4 * An implementation of the Nikoli game 'Loop the loop'.
5 * (c) Mike Pinna, 2005, 2006
6 * Substantially rewritten to allowing for more general types of grid.
7 * (c) Lambros Lambrou 2008
9 * vim: set shiftwidth=4 :set textwidth=80:
13 * Possible future solver enhancements:
15 * - There's an interesting deductive technique which makes use
16 * of topology rather than just graph theory. Each _face_ in
17 * the grid is either inside or outside the loop; you can tell
18 * that two faces are on the same side of the loop if they're
19 * separated by a LINE_NO (or, more generally, by a path
20 * crossing no LINE_UNKNOWNs and an even number of LINE_YESes),
21 * and on the opposite side of the loop if they're separated by
22 * a LINE_YES (or an odd number of LINE_YESes and no
23 * LINE_UNKNOWNs). Oh, and any face separated from the outside
24 * of the grid by a LINE_YES or a LINE_NO is on the inside or
25 * outside respectively. So if you can track this for all
26 * faces, you figure out the state of the line between a pair
27 * once their relative insideness is known.
28 * + The way I envisage this working is simply to keep an edsf
29 * of all _faces_, which indicates whether they're on
30 * opposite sides of the loop from one another. We also
31 * include a special entry in the edsf for the infinite
33 * + So, the simple way to do this is to just go through the
34 * edges: every time we see an edge in a state other than
35 * LINE_UNKNOWN which separates two faces that aren't in the
36 * same edsf class, we can rectify that by merging the
37 * classes. Then, conversely, an edge in LINE_UNKNOWN state
38 * which separates two faces that _are_ in the same edsf
39 * class can immediately have its state determined.
40 * + But you can go one better, if you're prepared to loop
41 * over all _pairs_ of edges. Suppose we have edges A and B,
42 * which respectively separate faces A1,A2 and B1,B2.
43 * Suppose that A,B are in the same edge-edsf class and that
44 * A1,B1 (wlog) are in the same face-edsf class; then we can
45 * immediately place A2,B2 into the same face-edsf class (as
46 * each other, not as A1 and A2) one way round or the other.
47 * And conversely again, if A1,B1 are in the same face-edsf
48 * class and so are A2,B2, then we can put A,B into the same
50 * * Of course, this deduction requires a quadratic-time
51 * loop over all pairs of edges in the grid, so it should
52 * be reserved until there's nothing easier left to be
55 * - The generalised grid support has made me (SGT) notice a
56 * possible extension to the loop-avoidance code. When you have
57 * a path of connected edges such that no other edges at all
58 * are incident on any vertex in the middle of the path - or,
59 * alternatively, such that any such edges are already known to
60 * be LINE_NO - then you know those edges are either all
61 * LINE_YES or all LINE_NO. Hence you can mentally merge the
62 * entire path into a single long curly edge for the purposes
63 * of loop avoidance, and look directly at whether or not the
64 * extreme endpoints of the path are connected by some other
65 * route. I find this coming up fairly often when I play on the
66 * octagonal grid setting, so it might be worth implementing in
69 * - (Just a speed optimisation.) Consider some todo list queue where every
70 * time we modify something we mark it for consideration by other bits of
71 * the solver, to save iteration over things that have already been done.
87 /* Debugging options */
95 /* ----------------------------------------------------------------------
96 * Struct, enum and function declarations
111 grid
*game_grid
; /* ref-counted (internally) */
113 /* Put -1 in a face that doesn't get a clue */
116 /* Array of line states, to store whether each line is
117 * YES, NO or UNKNOWN */
120 unsigned char *line_errors
;
121 int exactly_one_loop
;
126 /* Used in game_text_format(), so that it knows what type of
127 * grid it's trying to render as ASCII text. */
132 SOLVER_SOLVED
, /* This is the only solution the solver could find */
133 SOLVER_MISTAKE
, /* This is definitely not a solution */
134 SOLVER_AMBIGUOUS
, /* This _might_ be an ambiguous solution */
135 SOLVER_INCOMPLETE
/* This may be a partial solution */
138 /* ------ Solver state ------ */
139 typedef struct solver_state
{
141 enum solver_status solver_status
;
142 /* NB looplen is the number of dots that are joined together at a point, ie a
143 * looplen of 1 means there are no lines to a particular dot */
146 /* Difficulty level of solver. Used by solver functions that want to
147 * vary their behaviour depending on the requested difficulty level. */
153 char *face_yes_count
;
155 char *dot_solved
, *face_solved
;
158 /* Information for Normal level deductions:
159 * For each dline, store a bitmask for whether we know:
160 * (bit 0) at least one is YES
161 * (bit 1) at most one is YES */
164 /* Hard level information */
169 * Difficulty levels. I do some macro ickery here to ensure that my
170 * enum and the various forms of my name list always match up.
173 #define DIFFLIST(A) \
178 #define ENUM(upper,title,lower) DIFF_ ## upper,
179 #define TITLE(upper,title,lower) #title,
180 #define ENCODE(upper,title,lower) #lower
181 #define CONFIG(upper,title,lower) ":" #title
182 enum { DIFFLIST(ENUM
) DIFF_MAX
};
183 static char const *const diffnames
[] = { DIFFLIST(TITLE
) };
184 static char const diffchars
[] = DIFFLIST(ENCODE
);
185 #define DIFFCONFIG DIFFLIST(CONFIG)
188 * Solver routines, sorted roughly in order of computational cost.
189 * The solver will run the faster deductions first, and slower deductions are
190 * only invoked when the faster deductions are unable to make progress.
191 * Each function is associated with a difficulty level, so that the generated
192 * puzzles are solvable by applying only the functions with the chosen
193 * difficulty level or lower.
195 #define SOLVERLIST(A) \
196 A(trivial_deductions, DIFF_EASY) \
197 A(dline_deductions, DIFF_NORMAL) \
198 A(linedsf_deductions, DIFF_HARD) \
199 A(loop_deductions, DIFF_EASY)
200 #define SOLVER_FN_DECL(fn,diff) static int fn(solver_state *);
201 #define SOLVER_FN(fn,diff) &fn,
202 #define SOLVER_DIFF(fn,diff) diff,
203 SOLVERLIST(SOLVER_FN_DECL
)
204 static int (*(solver_fns
[]))(solver_state
*) = { SOLVERLIST(SOLVER_FN
) };
205 static int const solver_diffs
[] = { SOLVERLIST(SOLVER_DIFF
) };
206 static const int NUM_SOLVERS
= sizeof(solver_diffs
)/sizeof(*solver_diffs
);
214 /* line_drawstate is the same as line_state, but with the extra ERROR
215 * possibility. The drawing code copies line_state to line_drawstate,
216 * except in the case that the line is an error. */
217 enum line_state
{ LINE_YES
, LINE_UNKNOWN
, LINE_NO
};
218 enum line_drawstate
{ DS_LINE_YES
, DS_LINE_UNKNOWN
,
219 DS_LINE_NO
, DS_LINE_ERROR
};
221 #define OPP(line_state) \
225 struct game_drawstate
{
232 char *clue_satisfied
;
235 static char *validate_desc(const game_params
*params
, const char *desc
);
236 static int dot_order(const game_state
* state
, int i
, char line_type
);
237 static int face_order(const game_state
* state
, int i
, char line_type
);
238 static solver_state
*solve_game_rec(const solver_state
*sstate
);
241 static void check_caches(const solver_state
* sstate
);
243 #define check_caches(s)
247 * Grid type config options available in Loopy.
249 * Annoyingly, we have to use an enum here which doesn't match up
250 * exactly to the grid-type enum in grid.h. Values in params->types
251 * are given by names such as LOOPY_GRID_SQUARE, which shouldn't be
252 * confused with GRID_SQUARE which is the value you pass to grid_new()
253 * and friends. So beware!
255 * (This is partly for historical reasons - Loopy's version of the
256 * enum is encoded in game parameter strings, so we keep it for
257 * backwards compatibility. But also, we need to store additional data
258 * here alongside each enum value, such as names for the presets menu,
259 * which isn't stored in grid.h; so we have to have our own list macro
260 * here anyway, and C doesn't make it easy to enforce that that lines
261 * up exactly with grid.h.)
263 * Do not add values to this list _except_ at the end, or old game ids
266 #define GRIDLIST(A) \
267 A("Squares",SQUARE,3,3) \
268 A("Triangular",TRIANGULAR,3,3) \
269 A("Honeycomb",HONEYCOMB,3,3) \
270 A("Snub-Square",SNUBSQUARE,3,3) \
271 A("Cairo",CAIRO,3,4) \
272 A("Great-Hexagonal",GREATHEXAGONAL,3,3) \
273 A("Octagonal",OCTAGONAL,3,3) \
274 A("Kites",KITE,3,3) \
275 A("Floret",FLORET,1,2) \
276 A("Dodecagonal",DODECAGONAL,2,2) \
277 A("Great-Dodecagonal",GREATDODECAGONAL,2,2) \
278 A("Penrose (kite/dart)",PENROSE_P2,3,3) \
279 A("Penrose (rhombs)",PENROSE_P3,3,3) \
280 A("Great-Great-Dodecagonal",GREATGREATDODECAGONAL,2,2) \
283 #define GRID_NAME(title,type,amin,omin) title,
284 #define GRID_CONFIG(title,type,amin,omin) ":" title
285 #define GRID_LOOPYTYPE(title,type,amin,omin) LOOPY_GRID_ ## type,
286 #define GRID_GRIDTYPE(title,type,amin,omin) GRID_ ## type,
287 #define GRID_SIZES(title,type,amin,omin) \
289 "Width and height for this grid type must both be at least " #amin, \
290 "At least one of width and height for this grid type must be at least " #omin,},
291 enum { GRIDLIST(GRID_LOOPYTYPE
) };
292 static char const *const gridnames
[] = { GRIDLIST(GRID_NAME
) };
293 #define GRID_CONFIGS GRIDLIST(GRID_CONFIG)
294 static grid_type grid_types
[] = { GRIDLIST(GRID_GRIDTYPE
) };
295 #define NUM_GRID_TYPES (sizeof(grid_types) / sizeof(grid_types[0]))
296 static const struct {
299 } grid_size_limits
[] = { GRIDLIST(GRID_SIZES
) };
301 /* Generates a (dynamically allocated) new grid, according to the
302 * type and size requested in params. Does nothing if the grid is already
304 static grid
*loopy_generate_grid(const game_params
*params
,
305 const char *grid_desc
)
307 return grid_new(grid_types
[params
->type
], params
->w
, params
->h
, grid_desc
);
310 /* ----------------------------------------------------------------------
314 /* General constants */
315 #define PREFERRED_TILE_SIZE 32
316 #define BORDER(tilesize) ((tilesize) / 2)
317 #define FLASH_TIME 0.5F
319 #define BIT_SET(field, bit) ((field) & (1<<(bit)))
321 #define SET_BIT(field, bit) (BIT_SET(field, bit) ? FALSE : \
322 ((field) |= (1<<(bit)), TRUE))
324 #define CLEAR_BIT(field, bit) (BIT_SET(field, bit) ? \
325 ((field) &= ~(1<<(bit)), TRUE) : FALSE)
327 #define CLUE2CHAR(c) \
328 ((c < 0) ? ' ' : c < 10 ? c + '0' : c - 10 + 'A')
330 /* ----------------------------------------------------------------------
331 * General struct manipulation and other straightforward code
334 static game_state
*dup_game(const game_state
*state
)
336 game_state
*ret
= snew(game_state
);
338 ret
->game_grid
= state
->game_grid
;
339 ret
->game_grid
->refcount
++;
341 ret
->solved
= state
->solved
;
342 ret
->cheated
= state
->cheated
;
344 ret
->clues
= snewn(state
->game_grid
->num_faces
, signed char);
345 memcpy(ret
->clues
, state
->clues
, state
->game_grid
->num_faces
);
347 ret
->lines
= snewn(state
->game_grid
->num_edges
, char);
348 memcpy(ret
->lines
, state
->lines
, state
->game_grid
->num_edges
);
350 ret
->line_errors
= snewn(state
->game_grid
->num_edges
, unsigned char);
351 memcpy(ret
->line_errors
, state
->line_errors
, state
->game_grid
->num_edges
);
352 ret
->exactly_one_loop
= state
->exactly_one_loop
;
354 ret
->grid_type
= state
->grid_type
;
358 static void free_game(game_state
*state
)
361 grid_free(state
->game_grid
);
364 sfree(state
->line_errors
);
369 static solver_state
*new_solver_state(const game_state
*state
, int diff
) {
371 int num_dots
= state
->game_grid
->num_dots
;
372 int num_faces
= state
->game_grid
->num_faces
;
373 int num_edges
= state
->game_grid
->num_edges
;
374 solver_state
*ret
= snew(solver_state
);
376 ret
->state
= dup_game(state
);
378 ret
->solver_status
= SOLVER_INCOMPLETE
;
381 ret
->dotdsf
= snew_dsf(num_dots
);
382 ret
->looplen
= snewn(num_dots
, int);
384 for (i
= 0; i
< num_dots
; i
++) {
388 ret
->dot_solved
= snewn(num_dots
, char);
389 ret
->face_solved
= snewn(num_faces
, char);
390 memset(ret
->dot_solved
, FALSE
, num_dots
);
391 memset(ret
->face_solved
, FALSE
, num_faces
);
393 ret
->dot_yes_count
= snewn(num_dots
, char);
394 memset(ret
->dot_yes_count
, 0, num_dots
);
395 ret
->dot_no_count
= snewn(num_dots
, char);
396 memset(ret
->dot_no_count
, 0, num_dots
);
397 ret
->face_yes_count
= snewn(num_faces
, char);
398 memset(ret
->face_yes_count
, 0, num_faces
);
399 ret
->face_no_count
= snewn(num_faces
, char);
400 memset(ret
->face_no_count
, 0, num_faces
);
402 if (diff
< DIFF_NORMAL
) {
405 ret
->dlines
= snewn(2*num_edges
, char);
406 memset(ret
->dlines
, 0, 2*num_edges
);
409 if (diff
< DIFF_HARD
) {
412 ret
->linedsf
= snew_dsf(state
->game_grid
->num_edges
);
