2 * loopy.c: An implementation of the Nikoli game 'Loop the loop'.
3 * (c) Mike Pinna, 2005, 2006
5 * vim: set shiftwidth=4 :set textwidth=80:
11 * - Setting very high recursion depth seems to cause memory munching: are we
12 * recursing before checking completion, by any chance?
14 * - There's an interesting deductive technique which makes use of topology
15 * rather than just graph theory. Each _square_ in the grid is either inside
16 * or outside the loop; you can tell that two squares are on the same side
17 * of the loop if they're separated by an x (or, more generally, by a path
18 * crossing no LINE_UNKNOWNs and an even number of LINE_YESes), and on the
19 * opposite side of the loop if they're separated by a line (or an odd
20 * number of LINE_YESes and no LINE_UNKNOWNs). Oh, and any square separated
21 * from the outside of the grid by a LINE_YES or a LINE_NO is on the inside
22 * or outside respectively. So if you can track this for all squares, you
23 * figure out the state of the line between a pair once their relative
24 * insideness is known.
26 * - (Just a speed optimisation.) Consider some todo list queue where every
27 * time we modify something we mark it for consideration by other bits of
28 * the solver, to save iteration over things that have already been done.
41 /* Debugging options */
42 /*#define DEBUG_CACHES*/
43 /*#define SHOW_WORKING*/
45 /* ----------------------------------------------------------------------
46 * Struct, enum and function declarations
60 /* Put -1 in a square that doesn't get a clue */
63 /* Arrays of line states, stored left-to-right, top-to-bottom */
73 SOLVER_SOLVED
, /* This is the only solution the solver could find */
74 SOLVER_MISTAKE
, /* This is definitely not a solution */
75 SOLVER_AMBIGUOUS
, /* This _might_ be an ambiguous solution */
76 SOLVER_INCOMPLETE
/* This may be a partial solution */
79 typedef struct normal
{
88 typedef struct solver_state
{
90 int recursion_remaining
;
91 enum solver_status solver_status
;
92 /* NB looplen is the number of dots that are joined together at a point, ie a
93 * looplen of 1 means there are no lines to a particular dot */
99 char *square_yescount
;
100 char *square_nocount
;
101 char *dot_solved
, *square_solved
;
104 normal_mode_state
*normal
;
105 hard_mode_state
*hard
;
109 * Difficulty levels. I do some macro ickery here to ensure that my
110 * enum and the various forms of my name list always match up.
113 #define DIFFLIST(A) \
114 A(EASY,Easy,e,easy_mode_deductions) \
115 A(NORMAL,Normal,n,normal_mode_deductions) \
116 A(HARD,Hard,h,hard_mode_deductions)
117 #define ENUM(upper,title,lower,fn) DIFF_ ## upper,
118 #define TITLE(upper,title,lower,fn) #title,
119 #define ENCODE(upper,title,lower,fn) #lower
120 #define CONFIG(upper,title,lower,fn) ":" #title
121 #define SOLVER_FN_DECL(upper,title,lower,fn) static int fn(solver_state *);
122 #define SOLVER_FN(upper,title,lower,fn) &fn,
123 enum { DIFFLIST(ENUM
) DIFF_MAX
};
124 static char const *const diffnames
[] = { DIFFLIST(TITLE
) };
125 static char const diffchars
[] = DIFFLIST(ENCODE
);
126 #define DIFFCONFIG DIFFLIST(CONFIG)
127 DIFFLIST(SOLVER_FN_DECL
);
128 static int (*(solver_fns
[]))(solver_state
*) = { DIFFLIST(SOLVER_FN
) };
136 enum line_state
{ LINE_YES
, LINE_UNKNOWN
, LINE_NO
};
141 enum direction
{ UP
, LEFT
, RIGHT
, DOWN
};
143 #define OPP_DIR(dir) \
146 struct game_drawstate
{
148 int tilesize
, linewidth
;
154 static int game_can_format_as_text_now(game_params
*params
)
159 static char *game_text_format(game_state
*state
);
160 static char *state_to_text(const game_state
*state
);
161 static char *validate_desc(game_params
*params
, char *desc
);
162 static int get_line_status_from_point(const game_state
*state
,
163 int x
, int y
, enum direction d
);
164 static int dot_order(const game_state
* state
, int i
, int j
, char line_type
);
165 static int square_order(const game_state
* state
, int i
, int j
, char line_type
);
166 static solver_state
*solve_game_rec(const solver_state
*sstate
,
170 static void check_caches(const solver_state
* sstate
);
172 #define check_caches(s)
175 /* ----------------------------------------------------------------------
179 /* General constants */
180 #define PREFERRED_TILE_SIZE 32
181 #define TILE_SIZE (ds->tilesize)
182 #define LINEWIDTH (ds->linewidth)
183 #define BORDER (TILE_SIZE / 2)
184 #define FLASH_TIME 0.5F
186 /* Counts of various things that we're interested in */
187 #define HL_COUNT(state) ((state)->w * ((state)->h + 1))
188 #define VL_COUNT(state) (((state)->w + 1) * (state)->h)
189 #define LINE_COUNT(state) (HL_COUNT(state) + VL_COUNT(state))
190 #define DOT_COUNT(state) (((state)->w + 1) * ((state)->h + 1))
191 #define SQUARE_COUNT(state) ((state)->w * (state)->h)
193 /* For indexing into arrays */
194 #define DOT_INDEX(state, x, y) ((x) + ((state)->w + 1) * (y))
195 #define SQUARE_INDEX(state, x, y) ((x) + ((state)->w) * (y))
196 #define HL_INDEX(state, x, y) SQUARE_INDEX(state, x, y)
197 #define VL_INDEX(state, x, y) DOT_INDEX(state, x, y)
199 /* Useful utility functions */
200 #define LEGAL_DOT(state, i, j) ((i) >= 0 && (j) >= 0 && \
201 (i) <= (state)->w && (j) <= (state)->h)
202 #define LEGAL_SQUARE(state, i, j) ((i) >= 0 && (j) >= 0 && \
203 (i) < (state)->w && (j) < (state)->h)
205 #define CLUE_AT(state, i, j) (LEGAL_SQUARE(state, i, j) ? \
206 LV_CLUE_AT(state, i, j) : -1)
208 #define LV_CLUE_AT(state, i, j) ((state)->clues[SQUARE_INDEX(state, i, j)])
210 #define BIT_SET(field, bit) ((field) & (1<<(bit)))
212 #define SET_BIT(field, bit) (BIT_SET(field, bit) ? FALSE : \
213 ((field) |= (1<<(bit)), TRUE))
215 #define CLEAR_BIT(field, bit) (BIT_SET(field, bit) ? \
216 ((field) &= ~(1<<(bit)), TRUE) : FALSE)
219 ((d == UP) ? "up" : \
220 (d == DOWN) ? "down" : \
221 (d == LEFT) ? "left" : \
222 (d == RIGHT) ? "right" : "oops")
224 #define CLUE2CHAR(c) \
225 ((c < 0) ? ' ' : c + '0')
227 /* Lines that have particular relationships with given dots or squares */
228 #define ABOVE_SQUARE(state, i, j) ((state)->hl[(i) + (state)->w * (j)])
229 #define BELOW_SQUARE(state, i, j) ABOVE_SQUARE(state, i, (j)+1)
230 #define LEFTOF_SQUARE(state, i, j) ((state)->vl[(i) + ((state)->w + 1) * (j)])
231 #define RIGHTOF_SQUARE(state, i, j) LEFTOF_SQUARE(state, (i)+1, j)
234 * These macros return rvalues only, but can cope with being passed
235 * out-of-range coordinates.
237 /* XXX replace these with functions so we can create an array of function
238 * pointers for nicer iteration over them. This could probably be done with
239 * loads of other things for eliminating many nasty hacks. */
240 #define ABOVE_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || j <= 0) ? \
241 LINE_NO : LV_ABOVE_DOT(state, i, j))
242 #define BELOW_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || j >= (state)->h) ? \
243 LINE_NO : LV_BELOW_DOT(state, i, j))
245 #define LEFTOF_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || i <= 0) ? \
246 LINE_NO : LV_LEFTOF_DOT(state, i, j))
247 #define RIGHTOF_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || i >= (state)->w)? \
248 LINE_NO : LV_RIGHTOF_DOT(state, i, j))
251 * These macros expect to be passed valid coordinates, and return
254 #define LV_BELOW_DOT(state, i, j) ((state)->vl[VL_INDEX(state, i, j)])
255 #define LV_ABOVE_DOT(state, i, j) LV_BELOW_DOT(state, i, (j)-1)
257 #define LV_RIGHTOF_DOT(state, i, j) ((state)->hl[HL_INDEX(state, i, j)])
258 #define LV_LEFTOF_DOT(state, i, j) LV_RIGHTOF_DOT(state, (i)-1, j)
260 /* Counts of interesting things */
261 #define DOT_YES_COUNT(sstate, i, j) \
262 ((sstate)->dot_yescount[DOT_INDEX((sstate)->state, i, j)])
264 #define DOT_NO_COUNT(sstate, i, j) \
265 ((sstate)->dot_nocount[DOT_INDEX((sstate)->state, i, j)])
267 #define SQUARE_YES_COUNT(sstate, i, j) \
268 ((sstate)->square_yescount[SQUARE_INDEX((sstate)->state, i, j)])
270 #define SQUARE_NO_COUNT(sstate, i, j) \
271 ((sstate)->square_nocount[SQUARE_INDEX((sstate)->state, i, j)])
273 /* Iterators. NB these iterate over height more slowly than over width so that
274 * the elements come out in 'reading' order */
275 /* XXX considering adding a 'current' element to each of these which gets the
276 * address of the current dot, say. But expecting we'd need more than that
277 * most of the time. */
278 #define FORALL(i, j, w, h) \
279 for ((j) = 0; (j) < (h); ++(j)) \
280 for ((i) = 0; (i) < (w); ++(i))
282 #define FORALL_DOTS(state, i, j) \
283 FORALL(i, j, (state)->w + 1, (state)->h + 1)
285 #define FORALL_SQUARES(state, i, j) \
286 FORALL(i, j, (state)->w, (state)->h)
288 #define FORALL_HL(state, i, j) \
289 FORALL(i, j, (state)->w, (state)->h+1)
291 #define FORALL_VL(state, i, j) \
292 FORALL(i, j, (state)->w+1, (state)->h)
294 /* ----------------------------------------------------------------------
295 * General struct manipulation and other straightforward code
298 static game_state
*dup_game(game_state
*state
)
300 game_state
*ret
= snew(game_state
);
304 ret
->solved
= state
->solved
;
305 ret
->cheated
= state
->cheated
;
307 ret
->clues
= snewn(SQUARE_COUNT(state
), signed char);
308 memcpy(ret
->clues
, state
->clues
, SQUARE_COUNT(state
));
310 ret
->hl
= snewn(HL_COUNT(state
), char);
311 memcpy(ret
->hl
, state
->hl
, HL_COUNT(state
));
313 ret
->vl
= snewn(VL_COUNT(state
), char);
314 memcpy(ret
->vl
, state
->vl
, VL_COUNT(state
));
316 ret
->recursion_depth
= state
->recursion_depth
;
321 static void free_game(game_state
*state
)
331 static solver_state
*new_solver_state(const game_state
*state
, int diff
) {
333 solver_state
*ret
= snew(solver_state
);
335 ret
->state
= dup_game((game_state
*)state
);
337 ret
->recursion_remaining
= state
->recursion_depth
;
338 ret
->solver_status
= SOLVER_INCOMPLETE
;
340 ret
->dotdsf
= snew_dsf(DOT_COUNT(state
));
341 ret
->looplen
= snewn(DOT_COUNT(state
), int);
343 for (i
= 0; i
< DOT_COUNT(state
); i
++) {
347 ret
->dot_solved
= snewn(DOT_COUNT(state
), char);
348 ret
->square_solved
= snewn(SQUARE_COUNT(state
), char);
349 memset(ret
->dot_solved
, FALSE
, DOT_COUNT(state
));
350 memset(ret
->square_solved
, FALSE
, SQUARE_COUNT(state
));
352 ret
->dot_yescount
= snewn(DOT_COUNT(state
), char);
353 memset(ret
->dot_yescount
, 0, DOT_COUNT(state
));
354 ret
->dot_nocount
= snewn(DOT_COUNT(state
), char);
355 memset(ret
->dot_nocount
, 0, DOT_COUNT(state
));
356 ret
->square_yescount
= snewn(SQUARE_COUNT(state
), char);
357 memset(ret
->square_yescount
, 0, SQUARE_COUNT(state
));
358 ret
->square_nocount
= snewn(SQUARE_COUNT(state
), char);
359 memset(ret
->square_nocount
, 0, SQUARE_COUNT(state
));
361 /* dot_nocount needs special initialisation as we define lines coming off
362 * dots on edges as fixed at NO */
364 FORALL_DOTS(state
, i
, j
) {
365 if (i
== 0 || i
== state
->w
)
366 ++ret
->dot_nocount
[DOT_INDEX(state
, i
, j
)];
367 if (j
== 0 || j
== state
->h
)
368 ++ret
->dot_nocount
[DOT_INDEX(state
, i
, j
)];
371 if (diff
< DIFF_NORMAL
) {
374 ret
->normal
= snew(normal_mode_state
);
376 ret
->normal
->dot_atmostone
= snewn(DOT_COUNT(state
), char);
377 memset(ret
->normal
->dot_atmostone
, 0, DOT_COUNT(state
));
378 ret
->normal
->dot_atleastone
= snewn(DOT_COUNT(state
), char);
379 memset(ret
->normal
->dot_atleastone
, 0, DOT_COUNT(state
));
382 if (diff
< DIFF_HARD
) {
385 ret
->hard
= snew(hard_mode_state
);
386 ret
->hard
->linedsf
= snew_dsf(LINE_COUNT(state
));
392 static void free_solver_state(solver_state
*sstate
) {
394 free_game(sstate
->state
);
395 sfree(sstate
->dotdsf
);
396 sfree(sstate
->looplen
);
397 sfree(sstate
->dot_solved
);
398 sfree(sstate
->square_solved
);
399 sfree(sstate
->dot_yescount
);
400 sfree(sstate
->dot_nocount
);
401 sfree(sstate
->square_yescount
);
402 sfree(sstate
->square_nocount
);
404 if (sstate
->normal
) {
405 sfree(sstate
->normal
->dot_atleastone
);
406 sfree(sstate
->normal
->dot_atmostone
);
407 sfree(sstate
->normal
);
411 sfree(sstate
->hard
->linedsf
);
419 static solver_state
*dup_solver_state(const solver_state
*sstate
) {
422 solver_state
*ret
= snew(solver_state
);
424 ret
->state
= state
= dup_game(sstate
->state
);
426 ret
->recursion_remaining
= sstate
->recursion_remaining
;
427 ret
->solver_status
= sstate
->solver_status
;
429 ret
->dotdsf
= snewn(DOT_COUNT(state
), int);
430 ret
->looplen
= snewn(DOT_COUNT(state
), int);
431 memcpy(ret
->dotdsf
, sstate
->dotdsf
,
432 DOT_COUNT(state
) * sizeof(int));
433 memcpy(ret
->looplen
, sstate
->looplen
,
434 DOT_COUNT(state
