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
, 8, 1 },
507 { 3, 3, DIFF_HARD
, 9, 0 },
508 { 3, 3, DIFF_HARD
, 10, 0 },
509 { 6, 6, DIFF_HARD
, 11, 0 },
510 { 6, 6, DIFF_HARD
, 12, 0 },
512 { 7, 7, DIFF_EASY
, 0, 0 },
513 { 10, 10, DIFF_EASY
, 0, 0 },
514 { 7, 7, DIFF_NORMAL
, 0, 0 },
515 { 10, 10, DIFF_NORMAL
, 0, 0 },
516 { 7, 7, DIFF_HARD
, 0, 0 },
517 { 10, 10, DIFF_HARD
, 0, 0 },
518 { 10, 10, DIFF_HARD
, 1, 0 },
519 { 12, 10, DIFF_HARD
, 2, 0 },
520 { 7, 7, DIFF_HARD
, 3, 0 },
521 { 9, 9, DIFF_HARD
, 4, 0 },
522 { 5, 4, DIFF_HARD
, 5, 0 },
523 { 7, 7, DIFF_HARD
, 6, 0 },
524 { 5, 5, DIFF_HARD
, 7, 0 },
525 { 5, 5, DIFF_HARD
, 8, 0 },
526 { 5, 5, DIFF_HARD
, 8, 1 },
527 { 5, 4, DIFF_HARD
, 9, 0 },
528 { 5, 4, DIFF_HARD
, 10, 0 },
529 { 10, 10, DIFF_HARD
, 11, 0 },
530 { 10, 10, DIFF_HARD
, 12, 0 }
534 static int game_fetch_preset(int i
, char **name
, game_params
**params
)
539 if (i
< 0 || i
>= lenof(presets
))
542 tmppar
= snew(game_params
);
543 *tmppar
= presets
[i
];
545 sprintf(buf
, "%dx%d %s %s- %s", tmppar
->h
, tmppar
->w
,
546 gridnames
[tmppar
->type
], dualnames
[tmppar
->dual
],
547 diffnames
[tmppar
->diff
]);
553 static void free_params(game_params
*params
)
558 static void decode_params(game_params
*params
, char const *string
)
560 params
->h
= params
->w
= atoi(string
);
561 params
->diff
= DIFF_EASY
;
563 while (*string
&& isdigit((unsigned char)*string
)) string
++;
564 if (*string
== 'x') {
566 params
->h
= atoi(string
);
567 while (*string
&& isdigit((unsigned char)*string
)) string
++;
569 if (*string
== 'l') {
573 if (*string
== 't') {
575 params
->type
= atoi(string
);
576 while (*string
&& isdigit((unsigned char)*string
)) string
++;
578 if (*string
== 'd') {
581 for (i
= 0; i
< DIFF_MAX
; i
++)
582 if (*string
== diffchars
[i
])
584 if (*string
) string
++;
588 static char *encode_params(game_params
*params
, int full
)
591 sprintf(str
, "%dx%dt%d%s", params
->w
, params
->h
, params
->type
,
592 params
->dual ?
"l" : "");
594 sprintf(str
+ strlen(str
), "d%c", diffchars
[params
->diff
]);
598 static config_item
*game_configure(game_params
*params
)
603 ret
= snewn(6, config_item
);
605 ret
[0].name
= "Width";
606 ret
[0].type
= C_STRING
;
607 sprintf(buf
, "%d", params
->w
);
608 ret
[0].sval
= dupstr(buf
);
611 ret
[1].name
= "Height";
612 ret
[1].type
= C_STRING
;
613 sprintf(buf
, "%d", params
->h
);
614 ret
[1].sval
= dupstr(buf
);
617 ret
[2].name
= "Grid type";
618 ret
[2].type
= C_CHOICES
;
619 ret
[2].sval
= GRID_CONFIGS
;
620 ret
[2].ival
= params
->type
;
622 ret
[3].name
= "Difficulty";
623 ret
[3].type
= C_CHOICES
;
624 ret
[3].sval
= DIFFCONFIG
;
625 ret
[3].ival
= params
->diff
;
627 ret
[4].name
= "Dual";
628 ret
[4].type
= C_BOOLEAN
;
630 ret
[4].ival
= params
->dual
;
640 static game_params
*custom_params(config_item
*cfg
)
642 game_params
*ret
= snew(game_params
);
644 ret
->w
= atoi(cfg
[0].sval
);
645 ret
->h
= atoi(cfg
[1].sval
);
646 ret
->type
= cfg
[2].ival
;
647 ret
->diff
= cfg
[3].ival
;
648 ret
->dual
= cfg
[4].ival
;
653 static char *validate_params(game_params
*params
, int full
)
655 if (params
->type
< 0 || params
->type
>= NUM_GRID_TYPES
)
656 return "Illegal grid type";
657 if (params
->w
< grid_size_limits
[params
->type
].amin
||
658 params
->h
< grid_size_limits
[params
->type
].amin
)
659 return grid_size_limits
[params
->type
].aerr
;
660 if (params
->w
< grid_size_limits
[params
->type
].omin
&&
661 params
->h
< grid_size_limits
[params
->type
].omin
)
662 return grid_size_limits
[params
->type
].oerr
;
665 * This shouldn't be able to happen at all, since decode_params
666 * and custom_params will never generate anything that isn't
669 assert(params
->diff
< DIFF_MAX
);
674 /* Returns a newly allocated string describing the current puzzle */
675 static char *state_to_text(const game_state
*state
)
677 grid
*g
= state
->game_grid
;
679 int num_faces
= g
->num_faces
;
680 char *description
= snewn(num_faces
+ 1, char);
681 char *dp
= description
;
685 for (i
= 0; i
< num_faces
; i
++) {
686 if (state
->clues
[i
] < 0) {
687 if (empty_count
> 25) {
688 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
694 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
697 dp
+= sprintf(dp
, "%c", (int)CLUE2CHAR(state
->clues
[i
]));
702 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
704 retval
= dupstr(description
);
710 #define GRID_DESC_SEP '_'
712 /* Splits up a (optional) grid_desc from the game desc. Returns the
713 * grid_desc (which needs freeing) and updates the desc pointer to
714 * start of real desc, or returns NULL if no desc. */
715 static char *extract_grid_desc(char **desc
)
717 char *sep
= strchr(*desc
, GRID_DESC_SEP
), *gd
;
720 if (!sep
) return NULL
;
722 gd_len
= sep
- (*desc
);
723 gd
= snewn(gd_len
+1, char);
724 memcpy(gd
, *desc
, gd_len
);
732 /* We require that the params pass the test in validate_params and that the
733 * description fills the entire game area */
734 static char *validate_desc(game_params
*params
, char *desc
)
738 char *grid_desc
, *ret
;
740 /* It's pretty inefficient to do this just for validation. All we need to
741 * know is the precise number of faces. */
742 grid_desc
= extract_grid_desc(&desc
);
743 ret
= grid_validate_desc(grid_types
[params
->type
], params
->w
, params
->h
, params
->dual
, grid_desc
);
746 g
= loopy_generate_grid(params
, grid_desc
);
747 if (grid_desc
) sfree(grid_desc
);
749 for (; *desc
; ++desc
) {
750 if ((*desc
>= '0' && *desc
<= '9') || (*desc
>= 'A' && *desc
<= 'Z')) {
755 count
+= *desc
- 'a' + 1;
758 return "Unknown character in description";
761 if (count
< g
->num_faces
)
762 return "Description too short for board size";
763 if (count
> g
->num_faces
)
764 return "Description too long for board size";
771 /* Sums the lengths of the numbers in range [0,n) */
772 /* See equivalent function in solo.c for justification of this. */
773 static int len_0_to_n(int n
)
775 int len
= 1; /* Counting 0 as a bit of a special case */
778 for (i
= 1; i
< n
; i
*= 10) {
779 len
+= max(n
- i
, 0);
785 static char *encode_solve_move(const game_state
*state
)
790 int num_edges
= state
->game_grid
->num_edges
;
792 /* This is going to return a string representing the moves needed to set
793 * every line in a grid to be the same as the ones in 'state'. The exact
794 * length of this string is predictable. */
796 len
= 1; /* Count the 'S' prefix */
797 /* Numbers in all lines */
798 len
+= len_0_to_n(num_edges
);
799 /* For each line we also have a letter */
802 ret
= snewn(len
+ 1, char);
805 p
+= sprintf(p
, "S");
807 for (i
= 0; i
< num_edges
; i
++) {
808 switch (state
->lines
[i
]) {
810 p
+= sprintf(p
, "%dy", i
);
813 p
+= sprintf(p
, "%dn", i
);
818 /* No point in doing sums like that if they're going to be wrong */
819 assert(strlen(ret
) <= (size_t)len
);
823 static game_ui
*new_ui(game_state
*state
)
828 static void free_ui(game_ui
*ui
)
832 static char *encode_ui(game_ui
*ui
)
837 static void decode_ui(game_ui
*ui
, char *encoding
)
841 static void game_changed_state(game_ui
*ui
, game_state
*oldstate
,
842 game_state
*newstate
)
846 static void game_compute_size(game_params
*params
, int tilesize
,
849 int grid_width
, grid_height
, rendered_width
, rendered_height
;
852 grid_compute_size(grid_types
[params
->type
], params
->w
, params
->h
,
853 &g_tilesize
, &grid_width
, &grid_height
);
855 /* multiply first to minimise rounding error on integer division */
856 rendered_width
= grid_width
* tilesize
/ g_tilesize
;
857 rendered_height
= grid_height
* tilesize
/ g_tilesize
;
858 *x
= rendered_width
+ 2 * BORDER(tilesize
) + 1;
859 *y
= rendered_height
+ 2 * BORDER(tilesize
) + 1;
862 static void game_set_size(drawing
*dr
, game_drawstate
*ds
,
863 game_params
*params
, int tilesize
)
865 ds
->tilesize
= tilesize
;
868 static float *game_colours(frontend
*fe
, int *ncolours
)
870 float *ret
= snewn(4 * NCOLOURS
, float);
872 frontend_default_colour(fe
, &ret
[COL_BACKGROUND
* 3]);
874 ret
[COL_FOREGROUND
* 3 + 0] = 0.0F
;
875 ret
[COL_FOREGROUND
* 3 + 1] = 0.0F
;
876 ret
[COL_FOREGROUND
* 3 + 2] = 0.0F
;
879 * We want COL_LINEUNKNOWN to be a yellow which is a bit darker
880 * than the background. (I previously set it to 0.8,0.8,0, but
881 * found that this went badly with the 0.8,0.8,0.8 favoured as a
882 * background by the Java frontend.)
884 ret
[COL_LINEUNKNOWN
* 3 + 0] = ret
[COL_BACKGROUND
* 3 + 0] * 0.9F
;
885 ret
[COL_LINEUNKNOWN
* 3 + 1] = ret
[COL_BACKGROUND
* 3 + 1] * 0.9F
;
886 ret
[COL_LINEUNKNOWN
* 3 + 2] = 0.0F
;
888 ret
[COL_HIGHLIGHT
* 3 + 0] = 1.0F
;
889 ret
[COL_HIGHLIGHT
* 3 + 1] = 1.0F
;
890 ret
[COL_HIGHLIGHT
* 3 + 2] = 1.0F
;
892 ret
[COL_MISTAKE
* 3 + 0] = 1.0F
;
893 ret
[COL_MISTAKE
* 3 + 1] = 0.0F
;
894 ret
[COL_MISTAKE
* 3 + 2] = 0.0F
;
896 ret
[COL_SATISFIED
* 3 + 0] = 0.0F
;
897 ret
[COL_SATISFIED
* 3 + 1] = 0.0F
;
898 ret
[COL_SATISFIED
* 3 + 2] = 0.0F
;
900 /* We want the faint lines to be a bit darker than the background.
901 * Except if the background is pretty dark already; then it ought to be a
902 * bit lighter. Oy vey.