418 static void free_solver_state(solver_state
*sstate
) {
420 free_game(sstate
->state
);
421 sfree(sstate
->dotdsf
);
422 sfree(sstate
->looplen
);
423 sfree(sstate
->dot_solved
);
424 sfree(sstate
->face_solved
);
425 sfree(sstate
->dot_yes_count
);
426 sfree(sstate
->dot_no_count
);
427 sfree(sstate
->face_yes_count
);
428 sfree(sstate
->face_no_count
);
430 /* OK, because sfree(NULL) is a no-op */
431 sfree(sstate
->dlines
);
432 sfree(sstate
->linedsf
);
438 static solver_state
*dup_solver_state(const solver_state
*sstate
) {
439 game_state
*state
= sstate
->state
;
440 int num_dots
= state
->game_grid
->num_dots
;
441 int num_faces
= state
->game_grid
->num_faces
;
442 int num_edges
= state
->game_grid
->num_edges
;
443 solver_state
*ret
= snew(solver_state
);
445 ret
->state
= state
= dup_game(sstate
->state
);
447 ret
->solver_status
= sstate
->solver_status
;
448 ret
->diff
= sstate
->diff
;
450 ret
->dotdsf
= snewn(num_dots
, int);
451 ret
->looplen
= snewn(num_dots
, int);
452 memcpy(ret
->dotdsf
, sstate
->dotdsf
,
453 num_dots
* sizeof(int));
454 memcpy(ret
->looplen
, sstate
->looplen
,
455 num_dots
* sizeof(int));
457 ret
->dot_solved
= snewn(num_dots
, char);
458 ret
->face_solved
= snewn(num_faces
, char);
459 memcpy(ret
->dot_solved
, sstate
->dot_solved
, num_dots
);
460 memcpy(ret
->face_solved
, sstate
->face_solved
, num_faces
);
462 ret
->dot_yes_count
= snewn(num_dots
, char);
463 memcpy(ret
->dot_yes_count
, sstate
->dot_yes_count
, num_dots
);
464 ret
->dot_no_count
= snewn(num_dots
, char);
465 memcpy(ret
->dot_no_count
, sstate
->dot_no_count
, num_dots
);
467 ret
->face_yes_count
= snewn(num_faces
, char);
468 memcpy(ret
->face_yes_count
, sstate
->face_yes_count
, num_faces
);
469 ret
->face_no_count
= snewn(num_faces
, char);
470 memcpy(ret
->face_no_count
, sstate
->face_no_count
, num_faces
);
472 if (sstate
->dlines
) {
473 ret
->dlines
= snewn(2*num_edges
, char);
474 memcpy(ret
->dlines
, sstate
->dlines
,
480 if (sstate
->linedsf
) {
481 ret
->linedsf
= snewn(num_edges
, int);
482 memcpy(ret
->linedsf
, sstate
->linedsf
,
483 num_edges
* sizeof(int));
491 static game_params
*default_params(void)
493 game_params
*ret
= snew(game_params
);
502 ret
->diff
= DIFF_EASY
;
508 static game_params
*dup_params(const game_params
*params
)
510 game_params
*ret
= snew(game_params
);
512 *ret
= *params
; /* structure copy */
516 static const game_params loopy_presets_top
[] = {
518 { 7, 7, DIFF_EASY
, LOOPY_GRID_SQUARE
},
519 { 7, 7, DIFF_NORMAL
, LOOPY_GRID_SQUARE
},
520 { 7, 7, DIFF_HARD
, LOOPY_GRID_SQUARE
},
521 { 7, 7, DIFF_HARD
, LOOPY_GRID_TRIANGULAR
},
522 { 5, 5, DIFF_HARD
, LOOPY_GRID_SNUBSQUARE
},
523 { 7, 7, DIFF_HARD
, LOOPY_GRID_CAIRO
},
524 { 5, 5, DIFF_HARD
, LOOPY_GRID_KITE
},
525 { 6, 6, DIFF_HARD
, LOOPY_GRID_PENROSE_P2
},
526 { 6, 6, DIFF_HARD
, LOOPY_GRID_PENROSE_P3
},
528 { 7, 7, DIFF_EASY
, LOOPY_GRID_SQUARE
},
529 { 10, 10, DIFF_EASY
, LOOPY_GRID_SQUARE
},
530 { 7, 7, DIFF_NORMAL
, LOOPY_GRID_SQUARE
},
531 { 10, 10, DIFF_NORMAL
, LOOPY_GRID_SQUARE
},
532 { 7, 7, DIFF_HARD
, LOOPY_GRID_SQUARE
},
533 { 10, 10, DIFF_HARD
, LOOPY_GRID_SQUARE
},
534 { 12, 10, DIFF_HARD
, LOOPY_GRID_TRIANGULAR
},
535 { 7, 7, DIFF_HARD
, LOOPY_GRID_SNUBSQUARE
},
536 { 9, 9, DIFF_HARD
, LOOPY_GRID_CAIRO
},
537 { 5, 5, DIFF_HARD
, LOOPY_GRID_KITE
},
538 { 10, 10, DIFF_HARD
, LOOPY_GRID_PENROSE_P2
},
539 { 10, 10, DIFF_HARD
, LOOPY_GRID_PENROSE_P3
},
543 static const game_params loopy_presets_more
[] = {
545 { 7, 7, DIFF_HARD
, LOOPY_GRID_HONEYCOMB
},
546 { 5, 4, DIFF_HARD
, LOOPY_GRID_GREATHEXAGONAL
},
547 { 5, 5, DIFF_HARD
, LOOPY_GRID_OCTAGONAL
},
548 { 3, 3, DIFF_HARD
, LOOPY_GRID_FLORET
},
549 { 3, 3, DIFF_HARD
, LOOPY_GRID_DODECAGONAL
},
550 { 3, 3, DIFF_HARD
, LOOPY_GRID_GREATDODECAGONAL
},
551 { 3, 2, DIFF_HARD
, LOOPY_GRID_GREATGREATDODECAGONAL
},
553 { 10, 10, DIFF_HARD
, LOOPY_GRID_HONEYCOMB
},
554 { 5, 4, DIFF_HARD
, LOOPY_GRID_GREATHEXAGONAL
},
555 { 7, 7, DIFF_HARD
, LOOPY_GRID_OCTAGONAL
},
556 { 5, 5, DIFF_HARD
, LOOPY_GRID_FLORET
},
557 { 5, 4, DIFF_HARD
, LOOPY_GRID_DODECAGONAL
},
558 { 5, 4, DIFF_HARD
, LOOPY_GRID_GREATDODECAGONAL
},
559 { 5, 3, DIFF_HARD
, LOOPY_GRID_GREATGREATDODECAGONAL
},
563 static void preset_menu_add_preset_with_title(struct preset_menu
*menu
,
564 const game_params
*params
)
567 game_params
*dup_params
;
569 sprintf(buf
, "%dx%d %s - %s", params
->h
, params
->w
,
570 gridnames
[params
->type
], diffnames
[params
->diff
]);
572 dup_params
= snew(game_params
);
573 *dup_params
= *params
;
575 preset_menu_add_preset(menu
, dupstr(buf
), dup_params
);
578 static struct preset_menu
*game_preset_menu(void)
580 struct preset_menu
*top
, *more
;
583 top
= preset_menu_new();
584 for (i
= 0; i
< lenof(loopy_presets_top
); i
++)
585 preset_menu_add_preset_with_title(top
, &loopy_presets_top
[i
]);
587 more
= preset_menu_add_submenu(top
, dupstr("More..."));
588 for (i
= 0; i
< lenof(loopy_presets_more
); i
++)
589 preset_menu_add_preset_with_title(more
, &loopy_presets_more
[i
]);
594 static void free_params(game_params
*params
)
599 static void decode_params(game_params
*params
, char const *string
)
601 params
->h
= params
->w
= atoi(string
);
602 params
->diff
= DIFF_EASY
;
603 while (*string
&& isdigit((unsigned char)*string
)) string
++;
604 if (*string
== 'x') {
606 params
->h
= atoi(string
);
607 while (*string
&& isdigit((unsigned char)*string
)) string
++;
609 if (*string
== 't') {
611 params
->type
= atoi(string
);
612 while (*string
&& isdigit((unsigned char)*string
)) string
++;
614 if (*string
== 'd') {
617 for (i
= 0; i
< DIFF_MAX
; i
++)
618 if (*string
== diffchars
[i
])
620 if (*string
) string
++;
624 static char *encode_params(const game_params
*params
, int full
)
627 sprintf(str
, "%dx%dt%d", params
->w
, params
->h
, params
->type
);
629 sprintf(str
+ strlen(str
), "d%c", diffchars
[params
->diff
]);
633 static config_item
*game_configure(const game_params
*params
)
638 ret
= snewn(5, config_item
);
640 ret
[0].name
= "Width";
641 ret
[0].type
= C_STRING
;
642 sprintf(buf
, "%d", params
->w
);
643 ret
[0].sval
= dupstr(buf
);
646 ret
[1].name
= "Height";
647 ret
[1].type
= C_STRING
;
648 sprintf(buf
, "%d", params
->h
);
649 ret
[1].sval
= dupstr(buf
);
652 ret
[2].name
= "Grid type";
653 ret
[2].type
= C_CHOICES
;
654 ret
[2].sval
= GRID_CONFIGS
;
655 ret
[2].ival
= params
->type
;
657 ret
[3].name
= "Difficulty";
658 ret
[3].type
= C_CHOICES
;
659 ret
[3].sval
= DIFFCONFIG
;
660 ret
[3].ival
= params
->diff
;
670 static game_params
*custom_params(const config_item
*cfg
)
672 game_params
*ret
= snew(game_params
);
674 ret
->w
= atoi(cfg
[0].sval
);
675 ret
->h
= atoi(cfg
[1].sval
);
676 ret
->type
= cfg
[2].ival
;
677 ret
->diff
= cfg
[3].ival
;
682 static char *validate_params(const game_params
*params
, int full
)
684 if (params
->type
< 0 || params
->type
>= NUM_GRID_TYPES
)
685 return "Illegal grid type";
686 if (params
->w
< grid_size_limits
[params
->type
].amin
||
687 params
->h
< grid_size_limits
[params
->type
].amin
)
688 return grid_size_limits
[params
->type
].aerr
;
689 if (params
->w
< grid_size_limits
[params
->type
].omin
&&
690 params
->h
< grid_size_limits
[params
->type
].omin
)
691 return grid_size_limits
[params
->type
].oerr
;
694 * This shouldn't be able to happen at all, since decode_params
695 * and custom_params will never generate anything that isn't
698 assert(params
->diff
< DIFF_MAX
);
703 /* Returns a newly allocated string describing the current puzzle */
704 static char *state_to_text(const game_state
*state
)
706 grid
*g
= state
->game_grid
;
708 int num_faces
= g
->num_faces
;
709 char *description
= snewn(num_faces
+ 1, char);
710 char *dp
= description
;
714 for (i
= 0; i
< num_faces
; i
++) {
715 if (state
->clues
[i
] < 0) {
716 if (empty_count
> 25) {
717 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
723 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
726 dp
+= sprintf(dp
, "%c", (int)CLUE2CHAR(state
->clues
[i
]));
731 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
733 retval
= dupstr(description
);
739 #define GRID_DESC_SEP '_'
741 /* Splits up a (optional) grid_desc from the game desc. Returns the
742 * grid_desc (which needs freeing) and updates the desc pointer to
743 * start of real desc, or returns NULL if no desc. */
744 static char *extract_grid_desc(const char **desc
)
746 char *sep
= strchr(*desc
, GRID_DESC_SEP
), *gd
;
749 if (!sep
) return NULL
;
751 gd_len
= sep
- (*desc
);
752 gd
= snewn(gd_len
+1, char);
753 memcpy(gd
, *desc
, gd_len
);
761 /* We require that the params pass the test in validate_params and that the
762 * description fills the entire game area */
763 static char *validate_desc(const game_params
*params
, const char *desc
)
767 char *grid_desc
, *ret
;
769 /* It's pretty inefficient to do this just for validation. All we need to
770 * know is the precise number of faces. */
771 grid_desc
= extract_grid_desc(&desc
);
772 ret
= grid_validate_desc(grid_types
[params
->type
], params
->w
, params
->h
, grid_desc
);
775 g
= loopy_generate_grid(params
, grid_desc
);
776 if (grid_desc
) sfree(grid_desc
);
778 for (; *desc
; ++desc
) {
779 if ((*desc
>= '0' && *desc
<= '9') || (*desc
>= 'A' && *desc
<= 'Z')) {
784 count
+= *desc
- 'a' + 1;
787 return "Unknown character in description";
790 if (count
< g
->num_faces
)
791 return "Description too short for board size";
792 if (count
> g
->num_faces
)
793 return "Description too long for board size";
800 /* Sums the lengths of the numbers in range [0,n) */
801 /* See equivalent function in solo.c for justification of this. */
802 static int len_0_to_n(int n
)
804 int len
= 1; /* Counting 0 as a bit of a special case */
807 for (i
= 1; i
< n
; i
*= 10) {
808 len
+= max(n
- i
, 0);
814 static char *encode_solve_move(const game_state
*state
)
819 int num_edges
= state
->game_grid
->num_edges
;
821 /* This is going to return a string representing the moves needed to set
822 * every line in a grid to be the same as the ones in 'state'. The exact
823 * length of this string is predictable. */
825 len
= 1; /* Count the 'S' prefix */
826 /* Numbers in all lines */
827 len
+= len_0_to_n(num_edges
);
828 /* For each line we also have a letter */
831 ret
= snewn(len
+ 1, char);
834 p
+= sprintf(p
, "S");
836 for (i
= 0; i
< num_edges
; i
++) {
837 switch (state
->lines
[i
]) {
839 p
+= sprintf(p
, "%dy", i
);
842 p
+= sprintf(p
, "%dn", i
);
847 /* No point in doing sums like that if they're going to be wrong */
848 assert(strlen(ret
) <= (size_t)len
);
852 static game_ui
*new_ui(const game_state
*state
)
857 static void free_ui(game_ui
*ui
)
861 static char *encode_ui(const game_ui
*ui
)
866 static void decode_ui(game_ui
*ui
, const char *encoding
)
870 static void game_changed_state(game_ui
*ui
, const game_state
*oldstate
,
871 const game_state
*newstate
)
875 static void game_compute_size(const game_params
*params
, int tilesize
,
878 int grid_width
, grid_height
, rendered_width
, rendered_height
;
881 grid_compute_size(grid_types
[params
->type
], params
->w
, params
->h
,
882 &g_tilesize
, &grid_width
, &grid_height
);
884 /* multiply first to minimise rounding error on integer division */
885 rendered_width
= grid_width
* tilesize
/ g_tilesize
;
886 rendered_height
= grid_height
* tilesize
/ g_tilesize
;
887 *x
= rendered_width
+ 2 * BORDER(tilesize
) + 1;
888 *y
= rendered_height
+ 2 * BORDER(tilesize
) + 1;
891 static void game_set_size(drawing
*dr
, game_drawstate
*ds
,
892 const game_params
*params
, int tilesize
)
894 ds
->tilesize
= tilesize
;
897 static float *game_colours(frontend
*fe
, int *ncolours
)
899 float *ret
= snewn(3 * NCOLOURS
, float);
901 frontend_default_colour(fe
, &ret
[COL_BACKGROUND
* 3]);
903 ret
[COL_FOREGROUND
* 3 + 0] = 0.0F
;
904 ret
[COL_FOREGROUND
* 3 + 1] = 0.0F
;
905 ret
[COL_FOREGROUND
* 3 + 2] = 0.0F
;
908 * We want COL_LINEUNKNOWN to be a yellow which is a bit darker
909 * than the background. (I previously set it to 0.8,0.8,0, but
910 * found that this went badly with the 0.8,0.8,0.8 favoured as a
911 * background by the Java frontend.)
913 ret
[COL_LINEUNKNOWN
* 3 + 0] = ret
[COL_BACKGROUND
* 3 + 0] * 0.9F
;
914 ret
[COL_LINEUNKNOWN
* 3 + 1] = ret
[COL_BACKGROUND
* 3 + 1] * 0.9F
;
915 ret
[COL_LINEUNKNOWN
* 3 + 2] = 0.0F
;
917 ret
[COL_HIGHLIGHT
* 3 + 0] = 1.0F
;
918 ret
[COL_HIGHLIGHT
* 3 + 1] = 1.0F
;
919 ret
[COL_HIGHLIGHT
* 3 + 2] = 1.0F
;
921 ret
[COL_MISTAKE
* 3 + 0] = 1.0F
;
922 ret
[COL_MISTAKE
* 3 + 1] = 0.0F
;
923 ret
[COL_MISTAKE
* 3 + 2] = 0.0F
;
925 ret
[COL_SATISFIED
* 3 + 0] = 0.0F
;
926 ret
[COL_SATISFIED
* 3 + 1] = 0.0F
;
927 ret
[COL_SATISFIED
* 3 + 2] = 0.0F
;
929 /* We want the faint lines to be a bit darker than the background.
930 * Except if the background is pretty dark already; then it ought to be a
931 * bit lighter. Oy vey.