) * sizeof(int));
436 ret
->dot_solved
= snewn(DOT_COUNT(state
), char);
437 ret
->square_solved
= snewn(SQUARE_COUNT(state
), char);
438 memcpy(ret
->dot_solved
, sstate
->dot_solved
,
440 memcpy(ret
->square_solved
, sstate
->square_solved
,
441 SQUARE_COUNT(state
));
443 ret
->dot_yescount
= snewn(DOT_COUNT(state
), char);
444 memcpy(ret
->dot_yescount
, sstate
->dot_yescount
,
446 ret
->dot_nocount
= snewn(DOT_COUNT(state
), char);
447 memcpy(ret
->dot_nocount
, sstate
->dot_nocount
,
450 ret
->square_yescount
= snewn(SQUARE_COUNT(state
), char);
451 memcpy(ret
->square_yescount
, sstate
->square_yescount
,
452 SQUARE_COUNT(state
));
453 ret
->square_nocount
= snewn(SQUARE_COUNT(state
), char);
454 memcpy(ret
->square_nocount
, sstate
->square_nocount
,
455 SQUARE_COUNT(state
));
457 if (sstate
->normal
) {
458 ret
->normal
= snew(normal_mode_state
);
459 ret
->normal
->dot_atmostone
= snewn(DOT_COUNT(state
), char);
460 memcpy(ret
->normal
->dot_atmostone
, sstate
->normal
->dot_atmostone
,
463 ret
->normal
->dot_atleastone
= snewn(DOT_COUNT(state
), char);
464 memcpy(ret
->normal
->dot_atleastone
, sstate
->normal
->dot_atleastone
,
471 ret
->hard
= snew(hard_mode_state
);
472 ret
->hard
->linedsf
= snewn(LINE_COUNT(state
), int);
473 memcpy(ret
->hard
->linedsf
, sstate
->hard
->linedsf
,
474 LINE_COUNT(state
) * sizeof(int));
482 static game_params
*default_params(void)
484 game_params
*ret
= snew(game_params
);
493 ret
->diff
= DIFF_EASY
;
499 static game_params
*dup_params(game_params
*params
)
501 game_params
*ret
= snew(game_params
);
502 *ret
= *params
; /* structure copy */
506 static const game_params presets
[] = {
507 { 4, 4, DIFF_EASY
, 0 },
508 { 4, 4, DIFF_NORMAL
, 0 },
509 { 4, 4, DIFF_HARD
, 0 },
510 { 7, 7, DIFF_EASY
, 0 },
511 { 7, 7, DIFF_NORMAL
, 0 },
512 { 7, 7, DIFF_HARD
, 0 },
513 { 10, 10, DIFF_EASY
, 0 },
514 { 10, 10, DIFF_NORMAL
, 0 },
515 { 10, 10, DIFF_HARD
, 0 },
517 { 15, 15, DIFF_EASY
, 0 },
518 { 15, 15, DIFF_NORMAL
, 0 },
519 { 15, 15, DIFF_HARD
, 0 },
521 { 30, 20, DIFF_EASY
, 0 },
522 { 30, 20, DIFF_NORMAL
, 0 },
523 { 30, 20, DIFF_HARD
, 0 }
528 static int game_fetch_preset(int i
, char **name
, game_params
**params
)
533 if (i
< 0 || i
>= lenof(presets
))
536 tmppar
= snew(game_params
);
537 *tmppar
= presets
[i
];
539 sprintf(buf
, "%dx%d %s", tmppar
->h
, tmppar
->w
, diffnames
[tmppar
->diff
]);
545 static void free_params(game_params
*params
)
550 static void decode_params(game_params
*params
, char const *string
)
552 params
->h
= params
->w
= atoi(string
);
554 params
->diff
= DIFF_EASY
;
555 while (*string
&& isdigit((unsigned char)*string
)) string
++;
556 if (*string
== 'x') {
558 params
->h
= atoi(string
);
559 while (*string
&& isdigit((unsigned char)*string
)) string
++;
561 if (*string
== 'r') {
563 params
->rec
= atoi(string
);
564 while (*string
&& isdigit((unsigned char)*string
)) string
++;
566 if (*string
== 'd') {
569 for (i
= 0; i
< DIFF_MAX
; i
++)
570 if (*string
== diffchars
[i
])
572 if (*string
) string
++;
576 static char *encode_params(game_params
*params
, int full
)
579 sprintf(str
, "%dx%d", params
->w
, params
->h
);
581 sprintf(str
+ strlen(str
), "r%dd%c", params
->rec
, diffchars
[params
->diff
]);
585 static config_item
*game_configure(game_params
*params
)
590 ret
= snewn(4, config_item
);
592 ret
[0].name
= "Width";
593 ret
[0].type
= C_STRING
;
594 sprintf(buf
, "%d", params
->w
);
595 ret
[0].sval
= dupstr(buf
);
598 ret
[1].name
= "Height";
599 ret
[1].type
= C_STRING
;
600 sprintf(buf
, "%d", params
->h
);
601 ret
[1].sval
= dupstr(buf
);
604 ret
[2].name
= "Difficulty";
605 ret
[2].type
= C_CHOICES
;
606 ret
[2].sval
= DIFFCONFIG
;
607 ret
[2].ival
= params
->diff
;
617 static game_params
*custom_params(config_item
*cfg
)
619 game_params
*ret
= snew(game_params
);
621 ret
->w
= atoi(cfg
[0].sval
);
622 ret
->h
= atoi(cfg
[1].sval
);
624 ret
->diff
= cfg
[2].ival
;
629 static char *validate_params(game_params
*params
, int full
)
631 if (params
->w
< 4 || params
->h
< 4)
632 return "Width and height must both be at least 4";
634 return "Recursion depth can't be negative";
637 * This shouldn't be able to happen at all, since decode_params
638 * and custom_params will never generate anything that isn't
641 assert(params
->diff
< DIFF_MAX
);
646 /* Returns a newly allocated string describing the current puzzle */
647 static char *state_to_text(const game_state
*state
)
650 char *description
= snewn(SQUARE_COUNT(state
) + 1, char);
651 char *dp
= description
;
655 FORALL_SQUARES(state
, i
, j
) {
656 if (CLUE_AT(state
, i
, j
) < 0) {
657 if (empty_count
> 25) {
658 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
664 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
667 dp
+= sprintf(dp
, "%c", (int)CLUE2CHAR(CLUE_AT(state
, i
, j
)));
672 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
674 retval
= dupstr(description
);
680 /* We require that the params pass the test in validate_params and that the
681 * description fills the entire game area */
682 static char *validate_desc(game_params
*params
, char *desc
)
686 for (; *desc
; ++desc
) {
687 if (*desc
>= '0' && *desc
<= '9') {
692 count
+= *desc
- 'a' + 1;
695 return "Unknown character in description";
698 if (count
< SQUARE_COUNT(params
))
699 return "Description too short for board size";
700 if (count
> SQUARE_COUNT(params
))
701 return "Description too long for board size";
706 /* Sums the lengths of the numbers in range [0,n) */
707 /* See equivalent function in solo.c for justification of this. */
708 static int len_0_to_n(int n
)
710 int len
= 1; /* Counting 0 as a bit of a special case */
713 for (i
= 1; i
< n
; i
*= 10) {
714 len
+= max(n
- i
, 0);
720 static char *encode_solve_move(const game_state
*state
)
724 /* This is going to return a string representing the moves needed to set
725 * every line in a grid to be the same as the ones in 'state'. The exact
726 * length of this string is predictable. */
728 len
= 1; /* Count the 'S' prefix */
729 /* Numbers in horizontal lines */
730 /* Horizontal lines, x position */
731 len
+= len_0_to_n(state
->w
) * (state
->h
+ 1);
732 /* Horizontal lines, y position */
733 len
+= len_0_to_n(state
->h
+ 1) * (state
->w
);
734 /* Vertical lines, y position */
735 len
+= len_0_to_n(state
->h
) * (state
->w
+ 1);
736 /* Vertical lines, x position */
737 len
+= len_0_to_n(state
->w
+ 1) * (state
->h
);
738 /* For each line we also have two letters and a comma */
739 len
+= 3 * (LINE_COUNT(state
));
741 ret
= snewn(len
+ 1, char);
744 p
+= sprintf(p
, "S");
746 FORALL_HL(state
, i
, j
) {
747 switch (RIGHTOF_DOT(state
, i
, j
)) {
749 p
+= sprintf(p
, "%d,%dhy", i
, j
);
752 p
+= sprintf(p
, "%d,%dhn", i
, j
);
757 FORALL_VL(state
, i
, j
) {
758 switch (BELOW_DOT(state
, i
, j
)) {
760 p
+= sprintf(p
, "%d,%dvy", i
, j
);
763 p
+= sprintf(p
, "%d,%dvn", i
, j
);
768 /* No point in doing sums like that if they're going to be wrong */
769 assert(strlen(ret
) <= (size_t)len
);
773 static game_ui
*new_ui(game_state
*state
)
778 static void free_ui(game_ui
*ui
)
782 static char *encode_ui(game_ui
*ui
)
787 static void decode_ui(game_ui
*ui
, char *encoding
)
791 static void game_changed_state(game_ui
*ui
, game_state
*oldstate
,
792 game_state
*newstate
)
796 #define SIZE(d) ((d) * TILE_SIZE + 2 * BORDER + 1)
798 static void game_compute_size(game_params
*params
, int tilesize
,
801 struct { int tilesize
; } ads
, *ds
= &ads
;
802 ads
.tilesize
= tilesize
;
804 *x
= SIZE(params
->w
);
805 *y
= SIZE(params
->h
);
808 static void game_set_size(drawing
*dr
, game_drawstate
*ds
,
809 game_params
*params
, int tilesize
)
811 ds
->tilesize
= tilesize
;
812 ds
->linewidth
= max(1,tilesize
/16);
815 static float *game_colours(frontend
*fe
, int *ncolours
)
817 float *ret
= snewn(4 * NCOLOURS
, float);
819 frontend_default_colour(fe
, &ret
[COL_BACKGROUND
* 3]);
821 ret
[COL_FOREGROUND
* 3 + 0] = 0.0F
;
822 ret
[COL_FOREGROUND
* 3 + 1] = 0.0F
;
823 ret
[COL_FOREGROUND
* 3 + 2] = 0.0F
;
825 ret
[COL_HIGHLIGHT
* 3 + 0] = 1.0F
;
826 ret
[COL_HIGHLIGHT
* 3 + 1] = 1.0F
;
827 ret
[COL_HIGHLIGHT
* 3 + 2] = 1.0F
;
829 ret
[COL_MISTAKE
* 3 + 0] = 1.0F
;
830 ret
[COL_MISTAKE
* 3 + 1] = 0.0F
;
831 ret
[COL_MISTAKE
* 3 + 2] = 0.0F
;
833 *ncolours
= NCOLOURS
;
837 static game_drawstate
*game_new_drawstate(drawing
*dr
, game_state
*state
)
839 struct game_drawstate
*ds
= snew(struct game_drawstate
);
841 ds
->tilesize
= ds
->linewidth
= 0;
843 ds
->hl
= snewn(HL_COUNT(state
), char);
844 ds
->vl
= snewn(VL_COUNT(state
), char);
845 ds
->clue_error
= snewn(SQUARE_COUNT(state
), char);
848 memset(ds
->hl
, LINE_UNKNOWN
, HL_COUNT(state
));
849 memset(ds
->vl
, LINE_UNKNOWN
, VL_COUNT(state
));
850 memset(ds
->clue_error
, 0, SQUARE_COUNT(state
));
855 static void game_free_drawstate(drawing
*dr
, game_drawstate
*ds
)
857 sfree(ds
->clue_error
);
863 static int game_timing_state(game_state
*state
, game_ui
*ui
)
868 static float game_anim_length(game_state
*oldstate
, game_state
*newstate
,
869 int dir
, game_ui
*ui
)
874 static char *game_text_format(game_state
*state
)
880 len
= (2 * state
->w
+ 2) * (2 * state
->h
+ 1);
881 rp
= ret
= snewn(len
+ 1, char);
884 switch (ABOVE_SQUARE(state, i, j)) { \
886 rp += sprintf(rp, " -"); \
889 rp += sprintf(rp, " x"); \
892 rp += sprintf(rp, " "); \
895 assert(!"Illegal line state for HL"); \
899 switch (LEFTOF_SQUARE(state, i, j)) { \
901 rp += sprintf(rp, "|"); \
904 rp += sprintf(rp, "x"); \
907 rp += sprintf(rp, " "); \
910 assert(!"Illegal line state for VL"); \
913 for (j
= 0; j
< state
->h
; ++j
) {
914 for (i
= 0; i
< state
->w
; ++i
) {
917 rp
+= sprintf(rp
, " \n");
918 for (i
= 0; i
< state
->w
; ++i
) {
920 rp
+= sprintf(rp
, "%c", (int)CLUE2CHAR(CLUE_AT(state
, i
, j
)));
923 rp
+= sprintf(rp
, "\n");
925 for (i
= 0; i
< state
->w
; ++i
) {
928 rp
+= sprintf(rp
, " \n");
930 assert(strlen(ret
) == len
);
934 /* ----------------------------------------------------------------------
939 static void check_caches(const solver_state
* sstate
)
942 const game_state
*state
= sstate
->state
;
944 FORALL_DOTS(state
, i
, j
) {
946 fprintf(stderr
, "dot [%d,%d] y: %d %d n: %d %d\n", i
, j
,
947 dot_order(state
, i
, j
, LINE_YES
),
948 sstate
->dot_yescount
[i
+ (state
->w
+ 1) * j
],
949 dot_order(state
, i
, j
, LINE_NO
),
950 sstate
->dot_nocount
[i
+ (state
->w
+ 1) * j
]);
953 assert(dot_order(state
, i
, j
, LINE_YES
) ==
954 DOT_YES_COUNT(sstate
, i
, j
));
955 assert(dot_order(state
, i
, j
, LINE_NO
) ==
956 DOT_NO_COUNT(sstate
, i
, j
));
959 FORALL_SQUARES(state
, i
, j
) {
961 fprintf(stderr
, "square [%d,%d] y: %d %d n: %d %d\n", i
, j
,
962 square_order(state
, i
, j
, LINE_YES
),
963 sstate
->square_yescount
[i
+ state
->w
* j
],
964 square_order(state
, i
, j
, LINE_NO
),
965 sstate
->square_nocount
[i
+ state
->w
* j
]);
968 assert(square_order(state
, i
, j
, LINE_YES
) ==
969 SQUARE_YES_COUNT(sstate
, i
, j
));
970 assert(square_order(state
, i
, j
, LINE_NO
) ==
971 SQUARE_NO_COUNT(sstate
, i
, j
));
976 #define check_caches(s) \
978 fprintf(stderr, "check_caches at line %d\n", __LINE__); \
982 #endif /* DEBUG_CACHES */
984 /* ----------------------------------------------------------------------
985 * Solver utility functions
988 static int set_line_bydot(solver_state
*sstate
, int x
, int y
, enum direction d
,
989 enum line_state line_new
995 game_state
*state
= sstate
->state
;
997 /* This line borders at most two squares in our board. We figure out the
998 * x and y positions of those squares so we can record that their yes or no
999 * counts have been changed */
1000 int sq1_x
=-1, sq1_y
=-1, sq2_x
=-1, sq2_y
=-1;
1001 int otherdot_x
=-1, otherdot_y
=-1;
1003 int progress
= FALSE
;
1006 fprintf(stderr
, "set_line_bydot [%d,%d], %s, %d\n",
1007 x
, y
, DIR2STR(d
), line_new
);
1010 assert(line_new
!= LINE_UNKNOWN
);
1012 check_caches(sstate
);
1018 if (LEFTOF_DOT(state
, x
, y
) != line_new
) {
1019 LV_LEFTOF_DOT(state
, x
, y
) = line_new
;
1033 assert(x
< state
->w
);
1034 if (RIGHTOF_DOT(state
, x
, y
) != line_new
) {
1035 LV_RIGHTOF_DOT(state
, x
, y
) = line_new
;
1050 if (ABOVE_DOT(state
, x
, y
) != line_new
) {
1051 LV_ABOVE_DOT(state
, x
, y
) = line_new
;
1065 assert(y
< state
->h
);
1066 if (BELOW_DOT(state
, x
, y
) != line_new
) {
1067 LV_BELOW_DOT(state
, x
, y
) = line_new
;
1086 fprintf(stderr
, "set line [%d,%d] -> [%d,%d] to %s (%s)\n",
1087 x
, y
, otherdot_x
, otherdot_y
, line_new
== LINE_YES ?
