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 char *game_text_format(game_state
*state
);
155 static char *state_to_text(const game_state
*state
);
156 static char *validate_desc(game_params
*params
, char *desc
);
157 static int get_line_status_from_point(const game_state
*state
,
158 int x
, int y
, enum direction d
);
159 static int dot_order(const game_state
* state
, int i
, int j
, char line_type
);
160 static int square_order(const game_state
* state
, int i
, int j
, char line_type
);
161 static solver_state
*solve_game_rec(const solver_state
*sstate
,
165 static void check_caches(const solver_state
* sstate
);
167 #define check_caches(s)
170 /* ----------------------------------------------------------------------
174 /* General constants */
175 #define PREFERRED_TILE_SIZE 32
176 #define TILE_SIZE (ds->tilesize)
177 #define LINEWIDTH (ds->linewidth)
178 #define BORDER (TILE_SIZE / 2)
179 #define FLASH_TIME 0.5F
181 /* Counts of various things that we're interested in */
182 #define HL_COUNT(state) ((state)->w * ((state)->h + 1))
183 #define VL_COUNT(state) (((state)->w + 1) * (state)->h)
184 #define LINE_COUNT(state) (HL_COUNT(state) + VL_COUNT(state))
185 #define DOT_COUNT(state) (((state)->w + 1) * ((state)->h + 1))
186 #define SQUARE_COUNT(state) ((state)->w * (state)->h)
188 /* For indexing into arrays */
189 #define DOT_INDEX(state, x, y) ((x) + ((state)->w + 1) * (y))
190 #define SQUARE_INDEX(state, x, y) ((x) + ((state)->w) * (y))
191 #define HL_INDEX(state, x, y) SQUARE_INDEX(state, x, y)
192 #define VL_INDEX(state, x, y) DOT_INDEX(state, x, y)
194 /* Useful utility functions */
195 #define LEGAL_DOT(state, i, j) ((i) >= 0 && (j) >= 0 && \
196 (i) <= (state)->w && (j) <= (state)->h)
197 #define LEGAL_SQUARE(state, i, j) ((i) >= 0 && (j) >= 0 && \
198 (i) < (state)->w && (j) < (state)->h)
200 #define CLUE_AT(state, i, j) (LEGAL_SQUARE(state, i, j) ? \
201 LV_CLUE_AT(state, i, j) : -1)
203 #define LV_CLUE_AT(state, i, j) ((state)->clues[SQUARE_INDEX(state, i, j)])
205 #define BIT_SET(field, bit) ((field) & (1<<(bit)))
207 #define SET_BIT(field, bit) (BIT_SET(field, bit) ? FALSE : \
208 ((field) |= (1<<(bit)), TRUE))
210 #define CLEAR_BIT(field, bit) (BIT_SET(field, bit) ? \
211 ((field) &= ~(1<<(bit)), TRUE) : FALSE)
214 ((d == UP) ? "up" : \
215 (d == DOWN) ? "down" : \
216 (d == LEFT) ? "left" : \
217 (d == RIGHT) ? "right" : "oops")
219 #define CLUE2CHAR(c) \
220 ((c < 0) ? ' ' : c + '0')
222 /* Lines that have particular relationships with given dots or squares */
223 #define ABOVE_SQUARE(state, i, j) ((state)->hl[(i) + (state)->w * (j)])
224 #define BELOW_SQUARE(state, i, j) ABOVE_SQUARE(state, i, (j)+1)
225 #define LEFTOF_SQUARE(state, i, j) ((state)->vl[(i) + ((state)->w + 1) * (j)])
226 #define RIGHTOF_SQUARE(state, i, j) LEFTOF_SQUARE(state, (i)+1, j)
229 * These macros return rvalues only, but can cope with being passed
230 * out-of-range coordinates.