904 ret
[COL_FAINT
* 3 + 0] = ret
[COL_BACKGROUND
* 3 + 0] * 0.9F
;
905 ret
[COL_FAINT
* 3 + 1] = ret
[COL_BACKGROUND
* 3 + 1] * 0.9F
;
906 ret
[COL_FAINT
* 3 + 2] = ret
[COL_BACKGROUND
* 3 + 2] * 0.9F
;
908 *ncolours
= NCOLOURS
;
912 static game_drawstate
*game_new_drawstate(drawing
*dr
, game_state
*state
)
914 struct game_drawstate
*ds
= snew(struct game_drawstate
);
915 int num_faces
= state
->game_grid
->num_faces
;
916 int num_edges
= state
->game_grid
->num_edges
;
921 ds
->lines
= snewn(num_edges
, char);
922 ds
->clue_error
= snewn(num_faces
, char);
923 ds
->clue_satisfied
= snewn(num_faces
, char);
924 ds
->textx
= snewn(num_faces
, int);
925 ds
->texty
= snewn(num_faces
, int);
928 memset(ds
->lines
, LINE_UNKNOWN
, num_edges
);
929 memset(ds
->clue_error
, 0, num_faces
);
930 memset(ds
->clue_satisfied
, 0, num_faces
);
931 for (i
= 0; i
< num_faces
; i
++)
932 ds
->textx
[i
] = ds
->texty
[i
] = -1;
937 static void game_free_drawstate(drawing
*dr
, game_drawstate
*ds
)
941 sfree(ds
->clue_error
);
942 sfree(ds
->clue_satisfied
);
947 static int game_timing_state(game_state
*state
, game_ui
*ui
)
952 static float game_anim_length(game_state
*oldstate
, game_state
*newstate
,
953 int dir
, game_ui
*ui
)
958 static int game_can_format_as_text_now(game_params
*params
)
960 if (params
->type
!= 0)
965 static char *game_text_format(game_state
*state
)
971 grid
*g
= state
->game_grid
;
974 assert(state
->grid_type
== 0);
976 /* Work out the basic size unit */
977 f
= g
->faces
; /* first face */
978 assert(f
->order
== 4);
979 /* The dots are ordered clockwise, so the two opposite
980 * corners are guaranteed to span the square */
981 cell_size
= abs(f
->dots
[0]->x
- f
->dots
[2]->x
);
983 w
= (g
->highest_x
- g
->lowest_x
) / cell_size
;
984 h
= (g
->highest_y
- g
->lowest_y
) / cell_size
;
986 /* Create a blank "canvas" to "draw" on */
989 ret
= snewn(W
* H
+ 1, char);
990 for (y
= 0; y
< H
; y
++) {
991 for (x
= 0; x
< W
-1; x
++) {
994 ret
[y
*W
+ W
-1] = '\n';
998 /* Fill in edge info */
999 for (i
= 0; i
< g
->num_edges
; i
++) {
1000 grid_edge
*e
= g
->edges
+ i
;
1001 /* Cell coordinates, from (0,0) to (w-1,h-1) */
1002 int x1
= (e
->dot1
->x
- g
->lowest_x
) / cell_size
;
1003 int x2
= (e
->dot2
->x
- g
->lowest_x
) / cell_size
;
1004 int y1
= (e
->dot1
->y
- g
->lowest_y
) / cell_size
;
1005 int y2
= (e
->dot2
->y
- g
->lowest_y
) / cell_size
;
1006 /* Midpoint, in canvas coordinates (canvas coordinates are just twice
1007 * cell coordinates) */
1010 switch (state
->lines
[i
]) {
1012 ret
[y
*W
+ x
] = (y1
== y2
) ?
'-' : '|';
1018 break; /* already a space */
1020 assert(!"Illegal line state");
1025 for (i
= 0; i
< g
->num_faces
; i
++) {
1029 assert(f
->order
== 4);
1030 /* Cell coordinates, from (0,0) to (w-1,h-1) */
1031 x1
= (f
->dots
[0]->x
- g
->lowest_x
) / cell_size
;
1032 x2
= (f
->dots
[2]->x
- g
->lowest_x
) / cell_size
;
1033 y1
= (f
->dots
[0]->y
- g
->lowest_y
) / cell_size
;
1034 y2
= (f
->dots
[2]->y
- g
->lowest_y
) / cell_size
;
1035 /* Midpoint, in canvas coordinates */
1038 ret
[y
*W
+ x
] = CLUE2CHAR(state
->clues
[i
]);
1043 /* ----------------------------------------------------------------------
1048 static void check_caches(const solver_state
* sstate
)
1051 const game_state
*state
= sstate
->state
;
1052 const grid
*g
= state
->game_grid
;
1054 for (i
= 0; i
< g
->num_dots
; i
++) {
1055 assert(dot_order(state
, i
, LINE_YES
) == sstate
->dot_yes_count
[i
]);
1056 assert(dot_order(state
, i
, LINE_NO
) == sstate
->dot_no_count
[i
]);
1059 for (i
= 0; i
< g
->num_faces
; i
++) {
1060 assert(face_order(state
, i
, LINE_YES
) == sstate
->face_yes_count
[i
]);
1061 assert(face_order(state
, i
, LINE_NO
) == sstate
->face_no_count
[i
]);
1066 #define check_caches(s) \
1068 fprintf(stderr, "check_caches at line %d\n", __LINE__); \
1072 #endif /* DEBUG_CACHES */
1074 /* ----------------------------------------------------------------------
1075 * Solver utility functions
1078 /* Sets the line (with index i) to the new state 'line_new', and updates
1079 * the cached counts of any affected faces and dots.
1080 * Returns TRUE if this actually changed the line's state. */
1081 static int solver_set_line(solver_state
*sstate
, int i
,
1082 enum line_state line_new
1084 , const char *reason
1088 game_state
*state
= sstate
->state
;
1092 assert(line_new
!= LINE_UNKNOWN
);
1094 check_caches(sstate
);
1096 if (state
->lines
[i
] == line_new
) {
1097 return FALSE
; /* nothing changed */
1099 state
->lines
[i
] = line_new
;
1102 fprintf(stderr
, "solver: set line [%d] to %s (%s)\n",
1103 i
, line_new
== LINE_YES ?
"YES" : "NO",
1107 g
= state
->game_grid
;
1110 /* Update the cache for both dots and both faces affected by this. */
1111 if (line_new
== LINE_YES
) {
1112 sstate
->dot_yes_count
[e
->dot1
- g
->dots
]++;
1113 sstate
->dot_yes_count
[e
->dot2
- g
->dots
]++;
1115 sstate
->face_yes_count
[e
->face1
- g
->faces
]++;
1118 sstate
->face_yes_count
[e
->face2
- g
->faces
]++;
1121 sstate
->dot_no_count
[e
->dot1
- g
->dots
]++;
1122 sstate
->dot_no_count
[e
->dot2
- g
->dots
]++;
1124 sstate
->face_no_count
[e
->face1
- g
->faces
]++;
1127 sstate
->face_no_count
[e
->face2
- g
->faces
]++;
1131 check_caches(sstate
);
1136 #define solver_set_line(a, b, c) \
1137 solver_set_line(a, b, c, __FUNCTION__)
1141 * Merge two dots due to the existence of an edge between them.
1142 * Updates the dsf tracking equivalence classes, and keeps track of
1143 * the length of path each dot is currently a part of.
1144 * Returns TRUE if the dots were already linked, ie if they are part of a
1145 * closed loop, and false otherwise.
1147 static int merge_dots(solver_state
*sstate
, int edge_index
)
1150 grid
*g
= sstate
->state
->game_grid
;
1151 grid_edge
*e
= g
->edges
+ edge_index
;
1153 i
= e
->dot1
- g
->dots
;
1154 j
= e
->dot2
- g
->dots
;
1156 i
= dsf_canonify(sstate
->dotdsf
, i
);
1157 j
= dsf_canonify(sstate
->dotdsf
, j
);
1162 len
= sstate
->looplen
[i
] + sstate
->looplen
[j
];
1163 dsf_merge(sstate
->dotdsf
, i
, j
);
1164 i
= dsf_canonify(sstate
->dotdsf
, i
);
1165 sstate
->looplen
[i
] = len
;
1170 /* Merge two lines because the solver has deduced that they must be either
1171 * identical or opposite. Returns TRUE if this is new information, otherwise
1173 static int merge_lines(solver_state
*sstate
, int i
, int j
, int inverse
1175 , const char *reason
1181 assert(i
< sstate
->state
->game_grid
->num_edges
);
1182 assert(j
< sstate
->state
->game_grid
->num_edges
);
1184 i
= edsf_canonify(sstate
->linedsf
, i
, &inv_tmp
);
1186 j
= edsf_canonify(sstate
->linedsf
, j
, &inv_tmp
);
1189 edsf_merge(sstate
->linedsf
, i
, j
, inverse
);
1193 fprintf(stderr
, "%s [%d] [%d] %s(%s)\n",
1195 inverse ?
"inverse " : "", reason
);
1202 #define merge_lines(a, b, c, d) \
1203 merge_lines(a, b, c, d, __FUNCTION__)
1206 /* Count the number of lines of a particular type currently going into the
1208 static int dot_order(const game_state
* state
, int dot
, char line_type
)
1211 grid
*g
= state
->game_grid
;
1212 grid_dot
*d
= g
->dots
+ dot
;
1215 for (i
= 0; i
< d
->order
; i
++) {
1216 grid_edge
*e
= d
->edges
[i
];
1217 if (state
->lines
[e
- g
->edges
] == line_type
)
1223 /* Count the number of lines of a particular type currently surrounding the
1225 static int face_order(const game_state
* state
, int face
, char line_type
)
1228 grid
*g
= state
->game_grid
;
1229 grid_face
*f
= g
->faces
+ face
;
1232 for (i
= 0; i
< f
->order
; i
++) {
1233 grid_edge
*e
= f
->edges
[i
];
1234 if (state
->lines
[e
- g
->edges
] == line_type
)
1240 /* Set all lines bordering a dot of type old_type to type new_type
1241 * Return value tells caller whether this function actually did anything */
1242 static int dot_setall(solver_state
*sstate
, int dot
,
1243 char old_type
, char new_type
)
1245 int retval
= FALSE
, r
;
1246 game_state
*state
= sstate
->state
;
1251 if (old_type
== new_type
)
1254 g
= state
->game_grid
;
1257 for (i
= 0; i
< d
->order
; i
++) {
1258 int line_index
= d
->edges
[i
] - g
->edges
;
1259 if (state
->lines
[line_index
] == old_type
) {
1260 r
= solver_set_line(sstate
, line_index
, new_type
);
1268 /* Set all lines bordering a face of type old_type to type new_type */
1269 static int face_setall(solver_state
*sstate
, int face
,
1270 char old_type
, char new_type
)
1272 int retval
= FALSE
, r
;
1273 game_state
*state
= sstate
->state
;
1278 if (old_type
== new_type
)
1281 g
= state
->game_grid
;
1282 f
= g
->faces
+ face
;
1284 for (i
= 0; i
< f
->order
; i
++) {
1285 int line_index
= f
->edges
[i
] - g
->edges
;
1286 if (state
->lines
[line_index
] == old_type
) {
1287 r
= solver_set_line(sstate
, line_index
, new_type
);
1295 /* ----------------------------------------------------------------------
1296 * Loop generation and clue removal
1299 static void add_full_clues(game_state
*state
, random_state
*rs
)
1301 signed char *clues
= state
->clues
;
1302 grid
*g
= state
->game_grid
;
1303 char *board
= snewn(g
->num_faces
, char);
1306 generate_loop(g
, board
, rs
, NULL
, NULL
);
1308 /* Fill out all the clues by initialising to 0, then iterating over
1309 * all edges and incrementing each clue as we find edges that border
1310 * between BLACK/WHITE faces. While we're at it, we verify that the
1311 * algorithm does work, and there aren't any GREY faces still there. */
1312 memset(clues
, 0, g
->num_faces
);
1313 for (i
= 0; i
< g
->num_edges
; i
++) {
1314 grid_edge
*e
= g
->edges
+ i
;
1315 grid_face
*f1
= e
->face1
;
1316 grid_face
*f2
= e
->face2
;
1317 enum face_colour c1
= FACE_COLOUR(f1
);
1318 enum face_colour c2
= FACE_COLOUR(f2
);
1319 assert(c1
!= FACE_GREY
);
1320 assert(c2
!= FACE_GREY
);
1322 if (f1
) clues
[f1
- g
->faces
]++;
1323 if (f2
) clues
[f2
- g
->faces
]++;
1330 static int game_has_unique_soln(const game_state
*state
, int diff
)
1333 solver_state
*sstate_new
;
1334 solver_state
*sstate
= new_solver_state((game_state
*)state
, diff
);
1336 sstate_new
= solve_game_rec(sstate
);
1338 assert(sstate_new
->solver_status
!= SOLVER_MISTAKE
);
1339 ret
= (sstate_new
->solver_status
== SOLVER_SOLVED
);
1341 free_solver_state(sstate_new
);
1342 free_solver_state(sstate
);
1348 /* Remove clues one at a time at random. */
1349 static game_state
*remove_clues(game_state
*state
, random_state
*rs
,
1353 int num_faces
= state
->game_grid
->num_faces
;
1354 game_state
*ret
= dup_game(state
), *saved_ret
;
1357 /* We need to remove some clues. We'll do this by forming a list of all
1358 * available clues, shuffling it, then going along one at a
1359 * time clearing each clue in turn for which doing so doesn't render the
1360 * board unsolvable. */
1361 face_list
= snewn(num_faces
, int);
1362 for (n
= 0; n
< num_faces
; ++n
) {
1366 shuffle(face_list
, num_faces
, sizeof(int), rs
);
1368 for (n
= 0; n
< num_faces
; ++n
) {
1369 saved_ret
= dup_game(ret
);
1370 ret
->clues
[face_list
[n
]] = -1;
1372 if (game_has_unique_soln(ret
, diff
)) {
1373 free_game(saved_ret
);
1385 static char *new_game_desc(game_params
*params
, random_state
*rs
,
1386 char **aux
, int interactive
)
1388 /* solution and description both use run-length encoding in obvious ways */
1389 char *retval
, *game_desc
, *grid_desc
;
1391 game_state