"YES" : "NO",
1091 /* Above we updated the cache for the dot that the line in question reaches
1092 * from the dot we've been told about. Here we update that for the dot
1093 * named in our arguments. */
1094 if (line_new
== LINE_YES
) {
1095 if (sq1_x
>= 0 && sq1_y
>= 0)
1096 ++SQUARE_YES_COUNT(sstate
, sq1_x
, sq1_y
);
1097 if (sq2_x
< state
->w
&& sq2_y
< state
->h
)
1098 ++SQUARE_YES_COUNT(sstate
, sq2_x
, sq2_y
);
1099 ++DOT_YES_COUNT(sstate
, x
, y
);
1100 ++DOT_YES_COUNT(sstate
, otherdot_x
, otherdot_y
);
1102 if (sq1_x
>= 0 && sq1_y
>= 0)
1103 ++SQUARE_NO_COUNT(sstate
, sq1_x
, sq1_y
);
1104 if (sq2_x
< state
->w
&& sq2_y
< state
->h
)
1105 ++SQUARE_NO_COUNT(sstate
, sq2_x
, sq2_y
);
1106 ++DOT_NO_COUNT(sstate
, x
, y
);
1107 ++DOT_NO_COUNT(sstate
, otherdot_x
, otherdot_y
);
1110 check_caches(sstate
);
1115 #define set_line_bydot(a, b, c, d, e) \
1116 set_line_bydot(a, b, c, d, e, __FUNCTION__)
1120 * Merge two dots due to the existence of an edge between them.
1121 * Updates the dsf tracking equivalence classes, and keeps track of
1122 * the length of path each dot is currently a part of.
1123 * Returns TRUE if the dots were already linked, ie if they are part of a
1124 * closed loop, and false otherwise.
1126 static int merge_dots(solver_state
*sstate
, int x1
, int y1
, int x2
, int y2
)
1130 i
= y1
* (sstate
->state
->w
+ 1) + x1
;
1131 j
= y2
* (sstate
->state
->w
+ 1) + x2
;
1133 i
= dsf_canonify(sstate
->dotdsf
, i
);
1134 j
= dsf_canonify(sstate
->dotdsf
, j
);
1139 len
= sstate
->looplen
[i
] + sstate
->looplen
[j
];
1140 dsf_merge(sstate
->dotdsf
, i
, j
);
1141 i
= dsf_canonify(sstate
->dotdsf
, i
);
1142 sstate
->looplen
[i
] = len
;
1147 /* Seriously, these should be functions */
1149 #define LINEDSF_INDEX(state, x, y, d) \
1150 ((d == UP) ? ((y-1) * (state->w + 1) + x) : \
1151 (d == DOWN) ? ((y) * (state->w + 1) + x) : \
1152 (d == LEFT) ? ((y) * (state->w) + x-1 + VL_COUNT(state)) : \
1153 (d == RIGHT) ? ((y) * (state->w) + x + VL_COUNT(state)) : \
1154 (assert(!"bad direction value"), 0))
1156 static void linedsf_deindex(const game_state
*state
, int i
,
1157 int *px
, int *py
, enum direction
*pd
)
1160 if (i
< VL_COUNT(state
)) {
1162 *(px
) = (i
) % (state
->w
+1);
1163 *(py
) = (i
) / (state
->w
+1);
1165 i_mod
= i
- VL_COUNT(state
);
1167 *(px
) = (i_mod
) % (state
->w
);
1168 *(py
) = (i_mod
) / (state
->w
);
1172 /* Merge two lines because the solver has deduced that they must be either
1173 * identical or opposite. Returns TRUE if this is new information, otherwise
1175 static int merge_lines(solver_state
*sstate
,
1176 int x1
, int y1
, enum direction d1
,
1177 int x2
, int y2
, enum direction d2
,
1180 , const char *reason
1186 i
= LINEDSF_INDEX(sstate
->state
, x1
, y1
, d1
);
1187 j
= LINEDSF_INDEX(sstate
->state
, x2
, y2
, d2
);
1189 assert(i
< LINE_COUNT(sstate
->state
));
1190 assert(j
< LINE_COUNT(sstate
->state
));
1192 i
= edsf_canonify(sstate
->hard
->linedsf
, i
, &inv_tmp
);
1194 j
= edsf_canonify(sstate
->hard
->linedsf
, j
, &inv_tmp
);
1197 edsf_merge(sstate
->hard
->linedsf
, i
, j
, inverse
);
1201 fprintf(stderr
, "%s [%d,%d,%s] [%d,%d,%s] %s(%s)\n",
1203 x1
, y1
, DIR2STR(d1
),
1204 x2
, y2
, DIR2STR(d2
),
1205 inverse ?
"inverse " : "", reason
);
1212 #define merge_lines(a, b, c, d, e, f, g, h) \
1213 merge_lines(a, b, c, d, e, f, g, h, __FUNCTION__)
1216 /* Return 0 if the given lines are not in the same equivalence class, 1 if they
1217 * are known identical, or 2 if they are known opposite */
1219 static int lines_related(solver_state
*sstate
,
1220 int x1
, int y1
, enum direction d1
,
1221 int x2
, int y2
, enum direction d2
)
1223 int i
, j
, inv1
, inv2
;
1225 i
= LINEDSF_INDEX(sstate
->state
, x1
, y1
, d1
);
1226 j
= LINEDSF_INDEX(sstate
->state
, x2
, y2
, d2
);
1228 i
= edsf_canonify(sstate
->hard
->linedsf
, i
, &inv1
);
1229 j
= edsf_canonify(sstate
->hard
->linedsf
, j
, &inv2
);
1232 return (inv1
== inv2
) ?
1 : 2;
1238 /* Count the number of lines of a particular type currently going into the
1239 * given dot. Lines going off the edge of the board are assumed fixed no. */
1240 static int dot_order(const game_state
* state
, int i
, int j
, char line_type
)
1245 if (line_type
== LV_LEFTOF_DOT(state
, i
, j
))
1248 if (line_type
== LINE_NO
)
1252 if (line_type
== LV_RIGHTOF_DOT(state
, i
, j
))
1255 if (line_type
== LINE_NO
)
1259 if (line_type
== LV_ABOVE_DOT(state
, i
, j
))
1262 if (line_type
== LINE_NO
)
1266 if (line_type
== LV_BELOW_DOT(state
, i
, j
))
1269 if (line_type
== LINE_NO
)
1276 /* Count the number of lines of a particular type currently surrounding the
1278 static int square_order(const game_state
* state
, int i
, int j
, char line_type
)
1282 if (ABOVE_SQUARE(state
, i
, j
) == line_type
)
1284 if (BELOW_SQUARE(state
, i
, j
) == line_type
)
1286 if (LEFTOF_SQUARE(state
, i
, j
) == line_type
)
1288 if (RIGHTOF_SQUARE(state
, i
, j
) == line_type
)
1294 /* Set all lines bordering a dot of type old_type to type new_type
1295 * Return value tells caller whether this function actually did anything */
1296 static int dot_setall(solver_state
*sstate
, int i
, int j
,
1297 char old_type
, char new_type
)
1299 int retval
= FALSE
, r
;
1300 game_state
*state
= sstate
->state
;
1302 if (old_type
== new_type
)
1305 if (i
> 0 && LEFTOF_DOT(state
, i
, j
) == old_type
) {
1306 r
= set_line_bydot(sstate
, i
, j
, LEFT
, new_type
);
1311 if (i
< state
->w
&& RIGHTOF_DOT(state
, i
, j
) == old_type
) {
1312 r
= set_line_bydot(sstate
, i
, j
, RIGHT
, new_type
);
1317 if (j
> 0 && ABOVE_DOT(state
, i
, j
) == old_type
) {
1318 r
= set_line_bydot(sstate
, i
, j
, UP
, new_type
);
1323 if (j
< state
->h
&& BELOW_DOT(state
, i
, j
) == old_type
) {
1324 r
= set_line_bydot(sstate
, i
, j
, DOWN
, new_type
);
1332 /* Set all lines bordering a square of type old_type to type new_type */
1333 static int square_setall(solver_state
*sstate
, int i
, int j
,
1334 char old_type
, char new_type
)
1337 game_state
*state
= sstate
->state
;
1340 fprintf(stderr
, "square_setall [%d,%d] from %d to %d\n", i
, j
,
1341 old_type
, new_type
);
1343 if (ABOVE_SQUARE(state
, i
, j
) == old_type
) {
1344 r
= set_line_bydot(sstate
, i
, j
, RIGHT
, new_type
);
1347 if (BELOW_SQUARE(state
, i
, j
) == old_type
) {
1348 r
= set_line_bydot(sstate
, i
, j
+1, RIGHT
, new_type
);
1351 if (LEFTOF_SQUARE(state
, i
, j
) == old_type
) {
1352 r
= set_line_bydot(sstate
, i
, j
, DOWN
, new_type
);
1355 if (RIGHTOF_SQUARE(state
, i
, j
) == old_type
) {
1356 r
= set_line_bydot(sstate
, i
+1, j
, DOWN
, new_type
);
1363 /* ----------------------------------------------------------------------
1364 * Loop generation and clue removal
1367 /* We're going to store a list of current candidate squares for lighting.
1368 * Each square gets a 'score', which tells us how adding that square right
1369 * now would affect the length of the solution loop. We're trying to
1370 * maximise that quantity so will bias our random selection of squares to
1371 * light towards those with high scores */
1374 unsigned long random
;
1378 static int get_square_cmpfn(void *v1
, void *v2
)
1380 struct square
*s1
= v1
;
1381 struct square
*s2
= v2
;
1395 static int square_sort_cmpfn(void *v1
, void *v2
)
1397 struct square
*s1
= v1
;
1398 struct square
*s2
= v2
;
1401 r
= s2
->score
- s1
->score
;
1406 if (s1
->random
< s2
->random
)
1408 else if (s1
->random
> s2
->random
)
1412 * It's _just_ possible that two squares might have been given
1413 * the same random value. In that situation, fall back to
1414 * comparing based on the coordinates. This introduces a tiny
1415 * directional bias, but not a significant one.
1417 return get_square_cmpfn(v1
, v2
);
1420 enum { SQUARE_LIT
, SQUARE_UNLIT
};
1422 #define SQUARE_STATE(i, j) \
1423 ( LEGAL_SQUARE(state, i, j) ? \
1424 LV_SQUARE_STATE(i,j) : \
1427 #define LV_SQUARE_STATE(i, j) board[SQUARE_INDEX(state, i, j)]
1429 /* Generate a new complete set of clues for the given game_state (respecting
1430 * the dimensions provided by said game_state) */
1431 static void add_full_clues(game_state
*state
, random_state
*rs
)
1436 int board_area
= SQUARE_COUNT(state
);
1439 struct square
*square
, *tmpsquare
, *sq
;
1440 struct square square_pos
;
1442 /* These will contain exactly the same information, sorted into different
1444 tree234
*lightable_squares_sorted
, *lightable_squares_gettable
;
1446 #define SQUARE_REACHABLE(i,j) \
1447 (t = (SQUARE_STATE(i-1, j) == SQUARE_LIT || \
1448 SQUARE_STATE(i+1, j) == SQUARE_LIT || \
1449 SQUARE_STATE(i, j-1) == SQUARE_LIT || \
1450 SQUARE_STATE(i, j+1) == SQUARE_LIT), \
1453 /* One situation in which we may not light a square is if that'll leave one
1454 * square above/below and one left/right of us unlit, separated by a lit
1455 * square diagnonal from us */
1456 #define SQUARE_DIAGONAL_VIOLATION(i, j, h, v) \
1457 (t = (SQUARE_STATE((i)+(h), (j)) == SQUARE_UNLIT && \
1458 SQUARE_STATE((i), (j)+(v)) == SQUARE_UNLIT && \
1459 SQUARE_STATE((i)+(h), (j)+(v)) == SQUARE_LIT), \
1462 /* We also may not light a square if it will form a loop of lit squares
1463 * around some unlit squares, as then the game soln won't have a single
1465 #define SQUARE_LOOP_VIOLATION(i, j, lit1, lit2) \
1466 (SQUARE_STATE((i)+1, (j)) == lit1 && \
1467 SQUARE_STATE((i)-1, (j)) == lit1 && \
1468 SQUARE_STATE((i), (j)+1) == lit2 && \
1469 SQUARE_STATE((i), (j)-1) == lit2)
1471 #define CAN_LIGHT_SQUARE(i, j) \
1472 (SQUARE_REACHABLE(i, j) && \
1473 !SQUARE_DIAGONAL_VIOLATION(i, j, -1, -1) && \
1474 !SQUARE_DIAGONAL_VIOLATION(i, j, +1, -1) && \
1475 !SQUARE_DIAGONAL_VIOLATION(i, j, -1, +1) && \
1476 !SQUARE_DIAGONAL_VIOLATION(i, j, +1, +1) && \
1477 !SQUARE_LOOP_VIOLATION(i, j, SQUARE_LIT, SQUARE_UNLIT) && \
1478 !SQUARE_LOOP_VIOLATION(i, j, SQUARE_UNLIT, SQUARE_LIT))
1480 #define IS_LIGHTING_CANDIDATE(i, j) \
1481 (SQUARE_STATE(i, j) == SQUARE_UNLIT && \
1482 CAN_LIGHT_SQUARE(i,j))
1484 /* The 'score' of a square reflects its current desirability for selection
1485 * as the next square to light. We want to encourage moving into uncharted
1486 * areas so we give scores according to how many of the square's neighbours
1487 * are currently unlit. */
1494 #define SQUARE_SCORE(i,j) \
1495 (2*((SQUARE_STATE(i-1, j) == SQUARE_UNLIT) + \
1496 (SQUARE_STATE(i+1, j) == SQUARE_UNLIT) + \
1497 (SQUARE_STATE(i, j-1) == SQUARE_UNLIT) + \
1498 (SQUARE_STATE(i, j+1) == SQUARE_UNLIT)) - 4)
1500 /* When a square gets lit, this defines how far away from that square we
1501 * need to go recomputing scores */
1502 #define SCORE_DISTANCE 1
1504 board
= snewn(board_area
, char);
1505 clues
= state
->clues
;
1508 memset(board
, SQUARE_UNLIT
, board_area
);
1510 /* Seed the board with a single lit square near the middle */
1513 if (state
->w
& 1 && random_bits(rs
, 1))
1515 if (state
->h
& 1 && random_bits(rs
, 1))
1518 LV_SQUARE_STATE(i
, j
) = SQUARE_LIT
;
1520 /* We need a way of favouring squares that will increase our loopiness.
