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
;
125 /* Used in game_text_format(), so that it knows what type of
126 * grid it's trying to render as ASCII text. */
131 SOLVER_SOLVED
, /* This is the only solution the solver could find */
132 SOLVER_MISTAKE
, /* This is definitely not a solution */
133 SOLVER_AMBIGUOUS
, /* This _might_ be an ambiguous solution */
134 SOLVER_INCOMPLETE
/* This may be a partial solution */
137 /* ------ Solver state ------ */
138 typedef struct solver_state
{
140 enum solver_status solver_status
;
141 /* NB looplen is the number of dots that are joined together at a point, ie a
142 * looplen of 1 means there are no lines to a particular dot */
145 /* Difficulty level of solver. Used by solver functions that want to
146 * vary their behaviour depending on the requested difficulty level. */
152 char *face_yes_count
;
154 char *dot_solved
, *face_solved
;
157 /* Information for Normal level deductions:
158 * For each dline, store a bitmask for whether we know:
159 * (bit 0) at least one is YES
160 * (bit 1) at most one is YES */
163 /* Hard level information */
168 * Difficulty levels. I do some macro ickery here to ensure that my
169 * enum and the various forms of my name list always match up.
172 #define DIFFLIST(A) \
177 #define ENUM(upper,title,lower) DIFF_ ## upper,
178 #define TITLE(upper,title,lower) #title,
179 #define ENCODE(upper,title,lower) #lower
180 #define CONFIG(upper,title,lower) ":" #title
181 enum { DIFFLIST(ENUM
) DIFF_MAX
};
182 static char const *const diffnames
[] = { DIFFLIST(TITLE
) };
183 static char const diffchars
[] = DIFFLIST(ENCODE
);
184 #define DIFFCONFIG DIFFLIST(CONFIG)
187 * Solver routines, sorted roughly in order of computational cost.
188 * The solver will run the faster deductions first, and slower deductions are
189 * only invoked when the faster deductions are unable to make progress.
190 * Each function is associated with a difficulty level, so that the generated
191 * puzzles are solvable by applying only the functions with the chosen
192 * difficulty level or lower.
194 #define SOLVERLIST(A) \
195 A(trivial_deductions, DIFF_EASY) \
196 A(dline_deductions, DIFF_NORMAL) \
197 A(linedsf_deductions, DIFF_HARD) \
198 A(loop_deductions, DIFF_EASY)
199 #define SOLVER_FN_DECL(fn,diff) static int fn(solver_state *);
200 #define SOLVER_FN(fn,diff) &fn,
201 #define SOLVER_DIFF(fn,diff) diff,
202 SOLVERLIST(SOLVER_FN_DECL
)
203 static int (*(solver_fns
[]))(solver_state
*) = { SOLVERLIST(SOLVER_FN
) };
204 static int const solver_diffs
[] = { SOLVERLIST(SOLVER_DIFF
) };
205 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(game_params
*params
, 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)
246 /* ------- List of grid generators ------- */
247 #define GRIDLIST(A) \
248 A(Squares,GRID_SQUARE,3,3) \
249 A(Triangular,GRID_TRIANGULAR,3,3) \
250 A(Honeycomb,GRID_HONEYCOMB,3,3) \
251 A(Snub-Square,GRID_SNUBSQUARE,3,3) \
252 A(Cairo,GRID_CAIRO,3,4) \
253 A(Great-Hexagonal,GRID_GREATHEXAGONAL,3,3) \
254 A(Octagonal,GRID_OCTAGONAL,3,3) \
255 A(Kites,GRID_KITE,3,3) \
256 A(Floret,GRID_FLORET,1,2) \
257 A(Dodecagonal,GRID_DODECAGONAL,2,2) \
258 A(Great-Dodecagonal,GRID_GREATDODECAGONAL,2,2) \
259 A(Penrose (kite/dart),GRID_PENROSE_P2,3,3) \
260 A(Penrose (rhombs),GRID_PENROSE_P3,3,3) \
262 #define GRID_NAME(title,type,amin,omin) #title,
263 #define GRID_CONFIG(title,type,amin,omin) ":" #title
264 #define GRID_TYPE(title,type,amin,omin) type,
265 #define GRID_SIZES(title,type,amin,omin) \
267 "Width and height for this grid type must both be at least " #amin, \
268 "At least one of width and height for this grid type must be at least " #omin,},
269 static char const *const gridnames
[] = { GRIDLIST(GRID_NAME
) };
270 static char const *const dualnames
[] = { "", "(dual) " };
271 #define GRID_CONFIGS GRIDLIST(GRID_CONFIG)
272 static grid_type grid_types
[] = { GRIDLIST(GRID_TYPE
) };
273 #define NUM_GRID_TYPES (sizeof(grid_types) / sizeof(grid_types[0]))
274 static const struct {
277 } grid_size_limits
[] = { GRIDLIST(GRID_SIZES
) };
279 /* Generates a (dynamically allocated) new grid, according to the
280 * type and size requested in params. Does nothing if the grid is already
282 static grid
*loopy_generate_grid(game_params
*params
, char *grid_desc
)
284 return grid_new(grid_types
[params
->type
], params
->w
, params
->h
, params
->dual
, grid_desc
);
287 /* ----------------------------------------------------------------------
291 /* General constants */
292 #define PREFERRED_TILE_SIZE 32
293 #define BORDER(tilesize) ((tilesize) / 2)
294 #define FLASH_TIME 0.5F
296 #define BIT_SET(field, bit) ((field) & (1<<(bit)))
298 #define SET_BIT(field, bit) (BIT_SET(field, bit) ? FALSE : \
299 ((field) |= (1<<(bit)), TRUE))
301 #define CLEAR_BIT(field, bit) (BIT_SET(field, bit) ? \
302 ((field) &= ~(1<<(bit)), TRUE) : FALSE)
304 #define CLUE2CHAR(c) \
305 ((c < 0) ? ' ' : c < 10 ? c + '0' : c - 10 + 'A')
307 /* ----------------------------------------------------------------------
308 * General struct manipulation and other straightforward code
311 static game_state
*dup_game(game_state
*state
)
313 game_state
*ret
= snew(game_state
);
315 ret
->game_grid
= state
->game_grid
;
316 ret
->game_grid
->refcount
++;
318 ret
->solved
= state
->solved
;
319 ret
->cheated
= state
->cheated
;
321 ret
->clues
= snewn(state
->game_grid
->num_faces
, signed char);
322 memcpy(ret
->clues
, state
->clues
, state
->game_grid
->num_faces
);
324 ret
->lines
= snewn(state
->game_grid
->num_edges
, char);
325 memcpy(ret
->lines
, state
->lines
, state
->game_grid
->num_edges
);
327 ret
->line_errors
= snewn(state
->game_grid
->num_edges
, unsigned char);
328 memcpy(ret
->line_errors
, state
->line_errors
, state
->game_grid
->num_edges
);
330 ret
->grid_type
= state
->grid_type
;
334 static void free_game(game_state
*state
)
337 grid_free(state
->game_grid
);
340 sfree(state
->line_errors
);
345 static solver_state
*new_solver_state(game_state
*state
, int diff
) {
347 int num_dots
= state
->game_grid
->num_dots
;
348 int num_faces
= state
->game_grid
->num_faces
;
349 int num_edges
= state
->game_grid
->num_edges
;
350 solver_state
*ret
= snew(solver_state
);
352 ret
->state
= dup_game(state
);
354 ret
->solver_status
= SOLVER_INCOMPLETE
;
357 ret
->dotdsf
= snew_dsf(num_dots
);
358 ret
->looplen
= snewn(num_dots
, int);
360 for (i
= 0; i
< num_dots
; i
++) {
364 ret
->dot_solved
= snewn(num_dots
, char);
365 ret
->face_solved
= snewn(num_faces
, char);
366 memset(ret
->dot_solved
, FALSE
, num_dots
);
367 memset(ret
->face_solved
, FALSE
, num_faces
);
369 ret
->dot_yes_count
= snewn(num_dots
, char);
370 memset(ret
->dot_yes_count
, 0, num_dots
);
371 ret
->dot_no_count
= snewn(num_dots
, char);
372 memset(ret
->dot_no_count
, 0, num_dots
);
373 ret
->face_yes_count
= snewn(num_faces
, char);
374 memset(ret
->face_yes_count
, 0, num_faces
);
375 ret
->face_no_count
= snewn(num_faces
, char);
376 memset(ret
->face_no_count
, 0, num_faces
);
378 if (diff
< DIFF_NORMAL
) {
381 ret
->dlines
= snewn(2*num_edges
, char);
382 memset(ret
->dlines
, 0, 2*num_edges
);
385 if (diff
< DIFF_HARD
) {
388 ret
->linedsf
= snew_dsf(state
->game_grid
->num_edges
);
394 static void free_solver_state(solver_state
*sstate
) {
396 free_game(sstate
->state
);
397 sfree(sstate
->dotdsf
);
398 sfree(sstate
->looplen
);
399 sfree(sstate
->dot_solved
);
400 sfree(sstate
->face_solved
);
401 sfree(sstate
->dot_yes_count
);
402 sfree(sstate
->dot_no_count
);
403 sfree(sstate
->face_yes_count
);
404 sfree(sstate
->face_no_count
);
406 /* OK, because sfree(NULL) is a no-op */
407 sfree(sstate
->dlines
);
408 sfree(sstate
->linedsf
);
414 static solver_state
*dup_solver_state(const solver_state
*sstate
) {
415 game_state
*state
= sstate
->state
;
416 int num_dots
= state
->game_grid
->num_dots
;
417 int num_faces
= state
->game_grid
->num_faces
;
418 int num_edges
= state
->game_grid
->num_edges
;
419 solver_state
*ret
= snew(solver_state
);
421 ret
->state
= state
= dup_game(sstate
->state
);
423 ret
->solver_status
= sstate
->solver_status
;
424 ret
->diff
= sstate
->diff
;
426 ret
->dotdsf
= snewn(num_dots
, int);
427 ret
->looplen
= snewn(num_dots
, int);
428 memcpy(ret
->dotdsf
, sstate
->dotdsf
,
429 num_dots
* sizeof(int));
430 memcpy(ret
->looplen
, sstate
->looplen
,
431 num_dots
* sizeof(int));
433 ret
->dot_solved
= snewn(num_dots
, char);
434 ret
->face_solved
= snewn(num_faces
, char);
435 memcpy(ret
->dot_solved
, sstate
->dot_solved
, num_dots
);
436 memcpy(ret
->face_solved
, sstate
->face_solved
, num_faces
);
438 ret
->dot_yes_count
= snewn(num_dots
, char);
439 memcpy(ret
->dot_yes_count
, sstate
->dot_yes_count
, num_dots
);
440 ret
->dot_no_count
= snewn(num_dots
, char);
441 memcpy(ret
->dot_no_count
, sstate
->dot_no_count
, num_dots
);
443 ret
->face_yes_count
= snewn(num_faces
, char);
444 memcpy(ret
->face_yes_count
, sstate
->face_yes_count
, num_faces
);
445 ret
->face_no_count
= snewn(num_faces
, char);
446 memcpy(ret
->face_no_count
, sstate
->face_no_count
, num_faces
);
448 if (sstate
->dlines
) {
449 ret
->dlines
= snewn(2*num_edges
, char);
450 memcpy(ret
->dlines
, sstate
->dlines
,
456 if (sstate
->linedsf
) {
457 ret
->linedsf
= snewn(num_edges
, int);
458 memcpy(ret
->linedsf
, sstate
->linedsf
,
459 num_edges
* sizeof(int));
467 static game_params
*default_params(void)
469 game_params
*ret
= snew(game_params
);
478 ret
->diff
= DIFF_EASY
;
485 static game_params
*dup_params(game_params
*params
)
487 game_params
*ret
= snew(game_params
);
489 *ret
= *params
; /* structure copy */
493 static const game_params presets
[] = {
495 { 7, 7, DIFF_EASY
, 0, 0 },
496 { 7, 7, DIFF_NORMAL
, 0, 0 },
497 { 7, 7, DIFF_HARD
, 0, 0 },
498 { 7, 7, DIFF_HARD
, 1, 0 },
499 { 7, 7, DIFF_HARD
, 2, 0 },
500 { 5, 5, DIFF_HARD
, 3, 0 },
501 { 7, 7, DIFF_HARD
, 4, 0 },
502 { 5, 4, DIFF_HARD
, 5, 0 },
503 { 5, 5, DIFF_HARD
, 6, 0 },
504 { 5, 5, DIFF_HARD
, 7, 0 },
505 { 3, 3, DIFF_HARD
, 8, 0 },
506 { 3, 3, DIFF_HARD
, 9, 0 },
507 { 3, 3, DIFF_HARD
, 10, 0 },
508 { 6, 6, DIFF_HARD
, 11, 0 },
509 { 6, 6, DIFF_HARD
, 12, 0 },
511 { 7, 7, DIFF_EASY
, 0, 0 },
512 { 10, 10, DIFF_EASY
, 0, 0 },
513 { 7, 7, DIFF_NORMAL
, 0, 0 },
514 { 10, 10, DIFF_NORMAL
, 0, 0 },
515 { 7, 7, DIFF_HARD
, 0, 0 },
516 { 10, 10, DIFF_HARD
, 0, 0 },
517 { 10, 10, DIFF_HARD
, 1, 0 },
518 { 12, 10, DIFF_HARD
, 2, 0 },
519 { 7, 7, DIFF_HARD
, 3, 0 },
520 { 9, 9, DIFF_HARD
, 4, 0 },
521 { 5, 4, DIFF_HARD
, 5, 0 },
522 { 7, 7, DIFF_HARD
, 6, 0 },
523 { 5, 5, DIFF_HARD
, 7, 0 },
524 { 5, 5, DIFF_HARD
, 8, 0 },
525 { 5, 4, DIFF_HARD
, 9, 0 },
526 { 5, 4, DIFF_HARD
, 10, 0 },
527 { 10, 10, DIFF_HARD
, 11, 0 },
528 { 10, 10, DIFF_HARD
, 12, 0 }
532 static int game_fetch_preset(int i
, char **name
, game_params
**params
)
537 if (i
< 0 || i
>= lenof(presets
))
540 tmppar
= snew(game_params
);
541 *tmppar
= presets
[i
];
543 sprintf(buf
, "%dx%d %s %s- %s", tmppar
->h
, tmppar
->w
,
544 gridnames
[tmppar
->type
], dualnames
[tmppar
->dual
],
545 diffnames
[tmppar
->diff
]);
551 static void free_params(game_params
*params
)
556 static void decode_params(game_params
*params
, char const *string
)
558 params
->h
= params
->w
= atoi(string
);
559 params
->diff
= DIFF_EASY
;
561 while (*string
&& isdigit((unsigned char)*string
)) string
++;
562 if (*string
== 'x') {
564 params
->h
= atoi(string
);
565 while (*string
&& isdigit((unsigned char)*string
)) string
++;
567 if (*string
== 'l') {
571 if (*string
== 't') {
573 params
->type
= atoi(string
);
574 while (*string
&& isdigit((unsigned char)*string
)) string
++;
576 if (*string
== 'd') {
579 for (i
= 0; i
< DIFF_MAX
; i
++)
580 if (*string
== diffchars
[i
])
582 if (*string
) string
++;
586 static char *encode_params(game_params
*params
, int full
)
589 sprintf(str
, "%dx%dt%d%s", params
->w
, params
->h
, params
->type
,
590 params
->dual ?