*state
= snew(game_state
);
1392 game_state
*state_new
;
1394 grid_desc
= grid_new_desc(grid_types
[params
->type
], params
->w
, params
->h
, params
->dual
, rs
);
1395 state
->game_grid
= g
= loopy_generate_grid(params
, grid_desc
);
1397 state
->clues
= snewn(g
->num_faces
, signed char);
1398 state
->lines
= snewn(g
->num_edges
, char);
1399 state
->line_errors
= snewn(g
->num_edges
, unsigned char);
1401 state
->grid_type
= params
->type
;
1405 memset(state
->lines
, LINE_UNKNOWN
, g
->num_edges
);
1406 memset(state
->line_errors
, 0, g
->num_edges
);
1408 state
->solved
= state
->cheated
= FALSE
;
1410 /* Get a new random solvable board with all its clues filled in. Yes, this
1411 * can loop for ever if the params are suitably unfavourable, but
1412 * preventing games smaller than 4x4 seems to stop this happening */
1414 add_full_clues(state
, rs
);
1415 } while (!game_has_unique_soln(state
, params
->diff
));
1417 state_new
= remove_clues(state
, rs
, params
->diff
);
1422 if (params
->diff
> 0 && game_has_unique_soln(state
, params
->diff
-1)) {
1424 fprintf(stderr
, "Rejecting board, it is too easy\n");
1426 goto newboard_please
;
1429 game_desc
= state_to_text(state
);
1434 retval
= snewn(strlen(grid_desc
) + 1 + strlen(game_desc
) + 1, char);
1435 sprintf(retval
, "%s%c%s", grid_desc
, (int)GRID_DESC_SEP
, game_desc
);
1442 assert(!validate_desc(params
, retval
));
1447 static game_state
*new_game(midend
*me
, game_params
*params
, char *desc
)
1450 game_state
*state
= snew(game_state
);
1451 int empties_to_make
= 0;
1456 int num_faces
, num_edges
;
1458 grid_desc
= extract_grid_desc(&desc
);
1459 state
->game_grid
= g
= loopy_generate_grid(params
, grid_desc
);
1460 if (grid_desc
) sfree(grid_desc
);
1464 num_faces
= g
->num_faces
;
1465 num_edges
= g
->num_edges
;
1467 state
->clues
= snewn(num_faces
, signed char);
1468 state
->lines
= snewn(num_edges
, char);
1469 state
->line_errors
= snewn(num_edges
, unsigned char);
1471 state
->solved
= state
->cheated
= FALSE
;
1473 state
->grid_type
= params
->type
;
1475 for (i
= 0; i
< num_faces
; i
++) {
1476 if (empties_to_make
) {
1478 state
->clues
[i
] = -1;
1484 n2
= *dp
- 'A' + 10;
1485 if (n
>= 0 && n
< 10) {
1486 state
->clues
[i
] = n
;
1487 } else if (n2
>= 10 && n2
< 36) {
1488 state
->clues
[i
] = n2
;
1492 state
->clues
[i
] = -1;
1493 empties_to_make
= n
- 1;
1498 memset(state
->lines
, LINE_UNKNOWN
, num_edges
);
1499 memset(state
->line_errors
, 0, num_edges
);
1503 /* Calculates the line_errors data, and checks if the current state is a
1505 static int check_completion(game_state
*state
)
1507 grid
*g
= state
->game_grid
;
1509 int num_faces
= g
->num_faces
;
1511 int infinite_area
, finite_area
;
1512 int loops_found
= 0;
1513 int found_edge_not_in_loop
= FALSE
;
1515 memset(state
->line_errors
, 0, g
->num_edges
);
1517 /* LL implementation of SGT's idea:
1518 * A loop will partition the grid into an inside and an outside.
1519 * If there is more than one loop, the grid will be partitioned into
1520 * even more distinct regions. We can therefore track equivalence of
1521 * faces, by saying that two faces are equivalent when there is a non-YES
1522 * edge between them.
1523 * We could keep track of the number of connected components, by counting
1524 * the number of dsf-merges that aren't no-ops.
1525 * But we're only interested in 3 separate cases:
1526 * no loops, one loop, more than one loop.
1528 * No loops: all faces are equivalent to the infinite face.
1529 * One loop: only two equivalence classes - finite and infinite.
1530 * >= 2 loops: there are 2 distinct finite regions.
1532 * So we simply make two passes through all the edges.
1533 * In the first pass, we dsf-merge the two faces bordering each non-YES
1535 * In the second pass, we look for YES-edges bordering:
1536 * a) two non-equivalent faces.
1537 * b) two non-equivalent faces, and one of them is part of a different
1538 * finite area from the first finite area we've seen.
1540 * An occurrence of a) means there is at least one loop.
1541 * An occurrence of b) means there is more than one loop.
1542 * Edges satisfying a) are marked as errors.
1544 * While we're at it, we set a flag if we find a YES edge that is not
1546 * This information will help decide, if there's a single loop, whether it
1547 * is a candidate for being a solution (that is, all YES edges are part of
1550 * If there is a candidate loop, we then go through all clues and check
1551 * they are all satisfied. If so, we have found a solution and we can
1552 * unmark all line_errors.
1555 /* Infinite face is at the end - its index is num_faces.
1556 * This macro is just to make this obvious! */
1557 #define INF_FACE num_faces
1558 dsf
= snewn(num_faces
+ 1, int);
1559 dsf_init(dsf
, num_faces
+ 1);
1562 for (i
= 0; i
< g
->num_edges
; i
++) {
1563 grid_edge
*e
= g
->edges
+ i
;
1564 int f1
= e
->face1 ? e
->face1
- g
->faces
: INF_FACE
;
1565 int f2
= e
->face2 ? e
->face2
- g
->faces
: INF_FACE
;
1566 if (state
->lines
[i
] != LINE_YES
)
1567 dsf_merge(dsf
, f1
, f2
);
1571 infinite_area
= dsf_canonify(dsf
, INF_FACE
);
1573 for (i
= 0; i
< g
->num_edges
; i
++) {
1574 grid_edge
*e
= g
->edges
+ i
;
1575 int f1
= e
->face1 ? e
->face1
- g
->faces
: INF_FACE
;
1576 int can1
= dsf_canonify(dsf
, f1
);
1577 int f2
= e
->face2 ? e
->face2
- g
->faces
: INF_FACE
;
1578 int can2
= dsf_canonify(dsf
, f2
);
1579 if (state
->lines
[i
] != LINE_YES
) continue;
1582 /* Faces are equivalent, so this edge not part of a loop */
1583 found_edge_not_in_loop
= TRUE
;
1586 state
->line_errors
[i
] = TRUE
;
1587 if (loops_found
== 0) loops_found
= 1;
1589 /* Don't bother with further checks if we've already found 2 loops */
1590 if (loops_found
== 2) continue;
1592 if (finite_area
== -1) {
1593 /* Found our first finite area */
1594 if (can1
!= infinite_area
)
1600 /* Have we found a second area? */
1601 if (finite_area
!= -1) {
1602 if (can1
!= infinite_area
&& can1
!= finite_area
) {
1606 if (can2
!= infinite_area
&& can2
!= finite_area
) {
1613 printf("loops_found = %d\n", loops_found);
1614 printf("found_edge_not_in_loop = %s\n",
1615 found_edge_not_in_loop ? "TRUE" : "FALSE");
1618 sfree(dsf
); /* No longer need the dsf */
1620 /* Have we found a candidate loop? */
1621 if (loops_found
== 1 && !found_edge_not_in_loop
) {
1622 /* Yes, so check all clues are satisfied */
1623 int found_clue_violation
= FALSE
;
1624 for (i
= 0; i
< num_faces
; i
++) {
1625 int c
= state
->clues
[i
];
1627 if (face_order(state
, i
, LINE_YES
) != c
) {
1628 found_clue_violation
= TRUE
;
1634 if (!found_clue_violation
) {
1635 /* The loop is good */
1636 memset(state
->line_errors
, 0, g
->num_edges
);
1637 return TRUE
; /* No need to bother checking for dot violations */
1641 /* Check for dot violations */
1642 for (i
= 0; i
< g
->num_dots
; i
++) {
1643 int yes
= dot_order(state
, i
, LINE_YES
);
1644 int unknown
= dot_order(state
, i
, LINE_UNKNOWN
);
1645 if ((yes
== 1 && unknown
== 0) || (yes
>= 3)) {
1646 /* violation, so mark all YES edges as errors */
1647 grid_dot
*d
= g
->dots
+ i
;
1649 for (j
= 0; j
< d
->order
; j
++) {
1650 int e
= d
->edges
[j
] - g
->edges
;
1651 if (state
->lines
[e
] == LINE_YES
)
1652 state
->line_errors
[e
] = TRUE
;
1659 /* ----------------------------------------------------------------------
1662 * Our solver modes operate as follows. Each mode also uses the modes above it.
1665 * Just implement the rules of the game.
1667 * Normal and Tricky Modes
1668 * For each (adjacent) pair of lines through each dot we store a bit for
1669 * whether at least one of them is on and whether at most one is on. (If we
1670 * know both or neither is on that's already stored more directly.)
1673 * Use edsf data structure to make equivalence classes of lines that are
1674 * known identical to or opposite to one another.
1679 * For general grids, we consider "dlines" to be pairs of lines joined
1680 * at a dot. The lines must be adjacent around the dot, so we can think of
1681 * a dline as being a dot+face combination. Or, a dot+edge combination where
1682 * the second edge is taken to be the next clockwise edge from the dot.
1683 * Original loopy code didn't have this extra restriction of the lines being
1684 * adjacent. From my tests with square grids, this extra restriction seems to
1685 * take little, if anything, away from the quality of the puzzles.
1686 * A dline can be uniquely identified by an edge/dot combination, given that
1687 * a dline-pair always goes clockwise around its common dot. The edge/dot
1688 * combination can be represented by an edge/bool combination - if bool is
1689 * TRUE, use edge->dot1 else use edge->dot2. So the total number of dlines is
1690 * exactly twice the number of edges in the grid - although the dlines
1691 * spanning the infinite face are not all that useful to the solver.
1692 * Note that, by convention, a dline goes clockwise around its common dot,
1693 * which means the dline goes anti-clockwise around its common face.
1696 /* Helper functions for obtaining an index into an array of dlines, given
1697 * various information. We assume the grid layout conventions about how
1698 * the various lists are interleaved - see grid_make_consistent() for
1701 /* i points to the first edge of the dline pair, reading clockwise around
1703 static int dline_index_from_dot(grid
*g
, grid_dot
*d
, int i
)
1705 grid_edge
*e
= d
->edges
[i
];
1710 if (i2
== d
->order
) i2
= 0;
1713 ret
= 2 * (e
- g
->edges
) + ((e
->dot1
== d
) ?
1 : 0);
1715 printf("dline_index_from_dot: d=%d,i=%d, edges [%d,%d] - %d\n",
1716 (int)(d
- g
->dots
), i
, (int)(e
- g
->edges
),
1717 (int)(e2
- g
->edges
), ret
);
1721 /* i points to the second edge of the dline pair, reading clockwise around
1722 * the face. That is, the edges of the dline, starting at edge{i}, read
1723 * anti-clockwise around the face. By layout conventions, the common dot
1724 * of the dline will be f->dots[i] */
1725 static int dline_index_from_face(grid
*g
, grid_face
*f
, int i
)
1727 grid_edge
*e
= f
->edges
[i
];
1728 grid_dot
*d
= f
->dots
[i
];
1733 if (i2
< 0) i2
+= f
->order
;
1736 ret
= 2 * (e
- g
->edges
) + ((e
->dot1
== d
) ?
1 : 0);
1738 printf("dline_index_from_face: f=%d,i=%d, edges [%d,%d] - %d\n",
1739 (int)(f
- g
->faces
), i
, (int)(e
- g
->edges
),
1740 (int)(e2
- g
->edges
), ret
);
1744 static int is_atleastone(const char *dline_array
, int index
)
1746 return BIT_SET(dline_array
[index
], 0);
1748 static int set_atleastone(char *dline_array
, int index
)
1750 return SET_BIT(dline_array
[index
], 0);
1752 static int is_atmostone(const char *dline_array
, int index
)
1754 return BIT_SET(dline_array
[index
], 1);
1756 static int set_atmostone(char *dline_array
, int index
)
1758 return SET_BIT(dline_array
[index
], 1);
1761 static void array_setall(char *array
, char from
, char to
, int len
)
1763 char *p
= array
, *p_old
= p
;
1764 int len_remaining
= len
;
1766 while ((p
= memchr(p
, from
, len_remaining
))) {
1768 len_remaining
-= p
- p_old
;
1773 /* Helper, called when doing dline dot deductions, in the case where we
1774 * have 4 UNKNOWNs, and two of them (adjacent) have *exactly* one YES between
1775 * them (because of dline atmostone/atleastone).