1521 * We do this by maintaining a list of all candidate squares sorted by
1522 * their score and choose randomly from that with appropriate skew.
1523 * In order to avoid consistently biasing towards particular squares, we
1524 * need the sort order _within_ each group of scores to be completely
1525 * random. But it would be abusing the hospitality of the tree234 data
1526 * structure if our comparison function were nondeterministic :-). So with
1527 * each square we associate a random number that does not change during a
1528 * particular run of the generator, and use that as a secondary sort key.
1529 * Yes, this means we will be biased towards particular random squares in
1530 * any one run but that doesn't actually matter. */
1532 lightable_squares_sorted
= newtree234(square_sort_cmpfn
);
1533 lightable_squares_gettable
= newtree234(get_square_cmpfn
);
1534 #define ADD_SQUARE(s) \
1536 sq = add234(lightable_squares_sorted, s); \
1538 sq = add234(lightable_squares_gettable, s); \
1542 #define REMOVE_SQUARE(s) \
1544 sq = del234(lightable_squares_sorted, s); \
1546 sq = del234(lightable_squares_gettable, s); \
1550 #define HANDLE_DIR(a, b) \
1551 square = snew(struct square); \
1552 square->x = (i)+(a); \
1553 square->y = (j)+(b); \
1554 square->score = 2; \
1555 square->random = random_bits(rs, 31); \
1563 /* Light squares one at a time until the board is interesting enough */
1566 /* We have count234(lightable_squares) possibilities, and in
1567 * lightable_squares_sorted they are sorted with the most desirable
1569 c
= count234(lightable_squares_sorted
);
1572 assert(c
== count234(lightable_squares_gettable
));
1574 /* Check that the best square available is any good */
1575 square
= (struct square
*)index234(lightable_squares_sorted
, 0);
1579 * We never want to _decrease_ the loop's perimeter. Making
1580 * moves that leave the perimeter the same is occasionally
1581 * useful: if it were _never_ done then the user would be
1582 * able to deduce illicitly that any degree-zero vertex was
1583 * on the outside of the loop. So we do it sometimes but
1586 if (square
->score
< 0 || (square
->score
== 0 &&
1587 random_upto(rs
, 2) == 0)) {
1591 assert(square
->score
== SQUARE_SCORE(square
->x
, square
->y
));
1592 assert(SQUARE_STATE(square
->x
, square
->y
) == SQUARE_UNLIT
);
1593 assert(square
->x
>= 0 && square
->x
< state
->w
);
1594 assert(square
->y
>= 0 && square
->y
< state
->h
);
1596 /* Update data structures */
1597 LV_SQUARE_STATE(square
->x
, square
->y
) = SQUARE_LIT
;
1598 REMOVE_SQUARE(square
);
1600 /* We might have changed the score of any squares up to 2 units away in
1602 for (b
= -SCORE_DISTANCE
; b
<= SCORE_DISTANCE
; b
++) {
1603 for (a
= -SCORE_DISTANCE
; a
<= SCORE_DISTANCE
; a
++) {
1606 square_pos
.x
= square
->x
+ a
;
1607 square_pos
.y
= square
->y
+ b
;
1608 if (square_pos
.x
< 0 || square_pos
.x
>= state
->w
||
1609 square_pos
.y
< 0 || square_pos
.y
>= state
->h
) {
1612 tmpsquare
= find234(lightable_squares_gettable
, &square_pos
,
1615 assert(tmpsquare
->x
== square_pos
.x
);
1616 assert(tmpsquare
->y
== square_pos
.y
);
1617 assert(SQUARE_STATE(tmpsquare
->x
, tmpsquare
->y
) ==
1619 REMOVE_SQUARE(tmpsquare
);
1621 tmpsquare
= snew(struct square
);
1622 tmpsquare
->x
= square_pos
.x
;
1623 tmpsquare
->y
= square_pos
.y
;
1624 tmpsquare
->random
= random_bits(rs
, 31);
1626 tmpsquare
->score
= SQUARE_SCORE(tmpsquare
->x
, tmpsquare
->y
);
1628 if (IS_LIGHTING_CANDIDATE(tmpsquare
->x
, tmpsquare
->y
)) {
1629 ADD_SQUARE(tmpsquare
);
1639 while ((square
= delpos234(lightable_squares_gettable
, 0)) != NULL
)
1641 freetree234(lightable_squares_gettable
);
1642 freetree234(lightable_squares_sorted
);
1644 /* Copy out all the clues */
1645 FORALL_SQUARES(state
, i
, j
) {
1646 c
= SQUARE_STATE(i
, j
);
1647 LV_CLUE_AT(state
, i
, j
) = 0;
1648 if (SQUARE_STATE(i
-1, j
) != c
) ++LV_CLUE_AT(state
, i
, j
);
1649 if (SQUARE_STATE(i
+1, j
) != c
) ++LV_CLUE_AT(state
, i
, j
);
1650 if (SQUARE_STATE(i
, j
-1) != c
) ++LV_CLUE_AT(state
, i
, j
);
1651 if (SQUARE_STATE(i
, j
+1) != c
) ++LV_CLUE_AT(state
, i
, j
);
1657 static int game_has_unique_soln(const game_state
*state
, int diff
)
1660 solver_state
*sstate_new
;
1661 solver_state
*sstate
= new_solver_state((game_state
*)state
, diff
);
1663 sstate_new
= solve_game_rec(sstate
, diff
);
1665 assert(sstate_new
->solver_status
!= SOLVER_MISTAKE
);
1666 ret
= (sstate_new
->solver_status
== SOLVER_SOLVED
);
1668 free_solver_state(sstate_new
);
1669 free_solver_state(sstate
);
1674 /* Remove clues one at a time at random. */
1675 static game_state
*remove_clues(game_state
*state
, random_state
*rs
,
1678 int *square_list
, squares
;
1679 game_state
*ret
= dup_game(state
), *saved_ret
;
1685 /* We need to remove some clues. We'll do this by forming a list of all
1686 * available clues, shuffling it, then going along one at a
1687 * time clearing each clue in turn for which doing so doesn't render the
1688 * board unsolvable. */
1689 squares
= state
->w
* state
->h
;
1690 square_list
= snewn(squares
, int);
1691 for (n
= 0; n
< squares
; ++n
) {
1695 shuffle(square_list
, squares
, sizeof(int), rs
);
1697 for (n
= 0; n
< squares
; ++n
) {
1698 saved_ret
= dup_game(ret
);
1699 LV_CLUE_AT(ret
, square_list
[n
] % state
->w
,
1700 square_list
[n
] / state
->w
) = -1;
1703 desc
= state_to_text(ret
);
1704 fprintf(stderr
, "%dx%d:%s\n", state
->w
, state
->h
, desc
);
1708 if (game_has_unique_soln(ret
, diff
)) {
1709 free_game(saved_ret
);
1720 static char *new_game_desc(game_params
*params
, random_state
*rs
,
1721 char **aux
, int interactive
)
1723 /* solution and description both use run-length encoding in obvious ways */
1725 game_state
*state
= snew(game_state
), *state_new
;
1727 state
->h
= params
->h
;
1728 state
->w
= params
->w
;
1730 state
->clues
= snewn(SQUARE_COUNT(params
), signed char);
1731 state
->hl
= snewn(HL_COUNT(params
), char);
1732 state
->vl
= snewn(VL_COUNT(params
), char);
1735 memset(state
->hl
, LINE_UNKNOWN
, HL_COUNT(params
));
1736 memset(state
->vl
, LINE_UNKNOWN
, VL_COUNT(params
));
1738 state
->solved
= state
->cheated
= FALSE
;
1739 state
->recursion_depth
= params
->rec
;
1741 /* Get a new random solvable board with all its clues filled in. Yes, this
1742 * can loop for ever if the params are suitably unfavourable, but
1743 * preventing games smaller than 4x4 seems to stop this happening */
1746 add_full_clues(state
, rs
);
1747 } while (!game_has_unique_soln(state
, params
->diff
));
1749 state_new
= remove_clues(state
, rs
, params
->diff
);
1753 if (params
->diff
> 0 && game_has_unique_soln(state
, params
->diff
-1)) {
1755 fprintf(stderr
, "Rejecting board, it is too easy\n");
1757 goto newboard_please
;
1760 retval
= state_to_text(state
);
1764 assert(!validate_desc(params
, retval
));
1769 static game_state
*new_game(midend
*me
, game_params
*params
, char *desc
)
1772 game_state
*state
= snew(game_state
);
1773 int empties_to_make
= 0;
1775 const char *dp
= desc
;
1777 state
->recursion_depth
= 0; /* XXX pending removal, probably */
1779 state
->h
= params
->h
;
1780 state
->w
= params
->w
;
1782 state
->clues
= snewn(SQUARE_COUNT(params
), signed char);
1783 state
->hl
= snewn(HL_COUNT(params
), char);
1784 state
->vl
= snewn(VL_COUNT(params
), char);
1786 state
->solved
= state
->cheated
= FALSE
;
1788 FORALL_SQUARES(params
, i
, j
) {
1789 if (empties_to_make
) {
1791 LV_CLUE_AT(state
, i
, j
) = -1;
1797 if (n
>= 0 && n
< 10) {
1798 LV_CLUE_AT(state
, i
, j
) = n
;
1802 LV_CLUE_AT(state
, i
, j
) = -1;
1803 empties_to_make
= n
- 1;
1808 memset(state
->hl
, LINE_UNKNOWN
, HL_COUNT(params
));
1809 memset(state
->vl
, LINE_UNKNOWN
, VL_COUNT(params
));
1814 enum { LOOP_NONE
=0, LOOP_SOLN
, LOOP_NOT_SOLN
};
1816 /* ----------------------------------------------------------------------
1819 * Our solver modes operate as follows. Each mode also uses the modes above it.
1822 * Just implement the rules of the game.
1825 * For each pair of lines through each dot we store a bit for whether
1826 * at least one of them is on and whether at most one is on. (If we know
1827 * both or neither is on that's already stored more directly.) That's six
1828 * bits per dot. Bit number n represents the lines shown in dline_desc.
1831 * Use edsf data structure to make equivalence classes of lines that are
1832 * known identical to or opposite to one another.
1835 /* The order the following are defined in is very important, see below.
1836 * The last two fields may seem non-obvious: they specify that when talking
1837 * about a square the dx and dy offsets should be added to the square coords to
1838 * get to the right dot. Where dx and dy are -1 this means that the dline
1839 * doesn't make sense for a square. */
1840 /* XXX can this be done with a struct instead? */
1842 DLINE(DLINE_UD, UP, DOWN, -1, -1) \
1843 DLINE(DLINE_LR, LEFT, RIGHT, -1, -1) \
1844 DLINE(DLINE_UR, UP, RIGHT, 0, 1) \
1845 DLINE(DLINE_DL, DOWN, LEFT, 1, 0) \
1846 DLINE(DLINE_UL, UP, LEFT, 1, 1) \
1847 DLINE(DLINE_DR, DOWN, RIGHT, 0, 0)
1849 #define OPP_DLINE(dline_desc) ((dline_desc) ^ 1)
1852 #define DLINE(desc, dir1, dir2, dx, dy) \
1859 enum dline_desc desc
;
1860 enum direction dir1
, dir2
;
1864 const static struct dline dlines
[] = {
1865 #define DLINE(desc, dir1, dir2, dx, dy) \
1866 { desc, dir1, dir2, dx, dy },
1871 #define FORALL_DOT_DLINES(dl_iter) \
1872 for (dl_iter = 0; dl_iter < lenof(dlines); ++dl_iter)
1874 #define FORALL_SQUARE_DLINES(dl_iter) \
1875 for (dl_iter = 2; dl_iter < lenof(dlines); ++dl_iter)
1878 ((d==DLINE_UD) ? "DLINE_UD": \
1879 (d==DLINE_LR) ? "DLINE_LR": \
1880 (d==DLINE_UR) ? "DLINE_UR": \
1881 (d==DLINE_DL) ? "DLINE_DL": \
1882 (d==DLINE_UL) ? "DLINE_UL": \
1883 (d==DLINE_DR) ? "DLINE_DR": \
1886 #define CHECK_DLINE_SENSIBLE(d) assert(dlines[(d)].dx != -1 && dlines[(d)].dy != -1)
1888 /* This will fail an assertion if the directions handed to it are the same, as
1889 * no dline corresponds to that */
1890 static enum dline_desc
dline_desc_from_dirs(enum direction dir1
,
1891 enum direction dir2
)
1895 assert (dir1
!= dir2
);
1897 for (i
= 0; i
< lenof(dlines
); ++i
) {
1898 if ((dir1
== dlines
[i
].dir1
&& dir2
== dlines
[i
].dir2
) ||
1899 (dir1
== dlines
[i
].dir2
&& dir2
== dlines
[i
].dir1
)) {
1900 return dlines
[i
].desc
;
1904 assert(!"dline not found");
1905 return DLINE_UD
; /* placate compiler */
1908 /* The following functions allow you to get or set info about the selected
1909 * dline corresponding to the dot or square at [i,j]. You'll get an assertion
1910 * failure if you talk about a dline that doesn't exist, ie if you ask about
1911 * non-touching lines around a square. */
1912 static int get_dot_dline(const game_state
*state
, const char *dline_array
,
1913 int i
, int j
, enum dline_desc desc
)
1915 /* fprintf(stderr, "get_dot_dline %p [%d,%d] %s\n", dline_array, i, j, DL2STR(desc)); */
1916 return BIT_SET(dline_array
[i
+ (state
->w
+ 1) * j
], desc
);
1919 static int set_dot_dline(game_state
*state
, char *dline_array
,
1920 int i
, int j
, enum dline_desc desc
1922 , const char *reason
1927 ret
= SET_BIT(dline_array
[i
+ (state
->w
+ 1) * j
], desc
);
1931 fprintf(stderr
, "set_dot_dline %p [%d,%d] %s (%s)\n", dline_array
, i
, j
, DL2STR(desc
), reason
);
1936 static int get_square_dline(game_state
*state
, char *dline_array
,
1937 int i
, int j
, enum dline_desc desc
)
1939 CHECK_DLINE_SENSIBLE(desc
);
1940 /* fprintf(stderr, "get_square_dline %p [%d,%d] %s\n", dline_array, i, j, DL2STR(desc)); */
1941 return BIT_SET(dline_array
[(i
+dlines
[desc
].dx
) + (state
->w
+ 1) * (j
+dlines
[desc
].dy
)],
1945 static int set_square_dline(game_state
*state
, char *dline_array
,
1946 int i
, int j
, enum dline_desc desc
1948 , const char *reason
1953 CHECK_DLINE_SENSIBLE(desc
);
1954 ret
= SET_BIT(dline_array
[(i
+dlines
[desc
].dx
) + (state
->w
+ 1) * (j
+dlines
[desc
].dy
)], desc
);
1957 fprintf(stderr
, "set_square_dline %p [%d,%d] %s (%s)\n", dline_array
, i
, j
, DL2STR(desc
), reason
);
1963 #define set_dot_dline(a, b, c, d, e) \
1964 set_dot_dline(a, b, c, d, e, __FUNCTION__)
1965 #define set_square_dline(a, b, c, d, e) \
1966 set_square_dline(a, b, c, d, e, __FUNCTION__)
1969 static int set_dot_opp_dline(game_state
*state
, char *dline_array
,
1970 int i
, int j
, enum dline_desc desc
)
1972 return set_dot_dline(state
, dline_array
, i
, j
, OPP_DLINE(desc
));
1975 static int set_square_opp_dline(game_state
*state
, char *dline_array
,
1976 int i
, int j
, enum dline_desc desc
)
1978 return set_square_dline(state
, dline_array
, i
, j
, OPP_DLINE(desc
));
1981 /* Find out if both the lines in the given dline are UNKNOWN */
1982 static int dline_both_unknown(const game_state
*state
, int i
, int j
,
1983 enum dline_desc desc
)
1986 (get_line_status_from_point(state
, i
, j
, dlines
[desc
].dir1
) == LINE_UNKNOWN
) &&
1987 (get_line_status_from_point(state
, i
, j
, dlines
[desc
].dir2
) == LINE_UNKNOWN
);
1990 #define SQUARE_DLINES \
1991 HANDLE_DLINE(DLINE_UL, RIGHTOF_SQUARE, BELOW_SQUARE, 1, 1); \
1992 HANDLE_DLINE(DLINE_UR, LEFTOF_SQUARE, BELOW_SQUARE, 0, 1); \
1993 HANDLE_DLINE(DLINE_DL, RIGHTOF_SQUARE, ABOVE_SQUARE, 1, 0); \
1994 HANDLE_DLINE(DLINE_DR, LEFTOF_SQUARE, ABOVE_SQUARE, 0, 0);
1996 #define DOT_DLINES \
1997 HANDLE_DLINE(DLINE_UD, ABOVE_DOT, BELOW_DOT); \
1998 HANDLE_DLINE(DLINE_LR, LEFTOF_DOT, RIGHTOF_DOT); \
1999 HANDLE_DLINE(DLINE_UL, ABOVE_DOT, LEFTOF_DOT); \
2000 HANDLE_DLINE(DLINE_UR, ABOVE_DOT, RIGHTOF_DOT); \
2001 HANDLE_DLINE(DLINE_DL, BELOW_DOT, LEFTOF_DOT); \
2002 HANDLE_DLINE(DLINE_DR, BELOW_DOT, RIGHTOF_DOT);
2004 static void array_setall(char *array
, char from
, char to
, int len
)
2006 char *p
= array
, *p_old
= p
;
2007 int len_remaining
= len
;
2009 while ((p
= memchr(p
, from
, len_remaining
))) {
2011 len_remaining
-= p
- p_old
;
2018 static int get_line_status_from_point(const game_state
*state
,
2019 int x
, int y
, enum direction d
)
2023 return LEFTOF_DOT(state
, x
, y
);
2025 return RIGHTOF_DOT(state
, x
, y
);
2027 return ABOVE_DOT(state
, x
, y
);
2029 return BELOW_DOT(state
, x
, y
);
2035 /* First and second args are coord offset from top left of square to one end
2036 * of line in question, third and fourth args are the direction from the first
2037 * end of the line to the second. Fifth arg is the direction of the line from
2038 * the coord offset position.