232 /* XXX replace these with functions so we can create an array of function
233 * pointers for nicer iteration over them. This could probably be done with
234 * loads of other things for eliminating many nasty hacks. */
235 #define ABOVE_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || j <= 0) ? \
236 LINE_NO : LV_ABOVE_DOT(state, i, j))
237 #define BELOW_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || j >= (state)->h) ? \
238 LINE_NO : LV_BELOW_DOT(state, i, j))
240 #define LEFTOF_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || i <= 0) ? \
241 LINE_NO : LV_LEFTOF_DOT(state, i, j))
242 #define RIGHTOF_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || i >= (state)->w)? \
243 LINE_NO : LV_RIGHTOF_DOT(state, i, j))
246 * These macros expect to be passed valid coordinates, and return
249 #define LV_BELOW_DOT(state, i, j) ((state)->vl[VL_INDEX(state, i, j)])
250 #define LV_ABOVE_DOT(state, i, j) LV_BELOW_DOT(state, i, (j)-1)
252 #define LV_RIGHTOF_DOT(state, i, j) ((state)->hl[HL_INDEX(state, i, j)])
253 #define LV_LEFTOF_DOT(state, i, j) LV_RIGHTOF_DOT(state, (i)-1, j)
255 /* Counts of interesting things */
256 #define DOT_YES_COUNT(sstate, i, j) \
257 ((sstate)->dot_yescount[DOT_INDEX((sstate)->state, i, j)])
259 #define DOT_NO_COUNT(sstate, i, j) \
260 ((sstate)->dot_nocount[DOT_INDEX((sstate)->state, i, j)])
262 #define SQUARE_YES_COUNT(sstate, i, j) \
263 ((sstate)->square_yescount[SQUARE_INDEX((sstate)->state, i, j)])
265 #define SQUARE_NO_COUNT(sstate, i, j) \
266 ((sstate)->square_nocount[SQUARE_INDEX((sstate)->state, i, j)])
268 /* Iterators. NB these iterate over height more slowly than over width so that
269 * the elements come out in 'reading' order */
270 /* XXX considering adding a 'current' element to each of these which gets the
271 * address of the current dot, say. But expecting we'd need more than that
272 * most of the time. */
273 #define FORALL(i, j, w, h) \
274 for ((j) = 0; (j) < (h); ++(j)) \
275 for ((i) = 0; (i) < (w); ++(i))
277 #define FORALL_DOTS(state, i, j) \
278 FORALL(i, j, (state)->w + 1, (state)->h + 1)
280 #define FORALL_SQUARES(state, i, j) \
281 FORALL(i, j, (state)->w, (state)->h)
283 #define FORALL_HL(state, i, j) \
284 FORALL(i, j, (state)->w, (state)->h+1)
286 #define FORALL_VL(state, i, j) \
287 FORALL(i, j, (state)->w+1, (state)->h)
289 /* ----------------------------------------------------------------------
290 * General struct manipulation and other straightforward code
293 static game_state
*dup_game(game_state
*state
)
295 game_state
*ret
= snew(game_state
);
299 ret
->solved
= state
->solved
;
300 ret
->cheated
= state
->cheated
;
302 ret
->clues
= snewn(SQUARE_COUNT(state
), char);
303 memcpy(ret
->clues
, state
->clues
, SQUARE_COUNT(state
));
305 ret
->hl
= snewn(HL_COUNT(state
), char);
306 memcpy(ret
->hl
, state
->hl
, HL_COUNT(state
));
308 ret
->vl
= snewn(VL_COUNT(state
), char);
309 memcpy(ret
->vl
, state
->vl
, VL_COUNT(state
));
311 ret
->recursion_depth
= state
->recursion_depth
;
316 static void free_game(game_state
*state
)
326 static solver_state
*new_solver_state(const game_state
*state
, int diff
) {
328 solver_state
*ret
= snew(solver_state
);
330 ret
->state
= dup_game((game_state
*)state
);
332 ret
->recursion_remaining
= state
->recursion_depth
;
333 ret
->solver_status
= SOLVER_INCOMPLETE
;
335 ret
->dotdsf
= snew_dsf(DOT_COUNT(state
));
336 ret
->looplen
= snewn(DOT_COUNT(state
), int);
338 for (i
= 0; i
< DOT_COUNT(state
); i
++) {