933 ret
[COL_FAINT
* 3 + 0] = ret
[COL_BACKGROUND
* 3 + 0] * 0.9F
;
934 ret
[COL_FAINT
* 3 + 1] = ret
[COL_BACKGROUND
* 3 + 1] * 0.9F
;
935 ret
[COL_FAINT
* 3 + 2] = ret
[COL_BACKGROUND
* 3 + 2] * 0.9F
;
937 *ncolours
= NCOLOURS
;
941 static game_drawstate
*game_new_drawstate(drawing
*dr
, const game_state
*state
)
943 struct game_drawstate
*ds
= snew(struct game_drawstate
);
944 int num_faces
= state
->game_grid
->num_faces
;
945 int num_edges
= state
->game_grid
->num_edges
;
950 ds
->lines
= snewn(num_edges
, char);
951 ds
->clue_error
= snewn(num_faces
, char);
952 ds
->clue_satisfied
= snewn(num_faces
, char);
953 ds
->textx
= snewn(num_faces
, int);
954 ds
->texty
= snewn(num_faces
, int);
957 memset(ds
->lines
, LINE_UNKNOWN
, num_edges
);
958 memset(ds
->clue_error
, 0, num_faces
);
959 memset(ds
->clue_satisfied
, 0, num_faces
);
960 for (i
= 0; i
< num_faces
; i
++)
961 ds
->textx
[i
] = ds
->texty
[i
] = -1;
966 static void game_free_drawstate(drawing
*dr
, game_drawstate
*ds
)
970 sfree(ds
->clue_error
);
971 sfree(ds
->clue_satisfied
);
976 static int game_timing_state(const game_state
*state
, game_ui
*ui
)
981 static float game_anim_length(const game_state
*oldstate
,
982 const game_state
*newstate
, int dir
, game_ui
*ui
)
987 static int game_can_format_as_text_now(const game_params
*params
)
989 if (params
->type
!= 0)
994 static char *game_text_format(const game_state
*state
)
1000 grid
*g
= state
->game_grid
;
1003 assert(state
->grid_type
== 0);
1005 /* Work out the basic size unit */
1006 f
= g
->faces
; /* first face */
1007 assert(f
->order
== 4);
1008 /* The dots are ordered clockwise, so the two opposite
1009 * corners are guaranteed to span the square */
1010 cell_size
= abs(f
->dots
[0]->x
- f
->dots
[2]->x
);
1012 w
= (g
->highest_x
- g
->lowest_x
) / cell_size
;
1013 h
= (g
->highest_y
- g
->lowest_y
) / cell_size
;
1015 /* Create a blank "canvas" to "draw" on */
1018 ret
= snewn(W
* H
+ 1, char);
1019 for (y
= 0; y
< H
; y
++) {
1020 for (x
= 0; x
< W
-1; x
++) {
1023 ret
[y
*W
+ W
-1] = '\n';
1027 /* Fill in edge info */
1028 for (i
= 0; i
< g
->num_edges
; i
++) {
1029 grid_edge
*e
= g
->edges
+ i
;
1030 /* Cell coordinates, from (0,0) to (w-1,h-1) */
1031 int x1
= (e
->dot1
->x
- g
->lowest_x
) / cell_size
;
1032 int x2
= (e
->dot2
->x
- g
->lowest_x
) / cell_size
;
1033 int y1
= (e
->dot1
->y
- g
->lowest_y
) / cell_size
;
1034 int y2
= (e
->dot2
->y
- g
->lowest_y
) / cell_size
;
1035 /* Midpoint, in canvas coordinates (canvas coordinates are just twice
1036 * cell coordinates) */
1039 switch (state
->lines
[i
]) {
1041 ret
[y
*W
+ x
] = (y1
== y2
) ? '-' : '|';
1047 break; /* already a space */
1049 assert(!"Illegal line state");
1054 for (i
= 0; i
< g
->num_faces
; i
++) {
1058 assert(f
->order
== 4);
1059 /* Cell coordinates, from (0,0) to (w-1,h-1) */
1060 x1
= (f
->dots
[0]->x
- g
->lowest_x
) / cell_size
;
1061 x2
= (f
->dots
[2]->x
- g
->lowest_x
) / cell_size
;
1062 y1
= (f
->dots
[0]->y
- g
->lowest_y
) / cell_size
;
1063 y2
= (f
->dots
[2]->y
- g
->lowest_y
) / cell_size
;
1064 /* Midpoint, in canvas coordinates */
1067 ret
[y
*W
+ x
] = CLUE2CHAR(state
->clues
[i
]);
1072 /* ----------------------------------------------------------------------
1077 static void check_caches(const solver_state
* sstate
)
1080 const game_state
*state
= sstate
->state
;
1081 const grid
*g
= state
->game_grid
;
1083 for (i
= 0; i
< g
->num_dots
; i
++) {
1084 assert(dot_order(state
, i
, LINE_YES
) == sstate
->dot_yes_count
[i
]);
1085 assert(dot_order(state
, i
, LINE_NO
) == sstate
->dot_no_count
[i
]);
1088 for (i
= 0; i
< g
->num_faces
; i
++) {
1089 assert(face_order(state
, i
, LINE_YES
) == sstate
->face_yes_count
[i
]);
1090 assert(face_order(state
, i
, LINE_NO
) == sstate
->face_no_count
[i
]);
1095 #define check_caches(s) \
1097 fprintf(stderr, "check_caches at line %d\n", __LINE__); \
1101 #endif /* DEBUG_CACHES */
1103 /* ----------------------------------------------------------------------
1104 * Solver utility functions
1107 /* Sets the line (with index i) to the new state 'line_new', and updates
1108 * the cached counts of any affected faces and dots.
1109 * Returns TRUE if this actually changed the line's state. */
1110 static int solver_set_line(solver_state
*sstate
, int i
,
1111 enum line_state line_new
1113 , const char *reason
1117 game_state
*state
= sstate
->state
;
1121 assert(line_new
!= LINE_UNKNOWN
);
1123 check_caches(sstate
);
1125 if (state
->lines
[i
] == line_new
) {
1126 return FALSE
; /* nothing changed */
1128 state
->lines
[i
] = line_new
;
1131 fprintf(stderr
, "solver: set line [%d] to %s (%s)\n",
1132 i
, line_new
== LINE_YES
? "YES" : "NO",
1136 g
= state
->game_grid
;
1139 /* Update the cache for both dots and both faces affected by this. */
1140 if (line_new
== LINE_YES
) {
1141 sstate
->dot_yes_count
[e
->dot1
- g
->dots
]++;
1142 sstate
->dot_yes_count
[e
->dot2
- g
->dots
]++;
1144 sstate
->face_yes_count
[e
->face1
- g
->faces
]++;
1147 sstate
->face_yes_count
[e
->face2
- g
->faces
]++;
1150 sstate
->dot_no_count
[e
->dot1
- g
->dots
]++;
1151 sstate
->dot_no_count
[e
->dot2
- g
->dots
]++;
1153 sstate
->face_no_count
[e
->face1
- g
->faces
]++;
1156 sstate
->face_no_count
[e
->face2
- g
->faces
]++;
1160 check_caches(sstate
);
1165 #define solver_set_line(a, b, c) \
1166 solver_set_line(a, b, c, __FUNCTION__)
1170 * Merge two dots due to the existence of an edge between them.
1171 * Updates the dsf tracking equivalence classes, and keeps track of
1172 * the length of path each dot is currently a part of.
1173 * Returns TRUE if the dots were already linked, ie if they are part of a
1174 * closed loop, and false otherwise.
1176 static int merge_dots(solver_state
*sstate
, int edge_index
)
1179 grid
*g
= sstate
->state
->game_grid
;
1180 grid_edge
*e
= g
->edges
+ edge_index
;
1182 i
= e
->dot1
- g
->dots
;
1183 j
= e
->dot2
- g
->dots
;
1185 i
= dsf_canonify(sstate
->dotdsf
, i
);
1186 j
= dsf_canonify(sstate
->dotdsf
, j
);
1191 len
= sstate
->looplen
[i
] + sstate
->looplen
[j
];
1192 dsf_merge(sstate
->dotdsf
, i
, j
);
1193 i
= dsf_canonify(sstate
->dotdsf
, i
);
1194 sstate
->looplen
[i
] = len
;
1199 /* Merge two lines because the solver has deduced that they must be either
1200 * identical or opposite. Returns TRUE if this is new information, otherwise
1202 static int merge_lines(solver_state
*sstate
, int i
, int j
, int inverse
1204 , const char *reason
1210 assert(i
< sstate
->state
->game_grid
->num_edges
);
1211 assert(j
< sstate
->state
->game_grid
->num_edges
);
1213 i
= edsf_canonify(sstate
->linedsf
, i
, &inv_tmp
);
1215 j
= edsf_canonify(sstate
->linedsf
, j
, &inv_tmp
);
1218 edsf_merge(sstate
->linedsf
, i
, j
, inverse
);
1222 fprintf(stderr
, "%s [%d] [%d] %s(%s)\n",
1224 inverse
? "inverse " : "", reason
);
1231 #define merge_lines(a, b, c, d) \
1232 merge_lines(a, b, c, d, __FUNCTION__)
1235 /* Count the number of lines of a particular type currently going into the
1237 static int dot_order(const game_state
* state
, int dot
, char line_type
)
1240 grid
*g
= state
->game_grid
;
1241 grid_dot
*d
= g
->dots
+ dot
;
1244 for (i
= 0; i
< d
->order
; i
++) {
1245 grid_edge
*e
= d
->edges
[i
];
1246 if (state
->lines
[e
- g
->edges
] == line_type
)
1252 /* Count the number of lines of a particular type currently surrounding the
1254 static int face_order(const game_state
* state
, int face
, char line_type
)
1257 grid
*g
= state
->game_grid
;
1258 grid_face
*f
= g
->faces
+ face
;
1261 for (i
= 0; i
< f
->order
; i
++) {
1262 grid_edge
*e
= f
->edges
[i
];
1263 if (state
->lines
[e
- g
->edges
] == line_type
)
1269 /* Set all lines bordering a dot of type old_type to type new_type
1270 * Return value tells caller whether this function actually did anything */
1271 static int dot_setall(solver_state
*sstate
, int dot
,
1272 char old_type
, char new_type
)
1274 int retval
= FALSE
, r
;
1275 game_state
*state
= sstate
->state
;
1280 if (old_type
== new_type
)
1283 g
= state
->game_grid
;
1286 for (i
= 0; i
< d
->order
; i
++) {
1287 int line_index
= d
->edges
[i
] - g
->edges
;
1288 if (state
->lines
[line_index
] == old_type
) {
1289 r
= solver_set_line(sstate
, line_index
, new_type
);
1297 /* Set all lines bordering a face of type old_type to type new_type */
1298 static int face_setall(solver_state
*sstate
, int face
,
1299 char old_type
, char new_type
)
1301 int retval
= FALSE
, r
;
1302 game_state
*state
= sstate
->state
;
1307 if (old_type
== new_type
)
1310 g
= state
->game_grid
;
1311 f
= g
->faces
+ face
;
1313 for (i
= 0; i
< f
->order
; i
++) {
1314 int line_index
= f
->edges
[i
] - g
->edges
;
1315 if (state
->lines
[line_index
] == old_type
) {
1316 r
= solver_set_line(sstate
, line_index
, new_type
);
1324 /* ----------------------------------------------------------------------
1325 * Loop generation and clue removal
1328 static void add_full_clues(game_state
*state
, random_state
*rs
)
1330 signed char *clues
= state
->clues
;
1331 grid
*g
= state
->game_grid
;
1332 char *board
= snewn(g
->num_faces
, char);
1335 generate_loop(g
, board
, rs
, NULL
, NULL
);
1337 /* Fill out all the clues by initialising to 0, then iterating over
1338 * all edges and incrementing each clue as we find edges that border
1339 * between BLACK/WHITE faces. While we're at it, we verify that the
1340 * algorithm does work, and there aren't any GREY faces still there. */
1341 memset(clues
, 0, g
->num_faces
);
1342 for (i
= 0; i
< g
->num_edges
; i
++) {
1343 grid_edge
*e
= g
->edges
+ i
;
1344 grid_face
*f1
= e
->face1
;
1345 grid_face
*f2
= e
->face2
;
1346 enum face_colour c1
= FACE_COLOUR(f1
);
1347 enum face_colour c2
= FACE_COLOUR(f2
);
1348 assert(c1
!= FACE_GREY
);
1349 assert(c2
!= FACE_GREY
);
1351 if (f1
) clues
[f1
- g
->faces
]++;
1352 if (f2
) clues
[f2
- g
->faces
]++;
1359 static int game_has_unique_soln(const game_state
*state
, int diff
)
1362 solver_state
*sstate_new
;
1363 solver_state
*sstate
= new_solver_state((game_state
*)state
, diff
);
1365 sstate_new
= solve_game_rec(sstate
);
1367 assert(sstate_new
->solver_status
!= SOLVER_MISTAKE
);
1368 ret
= (sstate_new
->solver_status
== SOLVER_SOLVED
);
1370 free_solver_state(sstate_new
);
1371 free_solver_state(sstate
);
1377 /* Remove clues one at a time at random. */
1378 static game_state
*remove_clues(game_state
*state
, random_state
*rs
,
1382 int num_faces
= state
->game_grid
->num_faces
;
1383 game_state
*ret
= dup_game(state
), *saved_ret
;
1386 /* We need to remove some clues. We'll do this by forming a list of all
1387 * available clues, shuffling it, then going along one at a
1388 * time clearing each clue in turn for which doing so doesn't render the
1389 * board unsolvable. */
1390 face_list
= snewn(num_faces
, int);
1391 for (n
= 0; n
< num_faces
; ++n
) {
1395 shuffle(face_list
, num_faces
, sizeof(int), rs
);
1397 for (n
= 0; n
< num_faces
; ++n
) {
1398 saved_ret
= dup_game(ret
);
1399 ret
->clues
[face_list
[n
]] = -1;
1401 if (game_has_unique_soln(ret
, diff
)) {
1402 free_game(saved_ret
);
1414 static char *new_game_desc(const game_params
*params
, random_state
*rs
,
1415 char **aux
, int interactive
)
1417 /* solution and description both use run-length encoding in obvious ways */
1418 char *retval
, *game_desc
, *grid_desc
;
1420 game_state
*state
= snew(game_state
);
1421 game_state
*state_new
;
1423 grid_desc
= grid_new_desc(grid_types
[params
->type
], params
->w
, params
->h
, rs
);
1424 state
->game_grid
= g
= loopy_generate_grid(params
, grid_desc
);
1426 state
->clues
= snewn(g
->num_faces
, signed char);
1427 state
->lines
= snewn(g
->num_edges
, char);
1428 state
->line_errors
= snewn(g
->num_edges
, unsigned char);
1429 state
->exactly_one_loop
= FALSE
;
1431 state
->grid_type
= params
->type
;
1435 memset(state
->lines
, LINE_UNKNOWN
, g
->num_edges
);
1436 memset(state
->line_errors
, 0, g
->num_edges
);
1438 state
->solved
= state
->cheated
= FALSE
;
1440 /* Get a new random solvable board with all its clues filled in. Yes, this
1441 * can loop for ever if the params are suitably unfavourable, but
1442 * preventing games smaller than 4x4 seems to stop this happening */
1444 add_full_clues(state
, rs
);
1445 } while (!game_has_unique_soln(state
, params
->diff
));
1447 state_new
= remove_clues(state
, rs
, params
->diff
);
1452 if (params
->diff
> 0 && game_has_unique_soln(state
, params
->diff
-1)) {
1454 fprintf(stderr
, "Rejecting board, it is too easy\n");
1456 goto newboard_please
;
1459 game_desc
= state_to_text(state
);
1464 retval
= snewn(strlen(grid_desc
) + 1 + strlen(game_desc
) + 1, char);
1465 sprintf(retval
, "%s%c%s", grid_desc
, (int)GRID_DESC_SEP
, game_desc
);
1472 assert(!validate_desc(params
, retval
));
1477 static game_state
*new_game(midend
*me
, const game_params
*params
,
1481 game_state
*state
= snew(game_state
);
1482 int empties_to_make
= 0;
1487 int num_faces
, num_edges
;
1489 grid_desc
= extract_grid_desc(&desc
);
1490 state
->game_grid
= g
= loopy_generate_grid(params
, grid_desc
);
1491 if (grid_desc
) sfree(grid_desc
);
1495 num_faces
= g
->num_faces
;
1496 num_edges
= g
->num_edges
;
1498 state
->clues
= snewn(num_faces
, signed char);
1499 state
->lines
= snewn(num_edges
, char);
1500 state
->line_errors
= snewn(num_edges
, unsigned char);
1501 state
->exactly_one_loop
= FALSE
;
1503 state
->solved
= state
->cheated
= FALSE
;
1505 state
->grid_type
= params
->type
;
1507 for (i
= 0; i
< num_faces
; i
++) {
1508 if (empties_to_make
) {
1510 state
->clues
[i
] = -1;
1516 n2
= *dp
- 'A' + 10;
1517 if (n
>= 0 && n
< 10) {
1518 state
->clues
[i
] = n
;
1519 } else if (n2
>= 10 && n2
< 36) {
1520 state
->clues
[i
] = n2
;
1524 state
->clues
[i
] = -1;
1525 empties_to_make
= n
- 1;
1530 memset(state
->lines
, LINE_UNKNOWN
, num_edges
);
1531 memset(state
->line_errors
, 0, num_edges
);
1535 /* Calculates the line_errors data, and checks if the current state is a
1537 static int check_completion(game_state
*state
)
1539 grid
*g
= state
->game_grid
;
1541 int *dsf
, *component_state
;
1542 int nsilly
, nloop
, npath
, largest_comp
, largest_size
, total_pathsize
;
1543 enum { COMP_NONE
, COMP_LOOP
, COMP_PATH
, COMP_SILLY
, COMP_EMPTY
};
1545 memset(state
->line_errors
, 0, g
->num_edges
);
1548 * Find loops in the grid, and determine whether the puzzle is
1551 * Loopy is a bit more complicated than most puzzles that care
1552 * about loop detection. In most of them, loops are simply
1553 * _forbidden_; so the obviously right way to do
1554 * error-highlighting during play is to light up a graph edge red
1555 * iff it is part of a loop, which is exactly what the centralised
1556 * findloop.c makes easy.