"l" : "");
592 sprintf(str
+ strlen(str
), "d%c", diffchars
[params
->diff
]);
596 static config_item
*game_configure(game_params
*params
)
601 ret
= snewn(6, config_item
);
603 ret
[0].name
= "Width";
604 ret
[0].type
= C_STRING
;
605 sprintf(buf
, "%d", params
->w
);
606 ret
[0].sval
= dupstr(buf
);
609 ret
[1].name
= "Height";
610 ret
[1].type
= C_STRING
;
611 sprintf(buf
, "%d", params
->h
);
612 ret
[1].sval
= dupstr(buf
);
615 ret
[2].name
= "Grid type";
616 ret
[2].type
= C_CHOICES
;
617 ret
[2].sval
= GRID_CONFIGS
;
618 ret
[2].ival
= params
->type
;
620 ret
[3].name
= "Difficulty";
621 ret
[3].type
= C_CHOICES
;
622 ret
[3].sval
= DIFFCONFIG
;
623 ret
[3].ival
= params
->diff
;
625 ret
[4].name
= "Dual";
626 ret
[4].type
= C_BOOLEAN
;
628 ret
[4].ival
= params
->dual
;
638 static game_params
*custom_params(config_item
*cfg
)
640 game_params
*ret
= snew(game_params
);
642 ret
->w
= atoi(cfg
[0].sval
);
643 ret
->h
= atoi(cfg
[1].sval
);
644 ret
->type
= cfg
[2].ival
;
645 ret
->diff
= cfg
[3].ival
;
646 ret
->dual
= cfg
[4].ival
;
651 static char *validate_params(game_params
*params
, int full
)
653 if (params
->type
< 0 || params
->type
>= NUM_GRID_TYPES
)
654 return "Illegal grid type";
655 if (params
->w
< grid_size_limits
[params
->type
].amin
||
656 params
->h
< grid_size_limits
[params
->type
].amin
)
657 return grid_size_limits
[params
->type
].aerr
;
658 if (params
->w
< grid_size_limits
[params
->type
].omin
&&
659 params
->h
< grid_size_limits
[params
->type
].omin
)
660 return grid_size_limits
[params
->type
].oerr
;
663 * This shouldn't be able to happen at all, since decode_params
664 * and custom_params will never generate anything that isn't
667 assert(params
->diff
< DIFF_MAX
);
672 /* Returns a newly allocated string describing the current puzzle */
673 static char *state_to_text(const game_state
*state
)
675 grid
*g
= state
->game_grid
;
677 int num_faces
= g
->num_faces
;
678 char *description
= snewn(num_faces
+ 1, char);
679 char *dp
= description
;
683 for (i
= 0; i
< num_faces
; i
++) {
684 if (state
->clues
[i
] < 0) {
685 if (empty_count
> 25) {
686 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
692 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
695 dp
+= sprintf(dp
, "%c", (int)CLUE2CHAR(state
->clues
[i
]));
700 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
702 retval
= dupstr(description
);
708 #define GRID_DESC_SEP '_'
710 /* Splits up a (optional) grid_desc from the game desc. Returns the
711 * grid_desc (which needs freeing) and updates the desc pointer to
712 * start of real desc, or returns NULL if no desc. */
713 static char *extract_grid_desc(char **desc
)
715 char *sep
= strchr(*desc
, GRID_DESC_SEP
), *gd
;
718 if (!sep
) return NULL
;
720 gd_len
= sep
- (*desc
);
721 gd
= snewn(gd_len
+1, char);
722 memcpy(gd
, *desc
, gd_len
);
730 /* We require that the params pass the test in validate_params and that the
731 * description fills the entire game area */
732 static char *validate_desc(game_params
*params
, char *desc
)
736 char *grid_desc
, *ret
;
738 /* It's pretty inefficient to do this just for validation. All we need to
739 * know is the precise number of faces. */
740 grid_desc
= extract_grid_desc(&desc
);
741 ret
= grid_validate_desc(grid_types
[params
->type
], params
->w
, params
->h
, params
->dual
, grid_desc
);
744 g
= loopy_generate_grid(params
, grid_desc
);
745 if (grid_desc
) sfree(grid_desc
);
747 for (; *desc
; ++desc
) {
748 if ((*desc
>= '0' && *desc
<= '9') || (*desc
>= 'A' && *desc
<= 'Z')) {
753 count
+= *desc
- 'a' + 1;
756 return "Unknown character in description";
759 if (count
< g
->num_faces
)
760 return "Description too short for board size";
761 if (count
> g
->num_faces
)
762 return "Description too long for board size";
769 /* Sums the lengths of the numbers in range [0,n) */
770 /* See equivalent function in solo.c for justification of this. */
771 static int len_0_to_n(int n
)
773 int len
= 1; /* Counting 0 as a bit of a special case */
776 for (i
= 1; i
< n
; i
*= 10) {
777 len
+= max(n
- i
, 0);
783 static char *encode_solve_move(const game_state
*state
)
788 int num_edges
= state
->game_grid
->num_edges
;
790 /* This is going to return a string representing the moves needed to set
791 * every line in a grid to be the same as the ones in 'state'. The exact
792 * length of this string is predictable. */
794 len
= 1; /* Count the 'S' prefix */
795 /* Numbers in all lines */
796 len
+= len_0_to_n(num_edges
);
797 /* For each line we also have a letter */
800 ret
= snewn(len
+ 1, char);
803 p
+= sprintf(p
, "S");
805 for (i
= 0; i
< num_edges
; i
++) {
806 switch (state
->lines
[i
]) {
808 p
+= sprintf(p
, "%dy", i
);
811 p
+= sprintf(p
, "%dn", i
);
816 /* No point in doing sums like that if they're going to be wrong */
817 assert(strlen(ret
) <= (size_t)len
);
821 static game_ui
*new_ui(game_state
*state
)
826 static void free_ui(game_ui
*ui
)
830 static char *encode_ui(game_ui
*ui
)
835 static void decode_ui(game_ui
*ui
, char *encoding
)
839 static void game_changed_state(game_ui
*ui
, game_state
*oldstate
,
840 game_state
*newstate
)
844 static void game_compute_size(game_params
*params
, int tilesize
,
847 int grid_width
, grid_height
, rendered_width
, rendered_height
;
850 grid_compute_size(grid_types
[params
->type
], params
->w
, params
->h
,
851 &g_tilesize
, &grid_width
, &grid_height
);
853 /* multiply first to minimise rounding error on integer division */
854 rendered_width
= grid_width
* tilesize
/ g_tilesize
;
855 rendered_height
= grid_height
* tilesize
/ g_tilesize
;
856 *x
= rendered_width
+ 2 * BORDER(tilesize
) + 1;
857 *y
= rendered_height
+ 2 * BORDER(tilesize
) + 1;
860 static void game_set_size(drawing
*dr
, game_drawstate
*ds
,
861 game_params
*params
, int tilesize
)
863 ds
->tilesize
= tilesize
;
866 static float *game_colours(frontend
*fe
, int *ncolours
)
868 float *ret
= snewn(4 * NCOLOURS
, float);
870 frontend_default_colour(fe
, &ret
[COL_BACKGROUND
* 3]);
872 ret
[COL_FOREGROUND
* 3 + 0] = 0.0F
;
873 ret
[COL_FOREGROUND
* 3 + 1] = 0.0F
;
874 ret
[COL_FOREGROUND
* 3 + 2] = 0.0F
;
877 * We want COL_LINEUNKNOWN to be a yellow which is a bit darker
878 * than the background. (I previously set it to 0.8,0.8,0, but
879 * found that this went badly with the 0.8,0.8,0.8 favoured as a
880 * background by the Java frontend.)
882 ret
[COL_LINEUNKNOWN
* 3 + 0] = ret
[COL_BACKGROUND
* 3 + 0] * 0.9F
;
883 ret
[COL_LINEUNKNOWN
* 3 + 1] = ret
[COL_BACKGROUND
* 3 + 1] * 0.9F
;
884 ret
[COL_LINEUNKNOWN
* 3 + 2] = 0.0F
;
886 ret
[COL_HIGHLIGHT
* 3 + 0] = 1.0F
;
887 ret
[COL_HIGHLIGHT
* 3 + 1] = 1.0F
;
888 ret
[COL_HIGHLIGHT
* 3 + 2] = 1.0F
;
890 ret
[COL_MISTAKE
* 3 + 0] = 1.0F
;
891 ret
[COL_MISTAKE
* 3 + 1] = 0.0F
;
892 ret
[COL_MISTAKE
* 3 + 2] = 0.0F
;
894 ret
[COL_SATISFIED
* 3 + 0] = 0.0F
;
895 ret
[COL_SATISFIED
* 3 + 1] = 0.0F
;
896 ret
[COL_SATISFIED
* 3 + 2] = 0.0F
;
898 /* We want the faint lines to be a bit darker than the background.
899 * Except if the background is pretty dark already; then it ought to be a
900 * bit lighter. Oy vey.
902 ret
[COL_FAINT
* 3 + 0] = ret
[COL_BACKGROUND
* 3 + 0] * 0.9F
;
903 ret
[COL_FAINT
* 3 + 1] = ret
[COL_BACKGROUND
* 3 + 1] * 0.9F
;
904 ret
[COL_FAINT
* 3 + 2] = ret
[COL_BACKGROUND
* 3 + 2] * 0.9F
;
906 *ncolours
= NCOLOURS
;
910 static game_drawstate
*game_new_drawstate(drawing
*dr
, game_state
*state
)
912 struct game_drawstate
*ds
= snew(struct game_drawstate
);
913 int num_faces
= state
->game_grid
->num_faces
;
914 int num_edges
= state
->game_grid
->num_edges
;
919 ds
->lines
= snewn(num_edges
, char);
920 ds
->clue_error
= snewn(num_faces
, char);
921 ds
->clue_satisfied
= snewn(num_faces
, char);
922 ds
->textx
= snewn(num_faces
, int);
923 ds
->texty
= snewn(num_faces
, int);
926 memset(ds
->lines
, LINE_UNKNOWN
, num_edges
);
927 memset(ds
->clue_error
, 0, num_faces
);
928 memset(ds
->clue_satisfied
, 0, num_faces
);
929 for (i
= 0; i
< num_faces
; i
++)
930 ds
->textx
[i
] = ds
->texty
[i
] = -1;
935 static void game_free_drawstate(drawing
*dr
, game_drawstate
*ds
)
939 sfree(ds
->clue_error
);
940 sfree(ds
->clue_satisfied
);
945 static int game_timing_state(game_state
*state
, game_ui
*ui
)
950 static float game_anim_length(game_state
*oldstate
, game_state
*newstate
,
951 int dir
, game_ui
*ui
)
956 static int game_can_format_as_text_now(game_params
*params
)
958 if (params
->type
!= 0)
963 static char *game_text_format(game_state
*state
)
969 grid
*g
= state
->game_grid
;
972 assert(state
->grid_type
== 0);
974 /* Work out the basic size unit */
975 f
= g
->faces
; /* first face */
976 assert(f
->order
== 4);
977 /* The dots are ordered clockwise, so the two opposite
978 * corners are guaranteed to span the square */
979 cell_size
= abs(f
->dots
[0]->x
- f
->dots
[2]->x
);
981 w
= (g
->highest_x
- g
->lowest_x
) / cell_size
;
982 h
= (g
->highest_y
- g
->lowest_y
) / cell_size
;
984 /* Create a blank "canvas" to "draw" on */
987 ret
= snewn(W
* H
+ 1, char);
988 for (y
= 0; y
< H
; y
++) {
989 for (x
= 0; x
< W
-1; x
++) {
992 ret
[y
*W
+ W
-1] = '\n';
996 /* Fill in edge info */
997 for (i
= 0; i
< g
->num_edges
; i
++) {
998 grid_edge
*e
= g
->edges
+ i
;
999 /* Cell coordinates, from (0,0) to (w-1,h-1) */
1000 int x1
= (e
->dot1
->x
- g
->lowest_x
) / cell_size
;
1001 int x2
= (e
->dot2
->x
- g
->lowest_x
) / cell_size
;
1002 int y1
= (e
->dot1
->y
- g
->lowest_y
) / cell_size
;
1003 int y2
= (e
->dot2
->y
- g
->lowest_y
) / cell_size
;
1004 /* Midpoint, in canvas coordinates (canvas coordinates are just twice
1005 * cell coordinates) */
1008 switch (state
->lines
[i
]) {
1010 ret
[y
*W
+ x
] = (y1
== y2
) ?
