movelen, buf); movelen += len; } } } done: free_game(solved); return move; } static bool game_can_format_as_text_now(const game_params *params) { return true; } /* 'borrowed' from slant.c, mainly. I could have printed it one * character per cell (like debug_state) but that comes out tiny. * 'L' is used for 'light here' because 'O' looks too much like '0' * (black square with no surrounding lights). */ static char *game_text_format(const game_state *state) { int w = state->w, h = state->h, W = w+1, H = h+1; int x, y, len, lights; unsigned int flags; char *ret, *p; len = (h+H) * (w+W+1) + 1; ret = snewn(len, char); p = ret; for (y = 0; y < H; y++) { for (x = 0; x < W; x++) { *p++ = '+'; if (x < w) *p++ = '-'; } *p++ = '\n'; if (y < h) { for (x = 0; x < W; x++) { *p++ = '|'; if (x < w) { /* actual interesting bit. */ flags = GRID(state, flags, x, y); lights = GRID(state, lights, x, y); if (flags & F_BLACK) { if (flags & F_NUMBERED) *p++ = '0' + lights; else *p++ = '#'; } else { if (flags & F_LIGHT) *p++ = 'L'; else if (flags & F_IMPOSSIBLE) *p++ = 'x'; else if (lights > 0) *p++ = '.'; else *p++ = ' '; } } } *p++ = '\n'; } } *p++ = '\0'; assert(p - ret == len); return ret; } struct game_ui { int cur_x, cur_y; bool cur_visible; }; static game_ui *new_ui(const game_state *state) { game_ui *ui = snew(game_ui); ui->cur_x = ui->cur_y = 0; ui->cur_visible = false; return ui; } static void free_ui(game_ui *ui) { sfree(ui); } static char *encode_ui(const game_ui *ui) { /* nothing to encode. */ return NULL; } static void decode_ui(game_ui *ui, const char *encoding) { /* nothing to decode. */ } static void game_changed_state(game_ui *ui, const game_state *oldstate, const game_state *newstate) { if (newstate->completed) ui->cur_visible = false; } static const char *current_key_label(const game_ui *ui, const game_state *state, int button) { int cx = ui->cur_x, cy = ui->cur_y; unsigned int flags = GRID(state, flags, cx, cy); if (!ui->cur_visible) return ""; if (button == CURSOR_SELECT) { if (flags & (F_BLACK | F_IMPOSSIBLE)) return ""; if (flags & F_LIGHT) return "Clear"; return "Light"; } if (button == CURSOR_SELECT2) { if (flags & (F_BLACK | F_LIGHT)) return ""; if (flags & F_IMPOSSIBLE) return "Clear"; return "Mark"; } return ""; } #define DF_BLACK 1 /* black square */ #define DF_NUMBERED 2 /* black square with number */ #define DF_LIT 4 /* display (white) square lit up */ #define DF_LIGHT 8 /* display light in square */ #define DF_OVERLAP 16 /* display light as overlapped */ #define DF_CURSOR 32 /* display cursor */ #define DF_NUMBERWRONG 64 /* display black numbered square as error. */ #define DF_FLASH 128 /* background flash is on. */ #define DF_IMPOSSIBLE 256 /* display non-light little square */ struct game_drawstate { int tilesize, crad; int w, h; unsigned int *flags; /* width * height */ bool started; }; /* Believe it or not, this empty = "" hack is needed to get around a bug in * the prc-tools gcc when optimisation is turned on; before, it produced: lightup-sect.c: In function `interpret_move': lightup-sect.c:1416: internal error--unrecognizable insn: (insn 