1558 * But Loopy is unusual in that you're _supposed_ to be making a
1559 * loop - and yet _some_ loops are not the right loop. So we need
1560 * to be more discriminating, by identifying loops one by one and
1561 * then thinking about which ones to highlight, and so findloop.c
1562 * isn't quite the right tool for the job in this case.
1564 * Worse still, consider situations in which the grid contains a
1565 * loop and also some non-loop edges: there are some cases like
1566 * this in which the user's intuitive expectation would be to
1567 * highlight the loop (if you're only about half way through the
1568 * puzzle and have accidentally made a little loop in some corner
1569 * of the grid), and others in which they'd be more likely to
1570 * expect you to highlight the non-loop edges (if you've just
1571 * closed off a whole loop that you thought was the entire
1572 * solution, but forgot some disconnected edges in a corner
1573 * somewhere). So while it's easy enough to check whether the
1574 * solution is _right_, highlighting the wrong parts is a tricky
1575 * problem for this puzzle!
1577 * I'd quite like, in some situations, to identify the largest
1578 * loop among the player's YES edges, and then light up everything
1579 * other than that. But finding the longest cycle in a graph is an
1580 * NP-complete problem (because, in particular, it must return a
1581 * Hamilton cycle if one exists).
1583 * However, I think we can make the problem tractable by
1584 * exercising the Puzzles principle that it isn't absolutely
1585 * necessary to highlight _all_ errors: the key point is that by
1586 * the time the user has filled in the whole grid, they should
1587 * either have seen a completion flash, or have _some_ error
1588 * highlight showing them why the solution isn't right. So in
1589 * principle it would be *just about* good enough to highlight
1590 * just one error in the whole grid, if there was really no better
1591 * way. But we'd like to highlight as many errors as possible.
1593 * In this case, I think the simple approach is to make use of the
1594 * fact that no vertex may have degree > 2, and that's really
1595 * simple to detect. So the plan goes like this:
1597 * - Form the dsf of connected components of the graph vertices.
1599 * - Highlight an error at any vertex with degree > 2. (It so
1600 * happens that we do this by lighting up all the edges
1601 * incident to that vertex, but that's an output detail.)
1603 * - Any component that contains such a vertex is now excluded
1604 * from further consideration, because it already has a
1607 * - The remaining components have no vertex with degree > 2, and
1608 * hence they all consist of either a simple loop, or a simple
1609 * path with two endpoints.
1611 * - For these purposes, group together all the paths and imagine
1612 * them to be a single component (because in most normal
1613 * situations the player will gradually build up the solution
1614 * _not_ all in one connected segment, but as lots of separate
1615 * little path pieces that gradually connect to each other).
1617 * - After doing that, if there is exactly one (sensible)
1618 * component - be it a collection of paths or a loop - then
1619 * highlight no further edge errors. (The former case is normal
1620 * during play, and the latter is a potentially solved puzzle.)
1622 * - Otherwise, find the largest of the sensible components,
1623 * leave that one unhighlighted, and light the rest up in red.
1626 dsf
= snew_dsf(g
->num_dots
);
1628 /* Build the dsf. */
1629 for (i
= 0; i
< g
->num_edges
; i
++) {
1630 if (state
->lines
[i
] == LINE_YES
) {
1631 grid_edge
*e
= g
->edges
+ i
;
1632 int d1
= e
->dot1
- g
->dots
, d2
= e
->dot2
- g
->dots
;
1633 dsf_merge(dsf
, d1
, d2
);
1637 /* Initialise a state variable for each connected component. */
1638 component_state
= snewn(g
->num_dots
, int);
1639 for (i
= 0; i
< g
->num_dots
; i
++) {
1640 if (dsf_canonify(dsf
, i
) == i
)
1641 component_state
[i
] = COMP_LOOP
;
1643 component_state
[i
] = COMP_NONE
;
1646 /* Check for dots with degree > 3. Here we also spot dots of
1647 * degree 1 in which the user has marked all the non-edges as
1648 * LINE_NO, because those are also clear vertex-level errors, so
1649 * we give them the same treatment of excluding their connected
1650 * component from the subsequent loop analysis. */
1651 for (i
= 0; i
< g
->num_dots
; i
++) {
1652 int comp
= dsf_canonify(dsf
, i
);
1653 int yes
= dot_order(state
, i
, LINE_YES
);
1654 int unknown
= dot_order(state
, i
, LINE_UNKNOWN
);
1655 if ((yes
== 1 && unknown
== 0) || (yes
>= 3)) {
1656 /* violation, so mark all YES edges as errors */
1657 grid_dot
*d
= g
->dots
+ i
;
1659 for (j
= 0; j
< d
->order
; j
++) {
1660 int e
= d
->edges
[j
] - g
->edges
;
1661 if (state
->lines
[e
] == LINE_YES
)
1662 state
->line_errors
[e
] = TRUE
;
1664 /* And mark this component as not worthy of further
1666 component_state
[comp
] = COMP_SILLY
;
1668 } else if (yes
== 0) {
1669 /* A completely isolated dot must also be excluded it from
1670 * the subsequent loop highlighting pass, but we tag it
1671 * with a different enum value to avoid it counting
1672 * towards the components that inhibit returning a win
1674 component_state
[comp
] = COMP_EMPTY
;
1675 } else if (yes
== 1) {
1676 /* A dot with degree 1 that didn't fall into the 'clearly
1677 * erroneous' case above indicates that this connected
1678 * component will be a path rather than a loop - unless
1679 * something worse elsewhere in the component has
1680 * classified it as silly. */
1681 if (component_state
[comp
] != COMP_SILLY
)
1682 component_state
[comp
] = COMP_PATH
;
1686 /* Count up the components. Also, find the largest sensible
1687 * component. (Tie-breaking condition is derived from the order of
1688 * vertices in the grid data structure, which is fairly arbitrary
1689 * but at least stays stable throughout the game.) */
1690 nsilly
= nloop
= npath
= 0;
1692 largest_comp
= largest_size
= -1;
1693 for (i
= 0; i
< g
->num_dots
; i
++) {
1694 if (component_state
[i
] == COMP_SILLY
) {
1696 } else if (component_state
[i
] == COMP_PATH
) {
1697 total_pathsize
+= dsf_size(dsf
, i
);
1699 } else if (component_state
[i
] == COMP_LOOP
) {
1704 if ((this_size
= dsf_size(dsf
, i
)) > largest_size
) {
1706 largest_size
= this_size
;
1710 if (largest_size
< total_pathsize
) {
1711 largest_comp
= -1; /* means the paths */
1712 largest_size
= total_pathsize
;
1715 if (nloop
> 0 && nloop
+ npath
> 1) {
1717 * If there are at least two sensible components including at
1718 * least one loop, highlight all edges in every sensible
1719 * component that is not the largest one.
1721 for (i
= 0; i
< g
->num_edges
; i
++) {
1722 if (state
->lines
[i
] == LINE_YES
) {
1723 grid_edge
*e
= g
->edges
+ i
;
1724 int d1
= e
->dot1
- g
->dots
; /* either endpoint is good enough */
1725 int comp
= dsf_canonify(dsf
, d1
);
1726 if ((component_state
[comp
] == COMP_PATH
&&
1727 -1 != largest_comp
) ||
1728 (component_state
[comp
] == COMP_LOOP
&&
1729 comp
!= largest_comp
))
1730 state
->line_errors
[i
] = TRUE
;
1735 if (nloop
== 1 && npath
== 0 && nsilly
== 0) {
1737 * If there is exactly one component and it is a loop, then
1738 * the puzzle is potentially complete, so check the clues.
1742 for (i
= 0; i
< g
->num_faces
; i
++) {
1743 int c
= state
->clues
[i
];
1744 if (c
>= 0 && face_order(state
, i
, LINE_YES
) != c
) {
1751 * Also, whether or not the puzzle is actually complete, set
1752 * the flag that says this game_state has exactly one loop and
1753 * nothing else, which will be used to vary the semantics of
1754 * clue highlighting at display time.
1756 state
->exactly_one_loop
= TRUE
;
1759 state
->exactly_one_loop
= FALSE
;
1762 sfree(component_state
);
1768 /* ----------------------------------------------------------------------
1771 * Our solver modes operate as follows. Each mode also uses the modes above it.
1774 * Just implement the rules of the game.
1776 * Normal and Tricky Modes
1777 * For each (adjacent) pair of lines through each dot we store a bit for
1778 * whether at least one of them is on and whether at most one is on. (If we
1779 * know both or neither is on that's already stored more directly.)
1782 * Use edsf data structure to make equivalence classes of lines that are
1783 * known identical to or opposite to one another.
1788 * For general grids, we consider "dlines" to be pairs of lines joined
1789 * at a dot. The lines must be adjacent around the dot, so we can think of
1790 * a dline as being a dot+face combination. Or, a dot+edge combination where
1791 * the second edge is taken to be the next clockwise edge from the dot.
1792 * Original loopy code didn't have this extra restriction of the lines being
1793 * adjacent. From my tests with square grids, this extra restriction seems to
1794 * take little, if anything, away from the quality of the puzzles.
1795 * A dline can be uniquely identified by an edge/dot combination, given that
1796 * a dline-pair always goes clockwise around its common dot. The edge/dot
1797 * combination can be represented by an edge/bool combination - if bool is
1798 * TRUE, use edge->dot1 else use edge->dot2. So the total number of dlines is
1799 * exactly twice the number of edges in the grid - although the dlines
1800 * spanning the infinite face are not all that useful to the solver.
1801 * Note that, by convention, a dline goes clockwise around its common dot,
1802 * which means the dline goes anti-clockwise around its common face.
1805 /* Helper functions for obtaining an index into an array of dlines, given
1806 * various information. We assume the grid layout conventions about how
1807 * the various lists are interleaved - see grid_make_consistent() for
1810 /* i points to the first edge of the dline pair, reading clockwise around
1812 static int dline_index_from_dot(grid
*g
, grid_dot
*d
, int i
)
1814 grid_edge
*e
= d
->edges
[i
];
1819 if (i2
== d
->order
) i2
= 0;
1822 ret
= 2 * (e
- g
->edges
) + ((e
->dot1
== d
) ? 1 : 0);
1824 printf("dline_index_from_dot: d=%d,i=%d, edges [%d,%d] - %d\n",
1825 (int)(d
- g
->dots
), i
, (int)(e
- g
->edges
),
1826 (int)(e2
- g
->edges
), ret
);
1830 /* i points to the second edge of the dline pair, reading clockwise around
1831 * the face. That is, the edges of the dline, starting at edge{i}, read
1832 * anti-clockwise around the face. By layout conventions, the common dot
1833 * of the dline will be f->dots[i] */
1834 static int dline_index_from_face(grid
*g
, grid_face
*f
, int i
)
1836 grid_edge
*e
= f
->edges
[i
];
1837 grid_dot
*d
= f
->dots
[i
];
1842 if (i2
< 0) i2
+= f
->order
;
1845 ret
= 2 * (e
- g
->edges
) + ((e
->dot1
== d
) ? 1 : 0);
1847 printf("dline_index_from_face: f=%d,i=%d, edges [%d,%d] - %d\n",
1848 (int)(f
- g
->faces
), i
, (int)(e
- g
->edges
),
1849 (int)(e2
- g
->edges
), ret
);
1853 static int is_atleastone(const char *dline_array
, int index
)
1855 return BIT_SET(dline_array
[index
], 0);
1857 static int set_atleastone(char *dline_array
, int index
)
1859 return SET_BIT(dline_array
[index
], 0);
1861 static int is_atmostone(const char *dline_array
, int index
)
1863 return BIT_SET(dline_array
[index
], 1);
1865 static int set_atmostone(char *dline_array
, int index
)
1867 return SET_BIT(dline_array
[index
], 1);
1870 static void array_setall(char *array
, char from
, char to
, int len
)
1872 char *p
= array
, *p_old
= p
;
1873 int len_remaining
= len
;
1875 while ((p
= memchr(p
, from
, len_remaining
))) {
1877 len_remaining
-= p
- p_old
;
1882 /* Helper, called when doing dline dot deductions, in the case where we
1883 * have 4 UNKNOWNs, and two of them (adjacent) have *exactly* one YES between
1884 * them (because of dline atmostone/atleastone).
1885 * On entry, edge points to the first of these two UNKNOWNs. This function
1886 * will find the opposite UNKNOWNS (if they are adjacent to one another)
1887 * and set their corresponding dline to atleastone. (Setting atmostone
1888 * already happens in earlier dline deductions) */
1889 static int dline_set_opp_atleastone(solver_state
*sstate
,
1890 grid_dot
*d
, int edge
)
1892 game_state
*state
= sstate
->state
;
1893 grid
*g
= state
->game_grid
;
1896 for (opp
= 0; opp
< N
; opp
++) {
1897 int opp_dline_index
;
1898 if (opp
== edge
|| opp
== edge
+1 || opp
== edge
-1)
1900 if (opp
== 0 && edge
== N
-1)
1902 if (opp
== N
-1 && edge
== 0)
1905 if (opp2
== N
) opp2
= 0;
1906 /* Check if opp, opp2 point to LINE_UNKNOWNs */
1907 if (state
->lines
[d
->edges
[opp
] - g
->edges
] != LINE_UNKNOWN
)
1909 if (state
->lines
[d
->edges
[opp2
] - g
->edges
] != LINE_UNKNOWN
)
1911 /* Found opposite UNKNOWNS and they're next to each other */
1912 opp_dline_index
= dline_index_from_dot(g
, d
, opp
);
1913 return set_atleastone(sstate
->dlines
, opp_dline_index
);
1919 /* Set pairs of lines around this face which are known to be identical, to
1920 * the given line_state */
1921 static int face_setall_identical(solver_state
*sstate
, int face_index
,
1922 enum line_state line_new
)
1924 /* can[dir] contains the canonical line associated with the line in
1925 * direction dir from the square in question. Similarly inv[dir] is
1926 * whether or not the line in question is inverse to its canonical
1929 game_state
*state
= sstate
->state
;
1930 grid
*g
= state
->game_grid
;
1931 grid_face
*f
= g
->faces
+ face_index
;
1934 int can1
, can2
, inv1
, inv2
;
1936 for (i
= 0; i
< N
; i
++) {
1937 int line1_index
= f
->edges
[i
] - g
->edges
;
1938 if (state
->lines
[line1_index
] != LINE_UNKNOWN
)
1940 for (j
= i
+ 1; j
< N
; j
++) {
1941 int line2_index
= f
->edges
[j
] - g
->edges
;
1942 if (state
->lines
[line2_index
] != LINE_UNKNOWN
)
1945 /* Found two UNKNOWNS */
1946 can1
= edsf_canonify(sstate
->linedsf
, line1_index
, &inv1
);
1947 can2
= edsf_canonify(sstate
->linedsf
, line2_index
, &inv2
);
1948 if (can1
== can2
&& inv1
== inv2
) {
1949 solver_set_line(sstate
, line1_index
, line_new
);
1950 solver_set_line(sstate
, line2_index
, line_new
);
1957 /* Given a dot or face, and a count of LINE_UNKNOWNs, find them and
1958 * return the edge indices into e. */
1959 static void find_unknowns(game_state
*state
,
1960 grid_edge
**edge_list
, /* Edge list to search (from a face or a dot) */
1961 int expected_count
, /* Number of UNKNOWNs (comes from solver's cache) */
1962 int *e
/* Returned edge indices */)
1965 grid
*g
= state
->game_grid
;
1966 while (c
< expected_count
) {
1967 int line_index
= *edge_list
- g
->edges
;
1968 if (state
->lines
[line_index
] == LINE_UNKNOWN
) {
1976 /* If we have a list of edges, and we know whether the number of YESs should
1977 * be odd or even, and there are only a few UNKNOWNs, we can do some simple
1978 * linedsf deductions. This can be used for both face and dot deductions.