342 ret
->dot_solved
= snewn(DOT_COUNT(state
), char);
343 ret
->square_solved
= snewn(SQUARE_COUNT(state
), char);
344 memset(ret
->dot_solved
, FALSE
, DOT_COUNT(state
));
345 memset(ret
->square_solved
, FALSE
, SQUARE_COUNT(state
));
347 ret
->dot_yescount
= snewn(DOT_COUNT(state
), char);
348 memset(ret
->dot_yescount
, 0, DOT_COUNT(state
));
349 ret
->dot_nocount
= snewn(DOT_COUNT(state
), char);
350 memset(ret
->dot_nocount
, 0, DOT_COUNT(state
));
351 ret
->square_yescount
= snewn(SQUARE_COUNT(state
), char);
352 memset(ret
->square_yescount
, 0, SQUARE_COUNT(state
));
353 ret
->square_nocount
= snewn(SQUARE_COUNT(state
), char);
354 memset(ret
->square_nocount
, 0, SQUARE_COUNT(state
));
356 /* dot_nocount needs special initialisation as we define lines coming off
357 * dots on edges as fixed at NO */
359 FORALL_DOTS(state
, i
, j
) {
360 if (i
== 0 || i
== state
->w
)
361 ++ret
->dot_nocount
[DOT_INDEX(state
, i
, j
)];
362 if (j
== 0 || j
== state
->h
)
363 ++ret
->dot_nocount
[DOT_INDEX(state
, i
, j
)];
366 if (diff
< DIFF_NORMAL
) {
369 ret
->normal
= snew(normal_mode_state
);
371 ret
->normal
->dot_atmostone
= snewn(DOT_COUNT(state
), char);
372 memset(ret
->normal
->dot_atmostone
, 0, DOT_COUNT(state
));
373 ret
->normal
->dot_atleastone
= snewn(DOT_COUNT(state
), char);
374 memset(ret
->normal
->dot_atleastone
, 0, DOT_COUNT(state
));
377 if (diff
< DIFF_HARD
) {
380 ret
->hard
= snew(hard_mode_state
);
381 ret
->hard
->linedsf
= snew_dsf(LINE_COUNT(state
));
387 static void free_solver_state(solver_state
*sstate
) {
389 free_game(sstate
->state
);
390 sfree(sstate
->dotdsf
);
391 sfree(sstate
->looplen
);
392 sfree(sstate
->dot_solved
);
393 sfree(sstate
->square_solved
);
394 sfree(sstate
->dot_yescount
);
395 sfree(sstate
->dot_nocount
);
396 sfree(sstate
->square_yescount
);
397 sfree(sstate
->square_nocount
);
399 if (sstate
->normal
) {
400 sfree(sstate
->normal
->dot_atleastone
);
401 sfree(sstate
->normal
->dot_atmostone
);
402 sfree(sstate
->normal
);
406 sfree(sstate
->hard
->linedsf
);
414 static solver_state
*dup_solver_state(const solver_state
*sstate
) {
417 solver_state
*ret
= snew(solver_state
);
419 ret
->state
= state
= dup_game(sstate
->state
);
421 ret
->recursion_remaining
= sstate
->recursion_remaining
;
422 ret
->solver_status
= sstate
->solver_status
;
424 ret
->dotdsf
= snewn(DOT_COUNT(state
), int);
425 ret
->looplen
= snewn(DOT_COUNT(state
), int);
426 memcpy(ret
->dotdsf
, sstate
->dotdsf
,
427 DOT_COUNT(state
) * sizeof(int));
428 memcpy(ret
->looplen
, sstate
->looplen
,
429 DOT_COUNT(state
) * sizeof(int));
431 ret
->dot_solved
= snewn(DOT_COUNT(state
), char);
432 ret
->square_solved
= snewn(SQUARE_COUNT(state
), char);
433 memcpy(ret
->dot_solved
, sstate
->dot_solved
,
435 memcpy(ret
->square_solved
, sstate
->square_solved
,
436 SQUARE_COUNT(state
));
438 ret
->dot_yescount
= snewn(DOT_COUNT(state
), char);
439 memcpy(ret
->dot_yescount
, sstate
->dot_yescount
,
441 ret
->dot_nocount
= snewn(DOT_COUNT(state
), char);
442 memcpy(ret
->dot_nocount
, sstate
->dot_nocount
,
445 ret
->square_yescount
= snewn(SQUARE_COUNT(state
), char);
446 memcpy(ret
->square_yescount
, sstate
->square_yescount
,
447 SQUARE_COUNT(state
));
448 ret
->square_nocount
= snewn(SQUARE_COUNT(state
), char);
449 memcpy(ret
->square_nocount
, sstate
->square_nocount
,
450 SQUARE_COUNT(state
));
452 if (sstate
->normal
) {
453 ret
->normal
= snew(normal_mode_state
);
454 ret
->normal
->dot_atmostone