2041 #define SQUARE_LINES \
2042 SQUARE_LINE( 0, 0, RIGHT, RIGHTOF_DOT, UP); \
2043 SQUARE_LINE( 0, +1, RIGHT, RIGHTOF_DOT, DOWN); \
2044 SQUARE_LINE( 0, 0, DOWN, BELOW_DOT, LEFT); \
2045 SQUARE_LINE(+1, 0, DOWN, BELOW_DOT, RIGHT);
2047 /* Set pairs of lines around this square which are known to be identical to
2048 * the given line_state */
2049 static int square_setall_identical(solver_state
*sstate
, int x
, int y
,
2050 enum line_state line_new
)
2052 /* can[dir] contains the canonical line associated with the line in
2053 * direction dir from the square in question. Similarly inv[dir] is
2054 * whether or not the line in question is inverse to its canonical
2056 int can
[4], inv
[4], i
, j
;
2062 fprintf(stderr
, "Setting all identical unknown lines around square "
2063 "[%d,%d] to %d:\n", x
, y
, line_new
);
2066 #define SQUARE_LINE(dx, dy, linedir, dir_dot, sqdir) \
2068 edsf_canonify(sstate->hard->linedsf, \
2069 LINEDSF_INDEX(sstate->state, x+(dx), y+(dy), linedir), \
2076 for (j
= 0; j
< 4; ++j
) {
2077 for (i
= 0; i
< 4; ++i
) {
2081 if (can
[i
] == can
[j
] && inv
[i
] == inv
[j
]) {
2083 /* Lines in directions i and j are identical.
2084 * Only do j now, we'll do i when the loop causes us to
2085 * consider {i,j} in the opposite order. */
2086 #define SQUARE_LINE(dx, dy, dir, c, sqdir) \
2088 retval = set_line_bydot(sstate, x+(dx), y+(dy), dir, line_new); \
2105 /* Set all identical lines passing through the current dot to the chosen line
2106 * state. (implicitly this only looks at UNKNOWN lines) */
2107 static int dot_setall_identical(solver_state
*sstate
, int x
, int y
,
2108 enum line_state line_new
)
2110 /* The implementation of this is a little naughty but I can't see how to do
2111 * it elegantly any other way */
2112 int can
[4], inv
[4], i
, j
;
2116 for (d
= 0; d
< 4; ++d
) {
2117 can
[d
] = edsf_canonify(sstate
->hard
->linedsf
,
2118 LINEDSF_INDEX(sstate
->state
, x
, y
, d
),
2122 for (j
= 0; j
< 4; ++j
) {
2124 for (i
= 0; i
< j
; ++i
) {
2125 if (can
[i
] == can
[j
] && inv
[i
] == inv
[j
]) {
2126 /* Lines in directions i and j are identical */
2127 if (get_line_status_from_point(sstate
->state
, x
, y
, j
) ==
2129 set_line_bydot(sstate
->state
, x
, y
, j
,
2143 static int square_setboth_in_dline(solver_state
*sstate
, enum dline_desc dd
,
2144 int i
, int j
, enum line_state line_new
)
2147 const struct dline dll
= dlines
[dd
], *dl
= &dll
;
2150 fprintf(stderr
, "square_setboth_in_dline %s [%d,%d] to %d\n",
2151 DL2STR(dd
), i
, j
, line_new
);
2154 CHECK_DLINE_SENSIBLE(dd
);
2157 set_line_bydot(sstate
, i
+dl
->dx
, j
+dl
->dy
, dl
->dir1
, line_new
);
2159 set_line_bydot(sstate
, i
+dl
->dx
, j
+dl
->dy
, dl
->dir2
, line_new
);
2164 /* Call this function to register that the two unknown lines going into the dot
2165 * [x,y] are identical or opposite (depending on the value of 'inverse'). This
2166 * function will cause an assertion failure if anything other than exactly two
2167 * lines into the dot are unknown.
2168 * As usual returns TRUE if any progress was made, otherwise FALSE. */
2169 static int dot_relate_2_unknowns(solver_state
*sstate
, int x
, int y
, int inverse
)
2171 enum direction d1
=DOWN
, d2
=DOWN
; /* Just to keep compiler quiet */
2174 #define TRY_DIR(d) \
2175 if (get_line_status_from_point(sstate->state, x, y, d) == \
2177 if (dirs_set == 0) \
2180 assert(dirs_set == 1); \
2192 assert(dirs_set
== 2);
2196 fprintf(stderr
, "Lines in direction %s and %s from dot [%d,%d] are %s\n",
2197 DIR2STR(d1
), DIR2STR(d2
), x
, y
, inverse?
"opposite":"the same");
2200 return merge_lines(sstate
, x
, y
, d1
, x
, y
, d2
, inverse
);
2203 /* Very similar to dot_relate_2_unknowns. */
2204 static int square_relate_2_unknowns(solver_state
*sstate
, int x
, int y
, int inverse
)
2206 enum direction d1
=DOWN
, d2
=DOWN
;
2207 int x1
=-1, y1
=-1, x2
=-1, y2
=-1;
2211 fprintf(stderr
, "2 unknowns around square [%d,%d] are %s\n",
2212 x
, y
, inverse?
"opposite":"the same");
2215 #define TRY_DIR(i, j, d, dir_sq) \
2217 if (dir_sq(sstate->state, x, y) == LINE_UNKNOWN) { \
2218 if (dirs_set == 0) { \
2219 d1 = d; x1 = i; y1 = j; \
2221 assert(dirs_set == 1); \
2222 d2 = d; x2 = i; y2 = j; \
2228 TRY_DIR(x
, y
, RIGHT
, ABOVE_SQUARE
);
2229 TRY_DIR(x
, y
, DOWN
, LEFTOF_SQUARE
);
2230 TRY_DIR(x
+1, y
, DOWN
, RIGHTOF_SQUARE
);
2231 TRY_DIR(x
, y
+1, RIGHT
, BELOW_SQUARE
);
2234 assert(dirs_set
== 2);
2237 fprintf(stderr
, "Line in direction %s from dot [%d,%d] and line in direction %s from dot [%2d,%2d] are %s\n",
2238 DIR2STR(d1
), x1
, y1
, DIR2STR(d2
), x2
, y2
, inverse?
"opposite":"the same");
2241 return merge_lines(sstate
, x1
, y1
, d1
, x2
, y2
, d2
, inverse
);
2244 /* Figure out if any dlines can be 'collapsed' (and do so if they can). This
2245 * can happen if one of the lines is known and due to the dline status this
2246 * tells us state of the other, or if there's an interaction with the linedsf
2247 * (ie if atmostone is set for a dline and the lines are known identical they
2248 * must both be LINE_NO, etc). XXX at the moment only the former is
2249 * implemented, and indeed the latter should be implemented in the hard mode
2252 static int dot_collapse_dlines(solver_state
*sstate
, int i
, int j
)
2254 int progress
= FALSE
;
2255 enum direction dir1
, dir2
;
2258 game_state
*state
= sstate
->state
;
2261 for (dir1
= 0; dir1
< 4; dir1
++) {
2262 dir1st
= get_line_status_from_point(state
, i
, j
, dir1
);
2263 if (dir1st
== LINE_UNKNOWN
)
2265 /* dir2 iterates over the whole range rather than starting at dir1+1
2266 * because test below is asymmetric */
2267 for (dir2
= 0; dir2
< 4; dir2
++) {
2271 if ((i
== 0 && (dir1
== LEFT
|| dir2
== LEFT
)) ||
2272 (j
== 0 && (dir1
== UP
|| dir2
== UP
)) ||
2273 (i
== state
->w
&& (dir1
== RIGHT
|| dir2
== RIGHT
)) ||
2274 (j
== state
->h
&& (dir1
== DOWN
|| dir2
== DOWN
))) {
2279 fprintf(stderr
, "dot_collapse_dlines [%d,%d], %s %s\n", i
, j
,
2280 DIR2STR(dir1
), DIR2STR(dir2
));
2283 if (get_line_status_from_point(state
, i
, j
, dir2
) ==
2285 dd
= dline_desc_from_dirs(dir1
, dir2
);
2287 dlset
= get_dot_dline(state
, sstate
->normal
->dot_atmostone
, i
, j
, dd
);
2288 if (dlset
&& dir1st
== LINE_YES
) {
2289 /* fprintf(stderr, "setting %s to NO\n", DIR2STR(dir2)); */
2291 set_line_bydot(sstate
, i
, j
, dir2
, LINE_NO
);
2294 dlset
= get_dot_dline(state
, sstate
->normal
->dot_atleastone
, i
, j
, dd
);
2295 if (dlset
&& dir1st
== LINE_NO
) {
2296 /* fprintf(stderr, "setting %s to YES\n", DIR2STR(dir2)); */
2298 set_line_bydot(sstate
, i
, j
, dir2
, LINE_YES
);
2308 * These are the main solver functions.
2310 * Their return values are diff values corresponding to the lowest mode solver
2311 * that would notice the work that they have done. For example if the normal
2312 * mode solver adds actual lines or crosses, it will return DIFF_EASY as the
2313 * easy mode solver might be able to make progress using that. It doesn't make
2314 * sense for one of them to return a diff value higher than that of the
2317 * Each function returns the lowest value it can, as early as possible, in
2318 * order to try and pass as much work as possible back to the lower level
2319 * solvers which progress more quickly.
2322 /* PROPOSED NEW DESIGN:
2323 * We have a work queue consisting of 'events' notifying us that something has
2324 * happened that a particular solver mode might be interested in. For example
2325 * the hard mode solver might do something that helps the normal mode solver at
2326 * dot [x,y] in which case it will enqueue an event recording this fact. Then
2327 * we pull events off the work queue, and hand each in turn to the solver that
2328 * is interested in them. If a solver reports that it failed we pass the same
2329 * event on to progressively more advanced solvers and the loop detector. Once
2330 * we've exhausted an event, or it has helped us progress, we drop it and
2331 * continue to the next one. The events are sorted first in order of solver
2332 * complexity (easy first) then order of insertion (oldest first).
2333 * Once we run out of events we loop over each permitted solver in turn
2334 * (easiest first) until either a deduction is made (and an event therefore
2335 * emerges) or no further deductions can be made (in which case we've failed).
2338 * * How do we 'loop over' a solver when both dots and squares are concerned.
2339 * Answer: first all squares then all dots.