1776 * On entry, edge points to the first of these two UNKNOWNs. This function
1777 * will find the opposite UNKNOWNS (if they are adjacent to one another)
1778 * and set their corresponding dline to atleastone. (Setting atmostone
1779 * already happens in earlier dline deductions) */
1780 static int dline_set_opp_atleastone(solver_state
*sstate
,
1781 grid_dot
*d
, int edge
)
1783 game_state
*state
= sstate
->state
;
1784 grid
*g
= state
->game_grid
;
1787 for (opp
= 0; opp
< N
; opp
++) {
1788 int opp_dline_index
;
1789 if (opp
== edge
|| opp
== edge
+1 || opp
== edge
-1)
1791 if (opp
== 0 && edge
== N
-1)
1793 if (opp
== N
-1 && edge
== 0)
1796 if (opp2
== N
) opp2
= 0;
1797 /* Check if opp, opp2 point to LINE_UNKNOWNs */
1798 if (state
->lines
[d
->edges
[opp
] - g
->edges
] != LINE_UNKNOWN
)
1800 if (state
->lines
[d
->edges
[opp2
] - g
->edges
] != LINE_UNKNOWN
)
1802 /* Found opposite UNKNOWNS and they're next to each other */
1803 opp_dline_index
= dline_index_from_dot(g
, d
, opp
);
1804 return set_atleastone(sstate
->dlines
, opp_dline_index
);
1810 /* Set pairs of lines around this face which are known to be identical, to
1811 * the given line_state */
1812 static int face_setall_identical(solver_state
*sstate
, int face_index
,
1813 enum line_state line_new
)
1815 /* can[dir] contains the canonical line associated with the line in
1816 * direction dir from the square in question. Similarly inv[dir] is
1817 * whether or not the line in question is inverse to its canonical
1820 game_state
*state
= sstate
->state
;
1821 grid
*g
= state
->game_grid
;
1822 grid_face
*f
= g
->faces
+ face_index
;
1825 int can1
, can2
, inv1
, inv2
;
1827 for (i
= 0; i
< N
; i
++) {
1828 int line1_index
= f
->edges
[i
] - g
->edges
;
1829 if (state
->lines
[line1_index
] != LINE_UNKNOWN
)
1831 for (j
= i
+ 1; j
< N
; j
++) {
1832 int line2_index
= f
->edges
[j
] - g
->edges
;
1833 if (state
->lines
[line2_index
] != LINE_UNKNOWN
)
1836 /* Found two UNKNOWNS */
1837 can1
= edsf_canonify(sstate
->linedsf
, line1_index
, &inv1
);
1838 can2
= edsf_canonify(sstate
->linedsf
, line2_index
, &inv2
);
1839 if (can1
== can2
&& inv1
== inv2
) {
1840 solver_set_line(sstate
, line1_index
, line_new
);
1841 solver_set_line(sstate
, line2_index
, line_new
);
1848 /* Given a dot or face, and a count of LINE_UNKNOWNs, find them and
1849 * return the edge indices into e. */
1850 static void find_unknowns(game_state
*state
,
1851 grid_edge
**edge_list
, /* Edge list to search (from a face or a dot) */
1852 int expected_count
, /* Number of UNKNOWNs (comes from solver's cache) */
1853 int *e
/* Returned edge indices */)
1856 grid
*g
= state
->game_grid
;
1857 while (c
< expected_count
) {
1858 int line_index
= *edge_list
- g
->edges
;
1859 if (state
->lines
[line_index
] == LINE_UNKNOWN
) {
1867 /* If we have a list of edges, and we know whether the number of YESs should
1868 * be odd or even, and there are only a few UNKNOWNs, we can do some simple
1869 * linedsf deductions. This can be used for both face and dot deductions.
1870 * Returns the difficulty level of the next solver that should be used,
1871 * or DIFF_MAX if no progress was made. */
1872 static int parity_deductions(solver_state
*sstate
,
1873 grid_edge
**edge_list
, /* Edge list (from a face or a dot) */
1874 int total_parity
, /* Expected number of YESs modulo 2 (either 0 or 1) */
1877 game_state
*state
= sstate
->state
;
1878 int diff
= DIFF_MAX
;
1879 int *linedsf
= sstate
->linedsf
;
1881 if (unknown_count
== 2) {
1882 /* Lines are known alike/opposite, depending on inv. */
1884 find_unknowns(state
, edge_list
, 2, e
);
1885 if (merge_lines(sstate
, e
[0], e
[1], total_parity
))
1886 diff
= min(diff
, DIFF_HARD
);
1887 } else if (unknown_count
== 3) {
1889 int can
[3]; /* canonical edges */
1890 int inv
[3]; /* whether can[x] is inverse to e[x] */
1891 find_unknowns(state
, edge_list
, 3, e
);
1892 can
[0] = edsf_canonify(linedsf
, e
[0], inv
);
1893 can
[1] = edsf_canonify(linedsf
, e
[1], inv
+1);
1894 can
[2] = edsf_canonify(linedsf
, e
[2], inv
+2);
1895 if (can
[0] == can
[1]) {
1896 if (solver_set_line(sstate
, e
[2], (total_parity
^inv
[0]^inv
[1]) ?
1897 LINE_YES
: LINE_NO
))
1898 diff
= min(diff
, DIFF_EASY
);
1900 if (can
[0] == can
[2]) {
1901 if (solver_set_line(sstate
, e
[1], (total_parity
^inv
[0]^inv
[2]) ?
1902 LINE_YES
: LINE_NO
))
1903 diff
= min(diff
, DIFF_EASY
);
1905 if (can
[1] == can
[2]) {
1906 if (solver_set_line(sstate
, e
[0], (total_parity
^inv
[1]^inv
[2]) ?
1907 LINE_YES
: LINE_NO
))
1908 diff
= min(diff
, DIFF_EASY
);
1910 } else if (unknown_count
== 4) {
1912 int can
[4]; /* canonical edges */
1913 int inv
[4]; /* whether can[x] is inverse to e[x] */
1914 find_unknowns(state
, edge_list
, 4, e
);
1915 can
[0] = edsf_canonify(linedsf
, e
[0], inv
);
1916 can
[1] = edsf_canonify(linedsf
, e
[1], inv
+1);
1917 can
[2] = edsf_canonify(linedsf
, e
[2], inv
+2);
1918 can
[3] = edsf_canonify(linedsf
, e
[3], inv
+3);
1919 if (can
[0] == can
[1]) {
1920 if (merge_lines(sstate
, e
[2], e
[3], total_parity
^inv
[0]^inv
[1]))
1921 diff
= min(diff
, DIFF_HARD
);
1922 } else if (can
[0] == can
[2]) {
1923 if (merge_lines(sstate
, e
[1], e
[3], total_parity
^inv
[0]^inv
[2]))
1924 diff
= min(diff
, DIFF_HARD
);
1925 } else if (can
[0] == can
[3]) {
1926 if (merge_lines(sstate
, e
[1], e
[2], total_parity
^inv
[0]^inv
[3]))
1927 diff
= min(diff
, DIFF_HARD
);
1928 } else if (can
[1] == can
[2]) {
1929 if (merge_lines(sstate
, e
[0], e
[3], total_parity
^inv
[1]^inv
[2]))
1930 diff
= min(diff
, DIFF_HARD
);
1931 } else if (can
[1] == can
[3]) {
1932 if (merge_lines(sstate
, e
[0], e
[2], total_parity
^inv
[1]^inv
[3]))
1933 diff
= min(diff
, DIFF_HARD
);
1934 } else if (can
[2] == can
[3]) {
1935 if (merge_lines(sstate
, e
[0], e
[1], total_parity
^inv
[2]^inv
[3]))
1936 diff
= min(diff
, DIFF_HARD
);
1944 * These are the main solver functions.
1946 * Their return values are diff values corresponding to the lowest mode solver
1947 * that would notice the work that they have done. For example if the normal
1948 * mode solver adds actual lines or crosses, it will return DIFF_EASY as the
1949 * easy mode solver might be able to make progress using that. It doesn't make
1950 * sense for one of them to return a diff value higher than that of the
1953 * Each function returns the lowest value it can, as early as possible, in
1954 * order to try and pass as much work as possible back to the lower level
1955 * solvers which progress more quickly.
1958 /* PROPOSED NEW DESIGN:
1959 * We have a work queue consisting of 'events' notifying us that something has
1960 * happened that a particular solver mode might be interested in. For example
1961 * the hard mode solver might do something that helps the normal mode solver at
1962 * dot [x,y] in which case it will enqueue an event recording this fact. Then
1963 * we pull events off the work queue, and hand each in turn to the solver that
1964 * is interested in them. If a solver reports that it failed we pass the same
1965 * event on to progressively more advanced solvers and the loop detector. Once
1966 * we've exhausted an event, or it has helped us progress, we drop it and
1967 * continue to the next one. The events are sorted first in order of solver
1968 * complexity (easy first) then order of insertion (oldest first).
1969 * Once we run out of events we loop over each permitted solver in turn
1970 * (easiest first) until either a deduction is made (and an event therefore
1971 * emerges) or no further deductions can be made (in which case we've failed).
1974 * * How do we 'loop over' a solver when both dots and squares are concerned.
1975 * Answer: first all squares then all dots.
1978 static int trivial_deductions(solver_state
*sstate
)
1980 int i
, current_yes
, current_no
;
1981 game_state
*state
= sstate
->state
;
1982 grid
*g
= state
->game_grid
;
1983 int diff
= DIFF_MAX
;
1985 /* Per-face deductions */
1986 for (i
= 0; i
< g
->num_faces
; i
++) {
1987 grid_face
*f
= g
->faces
+ i
;
1989 if (sstate
->face_solved
[i
])
1992 current_yes
= sstate
->face_yes_count
[i
];
1993 current_no
= sstate
->face_no_count
[i
];
1995 if (current_yes
+ current_no
== f
->order
) {
1996 sstate
->face_solved
[i
] = TRUE
;
2000 if (state
->clues
[i
] < 0)
2004 * This code checks whether the numeric clue on a face is so
2005 * large as to permit all its remaining LINE_UNKNOWNs to be
2006 * filled in as LINE_YES, or alternatively so small as to
2007 * permit them all to be filled in as LINE_NO.
2010 if (state
->clues
[i
] < current_yes
) {
2011 sstate
->solver_status
= SOLVER_MISTAKE
;
2014 if (state
->clues
[i
] == current_yes
) {
2015 if (face_setall(sstate
, i
, LINE_UNKNOWN
, LINE_NO
))
2016 diff
= min(diff
, DIFF_EASY
);
2017 sstate
->face_solved
[i
] = TRUE
;
2021 if (f
->order
- state
->clues
[i
] < current_no
) {
2022 sstate
->solver_status
= SOLVER_MISTAKE
;
2025 if (f
->order
- state
->clues
[i
] == current_no
) {
2026 if (face_setall(sstate
, i
, LINE_UNKNOWN
, LINE_YES
))
2027 diff
= min(diff
, DIFF_EASY
);
2028 sstate
->face_solved
[i
] = TRUE
;
2032 if (f
->order
- state
->clues
[i
] == current_no
+ 1 &&
2033 f
->order
- current_yes
- current_no
> 2) {
2035 * One small refinement to the above: we also look for any
2036 * adjacent pair of LINE_UNKNOWNs around the face with
2037 * some LINE_YES incident on it from elsewhere. If we find
2038 * one, then we know that pair of LINE_UNKNOWNs can't
2039 * _both_ be LINE_YES, and hence that pushes us one line
2040 * closer to being able to determine all the rest.
2042 int j
, k
, e1
, e2
, e
, d
;
2044 for (j
= 0; j
< f
->order
; j
++) {
2045 e1
= f
->edges
[j
] - g
->edges
;
2046 e2
= f
->edges
[j
+1 < f
->order ? j
+1 : 0] - g
->edges
;
2048 if (g
->edges
[e1
].dot1
== g
->edges
[e2
].dot1
||
2049 g
->edges
[e1
].dot1
== g
->edges
[e2
].dot2
) {
2050 d
= g
->edges
[e1
].dot1
- g
->dots
;
2052 assert(g
->edges
[e1
].dot2
== g
->edges
[e2
].dot1
||
2053 g
->edges
[e1
].dot2
== g
->edges
[e2
].dot2
);
2054 d
= g
->edges
[e1
].dot2
- g
->dots
;
2057 if (state
->lines
[e1
] == LINE_UNKNOWN
&&
2058 state
->lines
[e2
] == LINE_UNKNOWN
) {
2059 for (k
= 0; k
< g
->dots
[d
].order
; k
++) {
2060 int e
= g
->dots
[d
].edges
[k
] - g
->edges
;
2061 if (state
->lines
[e
] == LINE_YES
)
2062 goto found
; /* multi-level break */
2070 * If we get here, we've found such a pair of edges, and
2071 * they're e1 and e2.