'-' : '|';
1016 break; /* already a space */
1018 assert(!"Illegal line state");
1023 for (i
= 0; i
< g
->num_faces
; i
++) {
1027 assert(f
->order
== 4);
1028 /* Cell coordinates, from (0,0) to (w-1,h-1) */
1029 x1
= (f
->dots
[0]->x
- g
->lowest_x
) / cell_size
;
1030 x2
= (f
->dots
[2]->x
- g
->lowest_x
) / cell_size
;
1031 y1
= (f
->dots
[0]->y
- g
->lowest_y
) / cell_size
;
1032 y2
= (f
->dots
[2]->y
- g
->lowest_y
) / cell_size
;
1033 /* Midpoint, in canvas coordinates */
1036 ret
[y
*W
+ x
] = CLUE2CHAR(state
->clues
[i
]);
1041 /* ----------------------------------------------------------------------
1046 static void check_caches(const solver_state
* sstate
)
1049 const game_state
*state
= sstate
->state
;
1050 const grid
*g
= state
->game_grid
;
1052 for (i
= 0; i
< g
->num_dots
; i
++) {
1053 assert(dot_order(state
, i
, LINE_YES
) == sstate
->dot_yes_count
[i
]);
1054 assert(dot_order(state
, i
, LINE_NO
) == sstate
->dot_no_count
[i
]);
1057 for (i
= 0; i
< g
->num_faces
; i
++) {
1058 assert(face_order(state
, i
, LINE_YES
) == sstate
->face_yes_count
[i
]);
1059 assert(face_order(state
, i
, LINE_NO
) == sstate
->face_no_count
[i
]);
1064 #define check_caches(s) \
1066 fprintf(stderr, "check_caches at line %d\n", __LINE__); \
1070 #endif /* DEBUG_CACHES */
1072 /* ----------------------------------------------------------------------
1073 * Solver utility functions
1076 /* Sets the line (with index i) to the new state 'line_new', and updates
1077 * the cached counts of any affected faces and dots.
1078 * Returns TRUE if this actually changed the line's state. */
1079 static int solver_set_line(solver_state
*sstate
, int i
,
1080 enum line_state line_new
1082 , const char *reason
1086 game_state
*state
= sstate
->state
;
1090 assert(line_new
!= LINE_UNKNOWN
);
1092 check_caches(sstate
);
1094 if (state
->lines
[i
] == line_new
) {
1095 return FALSE
; /* nothing changed */
1097 state
->lines
[i
] = line_new
;
1100 fprintf(stderr
, "solver: set line [%d] to %s (%s)\n",
1101 i
, line_new
== LINE_YES ?
"YES" : "NO",
1105 g
= state
->game_grid
;
1108 /* Update the cache for both dots and both faces affected by this. */
1109 if (line_new
== LINE_YES
) {
1110 sstate
->dot_yes_count
[e
->dot1
- g
->dots
]++;
1111 sstate
->dot_yes_count
[e
->dot2
- g
->dots
]++;
1113 sstate
->face_yes_count
[e
->face1
- g
->faces
]++;
1116 sstate
->face_yes_count
[e
->face2
- g
->faces
]++;
1119 sstate
->dot_no_count
[e
->dot1
- g
->dots
]++;
1120 sstate
->dot_no_count
[e
->dot2
- g
->dots
]++;
1122 sstate
->face_no_count
[e
->face1
- g
->faces
]++;
1125 sstate
->face_no_count
[e
->face2
- g
->faces
]++;
1129 check_caches(sstate
);
1134 #define solver_set_line(a, b, c) \
1135 solver_set_line(a, b, c, __FUNCTION__)
1139 * Merge two dots due to the existence of an edge between them.
1140 * Updates the dsf tracking equivalence classes, and keeps track of
1141 * the length of path each dot is currently a part of.
1142 * Returns TRUE if the dots were already linked, ie if they are part of a
1143 * closed loop, and false otherwise.
1145 static int merge_dots(solver_state
*sstate
, int edge_index
)
1148 grid
*g
= sstate
->state
->game_grid
;
1149 grid_edge
*e
= g
->edges
+ edge_index
;
1151 i
= e
->dot1
- g
->dots
;
1152 j
= e
->dot2
- g
->dots
;
1154 i
= dsf_canonify(sstate
->dotdsf
, i
);
1155 j
= dsf_canonify(sstate
->dotdsf
, j
);
1160 len
= sstate
->looplen
[i
] + sstate
->looplen
[j
];
1161 dsf_merge(sstate
->dotdsf
, i
, j
);
1162 i
= dsf_canonify(sstate
->dotdsf
, i
);
1163 sstate
->looplen
[i
] = len
;
1168 /* Merge two lines because the solver has deduced that they must be either
1169 * identical or opposite. Returns TRUE if this is new information, otherwise
1171 static int merge_lines(solver_state
*sstate
, int i
, int j
, int inverse
1173 , const char *reason
1179 assert(i
< sstate
->state
->game_grid
->num_edges
);
1180 assert(j
< sstate
->state
->game_grid
->num_edges
);
1182 i
= edsf_canonify(sstate
->linedsf
, i
, &inv_tmp
);
1184 j
= edsf_canonify(sstate
->linedsf
, j
, &inv_tmp
);
1187 edsf_merge(sstate
->linedsf
, i
, j
, inverse
);
1191 fprintf(stderr
, "%s [%d] [%d] %s(%s)\n",
1193 inverse ?
"inverse " : "", reason
);
1200 #define merge_lines(a, b, c, d) \
1201 merge_lines(a, b, c, d, __FUNCTION__)
1204 /* Count the number of lines of a particular type currently going into the
1206 static int dot_order(const game_state
* state
, int dot
, char line_type
)
1209 grid
*g
= state
->game_grid
;
1210 grid_dot
*d
= g
->dots
+ dot
;
1213 for (i
= 0; i
< d
->order
; i
++) {
1214 grid_edge
*e
= d
->edges
[i
];
1215 if (state
->lines
[e
- g
->edges
] == line_type
)
1221 /* Count the number of lines of a particular type currently surrounding the
1223 static int face_order(const game_state
* state
, int face
, char line_type
)
1226 grid
*g
= state
->game_grid
;
1227 grid_face
*f
= g
->faces
+ face
;
1230 for (i
= 0; i
< f
->order
; i
++) {
1231 grid_edge
*e
= f
->edges
[i
];
1232 if (state
->lines
[e
- g
->edges
] == line_type
)
1238 /* Set all lines bordering a dot of type old_type to type new_type
1239 * Return value tells caller whether this function actually did anything */
1240 static int dot_setall(solver_state
*sstate
, int dot
,
1241 char old_type
, char new_type
)
1243 int retval
= FALSE
, r
;
1244 game_state
*state
= sstate
->state
;
1249 if (old_type
== new_type
)
1252 g
= state
->game_grid
;
1255 for (i
= 0; i
< d
->order
; i
++) {
1256 int line_index
= d
->edges
[i
] - g
->edges
;
1257 if (state
->lines
[line_index
] == old_type
) {
1258 r
= solver_set_line(sstate
, line_index
, new_type
);
1266 /* Set all lines bordering a face of type old_type to type new_type */
1267 static int face_setall(solver_state
*sstate
, int face
,
1268 char old_type
, char new_type
)
1270 int retval
= FALSE
, r
;
1271 game_state
*state
= sstate
->state
;
1276 if (old_type
== new_type
)
1279 g
= state
->game_grid
;
1280 f
= g
->faces
+ face
;
1282 for (i
= 0; i
< f
->order
; i
++) {
1283 int line_index
= f
->edges
[i
] - g
->edges
;
1284 if (state
->lines
[line_index
] == old_type
) {
1285 r
= solver_set_line(sstate
, line_index
, new_type
);
1293 /* ----------------------------------------------------------------------
1294 * Loop generation and clue removal
1297 static void add_full_clues(game_state
*state
, random_state
*rs
)
1299 signed char *clues
= state
->clues
;
1300 grid
*g
= state
->game_grid
;
1301 char *board
= snewn(g
->num_faces
, char);
1304 generate_loop(g
, board
, rs
, NULL
, NULL
);
1306 /* Fill out all the clues by initialising to 0, then iterating over
1307 * all edges and incrementing each clue as we find edges that border
1308 * between BLACK/WHITE faces. While we're at it, we verify that the
1309 * algorithm does work, and there aren't any GREY faces still there. */
1310 memset(clues
, 0, g
->num_faces
);
1311 for (i
= 0; i
< g
->num_edges
; i
++) {
1312 grid_edge
*e
= g
->edges
+ i
;
1313 grid_face
*f1
= e
->face1
;
1314 grid_face
*f2
= e
->face2
;
1315 enum face_colour c1
= FACE_COLOUR(f1
);
1316 enum face_colour c2
= FACE_COLOUR(f2
);
1317 assert(c1
!= FACE_GREY
);
1318 assert(c2
!= FACE_GREY
);
1320 if (f1
) clues
[f1
- g
->faces
]++;
1321 if (f2
) clues
[f2
- g
->faces
]++;
1328 static int game_has_unique_soln(const game_state
*state
, int diff
)
1331 solver_state
*sstate_new
;
1332 solver_state
*sstate
= new_solver_state((game_state
*)state
, diff
);
1334 sstate_new
= solve_game_rec(sstate
);
1336 assert(sstate_new
->solver_status
!= SOLVER_MISTAKE
);
1337 ret
= (sstate_new
->solver_status
== SOLVER_SOLVED
);
1339 free_solver_state(sstate_new
);
1340 free_solver_state(sstate
);
1346 /* Remove clues one at a time at random. */
1347 static game_state
*remove_clues(game_state
*state
, random_state
*rs
,
1351 int num_faces
= state
->game_grid
->num_faces
;
1352 game_state
*ret
= dup_game(state
), *saved_ret
;
1355 /* We need to remove some clues. We'll do this by forming a list of all
1356 * available clues, shuffling it, then going along one at a
1357 * time clearing each clue in turn for which doing so doesn't render the
1358 * board unsolvable. */
1359 face_list
= snewn(num_faces
, int);
1360 for (n
= 0; n
< num_faces
; ++n
) {
1364 shuffle(face_list
, num_faces
, sizeof(int), rs
);
1366 for (n
= 0; n
< num_faces
; ++n
) {
1367 saved_ret
= dup_game(ret
);
1368 ret
->clues
[face_list
[n
]] = -1;
1370 if (game_has_unique_soln(ret
, diff
)) {
1371 free_game(saved_ret
);
1383 static char *new_game_desc(game_params
*params
, random_state
*rs
,
1384 char **aux
, int interactive
)
1386 /* solution and description both use run-length encoding in obvious ways */
1387 char *retval
, *game_desc
, *grid_desc
;
1389 game_state
*state
= snew(game_state
);
1390 game_state
*state_new
;
1392 grid_desc
= grid_new_desc(grid_types
[params
->type
], params
->w
, params
->h
, params
->dual
, rs
);
1393 state
->game_grid
= g
= loopy_generate_grid(params
, grid_desc
);
1395 state
->clues
= snewn(g
->num_faces
, signed char);
1396 state
->lines
= snewn(g
->num_edges
, char);
1397 state
->line_errors
= snewn(g
->num_edges
, unsigned char);
1399 state
->grid_type
= params
->type
;
1403 memset(state
->lines
, LINE_UNKNOWN
, g
->num_edges
);
1404 memset(state
->line_errors
, 0, g
->num_edges
);
1406 state
->solved
= state
->cheated
= FALSE
;
1408 /* Get a new random solvable board with all its clues filled in. Yes, this
1409 * can loop for ever if the params are suitably unfavourable, but
1410 * preventing games smaller than 4x4 seems to stop this happening */
1412 add_full_clues(state
, rs
);
1413 } while (!game_has_unique_soln(state
, params
->diff
));
1415 state_new
= remove_clues(state
, rs
, params
->diff
);
1420 if (params
->diff
> 0 && game_has_unique_soln(state
, params
->diff
-1)) {
1422 fprintf(stderr
, "Rejecting board, it is too easy\n");
1424 goto newboard_please
;
1427 game_desc
= state_to_text(state
);
1432 retval
= snewn(strlen(grid_desc
) + 1 + strlen(game_desc
) + 1, char);
1433 sprintf(retval
, "%s%c%s", grid_desc
, (int)GRID_DESC_SEP
, game_desc
);
1440 assert(!validate_desc(params
, retval
));
1445 static game_state
*new_game(midend
*me
, game_params
*params
, char *desc
)
1448 game_state
*state
= snew(game_state
);
1449 int empties_to_make
= 0;
1454 int num_faces
, num_edges
;
1456 grid_desc
= extract_grid_desc(&desc
);
1457 state
->game_grid
= g
= loopy_generate_grid(params
, grid_desc
);
1458 if (grid_desc
) sfree(grid_desc
);
1462 num_faces
= g
->num_faces
;
1463 num_edges
= g
->num_edges
;
1465 state
->clues
= snewn(num_faces
, signed char);
1466 state
->lines
= snewn(num_edges
, char);
1467 state
->line_errors
= snewn(num_edges
, unsigned char);
1469 state
->solved
= state
->cheated
= FALSE
;
1471 state
->grid_type
= params
->type
;
1473 for (i
= 0; i
< num_faces
; i
++) {
1474 if (empties_to_make
) {
1476 state
->clues
[i
] = -1;
1482 n2
= *dp
- 'A' + 10;
1483 if (n
>= 0 && n
< 10) {
1484 state
->clues
[i
] = n
;
1485 } else if (n2
>= 10 && n2
< 36) {
1486 state
->clues
[i
] = n2
;
1490 state
->clues
[i
] = -1;
1491 empties_to_make
= n
- 1;
1496 memset(state
->lines
, LINE_UNKNOWN
, num_edges
);
1497 memset(state
->line_errors
, 0, num_edges
);
1501 /* Calculates the line_errors data, and checks if the current state is a
1503 static int check_completion(game_state
*state
)
1505 grid
*g
= state
->game_grid
;
1507 int num_faces
= g
->num_faces
;
1509 int infinite_area
, finite_area
;
1510 int loops_found
= 0;
1511 int found_edge_not_in_loop
= FALSE
;
1513 memset(state
->line_errors
, 0, g
->num_edges
);
1515 /* LL implementation of SGT's idea:
1516 * A loop will partition the grid into an inside and an outside.
1517 * If there is more than one loop, the grid will be partitioned into
1518 * even more distinct regions. We can therefore track equivalence of
1519 * faces, by saying that two faces are equivalent when there is a non-YES
1520 * edge between them.
1521 * We could keep track of the number of connected components, by counting
1522 * the number of dsf-merges that aren't no-ops.
1523 * But we're only interested in 3 separate cases:
1524 * no loops, one loop, more than one loop.
1526 * No loops: all faces are equivalent to the infinite face.
1527 * One loop: only two equivalence classes - finite and infinite.
1528 * >= 2 loops: there are 2 distinct finite regions.
1530 * So we simply make two passes through all the edges.
1531 * In the first pass, we dsf-merge the two faces bordering each non-YES
1533 * In the second pass, we look for YES-edges bordering:
1534 * a) two non-equivalent faces.