1979 * Returns the difficulty level of the next solver that should be used,
1980 * or DIFF_MAX if no progress was made. */
1981 static int parity_deductions(solver_state
*sstate
,
1982 grid_edge
**edge_list
, /* Edge list (from a face or a dot) */
1983 int total_parity
, /* Expected number of YESs modulo 2 (either 0 or 1) */
1986 game_state
*state
= sstate
->state
;
1987 int diff
= DIFF_MAX
;
1988 int *linedsf
= sstate
->linedsf
;
1990 if (unknown_count
== 2) {
1991 /* Lines are known alike/opposite, depending on inv. */
1993 find_unknowns(state
, edge_list
, 2, e
);
1994 if (merge_lines(sstate
, e
[0], e
[1], total_parity
))
1995 diff
= min(diff
, DIFF_HARD
);
1996 } else if (unknown_count
== 3) {
1998 int can
[3]; /* canonical edges */
1999 int inv
[3]; /* whether can[x] is inverse to e[x] */
2000 find_unknowns(state
, edge_list
, 3, e
);
2001 can
[0] = edsf_canonify(linedsf
, e
[0], inv
);
2002 can
[1] = edsf_canonify(linedsf
, e
[1], inv
+1);
2003 can
[2] = edsf_canonify(linedsf
, e
[2], inv
+2);
2004 if (can
[0] == can
[1]) {
2005 if (solver_set_line(sstate
, e
[2], (total_parity
^inv
[0]^inv
[1]) ?
2006 LINE_YES
: LINE_NO
))
2007 diff
= min(diff
, DIFF_EASY
);
2009 if (can
[0] == can
[2]) {
2010 if (solver_set_line(sstate
, e
[1], (total_parity
^inv
[0]^inv
[2]) ?
2011 LINE_YES
: LINE_NO
))
2012 diff
= min(diff
, DIFF_EASY
);
2014 if (can
[1] == can
[2]) {
2015 if (solver_set_line(sstate
, e
[0], (total_parity
^inv
[1]^inv
[2]) ?
2016 LINE_YES
: LINE_NO
))
2017 diff
= min(diff
, DIFF_EASY
);
2019 } else if (unknown_count
== 4) {
2021 int can
[4]; /* canonical edges */
2022 int inv
[4]; /* whether can[x] is inverse to e[x] */
2023 find_unknowns(state
, edge_list
, 4, e
);
2024 can
[0] = edsf_canonify(linedsf
, e
[0], inv
);
2025 can
[1] = edsf_canonify(linedsf
, e
[1], inv
+1);
2026 can
[2] = edsf_canonify(linedsf
, e
[2], inv
+2);
2027 can
[3] = edsf_canonify(linedsf
, e
[3], inv
+3);
2028 if (can
[0] == can
[1]) {
2029 if (merge_lines(sstate
, e
[2], e
[3], total_parity
^inv
[0]^inv
[1]))
2030 diff
= min(diff
, DIFF_HARD
);
2031 } else if (can
[0] == can
[2]) {
2032 if (merge_lines(sstate
, e
[1], e
[3], total_parity
^inv
[0]^inv
[2]))
2033 diff
= min(diff
, DIFF_HARD
);
2034 } else if (can
[0] == can
[3]) {
2035 if (merge_lines(sstate
, e
[1], e
[2], total_parity
^inv
[0]^inv
[3]))
2036 diff
= min(diff
, DIFF_HARD
);
2037 } else if (can
[1] == can
[2]) {
2038 if (merge_lines(sstate
, e
[0], e
[3], total_parity
^inv
[1]^inv
[2]))
2039 diff
= min(diff
, DIFF_HARD
);
2040 } else if (can
[1] == can
[3]) {
2041 if (merge_lines(sstate
, e
[0], e
[2], total_parity
^inv
[1]^inv
[3]))
2042 diff
= min(diff
, DIFF_HARD
);
2043 } else if (can
[2] == can
[3]) {
2044 if (merge_lines(sstate
, e
[0], e
[1], total_parity
^inv
[2]^inv
[3]))
2045 diff
= min(diff
, DIFF_HARD
);
2053 * These are the main solver functions.
2055 * Their return values are diff values corresponding to the lowest mode solver
2056 * that would notice the work that they have done. For example if the normal
2057 * mode solver adds actual lines or crosses, it will return DIFF_EASY as the
2058 * easy mode solver might be able to make progress using that. It doesn't make
2059 * sense for one of them to return a diff value higher than that of the
2062 * Each function returns the lowest value it can, as early as possible, in
2063 * order to try and pass as much work as possible back to the lower level
2064 * solvers which progress more quickly.
2067 /* PROPOSED NEW DESIGN:
2068 * We have a work queue consisting of 'events' notifying us that something has
2069 * happened that a particular solver mode might be interested in. For example
2070 * the hard mode solver might do something that helps the normal mode solver at
2071 * dot [x,y] in which case it will enqueue an event recording this fact. Then
2072 * we pull events off the work queue, and hand each in turn to the solver that
2073 * is interested in them. If a solver reports that it failed we pass the same
2074 * event on to progressively more advanced solvers and the loop detector. Once
2075 * we've exhausted an event, or it has helped us progress, we drop it and
2076 * continue to the next one. The events are sorted first in order of solver
2077 * complexity (easy first) then order of insertion (oldest first).
2078 * Once we run out of events we loop over each permitted solver in turn
2079 * (easiest first) until either a deduction is made (and an event therefore
2080 * emerges) or no further deductions can be made (in which case we've failed).
2083 * * How do we 'loop over' a solver when both dots and squares are concerned.
2084 * Answer: first all squares then all dots.
2087 static int trivial_deductions(solver_state
*sstate
)
2089 int i
, current_yes
, current_no
;
2090 game_state
*state
= sstate
->state
;
2091 grid
*g
= state
->game_grid
;
2092 int diff
= DIFF_MAX
;
2094 /* Per-face deductions */
2095 for (i
= 0; i
< g
->num_faces
; i
++) {
2096 grid_face
*f
= g
->faces
+ i
;
2098 if (sstate
->face_solved
[i
])
2101 current_yes
= sstate
->face_yes_count
[i
];
2102 current_no
= sstate
->face_no_count
[i
];
2104 if (current_yes
+ current_no
== f
->order
) {
2105 sstate
->face_solved
[i
] = TRUE
;
2109 if (state
->clues
[i
] < 0)
2113 * This code checks whether the numeric clue on a face is so
2114 * large as to permit all its remaining LINE_UNKNOWNs to be
2115 * filled in as LINE_YES, or alternatively so small as to
2116 * permit them all to be filled in as LINE_NO.
2119 if (state
->clues
[i
] < current_yes
) {
2120 sstate
->solver_status
= SOLVER_MISTAKE
;
2123 if (state
->clues
[i
] == current_yes
) {
2124 if (face_setall(sstate
, i
, LINE_UNKNOWN
, LINE_NO
))
2125 diff
= min(diff
, DIFF_EASY
);
2126 sstate
->face_solved
[i
] = TRUE
;
2130 if (f
->order
- state
->clues
[i
] < current_no
) {
2131 sstate
->solver_status
= SOLVER_MISTAKE
;
2134 if (f
->order
- state
->clues
[i
] == current_no
) {
2135 if (face_setall(sstate
, i
, LINE_UNKNOWN
, LINE_YES
))
2136 diff
= min(diff
, DIFF_EASY
);
2137 sstate
->face_solved
[i
] = TRUE
;
2141 if (f
->order
- state
->clues
[i
] == current_no
+ 1 &&
2142 f
->order
- current_yes
- current_no
> 2) {
2144 * One small refinement to the above: we also look for any
2145 * adjacent pair of LINE_UNKNOWNs around the face with
2146 * some LINE_YES incident on it from elsewhere. If we find
2147 * one, then we know that pair of LINE_UNKNOWNs can't
2148 * _both_ be LINE_YES, and hence that pushes us one line
2149 * closer to being able to determine all the rest.
2151 int j
, k
, e1
, e2
, e
, d
;
2153 for (j
= 0; j
< f
->order
; j
++) {
2154 e1
= f
->edges
[j
] - g
->edges
;
2155 e2
= f
->edges
[j
+1 < f
->order
? j
+1 : 0] - g
->edges
;
2157 if (g
->edges
[e1
].dot1
== g
->edges
[e2
].dot1
||
2158 g
->edges
[e1
].dot1
== g
->edges
[e2
].dot2
) {
2159 d
= g
->edges
[e1
].dot1
- g
->dots
;
2161 assert(g
->edges
[e1
].dot2
== g
->edges
[e2
].dot1
||
2162 g
->edges
[e1
].dot2
== g
->edges
[e2
].dot2
);
2163 d
= g
->edges
[e1
].dot2
- g
->dots
;
2166 if (state
->lines
[e1
] == LINE_UNKNOWN
&&
2167 state
->lines
[e2
] == LINE_UNKNOWN
) {
2168 for (k
= 0; k
< g
->dots
[d
].order
; k
++) {
2169 int e
= g
->dots
[d
].edges
[k
] - g
->edges
;
2170 if (state
->lines
[e
] == LINE_YES
)
2171 goto found
; /* multi-level break */
2179 * If we get here, we've found such a pair of edges, and
2180 * they're e1 and e2.
2182 for (j
= 0; j
< f
->order
; j
++) {
2183 e
= f
->edges
[j
] - g
->edges
;
2184 if (state
->lines
[e
] == LINE_UNKNOWN
&& e
!= e1
&& e
!= e2
) {
2185 int r
= solver_set_line(sstate
, e
, LINE_YES
);
2187 diff
= min(diff
, DIFF_EASY
);
2193 check_caches(sstate
);
2195 /* Per-dot deductions */
2196 for (i
= 0; i
< g
->num_dots
; i
++) {
2197 grid_dot
*d
= g
->dots
+ i
;
2198 int yes
, no
, unknown
;
2200 if (sstate
->dot_solved
[i
])
2203 yes
= sstate
->dot_yes_count
[i
];
2204 no
= sstate
->dot_no_count
[i
];
2205 unknown
= d
->order
- yes
- no
;
2209 sstate
->dot_solved
[i
] = TRUE
;
2210 } else if (unknown
== 1) {
2211 dot_setall(sstate
, i
, LINE_UNKNOWN
, LINE_NO
);
2212 diff
= min(diff
, DIFF_EASY
);
2213 sstate
->dot_solved
[i
] = TRUE
;
2215 } else if (yes
== 1) {
2217 sstate
->solver_status
= SOLVER_MISTAKE
;
2219 } else if (unknown
== 1) {
2220 dot_setall(sstate
, i
, LINE_UNKNOWN
, LINE_YES
);
2221 diff
= min(diff
, DIFF_EASY
);
2223 } else if (yes
== 2) {
2225 dot_setall(sstate
, i
, LINE_UNKNOWN
, LINE_NO
);
2226 diff
= min(diff
, DIFF_EASY
);
2228 sstate
->dot_solved
[i
] = TRUE
;
2230 sstate
->solver_status
= SOLVER_MISTAKE
;
2235 check_caches(sstate
);
2240 static int dline_deductions(solver_state
*sstate
)
2242 game_state
*state
= sstate
->state
;
2243 grid
*g
= state
->game_grid
;
2244 char *dlines
= sstate
->dlines
;
2246 int diff
= DIFF_MAX
;
2248 /* ------ Face deductions ------ */
2250 /* Given a set of dline atmostone/atleastone constraints, need to figure
2251 * out if we can deduce any further info. For more general faces than
2252 * squares, this turns out to be a tricky problem.
2253 * The approach taken here is to define (per face) NxN matrices:
2254 * "maxs" and "mins".
2255 * The entries maxs(j,k) and mins(j,k) define the upper and lower limits
2256 * for the possible number of edges that are YES between positions j and k
2257 * going clockwise around the face. Can think of j and k as marking dots
2258 * around the face (recall the labelling scheme: edge0 joins dot0 to dot1,
2259 * edge1 joins dot1 to dot2 etc).
2260 * Trivially, mins(j,j) = maxs(j,j) = 0, and we don't even bother storing
2261 * these. mins(j,j+1) and maxs(j,j+1) are determined by whether edge{j}
2262 * is YES, NO or UNKNOWN. mins(j,j+2) and maxs(j,j+2) are related to
2263 * the dline atmostone/atleastone status for edges j and j+1.
2265 * Then we calculate the remaining entries recursively. We definitely
2267 * mins(j,k) >= { mins(j,u) + mins(u,k) } for any u between j and k.
2268 * This is because any valid placement of YESs between j and k must give
2269 * a valid placement between j and u, and also between u and k.
2270 * I believe it's sufficient to use just the two values of u:
2271 * j+1 and j+2. Seems to work well in practice - the bounds we compute
2272 * are rigorous, even if they might not be best-possible.
2274 * Once we have maxs and mins calculated, we can make inferences about
2275 * each dline{j,j+1} by looking at the possible complementary edge-counts
2276 * mins(j+2,j) and maxs(j+2,j) and comparing these with the face clue.
2277 * As well as dlines, we can make similar inferences about single edges.
2278 * For example, consider a pentagon with clue 3, and we know at most one
2279 * of (edge0, edge1) is YES, and at most one of (edge2, edge3) is YES.
2280 * We could then deduce edge4 is YES, because maxs(0,4) would be 2, so
2281 * that final edge would have to be YES to make the count up to 3.