2073 for (j
= 0; j
< f
->order
; j
++) {
2074 e
= f
->edges
[j
] - g
->edges
;
2075 if (state
->lines
[e
] == LINE_UNKNOWN
&& e
!= e1
&& e
!= e2
) {
2076 int r
= solver_set_line(sstate
, e
, LINE_YES
);
2078 diff
= min(diff
, DIFF_EASY
);
2084 check_caches(sstate
);
2086 /* Per-dot deductions */
2087 for (i
= 0; i
< g
->num_dots
; i
++) {
2088 grid_dot
*d
= g
->dots
+ i
;
2089 int yes
, no
, unknown
;
2091 if (sstate
->dot_solved
[i
])
2094 yes
= sstate
->dot_yes_count
[i
];
2095 no
= sstate
->dot_no_count
[i
];
2096 unknown
= d
->order
- yes
- no
;
2100 sstate
->dot_solved
[i
] = TRUE
;
2101 } else if (unknown
== 1) {
2102 dot_setall(sstate
, i
, LINE_UNKNOWN
, LINE_NO
);
2103 diff
= min(diff
, DIFF_EASY
);
2104 sstate
->dot_solved
[i
] = TRUE
;
2106 } else if (yes
== 1) {
2108 sstate
->solver_status
= SOLVER_MISTAKE
;
2110 } else if (unknown
== 1) {
2111 dot_setall(sstate
, i
, LINE_UNKNOWN
, LINE_YES
);
2112 diff
= min(diff
, DIFF_EASY
);
2114 } else if (yes
== 2) {
2116 dot_setall(sstate
, i
, LINE_UNKNOWN
, LINE_NO
);
2117 diff
= min(diff
, DIFF_EASY
);
2119 sstate
->dot_solved
[i
] = TRUE
;
2121 sstate
->solver_status
= SOLVER_MISTAKE
;
2126 check_caches(sstate
);
2131 static int dline_deductions(solver_state
*sstate
)
2133 game_state
*state
= sstate
->state
;
2134 grid
*g
= state
->game_grid
;
2135 char *dlines
= sstate
->dlines
;
2137 int diff
= DIFF_MAX
;
2139 /* ------ Face deductions ------ */
2141 /* Given a set of dline atmostone/atleastone constraints, need to figure
2142 * out if we can deduce any further info. For more general faces than
2143 * squares, this turns out to be a tricky problem.
2144 * The approach taken here is to define (per face) NxN matrices:
2145 * "maxs" and "mins".
2146 * The entries maxs(j,k) and mins(j,k) define the upper and lower limits
2147 * for the possible number of edges that are YES between positions j and k
2148 * going clockwise around the face. Can think of j and k as marking dots
2149 * around the face (recall the labelling scheme: edge0 joins dot0 to dot1,
2150 * edge1 joins dot1 to dot2 etc).
2151 * Trivially, mins(j,j) = maxs(j,j) = 0, and we don't even bother storing
2152 * these. mins(j,j+1) and maxs(j,j+1) are determined by whether edge{j}
2153 * is YES, NO or UNKNOWN. mins(j,j+2) and maxs(j,j+2) are related to
2154 * the dline atmostone/atleastone status for edges j and j+1.
2156 * Then we calculate the remaining entries recursively. We definitely
2158 * mins(j,k) >= { mins(j,u) + mins(u,k) } for any u between j and k.
2159 * This is because any valid placement of YESs between j and k must give
2160 * a valid placement between j and u, and also between u and k.
2161 * I believe it's sufficient to use just the two values of u:
2162 * j+1 and j+2. Seems to work well in practice - the bounds we compute
2163 * are rigorous, even if they might not be best-possible.
2165 * Once we have maxs and mins calculated, we can make inferences about
2166 * each dline{j,j+1} by looking at the possible complementary edge-counts
2167 * mins(j+2,j) and maxs(j+2,j) and comparing these with the face clue.
2168 * As well as dlines, we can make similar inferences about single edges.
2169 * For example, consider a pentagon with clue 3, and we know at most one
2170 * of (edge0, edge1) is YES, and at most one of (edge2, edge3) is YES.
2171 * We could then deduce edge4 is YES, because maxs(0,4) would be 2, so
2172 * that final edge would have to be YES to make the count up to 3.
2175 /* Much quicker to allocate arrays on the stack than the heap, so
2176 * define the largest possible face size, and base our array allocations
2177 * on that. We check this with an assertion, in case someone decides to
2178 * make a grid which has larger faces than this. Note, this algorithm
2179 * could get quite expensive if there are many large faces. */
2180 #define MAX_FACE_SIZE 12
2182 for (i
= 0; i
< g
->num_faces
; i
++) {
2183 int maxs
[MAX_FACE_SIZE
][MAX_FACE_SIZE
];
2184 int mins
[MAX_FACE_SIZE
][MAX_FACE_SIZE
];
2185 grid_face
*f
= g
->faces
+ i
;
2188 int clue
= state
->clues
[i
];
2189 assert(N
<= MAX_FACE_SIZE
);
2190 if (sstate
->face_solved
[i
])
2192 if (clue
< 0) continue;
2194 /* Calculate the (j,j+1) entries */
2195 for (j
= 0; j
< N
; j
++) {
2196 int edge_index
= f
->edges
[j
] - g
->edges
;
2198 enum line_state line1
= state
->lines
[edge_index
];
2199 enum line_state line2
;
2203 maxs
[j
][k
] = (line1
== LINE_NO
) ?
0 : 1;
2204 mins
[j
][k
] = (line1
== LINE_YES
) ?
1 : 0;
2205 /* Calculate the (j,j+2) entries */
2206 dline_index
= dline_index_from_face(g
, f
, k
);
2207 edge_index
= f
->edges
[k
] - g
->edges
;
2208 line2
= state
->lines
[edge_index
];
2214 if (line1
== LINE_NO
) tmp
--;
2215 if (line2
== LINE_NO
) tmp
--;
2216 if (tmp
== 2 && is_atmostone(dlines
, dline_index
))
2222 if (line1
== LINE_YES
) tmp
++;
2223 if (line2
== LINE_YES
) tmp
++;
2224 if (tmp
== 0 && is_atleastone(dlines
, dline_index
))
2229 /* Calculate the (j,j+m) entries for m between 3 and N-1 */
2230 for (m
= 3; m
< N
; m
++) {
2231 for (j
= 0; j
< N
; j
++) {
2239 maxs
[j
][k
] = maxs
[j
][u
] + maxs
[u
][k
];
2240 mins
[j
][k
] = mins
[j
][u
] + mins
[u
][k
];
2241 tmp
= maxs
[j
][v
] + maxs
[v
][k
];
2242 maxs
[j
][k
] = min(maxs
[j
][k
], tmp
);
2243 tmp
= mins
[j
][v
] + mins
[v
][k
];
2244 mins
[j
][k
] = max(mins
[j
][k
], tmp
);
2248 /* See if we can make any deductions */
2249 for (j
= 0; j
< N
; j
++) {
2251 grid_edge
*e
= f
->edges
[j
];
2252 int line_index
= e
- g
->edges
;
2255 if (state
->lines
[line_index
] != LINE_UNKNOWN
)
2260 /* minimum YESs in the complement of this edge */
2261 if (mins
[k
][j
] > clue
) {
2262 sstate
->solver_status
= SOLVER_MISTAKE
;
2265 if (mins
[k
][j
] == clue
) {
2266 /* setting this edge to YES would make at least
2267 * (clue+1) edges - contradiction */
2268 solver_set_line(sstate
, line_index
, LINE_NO
);
2269 diff
= min(diff
, DIFF_EASY
);
2271 if (maxs
[k
][j
] < clue
- 1) {
2272 sstate
->solver_status
= SOLVER_MISTAKE
;
2275 if (maxs
[k
][j
] == clue
- 1) {
2276 /* Only way to satisfy the clue is to set edge{j} as YES */
2277 solver_set_line(sstate
, line_index
, LINE_YES
);
2278 diff
= min(diff
, DIFF_EASY
);
2281 /* More advanced deduction that allows propagation along diagonal
2282 * chains of faces connected by dots, for example, 3-2-...-2-3
2283 * in square grids. */
2284 if (sstate
->diff
>= DIFF_TRICKY
) {
2285 /* Now see if we can make dline deduction for edges{j,j+1} */
2287 if (state
->lines
[e
- g
->edges
] != LINE_UNKNOWN
)
2288 /* Only worth doing this for an UNKNOWN,UNKNOWN pair.
2289 * Dlines where one of the edges is known, are handled in the
2293 dline_index
= dline_index_from_face(g
, f
, k
);
2297 /* minimum YESs in the complement of this dline */
2298 if (mins
[k
][j
] > clue
- 2) {
2299 /* Adding 2 YESs would break the clue */
2300 if (set_atmostone(dlines
, dline_index
))
2301 diff
= min(diff
, DIFF_NORMAL
);
2303 /* maximum YESs in the complement of this dline */
2304 if (maxs
[k
][j
] < clue
) {
2305 /* Adding 2 NOs would mean not enough YESs */
2306 if (set_atleastone(dlines
, dline_index
))
2307 diff
= min(diff
, DIFF_NORMAL
);
2313 if (diff
< DIFF_NORMAL
)
2316 /* ------ Dot deductions ------ */
2318 for (i
= 0; i
< g
->num_dots
; i
++) {
2319 grid_dot
*d
= g
->dots
+ i
;
2321 int yes
, no
, unknown
;
2323 if (sstate
->dot_solved
[i
])
2325 yes
= sstate
->dot_yes_count
[i
];
2326 no
= sstate
->dot_no_count
[i
];
2327 unknown
= N
- yes
- no
;
2329 for (j
= 0; j
< N
; j
++) {
2332 int line1_index
, line2_index
;
2333 enum line_state line1
, line2
;
2336 dline_index
= dline_index_from_dot(g
, d
, j
);
2337 line1_index
= d
->edges
[j
] - g
->edges
;
2338 line2_index
= d
->edges
[k
] - g
->edges
;
2339 line1
= state
->lines
[line1_index
];
2340 line2
= state
->lines
[line2_index
];
2342 /* Infer dline state from line state */
2343 if (line1
== LINE_NO
|| line2
== LINE_NO
) {
2344 if (set_atmostone(dlines
, dline_index
))
2345 diff
= min(diff
, DIFF_NORMAL
);
2347 if (line1
== LINE_YES
|| line2
== LINE_YES
) {
2348 if (set_atleastone(dlines
, dline_index
))
2349 diff
= min(diff
, DIFF_NORMAL
);
2351 /* Infer line state from dline state */
2352 if (is_atmostone(dlines
, dline_index
)) {
2353 if (line1
== LINE_YES
&& line2
== LINE_UNKNOWN
) {
2354 solver_set_line(sstate
, line2_index
, LINE_NO
);
2355 diff
= min(diff
, DIFF_EASY
);
2357 if (line2
== LINE_YES
&& line1
== LINE_UNKNOWN
) {
2358 solver_set_line(sstate
, line1_index
, LINE_NO
);
2359 diff
= min(diff
, DIFF_EASY
);
2362 if (is_atleastone(dlines
, dline_index
)) {
2363 if (line1
== LINE_NO
&& line2
== LINE_UNKNOWN
) {
2364 solver_set_line(sstate
, line2_index
, LINE_YES
);
2365 diff
= min(diff
, DIFF_EASY
);
2367 if (line2
== LINE_NO
&& line1
== LINE_UNKNOWN
) {
2368 solver_set_line(sstate
, line1_index
, LINE_YES
);
2369 diff
= min(diff
, DIFF_EASY
);
2372 /* Deductions that depend on the numbers of lines.