1535 * b) two non-equivalent faces, and one of them is part of a different
1536 * finite area from the first finite area we've seen.
1538 * An occurrence of a) means there is at least one loop.
1539 * An occurrence of b) means there is more than one loop.
1540 * Edges satisfying a) are marked as errors.
1542 * While we're at it, we set a flag if we find a YES edge that is not
1544 * This information will help decide, if there's a single loop, whether it
1545 * is a candidate for being a solution (that is, all YES edges are part of
1548 * If there is a candidate loop, we then go through all clues and check
1549 * they are all satisfied. If so, we have found a solution and we can
1550 * unmark all line_errors.
1553 /* Infinite face is at the end - its index is num_faces.
1554 * This macro is just to make this obvious! */
1555 #define INF_FACE num_faces
1556 dsf
= snewn(num_faces
+ 1, int);
1557 dsf_init(dsf
, num_faces
+ 1);
1560 for (i
= 0; i
< g
->num_edges
; i
++) {
1561 grid_edge
*e
= g
->edges
+ i
;
1562 int f1
= e
->face1 ? e
->face1
- g
->faces
: INF_FACE
;
1563 int f2
= e
->face2 ? e
->face2
- g
->faces
: INF_FACE
;
1564 if (state
->lines
[i
] != LINE_YES
)
1565 dsf_merge(dsf
, f1
, f2
);
1569 infinite_area
= dsf_canonify(dsf
, INF_FACE
);
1571 for (i
= 0; i
< g
->num_edges
; i
++) {
1572 grid_edge
*e
= g
->edges
+ i
;
1573 int f1
= e
->face1 ? e
->face1
- g
->faces
: INF_FACE
;
1574 int can1
= dsf_canonify(dsf
, f1
);
1575 int f2
= e
->face2 ? e
->face2
- g
->faces
: INF_FACE
;
1576 int can2
= dsf_canonify(dsf
, f2
);
1577 if (state
->lines
[i
] != LINE_YES
) continue;
1580 /* Faces are equivalent, so this edge not part of a loop */
1581 found_edge_not_in_loop
= TRUE
;
1584 state
->line_errors
[i
] = TRUE
;
1585 if (loops_found
== 0) loops_found
= 1;
1587 /* Don't bother with further checks if we've already found 2 loops */
1588 if (loops_found
== 2) continue;
1590 if (finite_area
== -1) {
1591 /* Found our first finite area */
1592 if (can1
!= infinite_area
)
1598 /* Have we found a second area? */
1599 if (finite_area
!= -1) {
1600 if (can1
!= infinite_area
&& can1
!= finite_area
) {
1604 if (can2
!= infinite_area
&& can2
!= finite_area
) {
1611 printf("loops_found = %d\n", loops_found);
1612 printf("found_edge_not_in_loop = %s\n",
1613 found_edge_not_in_loop ? "TRUE" : "FALSE");
1616 sfree(dsf
); /* No longer need the dsf */
1618 /* Have we found a candidate loop? */
1619 if (loops_found
== 1 && !found_edge_not_in_loop
) {
1620 /* Yes, so check all clues are satisfied */
1621 int found_clue_violation
= FALSE
;
1622 for (i
= 0; i
< num_faces
; i
++) {
1623 int c
= state
->clues
[i
];
1625 if (face_order(state
, i
, LINE_YES
) != c
) {
1626 found_clue_violation
= TRUE
;
1632 if (!found_clue_violation
) {
1633 /* The loop is good */
1634 memset(state
->line_errors
, 0, g
->num_edges
);
1635 return TRUE
; /* No need to bother checking for dot violations */
1639 /* Check for dot violations */
1640 for (i
= 0; i
< g
->num_dots
; i
++) {
1641 int yes
= dot_order(state
, i
, LINE_YES
);
1642 int unknown
= dot_order(state
, i
, LINE_UNKNOWN
);
1643 if ((yes
== 1 && unknown
== 0) || (yes
>= 3)) {
1644 /* violation, so mark all YES edges as errors */
1645 grid_dot
*d
= g
->dots
+ i
;
1647 for (j
= 0; j
< d
->order
; j
++) {
1648 int e
= d
->edges
[j
] - g
->edges
;
1649 if (state
->lines
[e
] == LINE_YES
)
1650 state
->line_errors
[e
] = TRUE
;
1657 /* ----------------------------------------------------------------------
1660 * Our solver modes operate as follows. Each mode also uses the modes above it.
1663 * Just implement the rules of the game.
1665 * Normal and Tricky Modes
1666 * For each (adjacent) pair of lines through each dot we store a bit for
1667 * whether at least one of them is on and whether at most one is on. (If we
1668 * know both or neither is on that's already stored more directly.)
1671 * Use edsf data structure to make equivalence classes of lines that are
1672 * known identical to or opposite to one another.
1677 * For general grids, we consider "dlines" to be pairs of lines joined
1678 * at a dot. The lines must be adjacent around the dot, so we can think of
1679 * a dline as being a dot+face combination. Or, a dot+edge combination where
1680 * the second edge is taken to be the next clockwise edge from the dot.
1681 * Original loopy code didn't have this extra restriction of the lines being
1682 * adjacent. From my tests with square grids, this extra restriction seems to
1683 * take little, if anything, away from the quality of the puzzles.
1684 * A dline can be uniquely identified by an edge/dot combination, given that
1685 * a dline-pair always goes clockwise around its common dot. The edge/dot
1686 * combination can be represented by an edge/bool combination - if bool is
1687 * TRUE, use edge->dot1 else use edge->dot2. So the total number of dlines is
1688 * exactly twice the number of edges in the grid - although the dlines
1689 * spanning the infinite face are not all that useful to the solver.
1690 * Note that, by convention, a dline goes clockwise around its common dot,
1691 * which means the dline goes anti-clockwise around its common face.
1694 /* Helper functions for obtaining an index into an array of dlines, given
1695 * various information. We assume the grid layout conventions about how
1696 * the various lists are interleaved - see grid_make_consistent() for
1699 /* i points to the first edge of the dline pair, reading clockwise around
1701 static int dline_index_from_dot(grid
*g
, grid_dot
*d
, int i
)
1703 grid_edge
*e
= d
->edges
[i
];
1708 if (i2
== d
->order
) i2
= 0;
1711 ret
= 2 * (e
- g
->edges
) + ((e
->dot1
== d
) ?
1 : 0);
1713 printf("dline_index_from_dot: d=%d,i=%d, edges [%d,%d] - %d\n",
1714 (int)(d
- g
->dots
), i
, (int)(e
- g
->edges
),
1715 (int)(e2
- g
->edges
), ret
);
1719 /* i points to the second edge of the dline pair, reading clockwise around
1720 * the face. That is, the edges of the dline, starting at edge{i}, read
1721 * anti-clockwise around the face. By layout conventions, the common dot
1722 * of the dline will be f->dots[i] */
1723 static int dline_index_from_face(grid
*g
, grid_face
*f
, int i
)
1725 grid_edge
*e
= f
->edges
[i
];
1726 grid_dot
*d
= f
->dots
[i
];
1731 if (i2
< 0) i2
+= f
->order
;
1734 ret
= 2 * (e
- g
->edges
) + ((e
->dot1
== d
) ?
1 : 0);
1736 printf("dline_index_from_face: f=%d,i=%d, edges [%d,%d] - %d\n",
1737 (int)(f
- g
->faces
), i
, (int)(e
- g
->edges
),
1738 (int)(e2
- g
->edges
), ret
);
1742 static int is_atleastone(const char *dline_array
, int index
)
1744 return BIT_SET(dline_array
[index
], 0);
1746 static int set_atleastone(char *dline_array
, int index
)
1748 return SET_BIT(dline_array
[index
], 0);
1750 static int is_atmostone(const char *dline_array
, int index
)
1752 return BIT_SET(dline_array
[index
], 1);
1754 static int set_atmostone(char *dline_array
, int index
)
1756 return SET_BIT(dline_array
[index
], 1);
1759 static void array_setall(char *array
, char from
, char to
, int len
)
1761 char *p
= array
, *p_old
= p
;
1762 int len_remaining
= len
;
1764 while ((p
= memchr(p
, from
, len_remaining
))) {
1766 len_remaining
-= p
- p_old
;
1771 /* Helper, called when doing dline dot deductions, in the case where we
1772 * have 4 UNKNOWNs, and two of them (adjacent) have *exactly* one YES between
1773 * them (because of dline atmostone/atleastone).
1774 * On entry, edge points to the first of these two UNKNOWNs. This function
1775 * will find the opposite UNKNOWNS (if they are adjacent to one another)
1776 * and set their corresponding dline to atleastone. (Setting atmostone
1777 * already happens in earlier dline deductions) */
1778 static int dline_set_opp_atleastone(solver_state
*sstate
,
1779 grid_dot
*d
, int edge
)
1781 game_state
*state
= sstate
->state
;
1782 grid
*g
= state
->game_grid
;
1785 for (opp
= 0; opp
< N
; opp
++) {
1786 int opp_dline_index
;
1787 if (opp
== edge
|| opp
== edge
+1 || opp
== edge
-1)
1789 if (opp
== 0 && edge
== N
-1)
1791 if (opp
== N
-1 && edge
== 0)
1794 if (opp2
== N
) opp2
= 0;
1795 /* Check if opp, opp2 point to LINE_UNKNOWNs */
1796 if (state
->lines
[d
->edges
[opp
] - g
->edges
] != LINE_UNKNOWN
)
1798 if (state
->lines
[d
->edges
[opp2
] - g
->edges
] != LINE_UNKNOWN
)
1800 /* Found opposite UNKNOWNS and they're next to each other */
1801 opp_dline_index
= dline_index_from_dot(g
, d
, opp
);
1802 return set_atleastone(sstate
->dlines
, opp_dline_index
);
1808 /* Set pairs of lines around this face which are known to be identical, to
1809 * the given line_state */
1810 static int face_setall_identical(solver_state
*sstate
, int face_index
,
1811 enum line_state line_new
)
1813 /* can[dir] contains the canonical line associated with the line in
1814 * direction dir from the square in question. Similarly inv[dir] is
1815 * whether or not the line in question is inverse to its canonical
1818 game_state
*state
= sstate
->state
;
1819 grid
*g
= state
->game_grid
;
1820 grid_face
*f
= g
->faces
+ face_index
;
1823 int can1
, can2
, inv1
, inv2
;
1825 for (i
= 0; i
< N
; i
++) {
1826 int line1_index
= f
->edges
[i
] - g
->edges
;
1827 if (state
->lines
[line1_index
] != LINE_UNKNOWN
)
1829 for (j
= i
+ 1; j
< N
; j
++) {
1830 int line2_index
= f
->edges
[j
] - g
->edges
;
1831 if (state
->lines
[line2_index
] != LINE_UNKNOWN
)
1834 /* Found two UNKNOWNS */
1835 can1
= edsf_canonify(sstate
->linedsf
, line1_index
, &inv1
);
1836 can2
= edsf_canonify(sstate
->linedsf
, line2_index
, &inv2
);
1837 if (can1
== can2
&& inv1
== inv2
) {
1838 solver_set_line(sstate
, line1_index
, line_new
);
1839 solver_set_line(sstate
, line2_index
, line_new
);
1846 /* Given a dot or face, and a count of LINE_UNKNOWNs, find them and
1847 * return the edge indices into e. */
1848 static void find_unknowns(game_state
*state
,
1849 grid_edge
**edge_list
, /* Edge list to search (from a face or a dot) */
1850 int expected_count
, /* Number of UNKNOWNs (comes from solver's cache) */
1851 int *e
/* Returned edge indices */)
1854 grid
*g
= state
->game_grid
;
1855 while (c
< expected_count
) {
1856 int line_index
= *edge_list
- g
->edges
;
1857 if (state
->lines
[line_index
] == LINE_UNKNOWN
) {
1865 /* If we have a list of edges, and we know whether the number of YESs should
1866 * be odd or even, and there are only a few UNKNOWNs, we can do some simple
1867 * linedsf deductions. This can be used for both face and dot deductions.
1868 * Returns the difficulty level of the next solver that should be used,
1869 * or DIFF_MAX if no progress was made. */
1870 static int parity_deductions(solver_state
*sstate
,
1871 grid_edge
**edge_list
, /* Edge list (from a face or a dot) */
1872 int total_parity
, /* Expected number of YESs modulo 2 (either 0 or 1) */
1875 game_state
*state
= sstate
->state
;
1876 int diff
= DIFF_MAX
;
1877 int *linedsf
= sstate
->linedsf
;
1879 if (unknown_count
== 2) {
1880 /* Lines are known alike/opposite, depending on inv. */
1882 find_unknowns(state
, edge_list
, 2, e
);
1883 if (merge_lines(sstate
, e
[0], e
[1], total_parity
))
1884 diff
= min(diff
, DIFF_HARD
);
1885 } else if (unknown_count
== 3) {
1887 int can
[3]; /* canonical edges */
1888 int inv
[3]; /* whether can[x] is inverse to e[x] */
1889 find_unknowns(state
, edge_list
, 3, e
);
1890 can
[0] = edsf_canonify(linedsf
, e
[0], inv
);
1891 can
[1] = edsf_canonify(linedsf
, e
[1], inv
+1);
1892 can
[2] = edsf_canonify(linedsf
, e
[2], inv
+2);
1893 if (can
[0] == can
[1]) {
1894 if (solver_set_line(sstate
, e
[2], (total_parity
^inv
[0]^inv
[1]) ?
1895 LINE_YES
: LINE_NO
))
1896 diff
= min(diff
, DIFF_EASY
);
1898 if (can
[0] == can
[2]) {
1899 if (solver_set_line(sstate
, e
[1], (total_parity
^inv
[0]^inv
[2]) ?
1900 LINE_YES
: LINE_NO
))
1901 diff
= min(diff
, DIFF_EASY
);
1903 if (can
[1] == can
[2]) {
1904 if (solver_set_line(sstate
, e
[0], (total_parity
^inv
[1]^inv
[2]) ?