2342 static int easy_mode_deductions(solver_state
*sstate
)
2344 int i
, j
, h
, w
, current_yes
, current_no
;
2346 int diff
= DIFF_MAX
;
2348 state
= sstate
->state
;
2352 /* Per-square deductions */
2353 FORALL_SQUARES(state
, i
, j
) {
2354 if (sstate
->square_solved
[SQUARE_INDEX(state
, i
, j
)])
2357 current_yes
= SQUARE_YES_COUNT(sstate
, i
, j
);
2358 current_no
= SQUARE_NO_COUNT(sstate
, i
, j
);
2360 if (current_yes
+ current_no
== 4) {
2361 sstate
->square_solved
[SQUARE_INDEX(state
, i
, j
)] = TRUE
;
2362 /* diff = min(diff, DIFF_EASY); */
2366 if (CLUE_AT(state
, i
, j
) < 0)
2369 if (CLUE_AT(state
, i
, j
) < current_yes
) {
2371 fprintf(stderr
, "detected error [%d,%d] in %s at line %d\n", i
, j
, __FUNCTION__
, __LINE__
);
2373 sstate
->solver_status
= SOLVER_MISTAKE
;
2376 if (CLUE_AT(state
, i
, j
) == current_yes
) {
2377 if (square_setall(sstate
, i
, j
, LINE_UNKNOWN
, LINE_NO
))
2378 diff
= min(diff
, DIFF_EASY
);
2379 sstate
->square_solved
[SQUARE_INDEX(state
, i
, j
)] = TRUE
;
2383 if (4 - CLUE_AT(state
, i
, j
) < current_no
) {
2385 fprintf(stderr
, "detected error [%d,%d] in %s at line %d\n", i
, j
, __FUNCTION__
, __LINE__
);
2387 sstate
->solver_status
= SOLVER_MISTAKE
;
2390 if (4 - CLUE_AT(state
, i
, j
) == current_no
) {
2391 if (square_setall(sstate
, i
, j
, LINE_UNKNOWN
, LINE_YES
))
2392 diff
= min(diff
, DIFF_EASY
);
2393 sstate
->square_solved
[SQUARE_INDEX(state
, i
, j
)] = TRUE
;
2398 check_caches(sstate
);
2400 /* Per-dot deductions */
2401 FORALL_DOTS(state
, i
, j
) {
2402 if (sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)])
2405 switch (DOT_YES_COUNT(sstate
, i
, j
)) {
2407 switch (DOT_NO_COUNT(sstate
, i
, j
)) {
2410 fprintf(stderr
, "dot [%d,%d]: 0 yes, 3 no\n", i
, j
);
2412 dot_setall(sstate
, i
, j
, LINE_UNKNOWN
, LINE_NO
);
2413 diff
= min(diff
, DIFF_EASY
);
2416 sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)] = TRUE
;
2421 switch (DOT_NO_COUNT(sstate
, i
, j
)) {
2422 case 2: /* 1 yes, 2 no */
2424 fprintf(stderr
, "dot [%d,%d]: 1 yes, 2 no\n", i
, j
);
2426 dot_setall(sstate
, i
, j
, LINE_UNKNOWN
, LINE_YES
);
2427 diff
= min(diff
, DIFF_EASY
);
2428 sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)] = TRUE
;
2430 case 3: /* 1 yes, 3 no */
2432 fprintf(stderr
, "detected error [%d,%d] in %s at line %d\n", i
, j
, __FUNCTION__
, __LINE__
);
2434 sstate
->solver_status
= SOLVER_MISTAKE
;
2440 fprintf(stderr
, "dot [%d,%d]: 2 yes\n", i
, j
);
2442 dot_setall(sstate
, i
, j
, LINE_UNKNOWN
, LINE_NO
);
2443 diff
= min(diff
, DIFF_EASY
);
2444 sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)] = TRUE
;
2449 fprintf(stderr
, "detected error [%d,%d] in %s at line %d\n", i
, j
, __FUNCTION__
, __LINE__
);
2451 sstate
->solver_status
= SOLVER_MISTAKE
;
2456 check_caches(sstate
);
2461 static int normal_mode_deductions(solver_state
*sstate
)
2464 game_state
*state
= sstate
->state
;
2466 int diff
= DIFF_MAX
;
2468 FORALL_SQUARES(state
, i
, j
) {
2469 if (sstate
->square_solved
[SQUARE_INDEX(state
, i
, j
)])
2472 if (CLUE_AT(state
, i
, j
) < 0)
2475 switch (CLUE_AT(state
, i
, j
)) {
2478 fprintf(stderr
, "clue [%d,%d] is 1, doing dline ops\n",
2481 FORALL_SQUARE_DLINES(dd
) {
2482 /* At most one of any DLINE can be set */
2483 if (set_square_dline(state
,
2484 sstate
->normal
->dot_atmostone
,
2486 diff
= min(diff
, DIFF_NORMAL
);
2489 if (get_square_dline(state
,
2490 sstate
->normal
->dot_atleastone
,
2492 /* This DLINE provides enough YESes to solve the clue */
2493 if (square_setboth_in_dline(sstate
, OPP_DLINE(dd
),
2495 diff
= min(diff
, DIFF_EASY
);
2502 /* If at least one of one DLINE is set, at most one
2503 * of the opposing one is and vice versa */
2505 fprintf(stderr
, "clue [%d,%d] is 2, doing dline ops\n",
2508 FORALL_SQUARE_DLINES(dd
) {
2509 if (get_square_dline(state
,
2510 sstate
->normal
->dot_atmostone
,
2512 if (set_square_opp_dline(state
,
2513 sstate
->normal
->dot_atleastone
,
2515 diff
= min(diff
, DIFF_NORMAL
);
2518 if (get_square_dline(state
,
2519 sstate
->normal
->dot_atleastone
,
2521 if (set_square_opp_dline(state
,
2522 sstate
->normal
->dot_atmostone
,
2524 diff
= min(diff
, DIFF_NORMAL
);
2531 fprintf(stderr
, "clue [%d,%d] is 3, doing dline ops\n",
2534 FORALL_SQUARE_DLINES(dd
) {
2535 /* At least one of any DLINE must be set */
2536 if (set_square_dline(state
,
2537 sstate
->normal
->dot_atleastone
,
2539 diff
= min(diff
, DIFF_NORMAL
);
2542 if (get_square_dline(state
,
2543 sstate
->normal
->dot_atmostone
,
2545 /* This DLINE provides enough NOs to solve the clue */
2546 if (square_setboth_in_dline(sstate
, OPP_DLINE(dd
),
2548 diff
= min(diff
, DIFF_EASY
);
2556 check_caches(sstate
);
2558 if (diff
< DIFF_NORMAL
)
2561 FORALL_DOTS(state
, i
, j
) {
2562 if (sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)])
2566 text
= game_text_format(state
);
2567 fprintf(stderr
, "-----------------\n%s", text
);
2571 switch (DOT_YES_COUNT(sstate
, i
, j
)) {
2573 switch (DOT_NO_COUNT(sstate
, i
, j
)) {
2575 /* Make note that at most one of each unknown DLINE
2582 switch (DOT_NO_COUNT(sstate
, i
, j
)) {
2584 /* 1 yes, 1 no, so exactly one of unknowns is
2587 fprintf(stderr
, "dot [%d,%d]: 1 yes, 1 no\n", i
, j
);
2589 FORALL_DOT_DLINES(dd
) {
2590 if (dline_both_unknown(state
,
2592 if (set_dot_dline(state
,
2593 sstate
->normal
->dot_atleastone
,
2595 diff
= min(diff
, DIFF_NORMAL
);
2603 fprintf(stderr
, "dot [%d,%d]: 1 yes, 0 or 1 no\n", i
, j
);
2605 /* 1 yes, fewer than 2 no, so at most one of
2606 * unknowns is yes */
2607 FORALL_DOT_DLINES(dd
) {
2608 if (dline_both_unknown(state
,
2610 if (set_dot_dline(state
,
2611 sstate
->normal
->dot_atmostone
,
2613 diff
= min(diff
, DIFF_NORMAL
);
2622 /* DLINE deductions that don't depend on the exact number of
2623 * LINE_YESs or LINE_NOs */
2625 /* If at least one of a dline in a dot is YES, at most one
2626 * of the opposite dline to that dot must be YES. */
2627 FORALL_DOT_DLINES(dd
) {
2628 if (get_dot_dline(state
,
2629 sstate
->normal
->dot_atleastone
,
2631 if (set_dot_opp_dline(state
,
2632 sstate
->normal
->dot_atmostone
,
2634 diff
= min(diff
, DIFF_NORMAL
);
2639 if (dot_collapse_dlines(sstate
, i
, j
))
2640 diff
= min(diff
, DIFF_EASY
);
2642 check_caches(sstate
);
2647 static int hard_mode_deductions(solver_state
*sstate
)
2650 game_state
*state
= sstate
->state
;
2651 const int h
=state
->h
, w
=state
->w
;
2652 enum direction dir1
, dir2
;
2653 int can1
, can2
, inv1
, inv2
;
2654 int diff
= DIFF_MAX
;
2657 FORALL_SQUARES(state
, i
, j
) {
2658 if (sstate
->square_solved
[SQUARE_INDEX(state
, i
, j
)])
2661 switch (CLUE_AT(state
, i
, j
)) {
2666 if (square_setall_identical(sstate
, i
, j
, LINE_NO
))
2667 diff
= min(diff
, DIFF_EASY
);
2670 if (square_setall_identical(sstate
, i
, j
, LINE_YES
))
2671 diff
= min(diff
, DIFF_EASY
);
2675 if (SQUARE_YES_COUNT(sstate
, i
, j
) +
2676 SQUARE_NO_COUNT(sstate
, i
, j
) == 2) {
2677 /* There are exactly two unknown lines bordering this
2679 if (SQUARE_YES_COUNT(sstate
, i
, j
) + 1 ==
2680 CLUE_AT(state
, i
, j
)) {
2681 /* They must be different */
2682 if (square_relate_2_unknowns(sstate
, i
, j
, TRUE
))
2683 diff
= min(diff
, DIFF_HARD
);
2688 check_caches(sstate
);
2690 FORALL_DOTS(state
, i
, j
) {
2691 if (DOT_YES_COUNT(sstate
, i
, j
) == 1 &&
2692 DOT_NO_COUNT(sstate
, i
, j
) == 1) {
2693 if (dot_relate_2_unknowns(sstate
, i
, j
, TRUE
))
2694 diff
= min(diff
, DIFF_HARD
);
2698 if (DOT_YES_COUNT(sstate
, i
, j
) == 0 &&
2699 DOT_NO_COUNT(sstate
, i
, j
) == 2) {
2700 if (dot_relate_2_unknowns(sstate
, i
, j
, FALSE
))
2701 diff
= min(diff
, DIFF_HARD
);
2706 /* If two lines into a dot are related, the other two lines into that dot
2707 * are related in the same way. */
2709 /* iter over points that aren't on edges */
2710 for (i
= 1; i
< w
; ++i
) {
2711 for (j
= 1; j
< h
; ++j
) {
2712 if (sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)])
2715 /* iter over directions */
2716 for (dir1
= 0; dir1
< 4; ++dir1
) {
2717 for (dir2
= dir1
+1; dir2
< 4; ++dir2
) {
2718 /* canonify both lines */
2719 can1
= edsf_canonify
2720 (sstate
->hard
->linedsf
,
2721 LINEDSF_INDEX(state
, i
, j
, dir1
),
2723 can2
= edsf_canonify
2724 (sstate
->hard
->linedsf
,
2725 LINEDSF_INDEX(state
, i
, j
, dir2
),
2727 /* merge opposite lines */
2729 if (merge_lines(sstate
,
2730 i
, j
, OPP_DIR(dir1
),
2731 i
, j
, OPP_DIR(dir2
),
2733 diff
= min(diff
, DIFF_HARD
);
2741 /* If the state of a line is known, deduce the state of its canonical line
2743 FORALL_DOTS(state
, i
, j
) {
2744 /* Do this even if the dot we're on is solved */
2746 can1
= edsf_canonify(sstate
->hard
->linedsf
,
2747 LINEDSF_INDEX(state
, i
, j
, RIGHT
),
2749 linedsf_deindex(state
, can1
, &a
, &b
, &dir1
);
2750 s
= RIGHTOF_DOT(state
, i
, j
);
2751 if (s
!= LINE_UNKNOWN
)
2753 if (set_line_bydot(sstate
, a
, b
, dir1
, inv1 ?
OPP(s
) : s
))
2754 diff
= min(diff
, DIFF_EASY
);
2758 can1
= edsf_canonify(sstate
->hard
->linedsf
,
2759 LINEDSF_INDEX(state
, i
, j
, DOWN
),
2761 linedsf_deindex(state
, can1
, &a
, &b
, &dir1
);
2762 s
= BELOW_DOT(state
, i
, j
);
2763 if (s
!= LINE_UNKNOWN
)
2765 if (set_line_bydot(sstate
, a
, b
, dir1
, inv1 ?
OPP(s
) : s
))
2766 diff
= min(diff
, DIFF_EASY
);
2771 /* Interactions between dline and linedsf */
2772 FORALL_DOTS(state
, i
, j
) {
2773 if (sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)])
2776 FORALL_DOT_DLINES(dd
) {
2777 const struct dline dll
= dlines
[dd
], *dl
= &dll
;
2778 if (i
== 0 && (dl
->dir1
== LEFT
|| dl
->dir2
== LEFT
))
2780 if (i
== w
&& (dl
->dir1
== RIGHT
|| dl
->dir2
== RIGHT
))
2782 if (j
== 0 && (dl
->dir1
== UP
|| dl
->dir2
== UP
))
2784 if (j
== h
&& (dl
->dir1
== DOWN
|| dl
->dir2
== DOWN
))
2787 if (get_dot_dline(state
, sstate
->normal
->dot_atleastone
,
2789 get_dot_dline(state
, sstate
->normal
->dot_atmostone
,
2791 /* atleastone && atmostone => inverse */
2792 if (merge_lines(sstate
, i
, j
, dl
->dir1
, i
, j
, dl
->dir2
, 1)) {
2793 diff
= min(diff
, DIFF_HARD
);
2796 /* don't have atleastone and atmostone for this dline */
2797 can1
= edsf_canonify(sstate
->hard
->linedsf
,
2798 LINEDSF_INDEX(state
, i
, j
, dl
->dir1
),
2800 can2
= edsf_canonify(sstate
->hard
->linedsf
,
2801 LINEDSF_INDEX(state
, i
, j
, dl
->dir2
),
2805 /* identical => collapse dline */
2806 if (get_dot_dline(state
,
2807 sstate
->normal
->dot_atleastone
,
2809 if (set_line_bydot(sstate
, i
, j
,
2810 dl
->dir1
, LINE_YES
)) {
2811 diff
= min(diff
, DIFF_EASY
);
2813 if (set_line_bydot(sstate
, i
, j
,
2814 dl
->dir2
, LINE_YES
)) {
2815 diff
= min(diff
, DIFF_EASY
);
2817 } else if (get_dot_dline(state
,
2818 sstate
->normal
->dot_atmostone
,
2820 if (set_line_bydot(sstate
, i
, j
,
2821 dl
->dir1
, LINE_NO
)) {
2822 diff
= min(diff
, DIFF_EASY
);
2824 if (set_line_bydot(sstate
, i
, j
,
2825 dl
->dir2
, LINE_NO
)) {
2826 diff
= min(diff
, DIFF_EASY
);
2830 /* inverse => atleastone && atmostone */
2831 if (set_dot_dline(state
,
2832 sstate
->normal
->dot_atleastone
,
2834 diff
= min(diff
, DIFF_NORMAL
);
2836 if (set_dot_dline(state
,
2837 sstate
->normal
->dot_atmostone
,
2839 diff
= min(diff
, DIFF_NORMAL
);
2847 /* If the state of the canonical line for line 'l' is known, deduce the
2849 FORALL_DOTS(state
, i
, j
) {
2850 if (sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)])
2854 can1
= edsf_canonify(sstate
->hard
->linedsf
,
2855 LINEDSF_INDEX(state
, i
, j
, RIGHT
),
2857 linedsf_deindex(state
, can1
, &a
, &b
, &dir1
);
2858 s
= get_line_status_from_point(state
, a
, b
, dir1
);
2859 if (s
!= LINE_UNKNOWN
)
2861 if (set_line_bydot(sstate
, i
, j
, RIGHT
, inv1 ?