2373 * Only bother if both lines are UNKNOWN, otherwise the
2374 * easy-mode solver (or deductions above) would have taken
2376 if (line1
!= LINE_UNKNOWN
|| line2
!= LINE_UNKNOWN
)
2379 if (yes
== 0 && unknown
== 2) {
2380 /* Both these unknowns must be identical. If we know
2381 * atmostone or atleastone, we can make progress. */
2382 if (is_atmostone(dlines
, dline_index
)) {
2383 solver_set_line(sstate
, line1_index
, LINE_NO
);
2384 solver_set_line(sstate
, line2_index
, LINE_NO
);
2385 diff
= min(diff
, DIFF_EASY
);
2387 if (is_atleastone(dlines
, dline_index
)) {
2388 solver_set_line(sstate
, line1_index
, LINE_YES
);
2389 solver_set_line(sstate
, line2_index
, LINE_YES
);
2390 diff
= min(diff
, DIFF_EASY
);
2394 if (set_atmostone(dlines
, dline_index
))
2395 diff
= min(diff
, DIFF_NORMAL
);
2397 if (set_atleastone(dlines
, dline_index
))
2398 diff
= min(diff
, DIFF_NORMAL
);
2402 /* More advanced deduction that allows propagation along diagonal
2403 * chains of faces connected by dots, for example: 3-2-...-2-3
2404 * in square grids. */
2405 if (sstate
->diff
>= DIFF_TRICKY
) {
2406 /* If we have atleastone set for this dline, infer
2407 * atmostone for each "opposite" dline (that is, each
2408 * dline without edges in common with this one).
2409 * Again, this test is only worth doing if both these
2410 * lines are UNKNOWN. For if one of these lines were YES,
2411 * the (yes == 1) test above would kick in instead. */
2412 if (is_atleastone(dlines
, dline_index
)) {
2414 for (opp
= 0; opp
< N
; opp
++) {
2415 int opp_dline_index
;
2416 if (opp
== j
|| opp
== j
+1 || opp
== j
-1)
2418 if (j
== 0 && opp
== N
-1)
2420 if (j
== N
-1 && opp
== 0)
2422 opp_dline_index
= dline_index_from_dot(g
, d
, opp
);
2423 if (set_atmostone(dlines
, opp_dline_index
))
2424 diff
= min(diff
, DIFF_NORMAL
);
2426 if (yes
== 0 && is_atmostone(dlines
, dline_index
)) {
2427 /* This dline has *exactly* one YES and there are no
2428 * other YESs. This allows more deductions. */
2430 /* Third unknown must be YES */
2431 for (opp
= 0; opp
< N
; opp
++) {
2433 if (opp
== j
|| opp
== k
)
2435 opp_index
= d
->edges
[opp
] - g
->edges
;
2436 if (state
->lines
[opp_index
] == LINE_UNKNOWN
) {
2437 solver_set_line(sstate
, opp_index
,
2439 diff
= min(diff
, DIFF_EASY
);
2442 } else if (unknown
== 4) {
2443 /* Exactly one of opposite UNKNOWNS is YES. We've
2444 * already set atmostone, so set atleastone as
2447 if (dline_set_opp_atleastone(sstate
, d
, j
))
2448 diff
= min(diff
, DIFF_NORMAL
);
2458 static int linedsf_deductions(solver_state
*sstate
)
2460 game_state
*state
= sstate
->state
;
2461 grid
*g
= state
->game_grid
;
2462 char *dlines
= sstate
->dlines
;
2464 int diff
= DIFF_MAX
;
2467 /* ------ Face deductions ------ */
2469 /* A fully-general linedsf deduction seems overly complicated
2470 * (I suspect the problem is NP-complete, though in practice it might just
2471 * be doable because faces are limited in size).
2472 * For simplicity, we only consider *pairs* of LINE_UNKNOWNS that are
2473 * known to be identical. If setting them both to YES (or NO) would break
2474 * the clue, set them to NO (or YES). */
2476 for (i
= 0; i
< g
->num_faces
; i
++) {
2477 int N
, yes
, no
, unknown
;
2480 if (sstate
->face_solved
[i
])
2482 clue
= state
->clues
[i
];
2486 N
= g
->faces
[i
].order
;
2487 yes
= sstate
->face_yes_count
[i
];
2488 if (yes
+ 1 == clue
) {
2489 if (face_setall_identical(sstate
, i
, LINE_NO
))
2490 diff
= min(diff
, DIFF_EASY
);
2492 no
= sstate
->face_no_count
[i
];
2493 if (no
+ 1 == N
- clue
) {
2494 if (face_setall_identical(sstate
, i
, LINE_YES
))
2495 diff
= min(diff
, DIFF_EASY
);
2498 /* Reload YES count, it might have changed */
2499 yes
= sstate
->face_yes_count
[i
];
2500 unknown
= N
- no
- yes
;
2502 /* Deductions with small number of LINE_UNKNOWNs, based on overall
2503 * parity of lines. */
2504 diff_tmp
= parity_deductions(sstate
, g
->faces
[i
].edges
,
2505 (clue
- yes
) % 2, unknown
);
2506 diff
= min(diff
, diff_tmp
);
2509 /* ------ Dot deductions ------ */
2510 for (i
= 0; i
< g
->num_dots
; i
++) {
2511 grid_dot
*d
= g
->dots
+ i
;
2514 int yes
, no
, unknown
;
2515 /* Go through dlines, and do any dline<->linedsf deductions wherever
2516 * we find two UNKNOWNS. */
2517 for (j
= 0; j
< N
; j
++) {
2518 int dline_index
= dline_index_from_dot(g
, d
, j
);
2521 int can1
, can2
, inv1
, inv2
;
2523 line1_index
= d
->edges
[j
] - g
->edges
;
2524 if (state
->lines
[line1_index
] != LINE_UNKNOWN
)
2527 if (j2
== N
) j2
= 0;
2528 line2_index
= d
->edges
[j2
] - g
->edges
;
2529 if (state
->lines
[line2_index
] != LINE_UNKNOWN
)
2531 /* Infer dline flags from linedsf */
2532 can1
= edsf_canonify(sstate
->linedsf
, line1_index
, &inv1
);
2533 can2
= edsf_canonify(sstate
->linedsf
, line2_index
, &inv2
);
2534 if (can1
== can2
&& inv1
!= inv2
) {
2535 /* These are opposites, so set dline atmostone/atleastone */
2536 if (set_atmostone(dlines
, dline_index
))
2537 diff
= min(diff
, DIFF_NORMAL
);
2538 if (set_atleastone(dlines
, dline_index
))
2539 diff
= min(diff
, DIFF_NORMAL
);
2542 /* Infer linedsf from dline flags */
2543 if (is_atmostone(dlines
, dline_index
)
2544 && is_atleastone(dlines
, dline_index
)) {
2545 if (merge_lines(sstate
, line1_index
, line2_index
, 1))
2546 diff
= min(diff
, DIFF_HARD
);
2550 /* Deductions with small number of LINE_UNKNOWNs, based on overall
2551 * parity of lines. */
2552 yes
= sstate
->dot_yes_count
[i
];
2553 no
= sstate
->dot_no_count
[i
];
2554 unknown
= N
- yes
- no
;
2555 diff_tmp
= parity_deductions(sstate
, d
->edges
,
2557 diff
= min(diff
, diff_tmp
);
2560 /* ------ Edge dsf deductions ------ */
2562 /* If the state of a line is known, deduce the state of its canonical line
2563 * too, and vice versa. */
2564 for (i
= 0; i
< g
->num_edges
; i
++) {
2567 can
= edsf_canonify(sstate
->linedsf
, i
, &inv
);
2570 s
= sstate
->state
->lines
[can
];
2571 if (s
!= LINE_UNKNOWN
) {
2572 if (solver_set_line(sstate
, i
, inv ?
OPP(s
) : s
))
2573 diff
= min(diff
, DIFF_EASY
);
2575 s
= sstate
->state
->lines
[i
];
2576 if (s
!= LINE_UNKNOWN
) {
2577 if (solver_set_line(sstate
, can
, inv ?
OPP(s
) : s
))
2578 diff
= min(diff
, DIFF_EASY
);
2586 static int loop_deductions(solver_state
*sstate
)
2588 int edgecount
= 0, clues
= 0, satclues
= 0, sm1clues
= 0;
2589 game_state
*state
= sstate
->state
;
2590 grid
*g
= state
->game_grid
;
2591 int shortest_chainlen
= g
->num_dots
;
2592 int loop_found
= FALSE
;
2594 int progress
= FALSE
;
2598 * Go through the grid and update for all the new edges.
2599 * Since merge_dots() is idempotent, the simplest way to
2600 * do this is just to update for _all_ the edges.
2601 * Also, while we're here, we count the edges.
2603 for (i
= 0; i
< g
->num_edges
; i
++) {
2604 if (state
->lines
[i
] == LINE_YES
) {
2605 loop_found
|= merge_dots(sstate
, i
);
2611 * Count the clues, count the satisfied clues, and count the
2612 * satisfied-minus-one clues.
2614 for (i
= 0; i
< g
->num_faces
; i
++) {
2615 int c
= state
->clues
[i
];
2617 int o
= sstate
->face_yes_count
[i
];
2626 for (i
= 0; i
< g
->num_dots
; ++i
) {
2628 sstate
->looplen
[dsf_canonify(sstate
->dotdsf
, i
)];
2629 if (dots_connected
> 1)
2630 shortest_chainlen
= min(shortest_chainlen
, dots_connected
);
2633 assert(sstate
->solver_status
== SOLVER_INCOMPLETE
);
2635 if (satclues
== clues
&& shortest_chainlen
== edgecount
) {
2636 sstate
->solver_status
= SOLVER_SOLVED
;
2637 /* This discovery clearly counts as progress, even if we haven't
2638 * just added any lines or anything */
2640 goto finished_loop_deductionsing
;
2644 * Now go through looking for LINE_UNKNOWN edges which
2645 * connect two dots that are already in the same
2646 * equivalence class. If we find one, test to see if the
2647 * loop it would create is a solution.
2649 for (i
= 0; i
< g
->num_edges
; i
++) {
2650 grid_edge
*e
= g
->edges
+ i
;
2651 int d1
= e
->dot1
- g
->dots
;
2652 int d2
= e
->dot2
- g
->dots
;
2654 if (state
->lines
[i
] != LINE_UNKNOWN
)
2657 eqclass
= dsf_canonify(sstate
->dotdsf
, d1
);
2658 if (eqclass
!= dsf_canonify(sstate
->dotdsf
, d2
))
2661 val
= LINE_NO
; /* loop is bad until proven otherwise */
2664 * This edge would form a loop. Next
2665 * question: how long would the loop be?
2666 * Would it equal the total number of edges
2667 * (plus the one we'd be adding if we added
2670 if (sstate
->looplen
[eqclass
] == edgecount
+ 1) {
2674 * This edge would form a loop which
2675 * took in all the edges in the entire
2676 * grid. So now we need to work out
2677 * whether it would be a valid solution
2678 * to the puzzle, which means we have to
2679 * check if it satisfies all the clues.
2680 * This means that every clue must be
2681 * either satisfied or satisfied-minus-
2682 * 1, and also that the number of
2683 * satisfied-minus-1 clues must be at
2684 * most two and they must lie on either
2685 * side of this edge.
2689 int f
= e
->face1
- g
->faces
;
2690 int c
= state
->clues
[f
];
2691 if (c
>= 0 && sstate
->face_yes_count
[f
] == c
- 1)
2695 int f
= e
->face2
- g
->faces
;
2696 int c
= state
->clues
[f
];
2697 if (c
>= 0 && sstate
->face_yes_count
[f
] == c
- 1)
2700 if (sm1clues
== sm1_nearby
&&
2701 sm1clues
+ satclues
== clues
) {
2702 val
= LINE_YES
; /* loop is good! */
2707 * Right. Now we know that adding this edge
2708 * would form a loop, and we know whether
2709 * that loop would be a viable solution or
2712 * If adding this edge produces a solution,
2713 * then we know we've found _a_ solution but
2714 * we don't know that it's _the_ solution -
2715 * if it were provably the solution then
2716 * we'd have deduced this edge some time ago
2717 * without the need to do loop detection. So
2718 * in this state we return SOLVER_AMBIGUOUS,
2719 * which has the effect that hitting Solve
2720 * on a user-provided puzzle will fill in a
2721 * solution but using the solver to
2722 * construct new puzzles won't consider this
2723 * a reasonable deduction for the user to
2726 progress
= solver_set_line(sstate
, i
, val
);
2727 assert(progress
== TRUE
);
2728 if (val
== LINE_YES
) {
2729 sstate
->solver_status
= SOLVER_AMBIGUOUS
;
2730 goto finished_loop_deductionsing
;
2734 finished_loop_deductionsing
:
2735 return progress ? DIFF_EASY
: DIFF_MAX
;
2738 /* This will return a dynamically allocated solver_state containing the (more)
2740 static solver_state
*solve_game_rec(const solver_state
*sstate_start
)
2742 solver_state
*sstate
;
2744 /* Index of the solver we should call next. */
2747 /* As a speed-optimisation, we avoid re-running solvers that we know
2748 * won't make any progress. This happens when a high-difficulty
2749 * solver makes a deduction that can only help other high-difficulty
2751 * For example: if a new 'dline' flag is set by dline_deductions, the
2752 * trivial_deductions solver cannot do anything with this information.