1905 LINE_YES
: LINE_NO
))
1906 diff
= min(diff
, DIFF_EASY
);
1908 } else if (unknown_count
== 4) {
1910 int can
[4]; /* canonical edges */
1911 int inv
[4]; /* whether can[x] is inverse to e[x] */
1912 find_unknowns(state
, edge_list
, 4, e
);
1913 can
[0] = edsf_canonify(linedsf
, e
[0], inv
);
1914 can
[1] = edsf_canonify(linedsf
, e
[1], inv
+1);
1915 can
[2] = edsf_canonify(linedsf
, e
[2], inv
+2);
1916 can
[3] = edsf_canonify(linedsf
, e
[3], inv
+3);
1917 if (can
[0] == can
[1]) {
1918 if (merge_lines(sstate
, e
[2], e
[3], total_parity
^inv
[0]^inv
[1]))
1919 diff
= min(diff
, DIFF_HARD
);
1920 } else if (can
[0] == can
[2]) {
1921 if (merge_lines(sstate
, e
[1], e
[3], total_parity
^inv
[0]^inv
[2]))
1922 diff
= min(diff
, DIFF_HARD
);
1923 } else if (can
[0] == can
[3]) {
1924 if (merge_lines(sstate
, e
[1], e
[2], total_parity
^inv
[0]^inv
[3]))
1925 diff
= min(diff
, DIFF_HARD
);
1926 } else if (can
[1] == can
[2]) {
1927 if (merge_lines(sstate
, e
[0], e
[3], total_parity
^inv
[1]^inv
[2]))
1928 diff
= min(diff
, DIFF_HARD
);
1929 } else if (can
[1] == can
[3]) {
1930 if (merge_lines(sstate
, e
[0], e
[2], total_parity
^inv
[1]^inv
[3]))
1931 diff
= min(diff
, DIFF_HARD
);
1932 } else if (can
[2] == can
[3]) {
1933 if (merge_lines(sstate
, e
[0], e
[1], total_parity
^inv
[2]^inv
[3]))
1934 diff
= min(diff
, DIFF_HARD
);
1942 * These are the main solver functions.
1944 * Their return values are diff values corresponding to the lowest mode solver
1945 * that would notice the work that they have done. For example if the normal
1946 * mode solver adds actual lines or crosses, it will return DIFF_EASY as the
1947 * easy mode solver might be able to make progress using that. It doesn't make
1948 * sense for one of them to return a diff value higher than that of the
1951 * Each function returns the lowest value it can, as early as possible, in
1952 * order to try and pass as much work as possible back to the lower level
1953 * solvers which progress more quickly.
1956 /* PROPOSED NEW DESIGN:
1957 * We have a work queue consisting of 'events' notifying us that something has
1958 * happened that a particular solver mode might be interested in. For example
1959 * the hard mode solver might do something that helps the normal mode solver at
1960 * dot [x,y] in which case it will enqueue an event recording this fact. Then
1961 * we pull events off the work queue, and hand each in turn to the solver that
1962 * is interested in them. If a solver reports that it failed we pass the same
1963 * event on to progressively more advanced solvers and the loop detector. Once
1964 * we've exhausted an event, or it has helped us progress, we drop it and
1965 * continue to the next one. The events are sorted first in order of solver
1966 * complexity (easy first) then order of insertion (oldest first).
1967 * Once we run out of events we loop over each permitted solver in turn
1968 * (easiest first) until either a deduction is made (and an event therefore
1969 * emerges) or no further deductions can be made (in which case we've failed).
1972 * * How do we 'loop over' a solver when both dots and squares are concerned.
1973 * Answer: first all squares then all dots.
1976 static int trivial_deductions(solver_state
*sstate
)
1978 int i
, current_yes
, current_no
;
1979 game_state
*state
= sstate
->state
;
1980 grid
*g
= state
->game_grid
;
1981 int diff
= DIFF_MAX
;
1983 /* Per-face deductions */
1984 for (i
= 0; i
< g
->num_faces
; i
++) {
1985 grid_face
*f
= g
->faces
+ i
;
1987 if (sstate
->face_solved
[i
])
1990 current_yes
= sstate
->face_yes_count
[i
];
1991 current_no
= sstate
->face_no_count
[i
];
1993 if (current_yes
+ current_no
== f
->order
) {
1994 sstate
->face_solved
[i
] = TRUE
;
1998 if (state
->clues
[i
] < 0)
2002 * This code checks whether the numeric clue on a face is so
2003 * large as to permit all its remaining LINE_UNKNOWNs to be
2004 * filled in as LINE_YES, or alternatively so small as to
2005 * permit them all to be filled in as LINE_NO.
2008 if (state
->clues
[i
] < current_yes
) {
2009 sstate
->solver_status
= SOLVER_MISTAKE
;
2012 if (state
->clues
[i
] == current_yes
) {
2013 if (face_setall(sstate
, i
, LINE_UNKNOWN
, LINE_NO
))
2014 diff
= min(diff
, DIFF_EASY
);
2015 sstate
->face_solved
[i
] = TRUE
;
2019 if (f
->order
- state
->clues
[i
] < current_no
) {
2020 sstate
->solver_status
= SOLVER_MISTAKE
;
2023 if (f
->order
- state
->clues
[i
] == current_no
) {
2024 if (face_setall(sstate
, i
, LINE_UNKNOWN
, LINE_YES
))
2025 diff
= min(diff
, DIFF_EASY
);
2026 sstate
->face_solved
[i
] = TRUE
;
2030 if (f
->order
- state
->clues
[i
] == current_no
+ 1 &&
2031 f
->order
- current_yes
- current_no
> 2) {
2033 * One small refinement to the above: we also look for any
2034 * adjacent pair of LINE_UNKNOWNs around the face with
2035 * some LINE_YES incident on it from elsewhere. If we find
2036 * one, then we know that pair of LINE_UNKNOWNs can't
2037 * _both_ be LINE_YES, and hence that pushes us one line
2038 * closer to being able to determine all the rest.
2040 int j
, k
, e1
, e2
, e
, d
;
2042 for (j
= 0; j
< f
->order
; j
++) {
2043 e1
= f
->edges
[j
] - g
->edges
;
2044 e2
= f
->edges
[j
+1 < f
->order ? j
+1 : 0] - g
->edges
;
2046 if (g
->edges
[e1
].dot1
== g
->edges
[e2
].dot1
||
2047 g
->edges
[e1
].dot1
== g
->edges
[e2
].dot2
) {
2048 d
= g
->edges
[e1
].dot1
- g
->dots
;
2050 assert(g
->edges
[e1
].dot2
== g
->edges
[e2
].dot1
||
2051 g
->edges
[e1
].dot2
== g
->edges
[e2
].dot2
);
2052 d
= g
->edges
[e1
].dot2
- g
->dots
;
2055 if (state
->lines
[e1
] == LINE_UNKNOWN
&&
2056 state
->lines
[e2
] == LINE_UNKNOWN
) {
2057 for (k
= 0; k
< g
->dots
[d
].order
; k
++) {
2058 int e
= g
->dots
[d
].edges
[k
] - g
->edges
;
2059 if (state
->lines
[e
] == LINE_YES
)
2060 goto found
; /* multi-level break */
2068 * If we get here, we've found such a pair of edges, and
2069 * they're e1 and e2.
2071 for (j
= 0; j
< f
->order
; j
++) {
2072 e
= f
->edges
[j
] - g
->edges
;
2073 if (state
->lines
[e
] == LINE_UNKNOWN
&& e
!= e1
&& e
!= e2
) {
2074 int r
= solver_set_line(sstate
, e
, LINE_YES
);
2076 diff
= min(diff
, DIFF_EASY
);
2082 check_caches(sstate
);
2084 /* Per-dot deductions */
2085 for (i
= 0; i
< g
->num_dots
; i
++) {
2086 grid_dot
*d
= g
->dots
+ i
;
2087 int yes
, no
, unknown
;
2089 if (sstate
->dot_solved
[i
])
2092 yes
= sstate
->dot_yes_count
[i
];
2093 no
= sstate
->dot_no_count
[i
];
2094 unknown
= d
->order
- yes
- no
;
2098 sstate
->dot_solved
[i
] = TRUE
;
2099 } else if (unknown
== 1) {
2100 dot_setall(sstate
, i
, LINE_UNKNOWN
, LINE_NO
);
2101 diff
= min(diff
, DIFF_EASY
);
2102 sstate
->dot_solved
[i
] = TRUE
;
2104 } else if (yes
== 1) {
2106 sstate
->solver_status
= SOLVER_MISTAKE
;
2108 } else if (unknown
== 1) {
2109 dot_setall(sstate
, i
, LINE_UNKNOWN
, LINE_YES
);
2110 diff
= min(diff
, DIFF_EASY
);
2112 } else if (yes
== 2) {
2114 dot_setall(sstate
, i
, LINE_UNKNOWN
, LINE_NO
);
2115 diff
= min(diff
, DIFF_EASY
);
2117 sstate
->dot_solved
[i
] = TRUE
;
2119 sstate
->solver_status
= SOLVER_MISTAKE
;
2124 check_caches(sstate
);
2129 static int dline_deductions(solver_state
*sstate
)
2131 game_state
*state
= sstate
->state
;
2132 grid
*g
= state
->game_grid
;
2133 char *dlines
= sstate
->dlines
;
2135 int diff
= DIFF_MAX
;
2137 /* ------ Face deductions ------ */
2139 /* Given a set of dline atmostone/atleastone constraints, need to figure
2140 * out if we can deduce any further info. For more general faces than
2141 * squares, this turns out to be a tricky problem.
2142 * The approach taken here is to define (per face) NxN matrices:
2143 * "maxs" and "mins".
2144 * The entries maxs(j,k) and mins(j,k) define the upper and lower limits
2145 * for the possible number of edges that are YES between positions j and k
2146 * going clockwise around the face. Can think of j and k as marking dots
2147 * around the face (recall the labelling scheme: edge0 joins dot0 to dot1,
2148 * edge1 joins dot1 to dot2 etc).
2149 * Trivially, mins(j,j) = maxs(j,j) = 0, and we don't even bother storing
2150 * these. mins(j,j+1) and maxs(j,j+1) are determined by whether edge{j}
2151 * is YES, NO or UNKNOWN. mins(j,j+2) and maxs(j,j+2) are related to
2152 * the dline atmostone/atleastone status for edges j and j+1.
2154 * Then we calculate the remaining entries recursively. We definitely
2156 * mins(j,k) >= { mins(j,u) + mins(u,k) } for any u between j and k.
2157 * This is because any valid placement of YESs between j and k must give
2158 * a valid placement between j and u, and also between u and k.
2159 * I believe it's sufficient to use just the two values of u:
2160 * j+1 and j+2. Seems to work well in practice - the bounds we compute
2161 * are rigorous, even if they might not be best-possible.
2163 * Once we have maxs and mins calculated, we can make inferences about
2164 * each dline{j,j+1} by looking at the possible complementary edge-counts
2165 * mins(j+2,j) and maxs(j+2,j) and comparing these with the face clue.
2166 * As well as dlines, we can make similar inferences about single edges.
2167 * For example, consider a pentagon with clue 3, and we know at most one
2168 * of (edge0, edge1) is YES, and at most one of (edge2, edge3) is YES.
2169 * We could then deduce edge4 is YES, because maxs(0,4) would be 2, so
2170 * that final edge would have to be YES to make the count up to 3.
2173 /* Much quicker to allocate arrays on the stack than the heap, so
2174 * define the largest possible face size, and base our array allocations
2175 * on that. We check this with an assertion, in case someone decides to
2176 * make a grid which has larger faces than this. Note, this algorithm
2177 * could get quite expensive if there are many large faces. */
2178 #define MAX_FACE_SIZE 12
2180 for (i
= 0; i
< g
->num_faces
; i
++) {
2181 int maxs
[MAX_FACE_SIZE
][MAX_FACE_SIZE
];
2182 int mins
[MAX_FACE_SIZE
][MAX_FACE_SIZE
];
2183 grid_face
*f
= g
->faces
+ i
;
2186 int clue
= state
->clues
[i
];
2187 assert(N
<= MAX_FACE_SIZE
);
2188 if (sstate
->face_solved
[i
])
2190 if (clue
< 0) continue;
2192 /* Calculate the (j,j+1) entries */
2193 for (j
= 0; j
< N
; j
++) {
2194 int edge_index
= f
->edges
[j
] - g
->edges
;
2196 enum line_state line1
= state
->lines
[edge_index
];
2197 enum line_state line2
;
2201 maxs
[j
][k
] = (line1
== LINE_NO
) ?
0 : 1;
2202 mins
[j
][k
] = (line1
== LINE_YES
) ?
1 : 0;
2203 /* Calculate the (j,j+2) entries */
2204 dline_index
= dline_index_from_face(g
, f
, k
);
2205 edge_index
= f
->edges
[k
] - g
->edges
;
2206 line2
= state
->lines
[edge_index
];
2212 if (line1
== LINE_NO
) tmp
--;
2213 if (line2
== LINE_NO
) tmp
--;
2214 if (tmp
== 2 && is_atmostone(dlines
, dline_index
))
2220 if (line1
== LINE_YES
) tmp
++;
2221 if (line2
== LINE_YES
) tmp
++;
2222 if (tmp
== 0 && is_atleastone(dlines
, dline_index
))
2227 /* Calculate the (j,j+m) entries for m between 3 and N-1 */
2228 for (m
= 3; m
< N
; m
++) {
2229 for (j
= 0; j
< N
; j
++) {
2237 maxs
[j
][k
] = maxs
[j
][u
] + maxs
[u
][k
];
2238 mins
[j
][k
] = mins
[j
][u
] + mins
[u
][k
];
2239 tmp
= maxs
[j
][v
] + maxs
[v
][k
];
2240 maxs
[j
][k
] = min(maxs
[j
][k
], tmp
);
2241 tmp
= mins
[j
][v
] + mins
[v
][k
];
2242 mins
[j
][k
] = max(mins
[j
][k
], tmp
);
2246 /* See if we can make any deductions */
2247 for (j
= 0; j
< N
; j
++) {
2249 grid_edge
*e
= f
->edges
[j
];
2250 int line_index
= e
- g
->edges
;
2253 if (state
->lines
[line_index
] != LINE_UNKNOWN
)
2258 /* minimum YESs in the complement of this edge */
2259 if (mins
[k
][j
] > clue
) {
2260 sstate
->solver_status
= SOLVER_MISTAKE
;
2263 if (mins
[k
][j
] == clue
) {
2264 /* setting this edge to YES would make at least
2265 * (clue+1) edges - contradiction */
2266 solver_set_line(sstate
, line_index
, LINE_NO
);
2267 diff
= min(diff
, DIFF_EASY
);
2269 if (maxs
[k
][j
] < clue
- 1) {
2270 sstate
->solver_status
= SOLVER_MISTAKE
;
2273 if (maxs
[k
][j
] == clue
- 1) {
2274 /* Only way to satisfy the clue is to set edge{j} as YES */
2275 solver_set_line(sstate
, line_index
, LINE_YES
);
2276 diff
= min(diff
, DIFF_EASY
);
2279 /* More advanced deduction that allows propagation along diagonal
2280 * chains of faces connected by dots, for example, 3-2-...-2-3
2281 * in square grids. */
2282 if (sstate
->diff
>= DIFF_TRICKY
) {
2283 /* Now see if we can make dline deduction for edges{j,j+1} */
2285 if (state
->lines
[e
- g
->edges
] != LINE_UNKNOWN
)
2286 /* Only worth doing this for an UNKNOWN,UNKNOWN pair.