OPP(s
) : s
))
2862 diff
= min(diff
, DIFF_EASY
);
2866 can1
= edsf_canonify(sstate
->hard
->linedsf
,
2867 LINEDSF_INDEX(state
, i
, j
, DOWN
),
2869 linedsf_deindex(state
, can1
, &a
, &b
, &dir1
);
2870 s
= get_line_status_from_point(state
, a
, b
, dir1
);
2871 if (s
!= LINE_UNKNOWN
)
2873 if (set_line_bydot(sstate
, i
, j
, DOWN
, inv1 ?
OPP(s
) : s
))
2874 diff
= min(diff
, DIFF_EASY
);
2882 static int loop_deductions(solver_state
*sstate
)
2884 int edgecount
= 0, clues
= 0, satclues
= 0, sm1clues
= 0;
2885 game_state
*state
= sstate
->state
;
2886 int shortest_chainlen
= DOT_COUNT(state
);
2887 int loop_found
= FALSE
;
2890 int progress
= FALSE
;
2894 * Go through the grid and update for all the new edges.
2895 * Since merge_dots() is idempotent, the simplest way to
2896 * do this is just to update for _all_ the edges.
2898 * Also, while we're here, we count the edges, count the
2899 * clues, count the satisfied clues, and count the
2900 * satisfied-minus-one clues.
2902 FORALL_DOTS(state
, i
, j
) {
2903 if (RIGHTOF_DOT(state
, i
, j
) == LINE_YES
) {
2904 loop_found
|= merge_dots(sstate
, i
, j
, i
+1, j
);
2907 if (BELOW_DOT(state
, i
, j
) == LINE_YES
) {
2908 loop_found
|= merge_dots(sstate
, i
, j
, i
, j
+1);
2912 if (CLUE_AT(state
, i
, j
) >= 0) {
2913 int c
= CLUE_AT(state
, i
, j
);
2914 int o
= SQUARE_YES_COUNT(sstate
, i
, j
);
2923 for (i
= 0; i
< DOT_COUNT(state
); ++i
) {
2925 sstate
->looplen
[dsf_canonify(sstate
->dotdsf
, i
)];
2926 if (dots_connected
> 1)
2927 shortest_chainlen
= min(shortest_chainlen
, dots_connected
);
2930 assert(sstate
->solver_status
== SOLVER_INCOMPLETE
);
2932 if (satclues
== clues
&& shortest_chainlen
== edgecount
) {
2933 sstate
->solver_status
= SOLVER_SOLVED
;
2934 /* This discovery clearly counts as progress, even if we haven't
2935 * just added any lines or anything */
2937 goto finished_loop_deductionsing
;
2941 * Now go through looking for LINE_UNKNOWN edges which
2942 * connect two dots that are already in the same
2943 * equivalence class. If we find one, test to see if the
2944 * loop it would create is a solution.
2946 FORALL_DOTS(state
, i
, j
) {
2947 for (d
= 0; d
< 2; d
++) {
2948 int i2
, j2
, eqclass
, val
;
2951 if (RIGHTOF_DOT(state
, i
, j
) !=
2957 if (BELOW_DOT(state
, i
, j
) !=
2965 eqclass
= dsf_canonify(sstate
->dotdsf
, j
* (state
->w
+1) + i
);
2966 if (eqclass
!= dsf_canonify(sstate
->dotdsf
,
2967 j2
* (state
->w
+1) + i2
)) {
2971 val
= LINE_NO
; /* loop is bad until proven otherwise */
2974 * This edge would form a loop. Next
2975 * question: how long would the loop be?
2976 * Would it equal the total number of edges
2977 * (plus the one we'd be adding if we added
2980 if (sstate
->looplen
[eqclass
] == edgecount
+ 1) {
2985 * This edge would form a loop which
2986 * took in all the edges in the entire
2987 * grid. So now we need to work out
2988 * whether it would be a valid solution
2989 * to the puzzle, which means we have to
2990 * check if it satisfies all the clues.
2991 * This means that every clue must be
2992 * either satisfied or satisfied-minus-
2993 * 1, and also that the number of
2994 * satisfied-minus-1 clues must be at
2995 * most two and they must lie on either
2996 * side of this edge.
3001 if (CLUE_AT(state
, cx
,cy
) >= 0 &&
3002 square_order(state
, cx
,cy
, LINE_YES
) ==
3003 CLUE_AT(state
, cx
,cy
) - 1) {
3006 if (CLUE_AT(state
, i
, j
) >= 0 &&
3007 SQUARE_YES_COUNT(sstate
, i
, j
) ==
3008 CLUE_AT(state
, i
, j
) - 1) {
3011 if (sm1clues
== sm1_nearby
&&
3012 sm1clues
+ satclues
== clues
) {
3013 val
= LINE_YES
; /* loop is good! */
3018 * Right. Now we know that adding this edge
3019 * would form a loop, and we know whether
3020 * that loop would be a viable solution or
3023 * If adding this edge produces a solution,
3024 * then we know we've found _a_ solution but
3025 * we don't know that it's _the_ solution -
3026 * if it were provably the solution then
3027 * we'd have deduced this edge some time ago
3028 * without the need to do loop detection. So
3029 * in this state we return SOLVER_AMBIGUOUS,
3030 * which has the effect that hitting Solve
3031 * on a user-provided puzzle will fill in a
3032 * solution but using the solver to
3033 * construct new puzzles won't consider this
3034 * a reasonable deduction for the user to
3038 progress
= set_line_bydot(sstate
, i
, j
, RIGHT
, val
);
3039 assert(progress
== TRUE
);
3041 progress
= set_line_bydot(sstate
, i
, j
, DOWN
, val
);
3042 assert(progress
== TRUE
);
3044 if (val
== LINE_YES
) {
3045 sstate
->solver_status
= SOLVER_AMBIGUOUS
;
3046 goto finished_loop_deductionsing
;
3051 finished_loop_deductionsing
:
3052 return progress ? DIFF_EASY
: DIFF_MAX
;
3055 /* This will return a dynamically allocated solver_state containing the (more)
3057 static solver_state
*solve_game_rec(const solver_state
*sstate_start
,
3062 solver_state
*sstate
, *sstate_saved
, *sstate_tmp
;
3063 solver_state
*sstate_rec_solved
;
3064 int recursive_soln_count
;
3065 int solver_progress
;
3068 /* Indicates which solver we should call next. This is a sensible starting
3070 int current_solver
= DIFF_EASY
, next_solver
;
3076 printf("solve_game_rec: recursion_remaining = %d\n",
3077 sstate_start
->recursion_remaining
);
3080 sstate
= dup_solver_state(sstate_start
);
3082 /* Cache the values of some variables for readability */
3083 state
= sstate
->state
;
3087 sstate_saved
= NULL
;
3089 nonrecursive_solver
:
3090 solver_progress
= FALSE
;
3092 check_caches(sstate
);
3096 text
= game_text_format(state
);
3097 fprintf(stderr
, "-----------------\n%s", text
);
3101 if (sstate
->solver_status
== SOLVER_MISTAKE
)
3104 /* fprintf(stderr, "Invoking solver %d\n", current_solver); */
3105 next_solver
= solver_fns
[current_solver
](sstate
);
3107 if (next_solver
== DIFF_MAX
) {
3108 /* fprintf(stderr, "Current solver failed\n"); */
3109 if (current_solver
< diff
&& current_solver
+ 1 < DIFF_MAX
) {
3110 /* Try next beefier solver */
3111 next_solver
= current_solver
+ 1;
3113 /* fprintf(stderr, "Doing loop deductions\n"); */
3114 next_solver
= loop_deductions(sstate
);
3118 if (sstate
->solver_status
== SOLVER_SOLVED
||
3119 sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
3120 /* fprintf(stderr, "Solver completed\n"); */
3124 /* Once we've looped over all permitted solvers then the loop
3125 * deductions without making any progress, we'll exit this while loop */
3126 current_solver
= next_solver
;
3127 } while (current_solver
< DIFF_MAX
);
3129 if (sstate
->solver_status
== SOLVER_SOLVED
||
3130 sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
3131 /* s/LINE_UNKNOWN/LINE_NO/g */
3132 array_setall(sstate
->state
->hl
, LINE_UNKNOWN
, LINE_NO
,
3133 HL_COUNT(sstate
->state
));
3134 array_setall(sstate
->state
->vl
, LINE_UNKNOWN
, LINE_NO
,
3135 VL_COUNT(sstate
->state
));
3139 /* Perform recursive calls */
3140 if (sstate
->recursion_remaining
) {
3141 sstate_saved
= dup_solver_state(sstate
);
3143 sstate
->recursion_remaining
--;
3145 recursive_soln_count
= 0;
3146 sstate_rec_solved
= NULL
;
3148 /* Memory management:
3149 * sstate_saved won't be modified but needs to be freed when we have
3151 * sstate is expected to contain our 'best' solution by the time we
3152 * finish this section of code. It's the thing we'll try adding lines
3153 * to, seeing if they make it more solvable.
3154 * If sstate_rec_solved is non-NULL, it will supersede sstate
3155 * eventually. sstate_tmp should not hold a value persistently.
3158 /* NB SOLVER_AMBIGUOUS is like SOLVER_SOLVED except the solver is aware
3159 * of the possibility of additional solutions. So as soon as we have a
3160 * SOLVER_AMBIGUOUS we can safely propagate it back to our caller, but
3161 * if we get a SOLVER_SOLVED we want to keep trying in case we find
3162 * further solutions and have to mark it ambiguous.
3165 #define DO_RECURSIVE_CALL(dir_dot) \
3166 if (dir_dot(sstate->state, i, j) == LINE_UNKNOWN) { \
3167 debug(("Trying " #dir_dot " at [%d,%d]\n", i, j)); \
3168 LV_##dir_dot(sstate->state, i, j) = LINE_YES; \
3169 sstate_tmp = solve_game_rec(sstate, diff); \
3170 switch (sstate_tmp->solver_status) { \
3171 case SOLVER_AMBIGUOUS: \
3172 debug(("Solver ambiguous, returning\n")); \
3173 sstate_rec_solved = sstate_tmp; \
3174 goto finished_recursion; \
3175 case SOLVER_SOLVED: \
3176 switch (++recursive_soln_count) { \
3178 debug(("One solution found\n")); \
3179 sstate_rec_solved = sstate_tmp; \
3182 debug(("Ambiguous solutions found\n")); \
3183 free_solver_state(sstate_tmp); \
3184 sstate_rec_solved->solver_status = SOLVER_AMBIGUOUS; \
3185 goto finished_recursion; \
3187 assert(!"recursive_soln_count out of range"); \
3191 case SOLVER_MISTAKE: \
3192 debug(("Non-solution found\n")); \
3193 free_solver_state(sstate_tmp); \
3194 free_solver_state(sstate_saved); \
3195 LV_##dir_dot(sstate->state, i, j) = LINE_NO; \
3196 goto nonrecursive_solver; \
3197 case SOLVER_INCOMPLETE: \
3198 debug(("Recursive step inconclusive\n")); \
3199 free_solver_state(sstate_tmp); \
3202 free_solver_state(sstate); \
3203 sstate = dup_solver_state(sstate_saved); \
3206 FORALL_DOTS(state
, i
, j
) {
3207 /* Only perform recursive calls on 'loose ends' */
3208 if (DOT_YES_COUNT(sstate
, i
, j
) == 1) {
3209 DO_RECURSIVE_CALL(LEFTOF_DOT
);
3210 DO_RECURSIVE_CALL(RIGHTOF_DOT
);
3211 DO_RECURSIVE_CALL(ABOVE_DOT
);
3212 DO_RECURSIVE_CALL(BELOW_DOT
);
3218 if (sstate_rec_solved
) {
3219 free_solver_state(sstate
);
3220 sstate
= sstate_rec_solved
;
3228 #define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
3229 if (sstate->normal->dot_atmostone[i+a + (sstate->state->w + 1) * (j+b)] & \
3231 if (square_order(sstate->state, i, j, LINE_UNKNOWN) - 1 == \
3232 CLUE_AT(sstate->state, i, j) - '0') { \
3233 square_setall(sstate->state, i, j, LINE_UNKNOWN, LINE_YES); \
3234 /* XXX the following may overwrite known data! */ \
3235 dir1_sq(sstate->state, i, j) = LINE_UNKNOWN; \
3236 dir2_sq(sstate->state, i, j) = LINE_UNKNOWN; \
3243 static char *solve_game(game_state
*state
, game_state
*currstate
,
3244 char *aux
, char **error
)
3247 solver_state
*sstate
, *new_sstate
;
3249 sstate
= new_solver_state(state
, DIFF_MAX
);
3250 new_sstate
= solve_game_rec(sstate
, DIFF_MAX
);
3252 if (new_sstate
->solver_status
== SOLVER_SOLVED
) {
3253 soln
= encode_solve_move(new_sstate
->state
);
3254 } else if (new_sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
3255 soln
= encode_solve_move(new_sstate
->state
);
3256 /**error = "Solver found ambiguous solutions"; */
3258 soln
= encode_solve_move(new_sstate
->state
);
3259 /**error = "Solver failed"; */
3262 free_solver_state(new_sstate
);
3263 free_solver_state(sstate
);
3268 /* ----------------------------------------------------------------------
3269 * Drawing and mouse-handling
3272 static char *interpret_move(game_state
*state
, game_ui
*ui
, game_drawstate
*ds
,
3273 int x
, int y
, int button
)
3278 char button_char
= ' ';
3279 enum line_state old_state
;
3281 button
&= ~MOD_MASK
;
3283 /* Around each line is a diamond-shaped region where points within that
3284 * region are closer to this line than any other. We assume any click
3285 * within a line's diamond was meant for that line. It would all be a lot
3286 * simpler if the / and % operators respected modulo arithmetic properly
3287 * for negative numbers. */
3292 /* Get the coordinates of the square the click was in */
3293 i
= (x
+ TILE_SIZE
) / TILE_SIZE
- 1;
3294 j
= (y
+ TILE_SIZE
) / TILE_SIZE
- 1;
3296 /* Get the precise position inside square [i,j] */
3297 p
= (x
+ TILE_SIZE
) % TILE_SIZE
;
3298 q
= (y
+ TILE_SIZE
) % TILE_SIZE
;
3300 /* After this bit of magic [i,j] will correspond to the point either above
3301 * or to the left of the line selected */
3303 if (TILE_SIZE
- p
> q
) {
3306 hl_selected
= FALSE
;
3310 if (TILE_SIZE
- q
> p
) {
3311 hl_selected
= FALSE
;
3322 if (i
>= state
->w
|| j
>= state
->h
+ 1)
3325 if (i
>= state
->w
+ 1 || j
>= state
->h
)
3329 /* I think it's only possible to play this game with mouse clicks, sorry */
3330 /* Maybe will add mouse drag support some time */
3332 old_state
= RIGHTOF_DOT(state
, i
, j
);
3334 old_state
= BELOW_DOT(state
, i
, j
);
3338 switch (old_state
) {
3352 switch (old_state
) {
3367 sprintf(buf
, "%d,%d%c%c", i
, j
, (int)(hl_selected ?