2284 /* Much quicker to allocate arrays on the stack than the heap, so
2285 * define the largest possible face size, and base our array allocations
2286 * on that. We check this with an assertion, in case someone decides to
2287 * make a grid which has larger faces than this. Note, this algorithm
2288 * could get quite expensive if there are many large faces. */
2289 #define MAX_FACE_SIZE 12
2291 for (i
= 0; i
< g
->num_faces
; i
++) {
2292 int maxs
[MAX_FACE_SIZE
][MAX_FACE_SIZE
];
2293 int mins
[MAX_FACE_SIZE
][MAX_FACE_SIZE
];
2294 grid_face
*f
= g
->faces
+ i
;
2297 int clue
= state
->clues
[i
];
2298 assert(N
<= MAX_FACE_SIZE
);
2299 if (sstate
->face_solved
[i
])
2301 if (clue
< 0) continue;
2303 /* Calculate the (j,j+1) entries */
2304 for (j
= 0; j
< N
; j
++) {
2305 int edge_index
= f
->edges
[j
] - g
->edges
;
2307 enum line_state line1
= state
->lines
[edge_index
];
2308 enum line_state line2
;
2312 maxs
[j
][k
] = (line1
== LINE_NO
) ? 0 : 1;
2313 mins
[j
][k
] = (line1
== LINE_YES
) ? 1 : 0;
2314 /* Calculate the (j,j+2) entries */
2315 dline_index
= dline_index_from_face(g
, f
, k
);
2316 edge_index
= f
->edges
[k
] - g
->edges
;
2317 line2
= state
->lines
[edge_index
];
2323 if (line1
== LINE_NO
) tmp
--;
2324 if (line2
== LINE_NO
) tmp
--;
2325 if (tmp
== 2 && is_atmostone(dlines
, dline_index
))
2331 if (line1
== LINE_YES
) tmp
++;
2332 if (line2
== LINE_YES
) tmp
++;
2333 if (tmp
== 0 && is_atleastone(dlines
, dline_index
))
2338 /* Calculate the (j,j+m) entries for m between 3 and N-1 */
2339 for (m
= 3; m
< N
; m
++) {
2340 for (j
= 0; j
< N
; j
++) {
2348 maxs
[j
][k
] = maxs
[j
][u
] + maxs
[u
][k
];
2349 mins
[j
][k
] = mins
[j
][u
] + mins
[u
][k
];
2350 tmp
= maxs
[j
][v
] + maxs
[v
][k
];
2351 maxs
[j
][k
] = min(maxs
[j
][k
], tmp
);
2352 tmp
= mins
[j
][v
] + mins
[v
][k
];
2353 mins
[j
][k
] = max(mins
[j
][k
], tmp
);
2357 /* See if we can make any deductions */
2358 for (j
= 0; j
< N
; j
++) {
2360 grid_edge
*e
= f
->edges
[j
];
2361 int line_index
= e
- g
->edges
;
2364 if (state
->lines
[line_index
] != LINE_UNKNOWN
)
2369 /* minimum YESs in the complement of this edge */
2370 if (mins
[k
][j
] > clue
) {
2371 sstate
->solver_status
= SOLVER_MISTAKE
;
2374 if (mins
[k
][j
] == clue
) {
2375 /* setting this edge to YES would make at least
2376 * (clue+1) edges - contradiction */
2377 solver_set_line(sstate
, line_index
, LINE_NO
);
2378 diff
= min(diff
, DIFF_EASY
);
2380 if (maxs
[k
][j
] < clue
- 1) {
2381 sstate
->solver_status
= SOLVER_MISTAKE
;
2384 if (maxs
[k
][j
] == clue
- 1) {
2385 /* Only way to satisfy the clue is to set edge{j} as YES */
2386 solver_set_line(sstate
, line_index
, LINE_YES
);
2387 diff
= min(diff
, DIFF_EASY
);
2390 /* More advanced deduction that allows propagation along diagonal
2391 * chains of faces connected by dots, for example, 3-2-...-2-3
2392 * in square grids. */
2393 if (sstate
->diff
>= DIFF_TRICKY
) {
2394 /* Now see if we can make dline deduction for edges{j,j+1} */
2396 if (state
->lines
[e
- g
->edges
] != LINE_UNKNOWN
)
2397 /* Only worth doing this for an UNKNOWN,UNKNOWN pair.
2398 * Dlines where one of the edges is known, are handled in the
2402 dline_index
= dline_index_from_face(g
, f
, k
);
2406 /* minimum YESs in the complement of this dline */
2407 if (mins
[k
][j
] > clue
- 2) {
2408 /* Adding 2 YESs would break the clue */
2409 if (set_atmostone(dlines
, dline_index
))
2410 diff
= min(diff
, DIFF_NORMAL
);
2412 /* maximum YESs in the complement of this dline */
2413 if (maxs
[k
][j
] < clue
) {
2414 /* Adding 2 NOs would mean not enough YESs */
2415 if (set_atleastone(dlines
, dline_index
))
2416 diff
= min(diff
, DIFF_NORMAL
);
2422 if (diff
< DIFF_NORMAL
)
2425 /* ------ Dot deductions ------ */
2427 for (i
= 0; i
< g
->num_dots
; i
++) {
2428 grid_dot
*d
= g
->dots
+ i
;
2430 int yes
, no
, unknown
;
2432 if (sstate
->dot_solved
[i
])
2434 yes
= sstate
->dot_yes_count
[i
];
2435 no
= sstate
->dot_no_count
[i
];
2436 unknown
= N
- yes
- no
;
2438 for (j
= 0; j
< N
; j
++) {
2441 int line1_index
, line2_index
;
2442 enum line_state line1
, line2
;
2445 dline_index
= dline_index_from_dot(g
, d
, j
);
2446 line1_index
= d
->edges
[j
] - g
->edges
;
2447 line2_index
= d
->edges
[k
] - g
->edges
;
2448 line1
= state
->lines
[line1_index
];
2449 line2
= state
->lines
[line2_index
];
2451 /* Infer dline state from line state */
2452 if (line1
== LINE_NO
|| line2
== LINE_NO
) {
2453 if (set_atmostone(dlines
, dline_index
))
2454 diff
= min(diff
, DIFF_NORMAL
);
2456 if (line1
== LINE_YES
|| line2
== LINE_YES
) {
2457 if (set_atleastone(dlines
, dline_index
))
2458 diff
= min(diff
, DIFF_NORMAL
);
2460 /* Infer line state from dline state */
2461 if (is_atmostone(dlines
, dline_index
)) {
2462 if (line1
== LINE_YES
&& line2
== LINE_UNKNOWN
) {
2463 solver_set_line(sstate
, line2_index
, LINE_NO
);
2464 diff
= min(diff
, DIFF_EASY
);
2466 if (line2
== LINE_YES
&& line1
== LINE_UNKNOWN
) {
2467 solver_set_line(sstate
, line1_index
, LINE_NO
);
2468 diff
= min(diff
, DIFF_EASY
);
2471 if (is_atleastone(dlines
, dline_index
)) {
2472 if (line1
== LINE_NO
&& line2
== LINE_UNKNOWN
) {
2473 solver_set_line(sstate
, line2_index
, LINE_YES
);
2474 diff
= min(diff
, DIFF_EASY
);
2476 if (line2
== LINE_NO
&& line1
== LINE_UNKNOWN
) {
2477 solver_set_line(sstate
, line1_index
, LINE_YES
);
2478 diff
= min(diff
, DIFF_EASY
);
2481 /* Deductions that depend on the numbers of lines.
2482 * Only bother if both lines are UNKNOWN, otherwise the
2483 * easy-mode solver (or deductions above) would have taken
2485 if (line1
!= LINE_UNKNOWN
|| line2
!= LINE_UNKNOWN
)
2488 if (yes
== 0 && unknown
== 2) {
2489 /* Both these unknowns must be identical. If we know
2490 * atmostone or atleastone, we can make progress. */
2491 if (is_atmostone(dlines
, dline_index
)) {
2492 solver_set_line(sstate
, line1_index
, LINE_NO
);
2493 solver_set_line(sstate
, line2_index
, LINE_NO
);
2494 diff
= min(diff
, DIFF_EASY
);
2496 if (is_atleastone(dlines
, dline_index
)) {
2497 solver_set_line(sstate
, line1_index
, LINE_YES
);
2498 solver_set_line(sstate
, line2_index
, LINE_YES
);
2499 diff
= min(diff
, DIFF_EASY
);
2503 if (set_atmostone(dlines
, dline_index
))
2504 diff
= min(diff
, DIFF_NORMAL
);
2506 if (set_atleastone(dlines
, dline_index
))
2507 diff
= min(diff
, DIFF_NORMAL
);
2511 /* More advanced deduction that allows propagation along diagonal
2512 * chains of faces connected by dots, for example: 3-2-...-2-3
2513 * in square grids. */
2514 if (sstate
->diff
>= DIFF_TRICKY
) {
2515 /* If we have atleastone set for this dline, infer
2516 * atmostone for each "opposite" dline (that is, each
2517 * dline without edges in common with this one).
2518 * Again, this test is only worth doing if both these
2519 * lines are UNKNOWN. For if one of these lines were YES,
2520 * the (yes == 1) test above would kick in instead. */
2521 if (is_atleastone(dlines
, dline_index
)) {
2523 for (opp
= 0; opp
< N
; opp
++) {
2524 int opp_dline_index
;
2525 if (opp
== j
|| opp
== j
+1 || opp
== j
-1)
2527 if (j
== 0 && opp
== N
-1)
2529 if (j
== N
-1 && opp
== 0)
2531 opp_dline_index
= dline_index_from_dot(g
, d
, opp
);
2532 if (set_atmostone(dlines
, opp_dline_index
))
2533 diff
= min(diff
, DIFF_NORMAL
);
2535 if (yes
== 0 && is_atmostone(dlines
, dline_index
)) {
2536 /* This dline has *exactly* one YES and there are no
2537 * other YESs. This allows more deductions. */
2539 /* Third unknown must be YES */
2540 for (opp
= 0; opp
< N
; opp
++) {
2542 if (opp
== j
|| opp
== k
)
2544 opp_index
= d
->edges
[opp
] - g
->edges
;
2545 if (state
->lines
[opp_index
] == LINE_UNKNOWN
) {
2546 solver_set_line(sstate
, opp_index
,
2548 diff
= min(diff
, DIFF_EASY
);
2551 } else if (unknown
== 4) {
2552 /* Exactly one of opposite UNKNOWNS is YES. We've
2553 * already set atmostone, so set atleastone as
2556 if (dline_set_opp_atleastone(sstate
, d
, j
))
2557 diff
= min(diff
, DIFF_NORMAL
);
2567 static int linedsf_deductions(solver_state
*sstate
)
2569 game_state
*state
= sstate
->state
;
2570 grid
*g
= state
->game_grid
;
2571 char *dlines
= sstate
->dlines
;
2573 int diff
= DIFF_MAX
;
2576 /* ------ Face deductions ------ */
2578 /* A fully-general linedsf deduction seems overly complicated
2579 * (I suspect the problem is NP-complete, though in practice it might just
2580 * be doable because faces are limited in size).
2581 * For simplicity, we only consider *pairs* of LINE_UNKNOWNS that are
2582 * known to be identical. If setting them both to YES (or NO) would break
2583 * the clue, set them to NO (or YES). */
2585 for (i
= 0; i
< g
->num_faces
; i
++) {
2586 int N
, yes
, no
, unknown
;
2589 if (sstate
->face_solved
[i
])
2591 clue
= state
->clues
[i
];
2595 N
= g
->faces
[i
].order
;
2596 yes
= sstate
->face_yes_count
[i
];
2597 if (yes
+ 1 == clue
) {
2598 if (face_setall_identical(sstate
, i
, LINE_NO
))
2599 diff
= min(diff
, DIFF_EASY
);
2601 no
= sstate
->face_no_count
[i
];
2602 if (no
+ 1 == N
- clue
) {
2603 if (face_setall_identical(sstate
, i
, LINE_YES
))
2604 diff
= min(diff
, DIFF_EASY
);
2607 /* Reload YES count, it might have changed */
2608 yes
= sstate
->face_yes_count
[i
];
2609 unknown
= N
- no
- yes
;
2611 /* Deductions with small number of LINE_UNKNOWNs, based on overall
2612 * parity of lines. */
2613 diff_tmp
= parity_deductions(sstate
, g
->faces
[i
].edges
,
2614 (clue
- yes
) % 2, unknown
);
2615 diff
= min(diff
, diff_tmp
);
2618 /* ------ Dot deductions ------ */
2619 for (i
= 0; i
< g
->num_dots
; i
++) {
2620 grid_dot
*d
= g
->dots
+ i
;
2623 int yes
, no
, unknown
;
2624 /* Go through dlines, and do any dline<->linedsf deductions wherever
2625 * we find two UNKNOWNS. */
2626 for (j
= 0; j
< N
; j
++) {
2627 int dline_index
= dline_index_from_dot(g
, d
, j
);
2630 int can1
, can2
, inv1
, inv2
;
2632 line1_index
= d
->edges
[j
] - g
->edges
;
2633 if (state
->lines
[line1_index
] != LINE_UNKNOWN
)
2636 if (j2
== N
) j2
= 0;
2637 line2_index
= d
->edges
[j2
] - g
->edges
;
2638 if (state
->lines
[line2_index
] != LINE_UNKNOWN
)
2640 /* Infer dline flags from linedsf */
2641 can1
= edsf_canonify(sstate
->linedsf
, line1_index
, &inv1
);
2642 can2
= edsf_canonify(sstate
->linedsf
, line2_index
, &inv2
);
2643 if (can1
== can2
&& inv1
!= inv2
) {
2644 /* These are opposites, so set dline atmostone/atleastone */
2645 if (set_atmostone(dlines
, dline_index
))
2646 diff
= min(diff
, DIFF_NORMAL
);
2647 if (set_atleastone(dlines
, dline_index
))
2648 diff
= min(diff
, DIFF_NORMAL
);
2651 /* Infer linedsf from dline flags */
2652 if (is_atmostone(dlines
, dline_index
)
2653 && is_atleastone(dlines
, dline_index
)) {
2654 if (merge_lines(sstate
, line1_index
, line2_index
, 1))
2655 diff
= min(diff
, DIFF_HARD
);
2659 /* Deductions with small number of LINE_UNKNOWNs, based on overall
2660 * parity of lines. */
2661 yes
= sstate
->dot_yes_count
[i
];
2662 no
= sstate
->dot_no_count
[i
];
2663 unknown
= N
- yes
- no
;
2664 diff_tmp
= parity_deductions(sstate
, d
->edges
,
2666 diff
= min(diff
, diff_tmp
);
2669 /* ------ Edge dsf deductions ------ */
2671 /* If the state of a line is known, deduce the state of its canonical line
2672 * too, and vice versa. */
2673 for (i
= 0; i
< g
->num_edges
; i
++) {
2676 can
= edsf_canonify(sstate
->linedsf
, i
, &inv
);
2679 s
= sstate
->state
->lines
[can
];
2680 if (s
!= LINE_UNKNOWN
) {
2681 if (solver_set_line(sstate
, i
, inv
? OPP(s
) : s
))
2682 diff
= min(diff
, DIFF_EASY
);
2684 s
= sstate
->state
->lines
[i
];
2685 if (s
!= LINE_UNKNOWN
) {
2686 if (solver_set_line(sstate
, can
, inv
? OPP(s
) : s
))
2687 diff
= min(diff
, DIFF_EASY
);
2695 static int loop_deductions(solver_state
*sstate
)
2697 int edgecount
= 0, clues
= 0, satclues
= 0, sm1clues
= 0;
2698 game_state
*state
= sstate
->state
;
2699 grid
*g
= state
->game_grid
;
2700 int shortest_chainlen
= g
->num_dots
;
2701 int loop_found
= FALSE
;
2703 int progress
= FALSE
;
2707 * Go through the grid and update for all the new edges.
2708 * Since merge_dots() is idempotent, the simplest way to
2709 * do this is just to update for _all_ the edges.
2710 * Also, while we're here, we count the edges.
2712 for (i
= 0; i
< g
->num_edges
; i
++) {
2713 if (state
->lines
[i
] == LINE_YES
) {
2714 loop_found
|= merge_dots(sstate
, i
);
2720 * Count the clues, count the satisfied clues, and count the
2721 * satisfied-minus-one clues.
2723 for (i
= 0; i
< g
->num_faces
; i
++) {
2724 int c
= state
->clues
[i
];
2726 int o
= sstate
->face_yes_count
[i
];
2735 for (i
= 0; i
< g
->num_dots
; ++i
) {
2737 sstate
->looplen
[dsf_canonify(sstate
->dotdsf
, i
)];
2738 if (dots_connected
> 1)
2739 shortest_chainlen
= min(shortest_chainlen
, dots_connected
);
2742 assert(sstate
->solver_status
== SOLVER_INCOMPLETE
);
2744 if (satclues
== clues
&& shortest_chainlen
== edgecount
) {
2745 sstate
->solver_status
= SOLVER_SOLVED
;
2746 /* This discovery clearly counts as progress, even if we haven't
2747 * just added any lines or anything */
2749 goto finished_loop_deductionsing
;
2753 * Now go through looking for LINE_UNKNOWN edges which
2754 * connect two dots that are already in the same
2755 * equivalence class. If we find one, test to see if the
2756 * loop it would create is a solution.
2758 for (i
= 0; i
< g
->num_edges
; i
++) {
2759 grid_edge
*e
= g
->edges
+ i
;
2760 int d1
= e
->dot1
- g
->dots
;
2761 int d2
= e
->dot2
- g
->dots
;
2763 if (state
->lines
[i
] != LINE_UNKNOWN
)
2766 eqclass
= dsf_canonify(sstate
->dotdsf
, d1
);
2767 if (eqclass
!= dsf_canonify(sstate
->dotdsf
, d2
))
2770 val
= LINE_NO
; /* loop is bad until proven otherwise */
2773 * This edge would form a loop. Next
2774 * question: how long would the loop be?