2287 * Dlines where one of the edges is known, are handled in the
2291 dline_index
= dline_index_from_face(g
, f
, k
);
2295 /* minimum YESs in the complement of this dline */
2296 if (mins
[k
][j
] > clue
- 2) {
2297 /* Adding 2 YESs would break the clue */
2298 if (set_atmostone(dlines
, dline_index
))
2299 diff
= min(diff
, DIFF_NORMAL
);
2301 /* maximum YESs in the complement of this dline */
2302 if (maxs
[k
][j
] < clue
) {
2303 /* Adding 2 NOs would mean not enough YESs */
2304 if (set_atleastone(dlines
, dline_index
))
2305 diff
= min(diff
, DIFF_NORMAL
);
2311 if (diff
< DIFF_NORMAL
)
2314 /* ------ Dot deductions ------ */
2316 for (i
= 0; i
< g
->num_dots
; i
++) {
2317 grid_dot
*d
= g
->dots
+ i
;
2319 int yes
, no
, unknown
;
2321 if (sstate
->dot_solved
[i
])
2323 yes
= sstate
->dot_yes_count
[i
];
2324 no
= sstate
->dot_no_count
[i
];
2325 unknown
= N
- yes
- no
;
2327 for (j
= 0; j
< N
; j
++) {
2330 int line1_index
, line2_index
;
2331 enum line_state line1
, line2
;
2334 dline_index
= dline_index_from_dot(g
, d
, j
);
2335 line1_index
= d
->edges
[j
] - g
->edges
;
2336 line2_index
= d
->edges
[k
] - g
->edges
;
2337 line1
= state
->lines
[line1_index
];
2338 line2
= state
->lines
[line2_index
];
2340 /* Infer dline state from line state */
2341 if (line1
== LINE_NO
|| line2
== LINE_NO
) {
2342 if (set_atmostone(dlines
, dline_index
))
2343 diff
= min(diff
, DIFF_NORMAL
);
2345 if (line1
== LINE_YES
|| line2
== LINE_YES
) {
2346 if (set_atleastone(dlines
, dline_index
))
2347 diff
= min(diff
, DIFF_NORMAL
);
2349 /* Infer line state from dline state */
2350 if (is_atmostone(dlines
, dline_index
)) {
2351 if (line1
== LINE_YES
&& line2
== LINE_UNKNOWN
) {
2352 solver_set_line(sstate
, line2_index
, LINE_NO
);
2353 diff
= min(diff
, DIFF_EASY
);
2355 if (line2
== LINE_YES
&& line1
== LINE_UNKNOWN
) {
2356 solver_set_line(sstate
, line1_index
, LINE_NO
);
2357 diff
= min(diff
, DIFF_EASY
);
2360 if (is_atleastone(dlines
, dline_index
)) {
2361 if (line1
== LINE_NO
&& line2
== LINE_UNKNOWN
) {
2362 solver_set_line(sstate
, line2_index
, LINE_YES
);
2363 diff
= min(diff
, DIFF_EASY
);
2365 if (line2
== LINE_NO
&& line1
== LINE_UNKNOWN
) {
2366 solver_set_line(sstate
, line1_index
, LINE_YES
);
2367 diff
= min(diff
, DIFF_EASY
);
2370 /* Deductions that depend on the numbers of lines.
2371 * Only bother if both lines are UNKNOWN, otherwise the
2372 * easy-mode solver (or deductions above) would have taken
2374 if (line1
!= LINE_UNKNOWN
|| line2
!= LINE_UNKNOWN
)
2377 if (yes
== 0 && unknown
== 2) {
2378 /* Both these unknowns must be identical. If we know
2379 * atmostone or atleastone, we can make progress. */
2380 if (is_atmostone(dlines
, dline_index
)) {
2381 solver_set_line(sstate
, line1_index
, LINE_NO
);
2382 solver_set_line(sstate
, line2_index
, LINE_NO
);
2383 diff
= min(diff
, DIFF_EASY
);
2385 if (is_atleastone(dlines
, dline_index
)) {
2386 solver_set_line(sstate
, line1_index
, LINE_YES
);
2387 solver_set_line(sstate
, line2_index
, LINE_YES
);
2388 diff
= min(diff
, DIFF_EASY
);
2392 if (set_atmostone(dlines
, dline_index
))
2393 diff
= min(diff
, DIFF_NORMAL
);
2395 if (set_atleastone(dlines
, dline_index
))
2396 diff
= min(diff
, DIFF_NORMAL
);
2400 /* More advanced deduction that allows propagation along diagonal
2401 * chains of faces connected by dots, for example: 3-2-...-2-3
2402 * in square grids. */
2403 if (sstate
->diff
>= DIFF_TRICKY
) {
2404 /* If we have atleastone set for this dline, infer
2405 * atmostone for each "opposite" dline (that is, each
2406 * dline without edges in common with this one).
2407 * Again, this test is only worth doing if both these
2408 * lines are UNKNOWN. For if one of these lines were YES,
2409 * the (yes == 1) test above would kick in instead. */
2410 if (is_atleastone(dlines
, dline_index
)) {
2412 for (opp
= 0; opp
< N
; opp
++) {
2413 int opp_dline_index
;
2414 if (opp
== j
|| opp
== j
+1 || opp
== j
-1)
2416 if (j
== 0 && opp
== N
-1)
2418 if (j
== N
-1 && opp
== 0)
2420 opp_dline_index
= dline_index_from_dot(g
, d
, opp
);
2421 if (set_atmostone(dlines
, opp_dline_index
))
2422 diff
= min(diff
, DIFF_NORMAL
);
2424 if (yes
== 0 && is_atmostone(dlines
, dline_index
)) {
2425 /* This dline has *exactly* one YES and there are no
2426 * other YESs. This allows more deductions. */
2428 /* Third unknown must be YES */
2429 for (opp
= 0; opp
< N
; opp
++) {
2431 if (opp
== j
|| opp
== k
)
2433 opp_index
= d
->edges
[opp
] - g
->edges
;
2434 if (state
->lines
[opp_index
] == LINE_UNKNOWN
) {
2435 solver_set_line(sstate
, opp_index
,
2437 diff
= min(diff
, DIFF_EASY
);
2440 } else if (unknown
== 4) {
2441 /* Exactly one of opposite UNKNOWNS is YES. We've
2442 * already set atmostone, so set atleastone as
2445 if (dline_set_opp_atleastone(sstate
, d
, j
))
2446 diff
= min(diff
, DIFF_NORMAL
);
2456 static int linedsf_deductions(solver_state
*sstate
)
2458 game_state
*state
= sstate
->state
;
2459 grid
*g
= state
->game_grid
;
2460 char *dlines
= sstate
->dlines
;
2462 int diff
= DIFF_MAX
;
2465 /* ------ Face deductions ------ */
2467 /* A fully-general linedsf deduction seems overly complicated
2468 * (I suspect the problem is NP-complete, though in practice it might just
2469 * be doable because faces are limited in size).
2470 * For simplicity, we only consider *pairs* of LINE_UNKNOWNS that are
2471 * known to be identical. If setting them both to YES (or NO) would break
2472 * the clue, set them to NO (or YES). */
2474 for (i
= 0; i
< g
->num_faces
; i
++) {
2475 int N
, yes
, no
, unknown
;
2478 if (sstate
->face_solved
[i
])
2480 clue
= state
->clues
[i
];
2484 N
= g
->faces
[i
].order
;
2485 yes
= sstate
->face_yes_count
[i
];
2486 if (yes
+ 1 == clue
) {
2487 if (face_setall_identical(sstate
, i
, LINE_NO
))
2488 diff
= min(diff
, DIFF_EASY
);
2490 no
= sstate
->face_no_count
[i
];
2491 if (no
+ 1 == N
- clue
) {
2492 if (face_setall_identical(sstate
, i
, LINE_YES
))
2493 diff
= min(diff
, DIFF_EASY
);
2496 /* Reload YES count, it might have changed */
2497 yes
= sstate
->face_yes_count
[i
];
2498 unknown
= N
- no
- yes
;
2500 /* Deductions with small number of LINE_UNKNOWNs, based on overall
2501 * parity of lines. */
2502 diff_tmp
= parity_deductions(sstate
, g
->faces
[i
].edges
,
2503 (clue
- yes
) % 2, unknown
);
2504 diff
= min(diff
, diff_tmp
);
2507 /* ------ Dot deductions ------ */
2508 for (i
= 0; i
< g
->num_dots
; i
++) {
2509 grid_dot
*d
= g
->dots
+ i
;
2512 int yes
, no
, unknown
;
2513 /* Go through dlines, and do any dline<->linedsf deductions wherever
2514 * we find two UNKNOWNS. */
2515 for (j
= 0; j
< N
; j
++) {
2516 int dline_index
= dline_index_from_dot(g
, d
, j
);
2519 int can1
, can2
, inv1
, inv2
;
2521 line1_index
= d
->edges
[j
] - g
->edges
;
2522 if (state
->lines
[line1_index
] != LINE_UNKNOWN
)
2525 if (j2
== N
) j2
= 0;
2526 line2_index
= d
->edges
[j2
] - g
->edges
;
2527 if (state
->lines
[line2_index
] != LINE_UNKNOWN
)
2529 /* Infer dline flags from linedsf */
2530 can1
= edsf_canonify(sstate
->linedsf
, line1_index
, &inv1
);
2531 can2
= edsf_canonify(sstate
->linedsf
, line2_index
, &inv2
);
2532 if (can1
== can2
&& inv1
!= inv2
) {
2533 /* These are opposites, so set dline atmostone/atleastone */
2534 if (set_atmostone(dlines
, dline_index
))
2535 diff
= min(diff
, DIFF_NORMAL
);
2536 if (set_atleastone(dlines
, dline_index
))
2537 diff
= min(diff
, DIFF_NORMAL
);
2540 /* Infer linedsf from dline flags */
2541 if (is_atmostone(dlines
, dline_index
)
2542 && is_atleastone(dlines
, dline_index
)) {
2543 if (merge_lines(sstate
, line1_index
, line2_index
, 1))
2544 diff
= min(diff
, DIFF_HARD
);
2548 /* Deductions with small number of LINE_UNKNOWNs, based on overall
2549 * parity of lines. */
2550 yes
= sstate
->dot_yes_count
[i
];
2551 no
= sstate
->dot_no_count
[i
];
2552 unknown
= N
- yes
- no
;
2553 diff_tmp
= parity_deductions(sstate
, d
->edges
,
2555 diff
= min(diff
, diff_tmp
);
2558 /* ------ Edge dsf deductions ------ */
2560 /* If the state of a line is known, deduce the state of its canonical line
2561 * too, and vice versa. */
2562 for (i
= 0; i
< g
->num_edges
; i
++) {
2565 can
= edsf_canonify(sstate
->linedsf
, i
, &inv
);
2568 s
= sstate
->state
->lines
[can
];
2569 if (s
!= LINE_UNKNOWN
) {
2570 if (solver_set_line(sstate
, i
, inv ?
OPP(s
) : s
))
2571 diff
= min(diff
, DIFF_EASY
);
2573 s
= sstate
->state
->lines
[i
];
2574 if (s
!= LINE_UNKNOWN
) {
2575 if (solver_set_line(sstate
, can
, inv ?
OPP(s
) : s
))
2576 diff
= min(diff
, DIFF_EASY
);
2584 static int loop_deductions(solver_state
*sstate
)
2586 int edgecount
= 0, clues
= 0, satclues
= 0, sm1clues
= 0;
2587 game_state
*state
= sstate
->state
;
2588 grid
*g
= state
->game_grid
;
2589 int shortest_chainlen
= g
->num_dots
;
2590 int loop_found
= FALSE
;
2592 int progress
= FALSE
;
2596 * Go through the grid and update for all the new edges.
2597 * Since merge_dots() is idempotent, the simplest way to
2598 * do this is just to update for _all_ the edges.
2599 * Also, while we're here, we count the edges.
2601 for (i
= 0; i
< g
->num_edges
; i
++) {
2602 if (state
->lines
[i
] == LINE_YES
) {
2603 loop_found
|= merge_dots(sstate
, i
);
2609 * Count the clues, count the satisfied clues, and count the
2610 * satisfied-minus-one clues.
2612 for (i
= 0; i
< g
->num_faces
; i
++) {
2613 int c
= state
->clues
[i
];
2615 int o
= sstate
->face_yes_count
[i
];
2624 for (i
= 0; i
< g
->num_dots
; ++i
) {
2626 sstate
->looplen
[dsf_canonify(sstate
->dotdsf
, i
)];
2627 if (dots_connected
> 1)
2628 shortest_chainlen
= min(shortest_chainlen
, dots_connected
);
2631 assert(sstate
->solver_status
== SOLVER_INCOMPLETE
);
2633 if (satclues
== clues
&& shortest_chainlen
== edgecount
) {
2634 sstate
->solver_status
= SOLVER_SOLVED
;
2635 /* This discovery clearly counts as progress, even if we haven't
2636 * just added any lines or anything */
2638 goto finished_loop_deductionsing
;
2642 * Now go through looking for LINE_UNKNOWN edges which
2643 * connect two dots that are already in the same
2644 * equivalence class. If we find one, test to see if the
2645 * loop it would create is a solution.