2753 * If we've already run the trivial_deductions solver (because it's
2754 * earlier in the list), there's no point running it again.
2756 * Therefore: if a solver is earlier in the list than "threshold_index",
2757 * we don't bother running it if it's difficulty level is less than
2760 int threshold_diff
= 0;
2761 int threshold_index
= 0;
2763 sstate
= dup_solver_state(sstate_start
);
2765 check_caches(sstate
);
2767 while (i
< NUM_SOLVERS
) {
2768 if (sstate
->solver_status
== SOLVER_MISTAKE
)
2770 if (sstate
->solver_status
== SOLVER_SOLVED
||
2771 sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
2772 /* solver finished */
2776 if ((solver_diffs
[i
] >= threshold_diff
|| i
>= threshold_index
)
2777 && solver_diffs
[i
] <= sstate
->diff
) {
2778 /* current_solver is eligible, so use it */
2779 int next_diff
= solver_fns
[i
](sstate
);
2780 if (next_diff
!= DIFF_MAX
) {
2781 /* solver made progress, so use new thresholds and
2782 * start again at top of list. */
2783 threshold_diff
= next_diff
;
2784 threshold_index
= i
;
2789 /* current_solver is ineligible, or failed to make progress, so
2790 * go to the next solver in the list */
2794 if (sstate
->solver_status
== SOLVER_SOLVED
||
2795 sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
2796 /* s/LINE_UNKNOWN/LINE_NO/g */
2797 array_setall(sstate
->state
->lines
, LINE_UNKNOWN
, LINE_NO
,
2798 sstate
->state
->game_grid
->num_edges
);
2805 static char *solve_game(game_state
*state
, game_state
*currstate
,
2806 char *aux
, char **error
)
2809 solver_state
*sstate
, *new_sstate
;
2811 sstate
= new_solver_state(state
, DIFF_MAX
);
2812 new_sstate
= solve_game_rec(sstate
);
2814 if (new_sstate
->solver_status
== SOLVER_SOLVED
) {
2815 soln
= encode_solve_move(new_sstate
->state
);
2816 } else if (new_sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
2817 soln
= encode_solve_move(new_sstate
->state
);
2818 /**error = "Solver found ambiguous solutions"; */
2820 soln
= encode_solve_move(new_sstate
->state
);
2821 /**error = "Solver failed"; */
2824 free_solver_state(new_sstate
);
2825 free_solver_state(sstate
);
2830 /* ----------------------------------------------------------------------
2831 * Drawing and mouse-handling
2834 static char *interpret_move(game_state
*state
, game_ui
*ui
, game_drawstate
*ds
,
2835 int x
, int y
, int button
)
2837 grid
*g
= state
->game_grid
;
2841 char button_char
= ' ';
2842 enum line_state old_state
;
2844 button
&= ~MOD_MASK
;
2846 /* Convert mouse-click (x,y) to grid coordinates */
2847 x
-= BORDER(ds
->tilesize
);
2848 y
-= BORDER(ds
->tilesize
);
2849 x
= x
* g
->tilesize
/ ds
->tilesize
;
2850 y
= y
* g
->tilesize
/ ds
->tilesize
;
2854 e
= grid_nearest_edge(g
, x
, y
);
2860 /* I think it's only possible to play this game with mouse clicks, sorry */
2861 /* Maybe will add mouse drag support some time */
2862 old_state
= state
->lines
[i
];
2866 switch (old_state
) {
2884 switch (old_state
) {
2903 sprintf(buf
, "%d%c", i
, (int)button_char
);
2909 static game_state
*execute_move(game_state
*state
, char *move
)
2912 game_state
*newstate
= dup_game(state
);
2914 if (move
[0] == 'S') {
2916 newstate
->cheated
= TRUE
;
2921 if (i
< 0 || i
>= newstate
->game_grid
->num_edges
)
2923 move
+= strspn(move
, "1234567890");
2924 switch (*(move
++)) {
2926 newstate
->lines
[i
] = LINE_YES
;
2929 newstate
->lines
[i
] = LINE_NO
;
2932 newstate
->lines
[i
] = LINE_UNKNOWN
;
2940 * Check for completion.
2942 if (check_completion(newstate
))
2943 newstate
->solved
= TRUE
;
2948 free_game(newstate
);
2952 /* ----------------------------------------------------------------------
2956 /* Convert from grid coordinates to screen coordinates */
2957 static void grid_to_screen(const game_drawstate
*ds
, const grid
*g
,
2958 int grid_x
, int grid_y
, int *x
, int *y
)
2960 *x
= grid_x
- g
->lowest_x
;
2961 *y
= grid_y
- g
->lowest_y
;
2962 *x
= *x
* ds
->tilesize
/ g
->tilesize
;
2963 *y
= *y
* ds
->tilesize
/ g
->tilesize
;
2964 *x
+= BORDER(ds
->tilesize
);
2965 *y
+= BORDER(ds
->tilesize
);
2968 /* Returns (into x,y) position of centre of face for rendering the text clue.
2970 static void face_text_pos(const game_drawstate
*ds
, const grid
*g
,
2971 grid_face
*f
, int *xret
, int *yret
)
2973 int faceindex
= f
- g
->faces
;
2976 * Return the cached position for this face, if we've already
2979 if (ds
->textx
[faceindex
] >= 0) {
2980 *xret
= ds
->textx
[faceindex
];
2981 *yret
= ds
->texty
[faceindex
];
2986 * Otherwise, use the incentre computed by grid.c and convert it
2987 * to screen coordinates.
2989 grid_find_incentre(f
);
2990 grid_to_screen(ds
, g
, f
->ix
, f
->iy
,
2991 &ds
->textx
[faceindex
], &ds
->texty
[faceindex
]);
2993 *xret
= ds
->textx
[faceindex
];
2994 *yret
= ds
->texty
[faceindex
];
2997 static void face_text_bbox(game_drawstate
*ds
, grid
*g
, grid_face
*f
,
2998 int *x
, int *y
, int *w
, int *h
)
3001 face_text_pos(ds
, g
, f
, &xx
, &yy
);
3003 /* There seems to be a certain amount of trial-and-error involved
3004 * in working out the correct bounding-box for the text. */
3006 *x
= xx
- ds
->tilesize
/4 - 1;
3007 *y
= yy
- ds
->tilesize
/4 - 3;
3008 *w
= ds
->tilesize
/2 + 2;
3009 *h
= ds
->tilesize
/2 + 5;
3012 static void game_redraw_clue(drawing
*dr
, game_drawstate
*ds
,
3013 game_state
*state
, int i
)
3015 grid
*g
= state
->game_grid
;
3016 grid_face
*f
= g
->faces
+ i
;
3020 if (state
->clues
[i
] < 10) {
3021 c
[0] = CLUE2CHAR(state
->clues
[i
]);
3024 sprintf(c
, "%d", state
->clues
[i
]);
3027 face_text_pos(ds
, g
, f
, &x
, &y
);
3029 FONT_VARIABLE
, ds
->tilesize
/2,
3030 ALIGN_VCENTRE
| ALIGN_HCENTRE
,
3031 ds
->clue_error
[i
] ? COL_MISTAKE
:
3032 ds
->clue_satisfied
[i
] ? COL_SATISFIED
: COL_FOREGROUND
, c
);
3035 static void edge_bbox(game_drawstate
*ds
, grid
*g
, grid_edge
*e
,
3036 int *x
, int *y
, int *w
, int *h
)
3038 int x1
= e
->dot1
->x
;
3039 int y1
= e
->dot1
->y
;
3040 int x2
= e
->dot2
->x
;
3041 int y2
= e
->dot2
->y
;
3042 int xmin
, xmax
, ymin
, ymax
;
3044 grid_to_screen(ds
, g
, x1
, y1
, &x1
, &y1
);
3045 grid_to_screen(ds
, g
, x2
, y2
, &x2
, &y2
);
3046 /* Allow extra margin for dots, and thickness of lines */
3047 xmin
= min(x1
, x2
) - 2;
3048 xmax
= max(x1
, x2
) + 2;
3049 ymin
= min(y1
, y2
) - 2;
3050 ymax
= max(y1
, y2
) + 2;
3054 *w
= xmax
- xmin
+ 1;
3055 *h
= ymax
- ymin
+ 1;
3058 static void dot_bbox(game_drawstate
*ds
, grid
*g
, grid_dot
*d
,
3059 int *x
, int *y
, int *w
, int *h
)
3063 grid_to_screen(ds
, g
, d
->x
, d
->y
, &x1
, &y1
);
3071 static const int loopy_line_redraw_phases
[] = {
3072 COL_FAINT
, COL_LINEUNKNOWN
, COL_FOREGROUND
, COL_HIGHLIGHT
, COL_MISTAKE
3074 #define NPHASES lenof(loopy_line_redraw_phases)
3076 static void game_redraw_line(drawing
*dr
, game_drawstate
*ds
,
3077 game_state
*state
, int i
, int phase
)
3079 grid
*g
= state
->game_grid
;
3080 grid_edge
*e
= g
->edges
+ i
;
3084 if (state
->line_errors
[i
])
3085 line_colour
= COL_MISTAKE
;
3086 else if (state
->lines
[i
] == LINE_UNKNOWN
)
3087 line_colour
= COL_LINEUNKNOWN
;
3088 else if (state
->lines
[i
] == LINE_NO
)
3089 line_colour
= COL_FAINT
;
3090 else if (ds
->flashing
)
3091 line_colour
= COL_HIGHLIGHT
;
3093 line_colour
= COL_FOREGROUND
;
3094 if (line_colour
!= loopy_line_redraw_phases
[phase
])
3097 /* Convert from grid to screen coordinates */
3098 grid_to_screen(ds
, g
, e
->dot1
->x
, e
->dot1
->y
, &x1
, &y1
);
3099 grid_to_screen(ds
, g
, e
->dot2
->x
, e
->dot2
->y
, &x2
, &y2
);
3101 if (line_colour
== COL_FAINT
) {
3102 static int draw_faint_lines
= -1;
3103 if (draw_faint_lines
< 0) {
3104 char *env
= getenv("LOOPY_FAINT_LINES");
3105 draw_faint_lines
= (!env
|| (env
[0] == 'y' ||
3108 if (draw_faint_lines
)
3109 draw_line(dr
, x1
, y1
, x2
, y2
, line_colour
);
3111 draw_thick_line(dr
, 3.0,
3118 static void game_redraw_dot(drawing
*dr
, game_drawstate
*ds
,
3119 game_state
*state
, int i
)
3121 grid
*g
= state
->game_grid
;
3122 grid_dot
*d
= g
->dots
+ i
;
3125 grid_to_screen(ds
, g
, d
->x
, d
->y
, &x
, &y
);
3126 draw_circle(dr
, x
, y
, 2, COL_FOREGROUND
, COL_FOREGROUND
);
3129 static int boxes_intersect(int x0
, int y0
, int w0
, int h0
,
3130 int x1
, int y1
, int w1
, int h1
)
3133 * Two intervals intersect iff neither is wholly on one side of
3134 * the other. Two boxes intersect iff their horizontal and
3135 * vertical intervals both intersect.
3137 return (x0
< x1
+w1
&& x1
< x0
+w0
&& y0
< y1
+h1
&& y1
< y0
+h0
);
3140 static void game_redraw_in_rect(drawing
*dr
, game_drawstate
*ds
,
3141 game_state
*state
, int x
, int y
, int w
, int h
)
3143 grid
*g
= state
->game_grid
;
3147 clip(dr
, x
, y
, w
, h
);
3148 draw_rect(dr
, x
, y
, w
, h
, COL_BACKGROUND
);
3150 for (i
= 0; i
< g
->num_faces
; i
++) {
3151 if (state
->clues
[i
] >= 0) {
3152 face_text_bbox(ds
, g
, &g
->faces
[i
], &bx
, &by
, &bw
, &bh
);
3153 if (boxes_intersect(x
, y
, w
, h
, bx
, by
, bw
, bh
))
3154 game_redraw_clue(dr
, ds
, state
, i
);
3157 for (phase
= 0; phase
< NPHASES
; phase
++) {
3158 for (i
= 0; i
< g
->num_edges
; i
++) {
3159 edge_bbox(ds
, g
, &g
->edges
[i
], &bx
, &by
, &bw
, &bh
);
3160 if (boxes_intersect(x
, y
, w
, h
, bx
, by
, bw
, bh
))
3161 game_redraw_line(dr
, ds
, state
, i
, phase
);
3164 for (i
= 0; i
< g
->num_dots
; i
++) {
3165 dot_bbox(ds
, g
, &g
->dots
[i
], &bx
, &by
, &bw
, &bh
);
3166 if (boxes_intersect(x
, y
, w
, h
, bx
, by
, bw
, bh
))
3167 game_redraw_dot(dr
, ds
, state
, i
);
3171 draw_update(dr
, x
, y
, w
, h
);
3174 static void game_redraw(drawing
*dr
, game_drawstate
*ds
, game_state
*oldstate
,
3175 game_state
*state
, int dir
, game_ui
*ui
,
3176 float animtime
, float flashtime
)
3178 #define REDRAW_OBJECTS_LIMIT 16 /* Somewhat arbitrary tradeoff */
3180 grid
*g
= state
->game_grid
;
3181 int border
= BORDER(ds
->tilesize
);
3184 int redraw_everything
= FALSE
;
3186 int edges
[REDRAW_OBJECTS_LIMIT
], nedges
= 0;
3187 int faces
[REDRAW_OBJECTS_LIMIT
], nfaces
= 0;
3189 /* Redrawing is somewhat involved.