582 580 583 (set (reg:SI 134) (pc)) -1 (nil) (nil)) */ static char *interpret_move(const game_state *state, game_ui *ui, const game_drawstate *ds, int x, int y, int button) { enum { NONE, FLIP_LIGHT, FLIP_IMPOSSIBLE } action = NONE; int cx = -1, cy = -1; unsigned int flags; char buf[80], *nullret = UI_UPDATE, *empty = UI_UPDATE, c; if (button == LEFT_BUTTON || button == RIGHT_BUTTON) { if (ui->cur_visible) nullret = empty; ui->cur_visible = false; cx = FROMCOORD(x); cy = FROMCOORD(y); action = (button == LEFT_BUTTON) ? FLIP_LIGHT : FLIP_IMPOSSIBLE; } else if (IS_CURSOR_SELECT(button) || button == 'i' || button == 'I') { if (ui->cur_visible) { /* Only allow cursor-effect operations if the cursor is visible * (otherwise you have no idea which square it might be affecting) */ cx = ui->cur_x; cy = ui->cur_y; action = (button == 'i' || button == 'I' || button == CURSOR_SELECT2) ? FLIP_IMPOSSIBLE : FLIP_LIGHT; } ui->cur_visible = true; } else if (IS_CURSOR_MOVE(button)) { move_cursor(button, &ui->cur_x, &ui->cur_y, state->w, state->h, false); ui->cur_visible = true; nullret = empty; } else return NULL; switch (action) { case FLIP_LIGHT: case FLIP_IMPOSSIBLE: if (cx < 0 || cy < 0 || cx >= state->w || cy >= state->h) return nullret; flags = GRID(state, flags, cx, cy); if (flags & F_BLACK) return nullret; if (action == FLIP_LIGHT) { #ifdef STYLUS_BASED if (flags & F_IMPOSSIBLE || flags & F_LIGHT) c = 'I'; else c = 'L'; #else if (flags & F_IMPOSSIBLE) return nullret; c = 'L'; #endif } else { #ifdef STYLUS_BASED if (flags & F_IMPOSSIBLE || flags & F_LIGHT) c = 'L'; else c = 'I'; #else if (flags & F_LIGHT) return nullret; c = 'I'; #endif } sprintf(buf, "%c%d,%d", (int)c, cx, cy); break; case NONE: return nullret; default: assert(!"Shouldn't get here!"); } return dupstr(buf); } static game_state *execute_move(const game_state *state, const char *move) { game_state *ret = dup_game(state); int x, y, n, flags; char c; if (!*move) goto badmove; while (*move) { c = *move; if (c == 'S') { ret->used_solve = true; move++; } else if (c == 'L' || c == 'I') { move++; if (sscanf(move, "%d,%d%n", &x, &y, &n) != 2 || x < 0 || y < 0 || x >= ret->w || y >= ret->h) goto badmove; flags = GRID(ret, flags, x, y); if (flags & F_BLACK) goto badmove; /* LIGHT and IMPOSSIBLE are mutually exclusive. */ if (c == 'L') { GRID(ret, flags, x, y) &= ~F_IMPOSSIBLE; set_light(ret, x, y, !(flags & F_LIGHT)); } else { set_light(ret, x, y, false); GRID(ret, flags, x, y) ^= F_IMPOSSIBLE; } move += n; } else goto badmove; if (*move == ';') move++; else if (*move) goto badmove; } if (grid_correct(ret)) ret->completed = true; return ret; badmove: free_game(ret); return NULL; } /* ---------------------------------------------------------------------- * Drawing routines. */ /* XXX entirely cloned from fifteen.c; separate out? */ static void game_compute_size(const game_params *params, int tilesize, int *x, int *y) { /* Ick: fake up `ds->tilesize' for macro expansion purposes */ struct { int tilesize; } ads, *ds = &ads; ads.tilesize = tilesize; *x = TILE_SIZE * params->w + 2 * BORDER; *y = TILE_SIZE * params->h + 2 * BORDER; } static void game_set_size(drawing *dr, game_drawstate *ds, const game_params *params, int tilesize) { ds->tilesize = tilesize; ds->crad = 3*(tilesize-1)/8; } static float *game_colours(frontend *fe, int *ncolours) { float *ret = snewn(3 * NCOLOURS, float); int i; frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); for (i = 0; i < 3; i++) { ret[COL_BLACK * 3 + i] = 0.0F; ret[COL_LIGHT * 3 + i] = 1.0F; ret[COL_CURSOR * 3 + i] = ret[COL_BACKGROUND * 3 + i] / 2.0F; ret[COL_GRID * 3 + i] = ret[COL_BACKGROUND * 3 + i] / 1.5F; } ret[COL_ERROR * 3 + 0] = 1.0F; ret[COL_ERROR * 3 + 1] = 0.25F; ret[COL_ERROR * 3 + 2] = 0.25F; ret[COL_LIT * 3 + 0] = 1.0F; ret[COL_LIT * 3 + 1] = 1.0F; ret[COL_LIT * 3 + 2] = 0.0F; *ncolours = NCOLOURS; return ret; } static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state) { struct game_drawstate *ds = snew(struct game_drawstate); int i; ds->tilesize = ds->crad = 0; ds->w = state->w; ds->h = state->h; ds->flags = snewn(ds->w*ds->h, unsigned int); for (i = 0; i < ds->w*ds->h; i++) ds->flags[i] = -1; ds->started = false; return ds; } static void game_free_drawstate(drawing *dr, game_drawstate *ds) { sfree(ds->flags); sfree(ds); } /* At some stage we should put these into a real options struct. * Note that tile_redraw has no #ifdeffery; it relies on tile_flags not * to put those flags in. */ #define HINT_LIGHTS #define HINT_OVERLAPS #define HINT_NUMBERS static unsigned int tile_flags(game_drawstate *ds, const game_state *state, const game_ui *ui, int x, int y, bool flashing) { unsigned int flags = GRID(state, flags, x, y); int lights = GRID(state, lights, x, y); unsigned int ret = 0; if (flashing) ret |= DF_FLASH; if (ui && ui->cur_visible && x == ui->cur_x && y == ui->cur_y) ret |= DF_CURSOR; if (flags & F_BLACK) { ret |= DF_BLACK; if (flags & F_NUMBERED) { #ifdef HINT_NUMBERS if (number_wrong(state, x, y)) ret |= DF_NUMBERWRONG; #endif ret |= DF_NUMBERED; } } else { #ifdef HINT_LIGHTS if (lights > 0) ret |= DF_LIT; #endif if (flags & F_LIGHT) { ret |= DF_LIGHT; #ifdef HINT_OVERLAPS if (lights > 1) ret |= DF_OVERLAP; #endif } if (flags & F_IMPOSSIBLE) ret |= DF_IMPOSSIBLE; } return ret; } static void tile_redraw(drawing *dr, game_drawstate *ds, const game_state *state, int x, int y) { unsigned int ds_flags = GRID(ds, flags, x, y); int dx = COORD(x), dy = COORD(y); int lit = (ds_flags & DF_FLASH) ? COL_GRID : COL_LIT; if (ds_flags & DF_BLACK) { draw_rect(dr, dx, dy, TILE_SIZE, TILE_SIZE, COL_BLACK); if (ds_flags & DF_NUMBERED) { int ccol = (ds_flags & DF_NUMBERWRONG) ? COL_ERROR : COL_LIGHT; char str[32]; /* We know that this won't change over the course of the game * so it's OK to ignore this when calculating whether or not * to redraw the tile. */ sprintf(str, "%d", GRID(state, lights, x, y)); draw_text(dr, dx + TILE_SIZE/2, dy + TILE_SIZE/2, FONT_VARIABLE, TILE_SIZE*3/5, ALIGN_VCENTRE | ALIGN_HCENTRE, ccol, str); } } else { draw_rect(dr, dx, dy, TILE_SIZE, TILE_SIZE, (ds_flags & DF_LIT) ? lit : COL_BACKGROUND); draw_rect_outline(dr, dx, dy, TILE_SIZE, TILE_SIZE, COL_GRID); if (ds_flags & DF_LIGHT) { int lcol = (ds_flags & DF_OVERLAP) ? COL_ERROR : COL_LIGHT; draw_circle(dr, dx + TILE_SIZE/2, dy + TILE_SIZE/2, TILE_RADIUS, lcol, COL_BLACK); } else if ((ds_flags & DF_IMPOSSIBLE)) { static int draw_blobs_when_lit = -1; if (draw_blobs_when_lit < 0) { char *env = getenv("LIGHTUP_LIT_BLOBS"); draw_blobs_when_lit = (!env || (env[0] == 'y' || env[0] == 'Y')); } if (!