2647 for (i
= 0; i
< g
->num_edges
; i
++) {
2648 grid_edge
*e
= g
->edges
+ i
;
2649 int d1
= e
->dot1
- g
->dots
;
2650 int d2
= e
->dot2
- g
->dots
;
2652 if (state
->lines
[i
] != LINE_UNKNOWN
)
2655 eqclass
= dsf_canonify(sstate
->dotdsf
, d1
);
2656 if (eqclass
!= dsf_canonify(sstate
->dotdsf
, d2
))
2659 val
= LINE_NO
; /* loop is bad until proven otherwise */
2662 * This edge would form a loop. Next
2663 * question: how long would the loop be?
2664 * Would it equal the total number of edges
2665 * (plus the one we'd be adding if we added
2668 if (sstate
->looplen
[eqclass
] == edgecount
+ 1) {
2672 * This edge would form a loop which
2673 * took in all the edges in the entire
2674 * grid. So now we need to work out
2675 * whether it would be a valid solution
2676 * to the puzzle, which means we have to
2677 * check if it satisfies all the clues.
2678 * This means that every clue must be
2679 * either satisfied or satisfied-minus-
2680 * 1, and also that the number of
2681 * satisfied-minus-1 clues must be at
2682 * most two and they must lie on either
2683 * side of this edge.
2687 int f
= e
->face1
- g
->faces
;
2688 int c
= state
->clues
[f
];
2689 if (c
>= 0 && sstate
->face_yes_count
[f
] == c
- 1)
2693 int f
= e
->face2
- g
->faces
;
2694 int c
= state
->clues
[f
];
2695 if (c
>= 0 && sstate
->face_yes_count
[f
] == c
- 1)
2698 if (sm1clues
== sm1_nearby
&&
2699 sm1clues
+ satclues
== clues
) {
2700 val
= LINE_YES
; /* loop is good! */
2705 * Right. Now we know that adding this edge
2706 * would form a loop, and we know whether
2707 * that loop would be a viable solution or
2710 * If adding this edge produces a solution,
2711 * then we know we've found _a_ solution but
2712 * we don't know that it's _the_ solution -
2713 * if it were provably the solution then
2714 * we'd have deduced this edge some time ago
2715 * without the need to do loop detection. So
2716 * in this state we return SOLVER_AMBIGUOUS,
2717 * which has the effect that hitting Solve
2718 * on a user-provided puzzle will fill in a
2719 * solution but using the solver to
2720 * construct new puzzles won't consider this
2721 * a reasonable deduction for the user to
2724 progress
= solver_set_line(sstate
, i
, val
);
2725 assert(progress
== TRUE
);
2726 if (val
== LINE_YES
) {
2727 sstate
->solver_status
= SOLVER_AMBIGUOUS
;
2728 goto finished_loop_deductionsing
;
2732 finished_loop_deductionsing
:
2733 return progress ? DIFF_EASY
: DIFF_MAX
;
2736 /* This will return a dynamically allocated solver_state containing the (more)
2738 static solver_state
*solve_game_rec(const solver_state
*sstate_start
)
2740 solver_state
*sstate
;
2742 /* Index of the solver we should call next. */
2745 /* As a speed-optimisation, we avoid re-running solvers that we know
2746 * won't make any progress. This happens when a high-difficulty
2747 * solver makes a deduction that can only help other high-difficulty
2749 * For example: if a new 'dline' flag is set by dline_deductions, the
2750 * trivial_deductions solver cannot do anything with this information.
2751 * If we've already run the trivial_deductions solver (because it's
2752 * earlier in the list), there's no point running it again.
2754 * Therefore: if a solver is earlier in the list than "threshold_index",
2755 * we don't bother running it if it's difficulty level is less than
2758 int threshold_diff
= 0;
2759 int threshold_index
= 0;
2761 sstate
= dup_solver_state(sstate_start
);
2763 check_caches(sstate
);
2765 while (i
< NUM_SOLVERS
) {
2766 if (sstate
->solver_status
== SOLVER_MISTAKE
)
2768 if (sstate
->solver_status
== SOLVER_SOLVED
||
2769 sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
2770 /* solver finished */
2774 if ((solver_diffs
[i
] >= threshold_diff
|| i
>= threshold_index
)
2775 && solver_diffs
[i
] <= sstate
->diff
) {
2776 /* current_solver is eligible, so use it */
2777 int next_diff
= solver_fns
[i
](sstate
);
2778 if (next_diff
!= DIFF_MAX
) {
2779 /* solver made progress, so use new thresholds and
2780 * start again at top of list. */
2781 threshold_diff
= next_diff
;
2782 threshold_index
= i
;
2787 /* current_solver is ineligible, or failed to make progress, so
2788 * go to the next solver in the list */
2792 if (sstate
->solver_status
== SOLVER_SOLVED
||
2793 sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
2794 /* s/LINE_UNKNOWN/LINE_NO/g */
2795 array_setall(sstate
->state
->lines
, LINE_UNKNOWN
, LINE_NO
,
2796 sstate
->state
->game_grid
->num_edges
);
2803 static char *solve_game(game_state
*state
, game_state
*currstate
,
2804 char *aux
, char **error
)
2807 solver_state
*sstate
, *new_sstate
;
2809 sstate
= new_solver_state(state
, DIFF_MAX
);
2810 new_sstate
= solve_game_rec(sstate
);
2812 if (new_sstate
->solver_status
== SOLVER_SOLVED
) {
2813 soln
= encode_solve_move(new_sstate
->state
);
2814 } else if (new_sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
2815 soln
= encode_solve_move(new_sstate
->state
);
2816 /**error = "Solver found ambiguous solutions"; */
2818 soln
= encode_solve_move(new_sstate
->state
);
2819 /**error = "Solver failed"; */
2822 free_solver_state(new_sstate
);
2823 free_solver_state(sstate
);
2828 /* ----------------------------------------------------------------------
2829 * Drawing and mouse-handling
2832 static char *interpret_move(game_state
*state
, game_ui
*ui
, game_drawstate
*ds
,
2833 int x
, int y
, int button
)
2835 grid
*g
= state
->game_grid
;
2839 char button_char
= ' ';
2840 enum line_state old_state
;
2842 button
&= ~MOD_MASK
;
2844 /* Convert mouse-click (x,y) to grid coordinates */
2845 x
-= BORDER(ds
->tilesize
);
2846 y
-= BORDER(ds
->tilesize
);
2847 x
= x
* g
->tilesize
/ ds
->tilesize
;
2848 y
= y
* g
->tilesize
/ ds
->tilesize
;
2852 e
= grid_nearest_edge(g
, x
, y
);
2858 /* I think it's only possible to play this game with mouse clicks, sorry */
2859 /* Maybe will add mouse drag support some time */
2860 old_state
= state
->lines
[i
];
2864 switch (old_state
) {
2882 switch (old_state
) {
2901 sprintf(buf
, "%d%c", i
, (int)button_char
);
2907 static game_state
*execute_move(game_state
*state
, char *move
)
2910 game_state
*newstate
= dup_game(state
);
2912 if (move
[0] == 'S') {
2914 newstate
->cheated
= TRUE
;
2919 if (i
< 0 || i
>= newstate
->game_grid
->num_edges
)
2921 move
+= strspn(move
, "1234567890");
2922 switch (*(move
++)) {
2924 newstate
->lines
[i
] = LINE_YES
;
2927 newstate
->lines
[i
] = LINE_NO
;
2930 newstate
->lines
[i
] = LINE_UNKNOWN
;
2938 * Check for completion.
2940 if (check_completion(newstate
))
2941 newstate
->solved
= TRUE
;
2946 free_game(newstate
);
2950 /* ----------------------------------------------------------------------
2954 /* Convert from grid coordinates to screen coordinates */
2955 static void grid_to_screen(const game_drawstate
*ds
, const grid
*g
,
2956 int grid_x
, int grid_y
, int *x
, int *y
)
2958 *x
= grid_x
- g
->lowest_x
;
2959 *y
= grid_y
- g
->lowest_y
;
2960 *x
= *x
* ds
->tilesize
/ g
->tilesize
;
2961 *y
= *y
* ds
->tilesize
/ g
->tilesize
;
2962 *x
+= BORDER(ds
->tilesize
);
2963 *y
+= BORDER(ds
->tilesize
);
2966 /* Returns (into x,y) position of centre of face for rendering the text clue.
2968 static void face_text_pos(const game_drawstate
*ds
, const grid
*g
,
2969 grid_face
*f
, int *xret
, int *yret
)
2971 int faceindex
= f
- g
->faces
;
2974 * Return the cached position for this face, if we've already
2977 if (ds
->textx
[faceindex
] >= 0) {
2978 *xret
= ds
->textx
[faceindex
];
2979 *yret
= ds
->texty
[faceindex
];
2984 * Otherwise, use the incentre computed by grid.c and convert it
2985 * to screen coordinates.
2987 grid_find_incentre(f
);
2988 grid_to_screen(ds
, g
, f
->ix
, f
->iy
,
2989 &ds
->textx
[faceindex
], &ds
->texty
[faceindex
]);
2991 *xret
= ds
->textx
[faceindex
];
2992 *yret
= ds
->texty
[faceindex
];
2995 static void face_text_bbox(game_drawstate
*ds
, grid
*g
, grid_face
*f
,
2996 int *x
, int *y
, int *w
, int *h
)
2999 face_text_pos(ds
, g
, f
, &xx
, &yy
);
3001 /* There seems to be a certain amount of trial-and-error involved
3002 * in working out the correct bounding-box for the text. */
3004 *x
= xx
- ds
->tilesize
/4 - 1;
3005 *y
= yy
- ds
->tilesize
/4 - 3;
3006 *w
= ds
->tilesize
/2 + 2;
3007 *h
= ds
->tilesize
/2 + 5;
3010 static void game_redraw_clue(drawing
*dr
, game_drawstate
*ds
,
3011 game_state
*state
, int i
)
3013 grid
*g
= state
->game_grid
;
3014 grid_face
*f
= g
->faces
+ i
;
3018 if (state
->clues
[i
] < 10) {
3019 c
[0] = CLUE2CHAR(state
->clues
[i
]);
3022 sprintf(c
, "%d", state
->clues
[i
]);
3025 face_text_pos(ds
, g
, f
, &x
, &y
);
3027 FONT_VARIABLE
, ds
->tilesize
/2,
3028 ALIGN_VCENTRE
| ALIGN_HCENTRE
,
3029 ds
->clue_error
[i
] ? COL_MISTAKE
:
3030 ds
->clue_satisfied
[i
] ? COL_SATISFIED
: COL_FOREGROUND
, c
);
3033 static void edge_bbox(game_drawstate
*ds
, grid
*g
, grid_edge
*e
,
3034 int *x
, int *y
, int *w
, int *h
)
3036 int x1
= e
->dot1
->x
;
3037 int y1
= e
->dot1
->y
;
3038 int x2
= e
->dot2
->x
;
3039 int y2
= e
->dot2
->y
;
3040 int xmin
, xmax
, ymin
, ymax
;
3042 grid_to_screen(ds
, g
, x1
, y1
, &x1
, &y1
);
3043 grid_to_screen(ds
, g
, x2
, y2
, &x2
, &y2
);
3044 /* Allow extra margin for dots, and thickness of lines */
3045 xmin
= min(x1
, x2
) - 2;
3046 xmax
= max(x1
, x2
) + 2;
3047 ymin
= min(y1
, y2
) - 2;
3048 ymax
= max(y1
, y2
) + 2;
3052 *w
= xmax
- xmin
+ 1;
3053 *h
= ymax
- ymin
+ 1;
3056 static void dot_bbox(game_drawstate
*ds
, grid
*g
, grid_dot
*d
,
3057 int *x
, int *y
, int *w
, int *h
)
3061 grid_to_screen(ds
, g
, d
->x
, d
->y
, &x1
, &y1
);
3069 static const int loopy_line_redraw_phases
[] = {
3070 COL_FAINT
, COL_LINEUNKNOWN
, COL_FOREGROUND
, COL_HIGHLIGHT
, COL_MISTAKE
3072 #define NPHASES lenof(loopy_line_redraw_phases)
3074 static void game_redraw_line(drawing
*dr
, game_drawstate
*ds
,
3075 game_state
*state
, int i
, int phase
)
3077 grid
*g
= state
->game_grid
;
3078 grid_edge
*e
= g
->edges
+ i
;
3082 if (state
->line_errors
[i
])
3083 line_colour
= COL_MISTAKE
;
3084 else if (state
->lines
[i
] == LINE_UNKNOWN
)
3085 line_colour
= COL_LINEUNKNOWN
;
3086 else if (state
->lines
[i
] == LINE_NO
)
3087 line_colour
= COL_FAINT
;
3088 else if (ds
->flashing
)
3089 line_colour
= COL_HIGHLIGHT
;
3091 line_colour
= COL_FOREGROUND
;
3092 if (line_colour
!= loopy_line_redraw_phases
[phase
])
3095 /* Convert from grid to screen coordinates */
3096 grid_to_screen(ds
, g
, e
->dot1
->x
, e
->dot1
->y
, &x1
, &y1
);
3097 grid_to_screen(ds
, g
, e
->dot2
->x
, e
->dot2
->y
, &x2
, &y2
);
3099 if (line_colour
== COL_FAINT
) {
3100 static int draw_faint_lines
= -1;
3101 if (draw_faint_lines
< 0) {
3102 char *env
= getenv("LOOPY_FAINT_LINES");
3103 draw_faint_lines
= (!env
|| (env
[0] == 'y' ||
3106 if (draw_faint_lines
)
3107 draw_line(dr
, x1
, y1
, x2
, y2
, line_colour
);
3109 draw_thick_line(dr
, 3.0,
3116 static void game_redraw_dot(drawing
*dr
, game_drawstate
*ds
,
3117 game_state
*state
, int i
)
3119 grid
*g
= state
->game_grid
;
3120 grid_dot
*d
= g
->dots
+ i
;
3123 grid_to_screen(ds
, g
, d
->x
, d
->y
, &x
, &y
);
3124 draw_circle(dr
, x
, y
, 2, COL_FOREGROUND
, COL_FOREGROUND
);
3127 static int boxes_intersect(int x0
, int y0
, int w0
, int h0
,
3128 int x1
, int y1
, int w1
, int h1
)
3131 * Two intervals intersect iff neither is wholly on one side of
3132 * the other. Two boxes intersect iff their horizontal and
3133 * vertical intervals both intersect.