'h' : 'v'), (int)button_char
);
3373 static game_state
*execute_move(game_state
*state
, char *move
)
3376 game_state
*newstate
= dup_game(state
);
3378 if (move
[0] == 'S') {
3380 newstate
->cheated
= TRUE
;
3385 move
= strchr(move
, ',');
3389 move
+= strspn(move
, "1234567890");
3390 switch (*(move
++)) {
3392 if (i
>= newstate
->w
|| j
> newstate
->h
)
3394 switch (*(move
++)) {
3396 LV_RIGHTOF_DOT(newstate
, i
, j
) = LINE_YES
;
3399 LV_RIGHTOF_DOT(newstate
, i
, j
) = LINE_NO
;
3402 LV_RIGHTOF_DOT(newstate
, i
, j
) = LINE_UNKNOWN
;
3409 if (i
> newstate
->w
|| j
>= newstate
->h
)
3411 switch (*(move
++)) {
3413 LV_BELOW_DOT(newstate
, i
, j
) = LINE_YES
;
3416 LV_BELOW_DOT(newstate
, i
, j
) = LINE_NO
;
3419 LV_BELOW_DOT(newstate
, i
, j
) = LINE_UNKNOWN
;
3431 * Check for completion.
3433 i
= 0; /* placate optimiser */
3434 for (j
= 0; j
<= newstate
->h
; j
++) {
3435 for (i
= 0; i
< newstate
->w
; i
++)
3436 if (LV_RIGHTOF_DOT(newstate
, i
, j
) == LINE_YES
)
3438 if (i
< newstate
->w
)
3441 if (j
<= newstate
->h
) {
3447 * We've found a horizontal edge at (i,j). Follow it round
3448 * to see if it's part of a loop.
3452 int order
= dot_order(newstate
, x
, y
, LINE_YES
);
3454 goto completion_check_done
;
3456 if (LEFTOF_DOT(newstate
, x
, y
) == LINE_YES
&& prevdir
!= 'L') {
3459 } else if (RIGHTOF_DOT(newstate
, x
, y
) == LINE_YES
&&
3463 } else if (ABOVE_DOT(newstate
, x
, y
) == LINE_YES
&&
3467 } else if (BELOW_DOT(newstate
, x
, y
) == LINE_YES
&&
3472 assert(!"Can't happen"); /* dot_order guarantees success */
3477 if (x
== i
&& y
== j
)
3481 if (x
!= i
|| y
!= j
|| looplen
== 0)
3482 goto completion_check_done
;
3485 * We've traced our way round a loop, and we know how many
3486 * line segments were involved. Count _all_ the line
3487 * segments in the grid, to see if the loop includes them
3491 FORALL_DOTS(newstate
, i
, j
) {
3492 count
+= ((RIGHTOF_DOT(newstate
, i
, j
) == LINE_YES
) +
3493 (BELOW_DOT(newstate
, i
, j
) == LINE_YES
));
3495 assert(count
>= looplen
);
3496 if (count
!= looplen
)
3497 goto completion_check_done
;
3500 * The grid contains one closed loop and nothing else.
3501 * Check that all the clues are satisfied.
3503 FORALL_SQUARES(newstate
, i
, j
) {
3504 if (CLUE_AT(newstate
, i
, j
) >= 0) {
3505 if (square_order(newstate
, i
, j
, LINE_YES
) !=
3506 CLUE_AT(newstate
, i
, j
)) {
3507 goto completion_check_done
;
3515 newstate
->solved
= TRUE
;
3518 completion_check_done
:
3522 free_game(newstate
);
3526 /* ----------------------------------------------------------------------
3529 static void game_redraw(drawing
*dr
, game_drawstate
*ds
, game_state
*oldstate
,
3530 game_state
*state
, int dir
, game_ui
*ui
,
3531 float animtime
, float flashtime
)
3535 int line_colour
, flash_changed
;
3540 * The initial contents of the window are not guaranteed and
3541 * can vary with front ends. To be on the safe side, all games
3542 * should start by drawing a big background-colour rectangle
3543 * covering the whole window.
3545 draw_rect(dr
, 0, 0, SIZE(state
->w
), SIZE(state
->h
), COL_BACKGROUND
);
3548 FORALL_DOTS(state
, i
, j
) {
3550 BORDER
+ i
* TILE_SIZE
- LINEWIDTH
/2,
3551 BORDER
+ j
* TILE_SIZE
- LINEWIDTH
/2,
3552 LINEWIDTH
, LINEWIDTH
, COL_FOREGROUND
);
3556 FORALL_SQUARES(state
, i
, j
) {
3557 c
[0] = CLUE2CHAR(CLUE_AT(state
, i
, j
));
3560 BORDER
+ i
* TILE_SIZE
+ TILE_SIZE
/2,
3561 BORDER
+ j
* TILE_SIZE
+ TILE_SIZE
/2,
3562 FONT_VARIABLE
, TILE_SIZE
/2,
3563 ALIGN_VCENTRE
| ALIGN_HCENTRE
, COL_FOREGROUND
, c
);
3565 draw_update(dr
, 0, 0,
3566 state
->w
* TILE_SIZE
+ 2*BORDER
+ 1,
3567 state
->h
* TILE_SIZE
+ 2*BORDER
+ 1);
3571 if (flashtime
> 0 &&
3572 (flashtime
<= FLASH_TIME
/3 ||
3573 flashtime
>= FLASH_TIME
*2/3)) {
3574 flash_changed
= !ds
->flashing
;
3575 ds
->flashing
= TRUE
;
3576 line_colour
= COL_HIGHLIGHT
;
3578 flash_changed
= ds
->flashing
;
3579 ds
->flashing
= FALSE
;
3580 line_colour
= COL_FOREGROUND
;
3583 #define CROSS_SIZE (3 * LINEWIDTH / 2)
3585 /* Redraw clue colours if necessary */
3586 FORALL_SQUARES(state
, i
, j
) {
3587 n
= CLUE_AT(state
, i
, j
);
3591 assert(n
>= 0 && n
<= 4);
3593 c
[0] = CLUE2CHAR(CLUE_AT(state
, i
, j
));
3596 clue_mistake
= (square_order(state
, i
, j
, LINE_YES
) > n
||
3597 square_order(state
, i
, j
, LINE_NO
) > (4-n
));
3599 if (clue_mistake
!= ds
->clue_error
[SQUARE_INDEX(state
, i
, j
)]) {
3601 BORDER
+ i
* TILE_SIZE
+ CROSS_SIZE
,
3602 BORDER
+ j
* TILE_SIZE
+ CROSS_SIZE
,
3603 TILE_SIZE
- CROSS_SIZE
* 2, TILE_SIZE
- CROSS_SIZE
* 2,
3606 BORDER
+ i
* TILE_SIZE
+ TILE_SIZE
/2,
3607 BORDER
+ j
* TILE_SIZE
+ TILE_SIZE
/2,
3608 FONT_VARIABLE
, TILE_SIZE
/2,
3609 ALIGN_VCENTRE
| ALIGN_HCENTRE
,
3610 clue_mistake ? COL_MISTAKE
: COL_FOREGROUND
, c
);
3611 draw_update(dr
, i
* TILE_SIZE
+ BORDER
, j
* TILE_SIZE
+ BORDER
,
3612 TILE_SIZE
, TILE_SIZE
);
3614 ds
->clue_error
[SQUARE_INDEX(state
, i
, j
)] = clue_mistake
;
3618 /* I've also had a request to colour lines red if they make a non-solution
3619 * loop, or if more than two lines go into any point. I think that would
3620 * be good some time. */
3622 #define CLEAR_VL(i, j) \
3625 BORDER + i * TILE_SIZE - CROSS_SIZE, \
3626 BORDER + j * TILE_SIZE + LINEWIDTH - LINEWIDTH/2, \
3628 TILE_SIZE - LINEWIDTH, \
3631 BORDER + i * TILE_SIZE - CROSS_SIZE, \
3632 BORDER + j * TILE_SIZE - CROSS_SIZE, \
3634 TILE_SIZE + CROSS_SIZE*2); \
3637 #define CLEAR_HL(i, j) \
3640 BORDER + i * TILE_SIZE + LINEWIDTH - LINEWIDTH/2, \
3641 BORDER + j * TILE_SIZE - CROSS_SIZE, \
3642 TILE_SIZE - LINEWIDTH, \
3646 BORDER + i * TILE_SIZE - CROSS_SIZE, \
3647 BORDER + j * TILE_SIZE - CROSS_SIZE, \
3648 TILE_SIZE + CROSS_SIZE*2, \
3652 /* Vertical lines */
3653 FORALL_VL(state
, i
, j
) {
3654 switch (BELOW_DOT(state
, i
, j
)) {
3656 if (ds
->vl
[VL_INDEX(state
, i
, j
)] != BELOW_DOT(state
, i
, j
)) {
3661 if (ds
->vl
[VL_INDEX(state
, i
, j
)] != BELOW_DOT(state
, i
, j
) ||
3665 BORDER
+ i
* TILE_SIZE
- LINEWIDTH
/2,
3666 BORDER
+ j
* TILE_SIZE
+ LINEWIDTH
- LINEWIDTH
/2,
3667 LINEWIDTH
, TILE_SIZE
- LINEWIDTH
,
3672 if (ds
->vl
[VL_INDEX(state
, i
, j
)] != BELOW_DOT(state
, i
, j
)) {
3675 BORDER
+ i
* TILE_SIZE
- CROSS_SIZE
,
3676 BORDER
+ j
* TILE_SIZE
+ TILE_SIZE
/2 - CROSS_SIZE
,
3677 BORDER
+ i
* TILE_SIZE
+ CROSS_SIZE
- 1,
3678 BORDER
+ j
* TILE_SIZE
+ TILE_SIZE
/2 + CROSS_SIZE
- 1,
3681 BORDER
+ i
* TILE_SIZE
+ CROSS_SIZE
- 1,
3682 BORDER
+ j
* TILE_SIZE
+ TILE_SIZE
/2 - CROSS_SIZE
,
3683 BORDER
+ i
* TILE_SIZE
- CROSS_SIZE
,
3684 BORDER
+ j
* TILE_SIZE
+ TILE_SIZE
/2 + CROSS_SIZE
- 1,
3689 ds
->vl
[VL_INDEX(state
, i
, j
)] = BELOW_DOT(state
, i
, j
);
3692 /* Horizontal lines */
3693 FORALL_HL(state
, i
, j
) {
3694 switch (RIGHTOF_DOT(state
, i
, j
)) {
3696 if (ds
->hl
[HL_INDEX(state
, i
, j
)] != RIGHTOF_DOT(state
, i
, j
)) {
3701 if (ds
->hl
[HL_INDEX(state
, i
, j
)] != RIGHTOF_DOT(state
, i
, j
) ||
3705 BORDER
+ i
* TILE_SIZE
+ LINEWIDTH
- LINEWIDTH
/2,
3706 BORDER
+ j
* TILE_SIZE
- LINEWIDTH
/2,
3707 TILE_SIZE
- LINEWIDTH
, LINEWIDTH
,
3712 if (ds
->hl
[HL_INDEX(state
, i
, j
)] != RIGHTOF_DOT(state
, i
, j
)) {
3715 BORDER
+ i
* TILE_SIZE
+ TILE_SIZE
/2 - CROSS_SIZE
,
3716 BORDER
+ j
* TILE_SIZE
+ CROSS_SIZE
- 1,
3717 BORDER
+ i
* TILE_SIZE
+ TILE_SIZE
/2 + CROSS_SIZE
- 1,
3718 BORDER
+ j
* TILE_SIZE
- CROSS_SIZE
,
3721 BORDER
+ i
* TILE_SIZE
+ TILE_SIZE
/2 - CROSS_SIZE
,
3722 BORDER
+ j
* TILE_SIZE
- CROSS_SIZE
,
3723 BORDER
+ i
* TILE_SIZE
+ TILE_SIZE
/2 + CROSS_SIZE
- 1,
3724 BORDER
+ j
* TILE_SIZE
+ CROSS_SIZE
- 1,
3729 ds
->hl
[HL_INDEX(state
, i
, j
)] = RIGHTOF_DOT(state
, i
, j
);
3733 static float game_flash_length(game_state
*oldstate
, game_state
*newstate
,
3734 int dir
, game_ui
*ui
)
3736 if (!oldstate
->solved
&& newstate
->solved
&&
3737 !oldstate
->cheated
&& !newstate
->cheated
) {
3744 static void game_print_size(game_params
*params
, float *x
, float *y
)
3749 * I'll use 7mm squares by default.
3751 game_compute_size(params
, 700, &pw
, &ph
);
3756 static void game_print(drawing
*dr
, game_state
*state
, int tilesize
)
3758 int ink
= print_mono_colour(dr
, 0);
3760 game_drawstate ads
, *ds
= &ads
;
3762 game_set_size(dr
, ds
, NULL
, tilesize
);
3765 * Dots. I'll deliberately make the dots a bit wider than the
3766 * lines, so you can still see them. (And also because it's
3767 * annoyingly tricky to make them _exactly_ the same size...)
3769 FORALL_DOTS(state
, x
, y
) {
3770 draw_circle(dr
, BORDER
+ x
* TILE_SIZE
, BORDER
+ y
* TILE_SIZE
,
3771 LINEWIDTH
, ink
, ink
);
3777 FORALL_SQUARES(state
, x
, y
) {
3778 if (CLUE_AT(state
, x
, y
) >= 0) {
3781 c
[0] = CLUE2CHAR(CLUE_AT(state
, x
, y
));
3784 BORDER
+ x
* TILE_SIZE
+ TILE_SIZE
/2,
3785 BORDER
+ y
* TILE_SIZE
+ TILE_SIZE
/2,
3786 FONT_VARIABLE
, TILE_SIZE
/2,
3787 ALIGN_VCENTRE
| ALIGN_HCENTRE
, ink
, c
);
3792 * Lines. (At the moment, I'm not bothering with crosses.)
3794 FORALL_HL(state
, x
, y
) {
3795 if (RIGHTOF_DOT(state
, x
, y
) == LINE_YES
)
3796 draw_rect(dr
, BORDER
+ x
* TILE_SIZE
,
3797 BORDER
+ y
* TILE_SIZE
- LINEWIDTH
/2,
3798 TILE_SIZE
, (LINEWIDTH
/2) * 2 + 1, ink
);
3801 FORALL_VL(state
, x
, y
) {
3802 if (BELOW_DOT(state
, x
, y
) == LINE_YES
)
3803 draw_rect(dr
, BORDER
+ x
* TILE_SIZE
- LINEWIDTH
/2,
3804 BORDER
+ y
* TILE_SIZE
,
3805 (LINEWIDTH
/2) * 2 + 1, TILE_SIZE
, ink
);
3810 #define thegame loopy
3813 const struct game thegame
= {
3814 "Loopy", "games.loopy", "loopy",
3821 TRUE
, game_configure
, custom_params
,
3829 TRUE
, game_can_format_as_text_now
, game_text_format
,
3837 PREFERRED_TILE_SIZE
, game_compute_size
, game_set_size
,
3840 game_free_drawstate
,
3844 TRUE
, FALSE
, game_print_size
, game_print
,
3845 FALSE
/* wants_statusbar */,
3846 FALSE
, game_timing_state
,
3847 0, /* mouse_priorities */