(ds_flags & DF_LIT) || draw_blobs_when_lit) { int rlen = TILE_SIZE / 4; draw_rect(dr, dx + TILE_SIZE/2 - rlen/2, dy + TILE_SIZE/2 - rlen/2, rlen, rlen, COL_BLACK); } } } if (ds_flags & DF_CURSOR) { int coff = TILE_SIZE/8; draw_rect_outline(dr, dx + coff, dy + coff, TILE_SIZE - coff*2, TILE_SIZE - coff*2, COL_CURSOR); } draw_update(dr, dx, dy, TILE_SIZE, TILE_SIZE); } static void game_redraw(drawing *dr, game_drawstate *ds, const game_state *oldstate, const game_state *state, int dir, const game_ui *ui, float animtime, float flashtime) { bool flashing = false; int x,y; if (flashtime) flashing = (int)(flashtime * 3 / FLASH_TIME) != 1; if (!ds->started) { draw_rect_outline(dr, COORD(0)-1, COORD(0)-1, TILE_SIZE * ds->w + 2, TILE_SIZE * ds->h + 2, COL_GRID); draw_update(dr, 0, 0, TILE_SIZE * ds->w + 2 * BORDER, TILE_SIZE * ds->h + 2 * BORDER); ds->started = true; } for (x = 0; x < ds->w; x++) { for (y = 0; y < ds->h; y++) { unsigned int ds_flags = tile_flags(ds, state, ui, x, y, flashing); if (ds_flags != GRID(ds, flags, x, y)) { GRID(ds, flags, x, y) = ds_flags; tile_redraw(dr, ds, state, x, y); } } } } static float game_anim_length(const game_state *oldstate, const game_state *newstate, int dir, game_ui *ui) { return 0.0F; } static float game_flash_length(const game_state *oldstate, const game_state *newstate, int dir, game_ui *ui) { if (!oldstate->completed && newstate->completed && !oldstate->used_solve && !newstate->used_solve) return FLASH_TIME; return 0.0F; } static void game_get_cursor_location(const game_ui *ui, const game_drawstate *ds, const game_state *state, const game_params *params, int *x, int *y, int *w, int *h) { if(ui->cur_visible) { *x = COORD(ui->cur_x); *y = COORD(ui->cur_y); *w = *h = TILE_SIZE; } } static int game_status(const game_state *state) { return state->completed ? +1 : 0; } static void game_print_size(const game_params *params, float *x, float *y) { int pw, ph; /* * I'll use 6mm squares by default. */ game_compute_size(params, 600, &pw, &ph); *x = pw / 100.0F; *y = ph / 100.0F; } static void game_print(drawing *dr, const game_state *state, int tilesize) { int w = state->w, h = state->h; int ink = print_mono_colour(dr, 0); int paper = print_mono_colour(dr, 1); int x, y; /* Ick: fake up `ds->tilesize' for macro expansion purposes */ game_drawstate ads, *ds = &ads; game_set_size(dr, ds, NULL, tilesize); /* * Border. */ print_line_width(dr, TILE_SIZE / 16); draw_rect_outline(dr, COORD(0), COORD(0), TILE_SIZE * w, TILE_SIZE * h, ink); /* * Grid. */ print_line_width(dr, TILE_SIZE / 24); for (x = 1; x < w; x++) draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h), ink); for (y = 1; y < h; y++) draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y), ink); /* * Grid