3191 * An update can theoretically affect an arbitrary number of edges
3192 * (consider, for example, completing or breaking a cycle which doesn't
3193 * satisfy all the clues -- we'll switch many edges between error and
3194 * normal states). On the other hand, redrawing the whole grid takes a
3195 * while, making the game feel sluggish, and many updates are actually
3196 * quite well localized.
3198 * This redraw algorithm attempts to cope with both situations gracefully
3199 * and correctly. For localized changes, we set a clip rectangle, fill
3200 * it with background, and then redraw (a plausible but conservative
3201 * guess at) the objects which intersect the rectangle; if several
3202 * objects need redrawing, we'll do them individually. However, if lots
3203 * of objects are affected, we'll just redraw everything.
3205 * The reason for all of this is that it's just not safe to do the redraw
3206 * piecemeal. If you try to draw an antialiased diagonal line over
3207 * itself, you get a slightly thicker antialiased diagonal line, which
3208 * looks rather ugly after a while.
3210 * So, we take two passes over the grid. The first attempts to work out
3211 * what needs doing, and the second actually does it.
3215 redraw_everything
= TRUE
;
3218 /* First, trundle through the faces. */
3219 for (i
= 0; i
< g
->num_faces
; i
++) {
3220 grid_face
*f
= g
->faces
+ i
;
3221 int sides
= f
->order
;
3224 int n
= state
->clues
[i
];
3228 clue_mistake
= (face_order(state
, i
, LINE_YES
) > n
||
3229 face_order(state
, i
, LINE_NO
) > (sides
-n
));
3230 clue_satisfied
= (face_order(state
, i
, LINE_YES
) == n
&&
3231 face_order(state
, i
, LINE_NO
) == (sides
-n
));
3233 if (clue_mistake
!= ds
->clue_error
[i
] ||
3234 clue_satisfied
!= ds
->clue_satisfied
[i
]) {
3235 ds
->clue_error
[i
] = clue_mistake
;
3236 ds
->clue_satisfied
[i
] = clue_satisfied
;
3237 if (nfaces
== REDRAW_OBJECTS_LIMIT
)
3238 redraw_everything
= TRUE
;
3240 faces
[nfaces
++] = i
;
3244 /* Work out what the flash state needs to be. */
3245 if (flashtime
> 0 &&
3246 (flashtime
<= FLASH_TIME
/3 ||
3247 flashtime
>= FLASH_TIME
*2/3)) {
3248 flash_changed
= !ds
->flashing
;
3249 ds
->flashing
= TRUE
;
3251 flash_changed
= ds
->flashing
;
3252 ds
->flashing
= FALSE
;
3255 /* Now, trundle through the edges. */
3256 for (i
= 0; i
< g
->num_edges
; i
++) {
3258 state
->line_errors
[i
] ? DS_LINE_ERROR
: state
->lines
[i
];
3259 if (new_ds
!= ds
->lines
[i
] ||
3260 (flash_changed
&& state
->lines
[i
] == LINE_YES
)) {
3261 ds
->lines
[i
] = new_ds
;
3262 if (nedges
== REDRAW_OBJECTS_LIMIT
)
3263 redraw_everything
= TRUE
;
3265 edges
[nedges
++] = i
;
3270 /* Pass one is now done. Now we do the actual drawing. */
3271 if (redraw_everything
) {
3272 int grid_width
= g
->highest_x
- g
->lowest_x
;
3273 int grid_height
= g
->highest_y
- g
->lowest_y
;
3274 int w
= grid_width
* ds
->tilesize
/ g
->tilesize
;
3275 int h
= grid_height
* ds
->tilesize
/ g
->tilesize
;
3277 game_redraw_in_rect(dr
, ds
, state
,
3278 0, 0, w
+ 2*border
+ 1, h
+ 2*border
+ 1);
3281 /* Right. Now we roll up our sleeves. */
3283 for (i
= 0; i
< nfaces
; i
++) {
3284 grid_face
*f
= g
->faces
+ faces
[i
];
3287 face_text_bbox(ds
, g
, f
, &x
, &y
, &w
, &h
);
3288 game_redraw_in_rect(dr
, ds
, state
, x
, y
, w
, h
);
3291 for (i
= 0; i
< nedges
; i
++) {
3292 grid_edge
*e
= g
->edges
+ edges
[i
];
3295 edge_bbox(ds
, g
, e
, &x
, &y
, &w
, &h
);
3296 game_redraw_in_rect(dr
, ds
, state
, x
, y
, w
, h
);
3303 static float game_flash_length(game_state
*oldstate
, game_state
*newstate
,
3304 int dir
, game_ui
*ui
)
3306 if (!oldstate
->solved
&& newstate
->solved
&&
3307 !oldstate
->cheated
&& !newstate
->cheated
) {
3314 static int game_status(game_state
*state
)
3316 return state
->solved ?
+1 : 0;
3319 static void game_print_size(game_params
*params
, float *x
, float *y
)
3324 * I'll use 7mm "squares" by default.
3326 game_compute_size(params
, 700, &pw
, &ph
);
3331 static void game_print(drawing
*dr
, game_state
*state
, int tilesize
)
3333 int ink
= print_mono_colour(dr
, 0);
3335 game_drawstate ads
, *ds
= &ads
;
3336 grid
*g
= state
->game_grid
;
3338 ds
->tilesize
= tilesize
;
3339 ds
->textx
= snewn(g
->num_faces
, int);
3340 ds
->texty
= snewn(g
->num_faces
, int);
3341 for (i
= 0; i
< g
->num_faces
; i
++)
3342 ds
->textx
[i
] = ds
->texty
[i
] = -1;
3344 for (i
= 0; i
< g
->num_dots
; i
++) {
3346 grid_to_screen(ds
, g
, g
->dots
[i
].x
, g
->dots
[i
].y
, &x
, &y
);
3347 draw_circle(dr
, x
, y
, ds
->tilesize
/ 15, ink
, ink
);
3353 for (i
= 0; i
< g
->num_faces
; i
++) {
3354 grid_face
*f
= g
->faces
+ i
;
3355 int clue
= state
->clues
[i
];
3359 c
[0] = CLUE2CHAR(clue
);
3361 face_text_pos(ds
, g
, f
, &x
, &y
);
3363 FONT_VARIABLE
, ds
->tilesize
/ 2,
3364 ALIGN_VCENTRE
| ALIGN_HCENTRE
, ink
, c
);
3371 for (i
= 0; i
< g
->num_edges
; i
++) {
3372 int thickness
= (state
->lines
[i
] == LINE_YES
) ?
30 : 150;
3373 grid_edge
*e
= g
->edges
+ i
;
3375 grid_to_screen(ds
, g
, e
->dot1
->x
, e
->dot1
->y
, &x1
, &y1
);
3376 grid_to_screen(ds
, g
, e
->dot2
->x
, e
->dot2
->y
, &x2
, &y2
);
3377 if (state
->lines
[i
] == LINE_YES
)
3379 /* (dx, dy) points from (x1, y1) to (x2, y2).
3380 * The line is then "fattened" in a perpendicular
3381 * direction to create a thin rectangle. */
3382 double d
= sqrt(SQ((double)x1
- x2
) + SQ((double)y1
- y2
));
3383 double dx
= (x2
- x1
) / d
;
3384 double dy
= (y2
- y1
) / d
;
3387 dx
= (dx
* ds
->tilesize
) / thickness
;
3388 dy
= (dy
* ds
->tilesize
) / thickness
;
3389 points
[0] = x1
+ (int)dy
;
3390 points
[1] = y1
- (int)dx
;
3391 points
[2] = x1
- (int)dy
;
3392 points
[3] = y1
+ (int)dx
;
3393 points
[4] = x2
- (int)dy
;
3394 points
[5] = y2
+ (int)dx
;
3395 points
[6] = x2
+ (int)dy
;
3396 points
[7] = y2
- (int)dx
;
3397 draw_polygon(dr
, points
, 4, ink
, ink
);
3401 /* Draw a dotted line */
3404 for (j
= 1; j
< divisions
; j
++) {
3405 /* Weighted average */
3406 int x
= (x1
* (divisions
-j
) + x2
* j
) / divisions
;
3407 int y
= (y1
* (divisions
-j
) + y2
* j
) / divisions
;
3408 draw_circle(dr
, x
, y
, ds
->tilesize
/ thickness
, ink
, ink
);
3418 #define thegame loopy
3421 const struct game thegame
= {
3422 "Loopy", "games.loopy", "loopy",
3429 TRUE
, game_configure
, custom_params
,
3437 TRUE
, game_can_format_as_text_now
, game_text_format
,
3445 PREFERRED_TILE_SIZE
, game_compute_size
, game_set_size
,
3448 game_free_drawstate
,
3453 TRUE
, FALSE
, game_print_size
, game_print
,
3454 FALSE
/* wants_statusbar */,
3455 FALSE
, game_timing_state
,
3456 0, /* mouse_priorities */
3459 #ifdef STANDALONE_SOLVER
3462 * Half-hearted standalone solver. It can't output the solution to
3463 * anything but a square puzzle, and it can't log the deductions
3464 * it makes either. But it can solve square puzzles, and more
3465 * importantly it can use its solver to grade the difficulty of
3466 * any puzzle you give it.
3471 int main(int argc
, char **argv
)
3475 char *id
= NULL
, *desc
, *err
;
3478 #if 0 /* verbose solver not supported here (yet) */
3479 int really_verbose
= FALSE
;
3482 while (--argc
> 0) {
3484 #if 0 /* verbose solver not supported here (yet) */
3485 if (!strcmp(p
, "-v")) {
3486 really_verbose
= TRUE
;
3489 if (!strcmp(p
, "-g")) {
3491 } else if (*p
== '-') {
3492 fprintf(stderr
, "%s: unrecognised option `%s'\n", argv
[0], p
);
3500 fprintf(stderr
, "usage: %s [-g | -v] <game_id>\n", argv
[0]);
3504 desc
= strchr(id
, ':');
3506 fprintf(stderr
, "%s: game id expects a colon in it\n", argv
[0]);
3511 p
= default_params();
3512 decode_params(p
, id
);
3513 err
= validate_desc(p
, desc
);
3515 fprintf(stderr
, "%s: %s\n", argv
[0], err
);
3518 s
= new_game(NULL
, p
, desc
);
3521 * When solving an Easy puzzle, we don't want to bother the
3522 * user with Hard-level deductions. For this reason, we grade
3523 * the puzzle internally before doing anything else.
3525 ret
= -1; /* placate optimiser */
3526 for (diff
= 0; diff
< DIFF_MAX
; diff
++) {
3527 solver_state
*sstate_new
;
3528 solver_state
*sstate
= new_solver_state((game_state
*)s
, diff
);
3530 sstate_new
= solve_game_rec(sstate
);
3532 if (sstate_new
->solver_status
== SOLVER_MISTAKE
)
3534 else if (sstate_new
->solver_status
== SOLVER_SOLVED
)
3539 free_solver_state(sstate_new
);
3540 free_solver_state(sstate
);
3546 if (diff
== DIFF_MAX
) {
3548 printf("Difficulty rating: harder than Hard, or ambiguous\n");
3550 printf("Unable to find a unique solution\n");
3554 printf("Difficulty rating: impossible (no solution exists)\n");
3556 printf("Difficulty rating: %s\n", diffnames
[diff
]);
3558 solver_state
*sstate_new
;
3559 solver_state
*sstate
= new_solver_state((game_state
*)s
, diff
);
3561 /* If we supported a verbose solver, we'd set verbosity here */
3563 sstate_new
= solve_game_rec(sstate
);
3565 if (sstate_new
->solver_status
== SOLVER_MISTAKE
)
3566 printf("Puzzle is inconsistent\n");
3568 assert(sstate_new
->solver_status
== SOLVER_SOLVED
);
3569 if (s
->grid_type
== 0) {
3570 fputs(game_text_format(sstate_new
->state
), stdout
);
3572 printf("Unable to output non-square grids\n");
3576 free_solver_state(sstate_new
);
3577 free_solver_state(sstate
);
3586 /* vim: set shiftwidth=4 tabstop=8: */