2775 * Would it equal the total number of edges
2776 * (plus the one we'd be adding if we added
2779 if (sstate
->looplen
[eqclass
] == edgecount
+ 1) {
2783 * This edge would form a loop which
2784 * took in all the edges in the entire
2785 * grid. So now we need to work out
2786 * whether it would be a valid solution
2787 * to the puzzle, which means we have to
2788 * check if it satisfies all the clues.
2789 * This means that every clue must be
2790 * either satisfied or satisfied-minus-
2791 * 1, and also that the number of
2792 * satisfied-minus-1 clues must be at
2793 * most two and they must lie on either
2794 * side of this edge.
2798 int f
= e
->face1
- g
->faces
;
2799 int c
= state
->clues
[f
];
2800 if (c
>= 0 && sstate
->face_yes_count
[f
] == c
- 1)
2804 int f
= e
->face2
- g
->faces
;
2805 int c
= state
->clues
[f
];
2806 if (c
>= 0 && sstate
->face_yes_count
[f
] == c
- 1)
2809 if (sm1clues
== sm1_nearby
&&
2810 sm1clues
+ satclues
== clues
) {
2811 val
= LINE_YES
; /* loop is good! */
2816 * Right. Now we know that adding this edge
2817 * would form a loop, and we know whether
2818 * that loop would be a viable solution or
2821 * If adding this edge produces a solution,
2822 * then we know we've found _a_ solution but
2823 * we don't know that it's _the_ solution -
2824 * if it were provably the solution then
2825 * we'd have deduced this edge some time ago
2826 * without the need to do loop detection. So
2827 * in this state we return SOLVER_AMBIGUOUS,
2828 * which has the effect that hitting Solve
2829 * on a user-provided puzzle will fill in a
2830 * solution but using the solver to
2831 * construct new puzzles won't consider this
2832 * a reasonable deduction for the user to
2835 progress
= solver_set_line(sstate
, i
, val
);
2836 assert(progress
== TRUE
);
2837 if (val
== LINE_YES
) {
2838 sstate
->solver_status
= SOLVER_AMBIGUOUS
;
2839 goto finished_loop_deductionsing
;
2843 finished_loop_deductionsing
:
2844 return progress
? DIFF_EASY
: DIFF_MAX
;
2847 /* This will return a dynamically allocated solver_state containing the (more)
2849 static solver_state
*solve_game_rec(const solver_state
*sstate_start
)
2851 solver_state
*sstate
;
2853 /* Index of the solver we should call next. */
2856 /* As a speed-optimisation, we avoid re-running solvers that we know
2857 * won't make any progress. This happens when a high-difficulty
2858 * solver makes a deduction that can only help other high-difficulty
2860 * For example: if a new 'dline' flag is set by dline_deductions, the
2861 * trivial_deductions solver cannot do anything with this information.
2862 * If we've already run the trivial_deductions solver (because it's
2863 * earlier in the list), there's no point running it again.
2865 * Therefore: if a solver is earlier in the list than "threshold_index",
2866 * we don't bother running it if it's difficulty level is less than
2869 int threshold_diff
= 0;
2870 int threshold_index
= 0;
2872 sstate
= dup_solver_state(sstate_start
);
2874 check_caches(sstate
);
2876 while (i
< NUM_SOLVERS
) {
2877 if (sstate
->solver_status
== SOLVER_MISTAKE
)
2879 if (sstate
->solver_status
== SOLVER_SOLVED
||
2880 sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
2881 /* solver finished */
2885 if ((solver_diffs
[i
] >= threshold_diff
|| i
>= threshold_index
)
2886 && solver_diffs
[i
] <= sstate
->diff
) {
2887 /* current_solver is eligible, so use it */
2888 int next_diff
= solver_fns
[i
](sstate
);
2889 if (next_diff
!= DIFF_MAX
) {
2890 /* solver made progress, so use new thresholds and
2891 * start again at top of list. */
2892 threshold_diff
= next_diff
;
2893 threshold_index
= i
;
2898 /* current_solver is ineligible, or failed to make progress, so
2899 * go to the next solver in the list */
2903 if (sstate
->solver_status
== SOLVER_SOLVED
||
2904 sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
2905 /* s/LINE_UNKNOWN/LINE_NO/g */
2906 array_setall(sstate
->state
->lines
, LINE_UNKNOWN
, LINE_NO
,
2907 sstate
->state
->game_grid
->num_edges
);
2914 static char *solve_game(const game_state
*state
, const game_state
*currstate
,
2915 const char *aux
, char **error
)
2918 solver_state
*sstate
, *new_sstate
;
2920 sstate
= new_solver_state(state
, DIFF_MAX
);
2921 new_sstate
= solve_game_rec(sstate
);
2923 if (new_sstate
->solver_status
== SOLVER_SOLVED
) {
2924 soln
= encode_solve_move(new_sstate
->state
);
2925 } else if (new_sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
2926 soln
= encode_solve_move(new_sstate
->state
);
2927 /**error = "Solver found ambiguous solutions"; */
2929 soln
= encode_solve_move(new_sstate
->state
);
2930 /**error = "Solver failed"; */
2933 free_solver_state(new_sstate
);
2934 free_solver_state(sstate
);
2939 /* ----------------------------------------------------------------------
2940 * Drawing and mouse-handling
2943 static char *interpret_move(const game_state
*state
, game_ui
*ui
,
2944 const game_drawstate
*ds
,
2945 int x
, int y
, int button
)
2947 grid
*g
= state
->game_grid
;
2951 int movelen
, movesize
;
2952 char button_char
= ' ';
2953 enum line_state old_state
;
2955 button
&= ~MOD_MASK
;
2957 /* Convert mouse-click (x,y) to grid coordinates */
2958 x
-= BORDER(ds
->tilesize
);
2959 y
-= BORDER(ds
->tilesize
);
2960 x
= x
* g
->tilesize
/ ds
->tilesize
;
2961 y
= y
* g
->tilesize
/ ds
->tilesize
;
2965 e
= grid_nearest_edge(g
, x
, y
);
2971 /* I think it's only possible to play this game with mouse clicks, sorry */
2972 /* Maybe will add mouse drag support some time */
2973 old_state
= state
->lines
[i
];
2977 switch (old_state
) {
2995 switch (old_state
) {
3015 movebuf
= snewn(movesize
, char);
3016 movelen
= sprintf(movebuf
, "%d%c", i
, (int)button_char
);
3018 static enum { OFF
, FIXED
, ADAPTIVE
, DUNNO
} autofollow
= DUNNO
;
3019 if (autofollow
== DUNNO
) {
3020 const char *env
= getenv("LOOPY_AUTOFOLLOW");
3021 if (env
&& !strcmp(env
, "off"))
3023 else if (env
&& !strcmp(env
, "fixed"))
3025 else if (env
&& !strcmp(env
, "adaptive"))
3026 autofollow
= ADAPTIVE
;
3031 if (autofollow
!= OFF
) {
3033 for (dotid
= 0; dotid
< 2; dotid
++) {
3034 grid_dot
*dot
= (dotid
== 0 ? e
->dot1
: e
->dot2
);
3035 grid_edge
*e_this
= e
;
3039 grid_edge
*e_next
= NULL
;
3041 for (j
= n_found
= 0; j
< dot
->order
; j
++) {
3042 grid_edge
*e_candidate
= dot
->edges
[j
];
3043 int i_candidate
= e_candidate
- g
->edges
;
3044 if (e_candidate
!= e_this
&&
3045 (autofollow
== FIXED
||
3046 state
->lines
[i
] == LINE_NO
||
3047 state
->lines
[i_candidate
] != LINE_NO
)) {
3048 e_next
= e_candidate
;
3054 state
->lines
[e_next
- g
->edges
] != state
->lines
[i
])
3059 * Special case: we might have come all the
3060 * way round a loop and found our way back to
3061 * the same edge we started from. In that
3062 * situation, we must terminate not only this
3063 * while loop, but the 'for' outside it that
3064 * was tracing in both directions from the
3065 * starting edge, because if we let it trace
3066 * in the second direction then we'll only
3067 * find ourself traversing the same loop in
3068 * the other order and generate an encoded
3069 * move string that mentions the same set of
3072 goto autofollow_done
;
3075 dot
= (e_next
->dot1
!= dot
? e_next
->dot1
: e_next
->dot2
);
3076 if (movelen
> movesize
- 40) {
3077 movesize
= movesize
* 5 / 4 + 128;
3078 movebuf
= sresize(movebuf
, movesize
, char);
3081 movelen
+= sprintf(movebuf
+movelen
, "%d%c",
3082 (int)(e_this
- g
->edges
), button_char
);
3089 return sresize(movebuf
, movelen
+1, char);
3092 static game_state
*execute_move(const game_state
*state
, const char *move
)
3095 game_state
*newstate
= dup_game(state
);
3097 if (move
[0] == 'S') {
3099 newstate
->cheated
= TRUE
;
3104 if (i
< 0 || i
>= newstate
->game_grid
->num_edges
)
3106 move
+= strspn(move
, "1234567890");
3107 switch (*(move
++)) {
3109 newstate
->lines
[i
] = LINE_YES
;
3112 newstate
->lines
[i
] = LINE_NO
;
3115 newstate
->lines
[i
] = LINE_UNKNOWN
;
3123 * Check for completion.
3125 if (check_completion(newstate
))
3126 newstate
->solved
= TRUE
;
3131 free_game(newstate
);
3135 /* ----------------------------------------------------------------------
3139 /* Convert from grid coordinates to screen coordinates */
3140 static void grid_to_screen(const game_drawstate
*ds
, const grid
*g
,
3141 int grid_x
, int grid_y
, int *x
, int *y
)
3143 *x
= grid_x
- g
->lowest_x
;
3144 *y
= grid_y
- g
->lowest_y
;
3145 *x
= *x
* ds
->tilesize
/ g
->tilesize
;
3146 *y
= *y
* ds
->tilesize
/ g
->tilesize
;
3147 *x
+= BORDER(ds
->tilesize
);
3148 *y
+= BORDER(ds
->tilesize
);
3151 /* Returns (into x,y) position of centre of face for rendering the text clue.
3153 static void face_text_pos(const game_drawstate
*ds
, const grid
*g
,
3154 grid_face
*f
, int *xret
, int *yret
)
3156 int faceindex
= f
- g
->faces
;
3159 * Return the cached position for this face, if we've already
3162 if (ds
->textx
[faceindex
] >= 0) {
3163 *xret
= ds
->textx
[faceindex
];
3164 *yret
= ds
->texty
[faceindex
];
3169 * Otherwise, use the incentre computed by grid.c and convert it
3170 * to screen coordinates.
3172 grid_find_incentre(f
);
3173 grid_to_screen(ds
, g
, f
->ix
, f
->iy
,
3174 &ds
->textx
[faceindex
], &ds
->texty
[faceindex
]);
3176 *xret
= ds
->textx
[faceindex
];
3177 *yret
= ds
->texty
[faceindex
];
3180 static void face_text_bbox(game_drawstate
*ds
, grid
*g
, grid_face
*f
,
3181 int *x
, int *y
, int *w
, int *h
)
3184 face_text_pos(ds
, g
, f
, &xx
, &yy
);
3186 /* There seems to be a certain amount of trial-and-error involved
3187 * in working out the correct bounding-box for the text. */
3189 *x
= xx
- ds
->tilesize
/4 - 1;
3190 *y
= yy
- ds
->tilesize
/4 - 3;
3191 *w
= ds
->tilesize
/2 + 2;
3192 *h
= ds
->tilesize
/2 + 5;
3195 static void game_redraw_clue(drawing
*dr
, game_drawstate
*ds
,
3196 const game_state
*state
, int i
)
3198 grid
*g
= state
->game_grid
;
3199 grid_face
*f
= g
->faces
+ i
;
3203 sprintf(c
, "%d", state
->clues
[i
]);
3205 face_text_pos(ds
, g
, f
, &x
, &y
);
3207 FONT_VARIABLE
, ds
->tilesize
/2,
3208 ALIGN_VCENTRE
| ALIGN_HCENTRE
,
3209 ds
->clue_error
[i
] ? COL_MISTAKE
:
3210 ds
->clue_satisfied
[i
] ? COL_SATISFIED
: COL_FOREGROUND
, c
);
3213 static void edge_bbox(game_drawstate
*ds
, grid
*g
, grid_edge
*e
,
3214 int *x
, int *y
, int *w
, int *h
)
3216 int x1
= e
->dot1
->x
;
3217 int y1
= e
->dot1
->y
;
3218 int x2
= e
->dot2
->x
;
3219 int y2
= e
->dot2
->y
;
3220 int xmin
, xmax
, ymin
, ymax
;
3222 grid_to_screen(ds
, g
, x1
, y1
, &x1
, &y1
);
3223 grid_to_screen(ds
, g
, x2
, y2
, &x2
, &y2
);
3224 /* Allow extra margin for dots, and thickness of lines */
3225 xmin
= min(x1
, x2
) - 2;
3226 xmax
= max(x1
, x2
) + 2;
3227 ymin
= min(y1
, y2
) - 2;
3228 ymax
= max(y1
, y2
) + 2;
3232 *w
= xmax
- xmin
+ 1;
3233 *h
= ymax
- ymin
+ 1;
3236 static void dot_bbox(game_drawstate
*ds
, grid
*g
, grid_dot
*d
,
3237 int *x
, int *y
, int *w
, int *h
)
3241 grid_to_screen(ds
, g
, d
->x
, d
->y
, &x1
, &y1
);
3249 static const int loopy_line_redraw_phases
[] = {
3250 COL_FAINT
, COL_LINEUNKNOWN
, COL_FOREGROUND
, COL_HIGHLIGHT
, COL_MISTAKE
3252 #define NPHASES lenof(loopy_line_redraw_phases)
3254 static void game_redraw_line(drawing
*dr
, game_drawstate
*ds
,
3255 const game_state
*state
, int i
, int phase
)
3257 grid
*g
= state
->game_grid
;
3258 grid_edge
*e
= g
->edges
+ i
;
3262 if (state
->line_errors
[i
])
3263 line_colour
= COL_MISTAKE
;
3264 else if (state
->lines
[i
] == LINE_UNKNOWN
)
3265 line_colour
= COL_LINEUNKNOWN
;
3266 else if (state
->lines
[i
] == LINE_NO
)
3267 line_colour
= COL_FAINT
;
3268 else if (ds
->flashing
)
3269 line_colour
= COL_HIGHLIGHT
;
3271 line_colour
= COL_FOREGROUND
;
3272 if (line_colour
!= loopy_line_redraw_phases
[phase
])
3275 /* Convert from grid to screen coordinates */
3276 grid_to_screen(ds
, g
, e
->dot1
->x
, e
->dot1
->y
, &x1
, &y1
);
3277 grid_to_screen(ds
, g
, e
->dot2
->x
, e
->dot2
->y
, &x2
, &y2
);
3279 if (line_colour
== COL_FAINT
) {
3280 static int draw_faint_lines
= -1;
3281 if (draw_faint_lines
< 0) {
3282 char *env
= getenv("LOOPY_FAINT_LINES");
3283 draw_faint_lines
= (!env
|| (env
[0] == 'y' ||
3286 if (draw_faint_lines
)
3287 draw_line(dr
, x1
, y1
, x2
, y2
, line_colour
);
3289 draw_thick_line(dr
, 3.0,
3296 static void game_redraw_dot(drawing
*dr
, game_drawstate
*ds
,
3297 const game_state
*state
, int i
)
3299 grid
*g
= state
->game_grid
;
3300 grid_dot
*d
= g
->dots
+ i
;
3303 grid_to_screen(ds
, g
, d
->x
, d
->y
, &x
, &y
);
3304 draw_circle(dr
, x
, y
, 2, COL_FOREGROUND
, COL_FOREGROUND
);
3307 static int boxes_intersect(int x0
, int y0
, int w0
, int h0
,
3308 int x1
, int y1
, int w1
, int h1
)
3311 * Two intervals intersect iff neither is wholly on one side of
3312 * the other. Two boxes intersect iff their horizontal and
3313 * vertical intervals both intersect.