3135 return (x0
< x1
+w1
&& x1
< x0
+w0
&& y0
< y1
+h1
&& y1
< y0
+h0
);
3138 static void game_redraw_in_rect(drawing
*dr
, game_drawstate
*ds
,
3139 game_state
*state
, int x
, int y
, int w
, int h
)
3141 grid
*g
= state
->game_grid
;
3145 clip(dr
, x
, y
, w
, h
);
3146 draw_rect(dr
, x
, y
, w
, h
, COL_BACKGROUND
);
3148 for (i
= 0; i
< g
->num_faces
; i
++) {
3149 if (state
->clues
[i
] >= 0) {
3150 face_text_bbox(ds
, g
, &g
->faces
[i
], &bx
, &by
, &bw
, &bh
);
3151 if (boxes_intersect(x
, y
, w
, h
, bx
, by
, bw
, bh
))
3152 game_redraw_clue(dr
, ds
, state
, i
);
3155 for (phase
= 0; phase
< NPHASES
; phase
++) {
3156 for (i
= 0; i
< g
->num_edges
; i
++) {
3157 edge_bbox(ds
, g
, &g
->edges
[i
], &bx
, &by
, &bw
, &bh
);
3158 if (boxes_intersect(x
, y
, w
, h
, bx
, by
, bw
, bh
))
3159 game_redraw_line(dr
, ds
, state
, i
, phase
);
3162 for (i
= 0; i
< g
->num_dots
; i
++) {
3163 dot_bbox(ds
, g
, &g
->dots
[i
], &bx
, &by
, &bw
, &bh
);
3164 if (boxes_intersect(x
, y
, w
, h
, bx
, by
, bw
, bh
))
3165 game_redraw_dot(dr
, ds
, state
, i
);
3169 draw_update(dr
, x
, y
, w
, h
);
3172 static void game_redraw(drawing
*dr
, game_drawstate
*ds
, game_state
*oldstate
,
3173 game_state
*state
, int dir
, game_ui
*ui
,
3174 float animtime
, float flashtime
)
3176 #define REDRAW_OBJECTS_LIMIT 16 /* Somewhat arbitrary tradeoff */
3178 grid
*g
= state
->game_grid
;
3179 int border
= BORDER(ds
->tilesize
);
3182 int redraw_everything
= FALSE
;
3184 int edges
[REDRAW_OBJECTS_LIMIT
], nedges
= 0;
3185 int faces
[REDRAW_OBJECTS_LIMIT
], nfaces
= 0;
3187 /* Redrawing is somewhat involved.
3189 * An update can theoretically affect an arbitrary number of edges
3190 * (consider, for example, completing or breaking a cycle which doesn't
3191 * satisfy all the clues -- we'll switch many edges between error and
3192 * normal states). On the other hand, redrawing the whole grid takes a
3193 * while, making the game feel sluggish, and many updates are actually
3194 * quite well localized.
3196 * This redraw algorithm attempts to cope with both situations gracefully
3197 * and correctly. For localized changes, we set a clip rectangle, fill
3198 * it with background, and then redraw (a plausible but conservative
3199 * guess at) the objects which intersect the rectangle; if several
3200 * objects need redrawing, we'll do them individually. However, if lots
3201 * of objects are affected, we'll just redraw everything.
3203 * The reason for all of this is that it's just not safe to do the redraw
3204 * piecemeal. If you try to draw an antialiased diagonal line over
3205 * itself, you get a slightly thicker antialiased diagonal line, which
3206 * looks rather ugly after a while.
3208 * So, we take two passes over the grid. The first attempts to work out
3209 * what needs doing, and the second actually does it.
3213 redraw_everything
= TRUE
;
3216 /* First, trundle through the faces. */
3217 for (i
= 0; i
< g
->num_faces
; i
++) {
3218 grid_face
*f
= g
->faces
+ i
;
3219 int sides
= f
->order
;
3222 int n
= state
->clues
[i
];
3226 clue_mistake
= (face_order(state
, i
, LINE_YES
) > n
||
3227 face_order(state
, i
, LINE_NO
) > (sides
-n
));
3228 clue_satisfied
= (face_order(state
, i
, LINE_YES
) == n
&&
3229 face_order(state
, i
, LINE_NO
) == (sides
-n
));
3231 if (clue_mistake
!= ds
->clue_error
[i
] ||
3232 clue_satisfied
!= ds
->clue_satisfied
[i
]) {
3233 ds
->clue_error
[i
] = clue_mistake
;
3234 ds
->clue_satisfied
[i
] = clue_satisfied
;
3235 if (nfaces
== REDRAW_OBJECTS_LIMIT
)
3236 redraw_everything
= TRUE
;
3238 faces
[nfaces
++] = i
;
3242 /* Work out what the flash state needs to be. */
3243 if (flashtime
> 0 &&
3244 (flashtime
<= FLASH_TIME
/3 ||
3245 flashtime
>= FLASH_TIME
*2/3)) {
3246 flash_changed
= !ds
->flashing
;
3247 ds
->flashing
= TRUE
;
3249 flash_changed
= ds
->flashing
;
3250 ds
->flashing
= FALSE
;
3253 /* Now, trundle through the edges. */
3254 for (i
= 0; i
< g
->num_edges
; i
++) {
3256 state
->line_errors
[i
] ? DS_LINE_ERROR
: state
->lines
[i
];
3257 if (new_ds
!= ds
->lines
[i
] ||
3258 (flash_changed
&& state
->lines
[i
] == LINE_YES
)) {
3259 ds
->lines
[i
] = new_ds
;
3260 if (nedges
== REDRAW_OBJECTS_LIMIT
)
3261 redraw_everything
= TRUE
;
3263 edges
[nedges
++] = i
;
3268 /* Pass one is now done. Now we do the actual drawing. */
3269 if (redraw_everything
) {
3270 int grid_width
= g
->highest_x
- g
->lowest_x
;
3271 int grid_height
= g
->highest_y
- g
->lowest_y
;
3272 int w
= grid_width
* ds
->tilesize
/ g
->tilesize
;
3273 int h
= grid_height
* ds
->tilesize
/ g
->tilesize
;
3275 game_redraw_in_rect(dr
, ds
, state
,
3276 0, 0, w
+ 2*border
+ 1, h
+ 2*border
+ 1);
3279 /* Right. Now we roll up our sleeves. */
3281 for (i
= 0; i
< nfaces
; i
++) {
3282 grid_face
*f
= g
->faces
+ faces
[i
];
3285 face_text_bbox(ds
, g
, f
, &x
, &y
, &w
, &h
);
3286 game_redraw_in_rect(dr
, ds
, state
, x
, y
, w
, h
);
3289 for (i
= 0; i
< nedges
; i
++) {
3290 grid_edge
*e
= g
->edges
+ edges
[i
];
3293 edge_bbox(ds
, g
, e
, &x
, &y
, &w
, &h
);
3294 game_redraw_in_rect(dr
, ds
, state
, x
, y
, w
, h
);
3301 static float game_flash_length(game_state
*oldstate
, game_state
*newstate
,
3302 int dir
, game_ui
*ui
)
3304 if (!oldstate
->solved
&& newstate
->solved
&&
3305 !oldstate
->cheated
&& !newstate
->cheated
) {
3312 static int game_status(game_state
*state
)
3314 return state
->solved ?
+1 : 0;
3317 static void game_print_size(game_params
*params
, float *x
, float *y
)
3322 * I'll use 7mm "squares" by default.
3324 game_compute_size(params
, 700, &pw
, &ph
);
3329 static void game_print(drawing
*dr
, game_state
*state
, int tilesize
)
3331 int ink
= print_mono_colour(dr
, 0);
3333 game_drawstate ads
, *ds
= &ads
;
3334 grid
*g
= state
->game_grid
;
3336 ds
->tilesize
= tilesize
;
3337 ds
->textx
= snewn(g
->num_faces
, int);
3338 ds
->texty
= snewn(g
->num_faces
, int);
3339 for (i
= 0; i
< g
->num_faces
; i
++)
3340 ds
->textx
[i
] = ds
->texty
[i
] = -1;
3342 for (i
= 0; i
< g
->num_dots
; i
++) {
3344 grid_to_screen(ds
, g
, g
->dots
[i
].x
, g
->dots
[i
].y
, &x
, &y
);
3345 draw_circle(dr
, x
, y
, ds
->tilesize
/ 15, ink
, ink
);
3351 for (i
= 0; i
< g
->num_faces
; i
++) {
3352 grid_face
*f
= g
->faces
+ i
;
3353 int clue
= state
->clues
[i
];
3357 c
[0] = CLUE2CHAR(clue
);
3359 face_text_pos(ds
, g
, f
, &x
, &y
);
3361 FONT_VARIABLE
, ds
->tilesize
/ 2,
3362 ALIGN_VCENTRE
| ALIGN_HCENTRE
, ink
, c
);
3369 for (i
= 0; i
< g
->num_edges
; i
++) {
3370 int thickness
= (state
->lines
[i
] == LINE_YES
) ?
30 : 150;
3371 grid_edge
*e
= g
->edges
+ i
;
3373 grid_to_screen(ds
, g
, e
->dot1
->x
, e
->dot1
->y
, &x1
, &y1
);
3374 grid_to_screen(ds
, g
, e
->dot2
->x
, e
->dot2
->y
, &x2
, &y2
);
3375 if (state
->lines
[i
] == LINE_YES
)
3377 /* (dx, dy) points from (x1, y1) to (x2, y2).
3378 * The line is then "fattened" in a perpendicular
3379 * direction to create a thin rectangle. */
3380 double d
= sqrt(SQ((double)x1
- x2
) + SQ((double)y1
- y2
));
3381 double dx
= (x2
- x1
) / d
;
3382 double dy
= (y2
- y1
) / d
;
3385 dx
= (dx
* ds
->tilesize
) / thickness
;
3386 dy
= (dy
* ds
->tilesize
) / thickness
;
3387 points
[0] = x1
+ (int)dy
;
3388 points
[1] = y1
- (int)dx
;
3389 points
[2] = x1
- (int)dy
;
3390 points
[3] = y1
+ (int)dx
;
3391 points
[4] = x2
- (int)dy
;
3392 points
[5] = y2
+ (int)dx
;
3393 points
[6] = x2
+ (int)dy
;
3394 points
[7] = y2
- (int)dx
;
3395 draw_polygon(dr
, points
, 4, ink
, ink
);
3399 /* Draw a dotted line */
3402 for (j
= 1; j
< divisions
; j
++) {
3403 /* Weighted average */
3404 int x
= (x1
* (divisions
-j
) + x2
* j
) / divisions
;
3405 int y
= (y1
* (divisions
-j
) + y2
* j
) / divisions
;
3406 draw_circle(dr
, x
, y
, ds
->tilesize
/ thickness
, ink
, ink
);
3416 #define thegame loopy
3419 const struct game thegame
= {
3420 "Loopy", "games.loopy", "loopy",
3427 TRUE
, game_configure
, custom_params
,
3435 TRUE
, game_can_format_as_text_now
, game_text_format
,
3443 PREFERRED_TILE_SIZE
, game_compute_size
, game_set_size
,
3446 game_free_drawstate
,
3451 TRUE
, FALSE
, game_print_size
, game_print
,
3452 FALSE
/* wants_statusbar */,
3453 FALSE
, game_timing_state
,
3454 0, /* mouse_priorities */
3457 #ifdef STANDALONE_SOLVER
3460 * Half-hearted standalone solver. It can't output the solution to
3461 * anything but a square puzzle, and it can't log the deductions
3462 * it makes either. But it can solve square puzzles, and more
3463 * importantly it can use its solver to grade the difficulty of
3464 * any puzzle you give it.
3469 int main(int argc
, char **argv
)
3473 char *id
= NULL
, *desc
, *err
;
3476 #if 0 /* verbose solver not supported here (yet) */
3477 int really_verbose
= FALSE
;
3480 while (--argc
> 0) {
3482 #if 0 /* verbose solver not supported here (yet) */
3483 if (!strcmp(p
, "-v")) {
3484 really_verbose
= TRUE
;
3487 if (!strcmp(p
, "-g")) {
3489 } else if (*p
== '-') {
3490 fprintf(stderr
, "%s: unrecognised option `%s'\n", argv
[0], p
);
3498 fprintf(stderr
, "usage: %s [-g | -v] <game_id>\n", argv
[0]);
3502 desc
= strchr(id
, ':');
3504 fprintf(stderr
, "%s: game id expects a colon in it\n", argv
[0]);
3509 p
= default_params();
3510 decode_params(p
, id
);
3511 err
= validate_desc(p
, desc
);
3513 fprintf(stderr
, "%s: %s\n", argv
[0], err
);
3516 s
= new_game(NULL
, p
, desc
);
3519 * When solving an Easy puzzle, we don't want to bother the
3520 * user with Hard-level deductions. For this reason, we grade
3521 * the puzzle internally before doing anything else.
3523 ret
= -1; /* placate optimiser */
3524 for (diff
= 0; diff
< DIFF_MAX
; diff
++) {
3525 solver_state
*sstate_new
;
3526 solver_state
*sstate
= new_solver_state((game_state
*)s
, diff
);
3528 sstate_new
= solve_game_rec(sstate
);
3530 if (sstate_new
->solver_status
== SOLVER_MISTAKE
)
3532 else if (sstate_new
->solver_status
== SOLVER_SOLVED
)
3537 free_solver_state(sstate_new
);
3538 free_solver_state(sstate
);
3544 if (diff
== DIFF_MAX
) {
3546 printf("Difficulty rating: harder than Hard, or ambiguous\n");
3548 printf("Unable to find a unique solution\n");
3552 printf("Difficulty rating: impossible (no solution exists)\n");
3554 printf("Difficulty rating: %s\n", diffnames
[diff
]);
3556 solver_state
*sstate_new
;
3557 solver_state
*sstate
= new_solver_state((game_state
*)s
, diff
);
3559 /* If we supported a verbose solver, we'd set verbosity here */
3561 sstate_new
= solve_game_rec(sstate
);
3563 if (sstate_new
->solver_status
== SOLVER_MISTAKE
)
3564 printf("Puzzle is inconsistent\n");
3566 assert(sstate_new
->solver_status
== SOLVER_SOLVED
);
3567 if (s
->grid_type
== 0) {
3568 fputs(game_text_format(sstate_new
->state
), stdout
);
3570 printf("Unable to output non-square grids\n");
3574 free_solver_state(sstate_new
);
3575 free_solver_state(sstate
);
3584 /* vim: set shiftwidth=4 tabstop=8: */