contents. */ for (y = 0; y < h; y++) for (x = 0; x < w; x++) { unsigned int ds_flags = tile_flags(ds, state, NULL, x, y, false); int dx = COORD(x), dy = COORD(y); if (ds_flags & DF_BLACK) { draw_rect(dr, dx, dy, TILE_SIZE, TILE_SIZE, ink); if (ds_flags & DF_NUMBERED) { char str[32]; sprintf(str, "%d", GRID(state, lights, x, y)); draw_text(dr, dx + TILE_SIZE/2, dy + TILE_SIZE/2, FONT_VARIABLE, TILE_SIZE*3/5, ALIGN_VCENTRE | ALIGN_HCENTRE, paper, str); } } else if (ds_flags & DF_LIGHT) { draw_circle(dr, dx + TILE_SIZE/2, dy + TILE_SIZE/2, TILE_RADIUS, -1, ink); } } } #ifdef COMBINED #define thegame lightup #endif const struct game thegame = { "Light Up", "games.lightup", "lightup", default_params, game_fetch_preset, NULL, decode_params, encode_params, free_params, dup_params, true, game_configure, custom_params, validate_params, new_game_desc, validate_desc, new_game, dup_game, free_game, true, solve_game, true, game_can_format_as_text_now, game_text_format, new_ui, free_ui, encode_ui, decode_ui, NULL, /* game_request_keys */ game_changed_state, current_key_label, interpret_move, execute_move, PREFERRED_TILE_SIZE, game_compute_size, game_set_size, game_colours, game_new_drawstate, game_free_drawstate, game_redraw, game_anim_length, game_flash_length, game_get_cursor_location, game_status, true, false, game_print_size, game_print, false, /* wants_statusbar */ false, NULL, /* timing_state */ 0, /* flags */ }; #ifdef STANDALONE_SOLVER int main(int argc, char **argv) { game_params *p; game_state *s; char *id = NULL, *desc, *result; const char *err; int nsol, diff, really_verbose = 0; unsigned int sflags; while (--argc > 0) { char *p = *++argv; if (!strcmp(p, "-v")) { really_verbose++; } else if (*p == '-') { fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p); return 1; } else { id = p; } } if (!id) { fprintf(stderr, "usage: %s [-v] <game_id>\n", argv[0]); return 1; } desc = strchr(id, ':'); if (!desc) { fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]); return 1; } *desc++ = '\0'; p = default_params(); decode_params(p, id); err = validate_desc(p, desc); if (err) { fprintf(stderr, "%s: %s\n", argv[0], err); return 1; } s = new_game(NULL, p, desc); /* Run the solvers easiest to hardest until we find one that * can solve our puzzle. If it's soluble we know that the * hardest (recursive) solver will always find the solution. */ nsol = sflags = 0; for (diff = 0; diff <= DIFFCOUNT; diff++) { printf("\nSolving with difficulty %d.\n", diff); sflags = flags_from_difficulty(diff); unplace_lights(s); nsol = dosolve(s, sflags, NULL); if (nsol == 1) break; } printf("\n"); if (nsol == 0) { printf("Puzzle has no solution.\n"); } else if (nsol < 0) { printf("Unable to find a unique solution.\n"); } else if (nsol > 1) { printf("Puzzle has multiple solutions.\n"); } else { verbose = really_verbose; unplace_lights(s); printf("Puzzle has difficulty %d: solving...\n", diff); dosolve(s, sflags, NULL); /* sflags from last successful solve */ result = game_text_format(s); printf("%s", result); sfree(result); } return 0; } #endif /* vim: set shiftwidth=4 tabstop=8: */