3315 return (x0
< x1
+w1
&& x1
< x0
+w0
&& y0
< y1
+h1
&& y1
< y0
+h0
);
3318 static void game_redraw_in_rect(drawing
*dr
, game_drawstate
*ds
,
3319 const game_state
*state
,
3320 int x
, int y
, int w
, int h
)
3322 grid
*g
= state
->game_grid
;
3326 clip(dr
, x
, y
, w
, h
);
3327 draw_rect(dr
, x
, y
, w
, h
, COL_BACKGROUND
);
3329 for (i
= 0; i
< g
->num_faces
; i
++) {
3330 if (state
->clues
[i
] >= 0) {
3331 face_text_bbox(ds
, g
, &g
->faces
[i
], &bx
, &by
, &bw
, &bh
);
3332 if (boxes_intersect(x
, y
, w
, h
, bx
, by
, bw
, bh
))
3333 game_redraw_clue(dr
, ds
, state
, i
);
3336 for (phase
= 0; phase
< NPHASES
; phase
++) {
3337 for (i
= 0; i
< g
->num_edges
; i
++) {
3338 edge_bbox(ds
, g
, &g
->edges
[i
], &bx
, &by
, &bw
, &bh
);
3339 if (boxes_intersect(x
, y
, w
, h
, bx
, by
, bw
, bh
))
3340 game_redraw_line(dr
, ds
, state
, i
, phase
);
3343 for (i
= 0; i
< g
->num_dots
; i
++) {
3344 dot_bbox(ds
, g
, &g
->dots
[i
], &bx
, &by
, &bw
, &bh
);
3345 if (boxes_intersect(x
, y
, w
, h
, bx
, by
, bw
, bh
))
3346 game_redraw_dot(dr
, ds
, state
, i
);
3350 draw_update(dr
, x
, y
, w
, h
);
3353 static void game_redraw(drawing
*dr
, game_drawstate
*ds
,
3354 const game_state
*oldstate
, const game_state
*state
,
3355 int dir
, const game_ui
*ui
,
3356 float animtime
, float flashtime
)
3358 #define REDRAW_OBJECTS_LIMIT 16 /* Somewhat arbitrary tradeoff */
3360 grid
*g
= state
->game_grid
;
3361 int border
= BORDER(ds
->tilesize
);
3364 int redraw_everything
= FALSE
;
3366 int edges
[REDRAW_OBJECTS_LIMIT
], nedges
= 0;
3367 int faces
[REDRAW_OBJECTS_LIMIT
], nfaces
= 0;
3369 /* Redrawing is somewhat involved.
3371 * An update can theoretically affect an arbitrary number of edges
3372 * (consider, for example, completing or breaking a cycle which doesn't
3373 * satisfy all the clues -- we'll switch many edges between error and
3374 * normal states). On the other hand, redrawing the whole grid takes a
3375 * while, making the game feel sluggish, and many updates are actually
3376 * quite well localized.
3378 * This redraw algorithm attempts to cope with both situations gracefully
3379 * and correctly. For localized changes, we set a clip rectangle, fill
3380 * it with background, and then redraw (a plausible but conservative
3381 * guess at) the objects which intersect the rectangle; if several
3382 * objects need redrawing, we'll do them individually. However, if lots
3383 * of objects are affected, we'll just redraw everything.
3385 * The reason for all of this is that it's just not safe to do the redraw
3386 * piecemeal. If you try to draw an antialiased diagonal line over
3387 * itself, you get a slightly thicker antialiased diagonal line, which
3388 * looks rather ugly after a while.
3390 * So, we take two passes over the grid. The first attempts to work out
3391 * what needs doing, and the second actually does it.
3395 redraw_everything
= TRUE
;
3397 * But we must still go through the upcoming loops, so that we
3398 * set up stuff in ds correctly for the initial redraw.
3402 /* First, trundle through the faces. */
3403 for (i
= 0; i
< g
->num_faces
; i
++) {
3404 grid_face
*f
= g
->faces
+ i
;
3405 int sides
= f
->order
;
3406 int yes_order
, no_order
;
3409 int n
= state
->clues
[i
];
3413 yes_order
= face_order(state
, i
, LINE_YES
);
3414 if (state
->exactly_one_loop
) {
3416 * Special case: if the set of LINE_YES edges in the grid
3417 * consists of exactly one loop and nothing else, then we
3418 * switch to treating LINE_UNKNOWN the same as LINE_NO for
3419 * purposes of clue checking.
3421 * This is because some people like to play Loopy without
3422 * using the right-click, i.e. never setting anything to
3423 * LINE_NO. Without this special case, if a person playing
3424 * in that style fills in what they think is a correct
3425 * solution loop but in fact it has an underfilled clue,
3426 * then we will display no victory flash and also no error
3427 * highlight explaining why not. With this special case,
3428 * we light up underfilled clues at the instant the loop
3429 * is closed. (Of course, *overfilled* clues are fine
3432 * (It might still be considered unfortunate that we can't
3433 * warn this style of player any earlier, if they make a
3434 * mistake very near the beginning which doesn't show up
3435 * until they close the last edge of the loop. One other
3436 * thing we _could_ do here is to treat any LINE_UNKNOWN
3437 * as LINE_NO if either of its endpoints has yes-degree 2,
3438 * reflecting the fact that setting that line to YES would
3439 * be an obvious error. But I don't think even that could
3440 * catch _all_ clue errors in a timely manner; I think
3441 * there are some that won't be displayed until the loop
3442 * is filled in, even so, and there's no way to avoid that
3443 * with complete reliability except to switch to being a
3444 * player who sets things to LINE_NO.)
3446 no_order
= sides
- yes_order
;
3448 no_order
= face_order(state
, i
, LINE_NO
);
3451 clue_mistake
= (yes_order
> n
|| no_order
> (sides
-n
));
3452 clue_satisfied
= (yes_order
== n
&& no_order
== (sides
-n
));
3454 if (clue_mistake
!= ds
->clue_error
[i
] ||
3455 clue_satisfied
!= ds
->clue_satisfied
[i
]) {
3456 ds
->clue_error
[i
] = clue_mistake
;
3457 ds
->clue_satisfied
[i
] = clue_satisfied
;
3458 if (nfaces
== REDRAW_OBJECTS_LIMIT
)
3459 redraw_everything
= TRUE
;
3461 faces
[nfaces
++] = i
;
3465 /* Work out what the flash state needs to be. */
3466 if (flashtime
> 0 &&
3467 (flashtime
<= FLASH_TIME
/3 ||
3468 flashtime
>= FLASH_TIME
*2/3)) {
3469 flash_changed
= !ds
->flashing
;
3470 ds
->flashing
= TRUE
;
3472 flash_changed
= ds
->flashing
;
3473 ds
->flashing
= FALSE
;
3476 /* Now, trundle through the edges. */
3477 for (i
= 0; i
< g
->num_edges
; i
++) {
3479 state
->line_errors
[i
] ? DS_LINE_ERROR
: state
->lines
[i
];
3480 if (new_ds
!= ds
->lines
[i
] ||
3481 (flash_changed
&& state
->lines
[i
] == LINE_YES
)) {
3482 ds
->lines
[i
] = new_ds
;
3483 if (nedges
== REDRAW_OBJECTS_LIMIT
)
3484 redraw_everything
= TRUE
;
3486 edges
[nedges
++] = i
;
3490 /* Pass one is now done. Now we do the actual drawing. */
3491 if (redraw_everything
) {
3492 int grid_width
= g
->highest_x
- g
->lowest_x
;
3493 int grid_height
= g
->highest_y
- g
->lowest_y
;
3494 int w
= grid_width
* ds
->tilesize
/ g
->tilesize
;
3495 int h
= grid_height
* ds
->tilesize
/ g
->tilesize
;
3497 game_redraw_in_rect(dr
, ds
, state
,
3498 0, 0, w
+ 2*border
+ 1, h
+ 2*border
+ 1);
3501 /* Right. Now we roll up our sleeves. */
3503 for (i
= 0; i
< nfaces
; i
++) {
3504 grid_face
*f
= g
->faces
+ faces
[i
];
3507 face_text_bbox(ds
, g
, f
, &x
, &y
, &w
, &h
);
3508 game_redraw_in_rect(dr
, ds
, state
, x
, y
, w
, h
);
3511 for (i
= 0; i
< nedges
; i
++) {
3512 grid_edge
*e
= g
->edges
+ edges
[i
];
3515 edge_bbox(ds
, g
, e
, &x
, &y
, &w
, &h
);
3516 game_redraw_in_rect(dr
, ds
, state
, x
, y
, w
, h
);
3523 static float game_flash_length(const game_state
*oldstate
,
3524 const game_state
*newstate
, int dir
, game_ui
*ui
)
3526 if (!oldstate
->solved
&& newstate
->solved
&&
3527 !oldstate
->cheated
&& !newstate
->cheated
) {
3534 static int game_status(const game_state
*state
)
3536 return state
->solved
? +1 : 0;
3539 static void game_print_size(const game_params
*params
, float *x
, float *y
)
3544 * I'll use 7mm "squares" by default.
3546 game_compute_size(params
, 700, &pw
, &ph
);
3551 static void game_print(drawing
*dr
, const game_state
*state
, int tilesize
)
3553 int ink
= print_mono_colour(dr
, 0);
3555 game_drawstate ads
, *ds
= &ads
;
3556 grid
*g
= state
->game_grid
;
3558 ds
->tilesize
= tilesize
;
3559 ds
->textx
= snewn(g
->num_faces
, int);
3560 ds
->texty
= snewn(g
->num_faces
, int);
3561 for (i
= 0; i
< g
->num_faces
; i
++)
3562 ds
->textx
[i
] = ds
->texty
[i
] = -1;
3564 for (i
= 0; i
< g
->num_dots
; i
++) {
3566 grid_to_screen(ds
, g
, g
->dots
[i
].x
, g
->dots
[i
].y
, &x
, &y
);
3567 draw_circle(dr
, x
, y
, ds
->tilesize
/ 15, ink
, ink
);
3573 for (i
= 0; i
< g
->num_faces
; i
++) {
3574 grid_face
*f
= g
->faces
+ i
;
3575 int clue
= state
->clues
[i
];
3579 sprintf(c
, "%d", state
->clues
[i
]);
3580 face_text_pos(ds
, g
, f
, &x
, &y
);
3582 FONT_VARIABLE
, ds
->tilesize
/ 2,
3583 ALIGN_VCENTRE
| ALIGN_HCENTRE
, ink
, c
);
3590 for (i
= 0; i
< g
->num_edges
; i
++) {
3591 int thickness
= (state
->lines
[i
] == LINE_YES
) ? 30 : 150;
3592 grid_edge
*e
= g
->edges
+ i
;
3594 grid_to_screen(ds
, g
, e
->dot1
->x
, e
->dot1
->y
, &x1
, &y1
);
3595 grid_to_screen(ds
, g
, e
->dot2
->x
, e
->dot2
->y
, &x2
, &y2
);
3596 if (state
->lines
[i
] == LINE_YES
)
3598 /* (dx, dy) points from (x1, y1) to (x2, y2).
3599 * The line is then "fattened" in a perpendicular
3600 * direction to create a thin rectangle. */
3601 double d
= sqrt(SQ((double)x1
- x2
) + SQ((double)y1
- y2
));
3602 double dx
= (x2
- x1
) / d
;
3603 double dy
= (y2
- y1
) / d
;
3606 dx
= (dx
* ds
->tilesize
) / thickness
;
3607 dy
= (dy
* ds
->tilesize
) / thickness
;
3608 points
[0] = x1
+ (int)dy
;
3609 points
[1] = y1
- (int)dx
;
3610 points
[2] = x1
- (int)dy
;
3611 points
[3] = y1
+ (int)dx
;
3612 points
[4] = x2
- (int)dy
;
3613 points
[5] = y2
+ (int)dx
;
3614 points
[6] = x2
+ (int)dy
;
3615 points
[7] = y2
- (int)dx
;
3616 draw_polygon(dr
, points
, 4, ink
, ink
);
3620 /* Draw a dotted line */
3623 for (j
= 1; j
< divisions
; j
++) {
3624 /* Weighted average */
3625 int x
= (x1
* (divisions
-j
) + x2
* j
) / divisions
;
3626 int y
= (y1
* (divisions
-j
) + y2
* j
) / divisions
;
3627 draw_circle(dr
, x
, y
, ds
->tilesize
/ thickness
, ink
, ink
);
3637 #define thegame loopy
3640 const struct game thegame
= {
3641 "Loopy", "games.loopy", "loopy",
3643 NULL
, game_preset_menu
,
3648 TRUE
, game_configure
, custom_params
,
3656 TRUE
, game_can_format_as_text_now
, game_text_format
,
3664 PREFERRED_TILE_SIZE
, game_compute_size
, game_set_size
,
3667 game_free_drawstate
,
3672 TRUE
, FALSE
, game_print_size
, game_print
,
3673 FALSE
/* wants_statusbar */,
3674 FALSE
, game_timing_state
,
3675 0, /* mouse_priorities */
3678 #ifdef STANDALONE_SOLVER
3681 * Half-hearted standalone solver. It can't output the solution to
3682 * anything but a square puzzle, and it can't log the deductions
3683 * it makes either. But it can solve square puzzles, and more
3684 * importantly it can use its solver to grade the difficulty of
3685 * any puzzle you give it.
3690 int main(int argc
, char **argv
)
3694 char *id
= NULL
, *desc
, *err
;
3697 #if 0 /* verbose solver not supported here (yet) */
3698 int really_verbose
= FALSE
;
3701 while (--argc
> 0) {
3703 #if 0 /* verbose solver not supported here (yet) */
3704 if (!strcmp(p
, "-v")) {
3705 really_verbose
= TRUE
;
3708 if (!strcmp(p
, "-g")) {
3710 } else if (*p
== '-') {
3711 fprintf(stderr
, "%s: unrecognised option `%s'\n", argv
[0], p
);
3719 fprintf(stderr
, "usage: %s [-g | -v] <game_id>\n", argv
[0]);
3723 desc
= strchr(id
, ':');
3725 fprintf(stderr
, "%s: game id expects a colon in it\n", argv
[0]);
3730 p
= default_params();
3731 decode_params(p
, id
);
3732 err
= validate_desc(p
, desc
);
3734 fprintf(stderr
, "%s: %s\n", argv
[0], err
);
3737 s
= new_game(NULL
, p
, desc
);
3740 * When solving an Easy puzzle, we don't want to bother the
3741 * user with Hard-level deductions. For this reason, we grade
3742 * the puzzle internally before doing anything else.
3744 ret
= -1; /* placate optimiser */
3745 for (diff
= 0; diff
< DIFF_MAX
; diff
++) {
3746 solver_state
*sstate_new
;
3747 solver_state
*sstate
= new_solver_state((game_state
*)s
, diff
);
3749 sstate_new
= solve_game_rec(sstate
);
3751 if (sstate_new
->solver_status
== SOLVER_MISTAKE
)
3753 else if (sstate_new
->solver_status
== SOLVER_SOLVED
)
3758 free_solver_state(sstate_new
);
3759 free_solver_state(sstate
);
3765 if (diff
== DIFF_MAX
) {
3767 printf("Difficulty rating: harder than Hard, or ambiguous\n");
3769 printf("Unable to find a unique solution\n");
3773 printf("Difficulty rating: impossible (no solution exists)\n");
3775 printf("Difficulty rating: %s\n", diffnames
[diff
]);
3777 solver_state
*sstate_new
;
3778 solver_state
*sstate
= new_solver_state((game_state
*)s
, diff
);
3780 /* If we supported a verbose solver, we'd set verbosity here */
3782 sstate_new
= solve_game_rec(sstate
);
3784 if (sstate_new
->solver_status
== SOLVER_MISTAKE
)
3785 printf("Puzzle is inconsistent\n");
3787 assert(sstate_new
->solver_status
== SOLVER_SOLVED
);
3788 if (s
->grid_type
== 0) {
3789 fputs(game_text_format(sstate_new
->state
), stdout
);
3791 printf("Unable to output non-square grids\n");
3795 free_solver_state(sstate_new
);
3796 free_solver_state(sstate
);
3805 /* vim: set shiftwidth=4 tabstop=8: */