= snewn(DOT_COUNT(state
), char);
455 memcpy(ret
->normal
->dot_atmostone
, sstate
->normal
->dot_atmostone
,
458 ret
->normal
->dot_atleastone
= snewn(DOT_COUNT(state
), char);
459 memcpy(ret
->normal
->dot_atleastone
, sstate
->normal
->dot_atleastone
,
466 ret
->hard
= snew(hard_mode_state
);
467 ret
->hard
->linedsf
= snewn(LINE_COUNT(state
), int);
468 memcpy(ret
->hard
->linedsf
, sstate
->hard
->linedsf
,
469 LINE_COUNT(state
) * sizeof(int));
477 static game_params
*default_params(void)
479 game_params
*ret
= snew(game_params
);
488 ret
->diff
= DIFF_EASY
;
494 static game_params
*dup_params(game_params
*params
)
496 game_params
*ret
= snew(game_params
);
497 *ret
= *params
; /* structure copy */
501 static const game_params presets
[] = {
502 { 4, 4, DIFF_EASY
, 0 },
503 { 4, 4, DIFF_NORMAL
, 0 },
504 { 4, 4, DIFF_HARD
, 0 },
505 { 7, 7, DIFF_EASY
, 0 },
506 { 7, 7, DIFF_NORMAL
, 0 },
507 { 7, 7, DIFF_HARD
, 0 },
508 { 10, 10, DIFF_EASY
, 0 },
509 { 10, 10, DIFF_NORMAL
, 0 },
510 { 10, 10, DIFF_HARD
, 0 },
512 { 15, 15, DIFF_EASY
, 0 },
513 { 15, 15, DIFF_NORMAL
, 0 },
514 { 15, 15, DIFF_HARD
, 0 },
516 { 30, 20, DIFF_EASY
, 0 },
517 { 30, 20, DIFF_NORMAL
, 0 },
518 { 30, 20, DIFF_HARD
, 0 }
523 static int game_fetch_preset(int i
, char **name
, game_params
**params
)
528 if (i
< 0 || i
>= lenof(presets
))
531 tmppar
= snew(game_params
);
532 *tmppar
= presets
[i
];
534 sprintf(buf
, "%dx%d %s", tmppar
->h
, tmppar
->w
, diffnames
[tmppar
->diff
]);
540 static void free_params(game_params
*params
)
545 static void decode_params(game_params
*params
, char const *string
)
547 params
->h
= params
->w
= atoi(string
);
549 params
->diff
= DIFF_EASY
;
550 while (*string
&& isdigit((unsigned char)*string
)) string
++;
551 if (*string
== 'x') {
553 params
->h
= atoi(string
);
554 while (*string
&& isdigit((unsigned char)*string
)) string
++;
556 if (*string
== 'r') {
558 params
->rec
= atoi(string
);
559 while (*string
&& isdigit((unsigned char)*string
)) string
++;
561 if (*string
== 'd') {
564 for (i
= 0; i
< DIFF_MAX
; i
++)
565 if (*string
== diffchars
[i
])
567 if (*string
) string
++;
571 static char *encode_params(game_params
*params
, int full
)
574 sprintf(str
, "%dx%d", params
->w
, params
->h
);
576 sprintf(str
+ strlen(str
), "r%dd%c", params
->rec
, diffchars
[params
->diff
]);
580 static config_item
*game_configure(game_params
*params
)
585 ret
= snewn(4, config_item
);
587 ret
[0].name
= "Width";
588 ret
[0].type
= C_STRING
;
589 sprintf(buf
, "%d", params
->w
);
590 ret
[0].sval
= dupstr(buf
);
593 ret
[1].name
= "Height";
594 ret
[1].type
= C_STRING
;
595 sprintf(buf
, "%d", params
->h
);
596 ret
[1].sval
= dupstr(buf
);
599 ret
[2].name
= "Difficulty";
600 ret
[2].type
= C_CHOICES
;
601 ret
[2].sval
= DIFFCONFIG
;
602 ret
[2].ival
= params
->diff
;
612 static game_params
*custom_params(config_item
*cfg
)
614 game_params
*ret
= snew(game_params
);
616 ret
->w
= atoi(cfg
[0].sval
);
617 ret
->h
= atoi(cfg
[1].sval
);
619 ret
->diff
= cfg
[2].ival
;
624 static char *validate_params(game_params
*params
, int full
)
626 if (params
->w
< 4 || params
->h
< 4)
627 return "Width and height must both be at least 4";
629 return "Recursion depth can't be negative";
632 * This shouldn't be able to happen at all, since decode_params
633 * and custom_params will never generate anything that isn't
636 assert(params
->diff
< DIFF_MAX
);
641 /* Returns a newly allocated string describing the current puzzle */
642 static char *state_to_text(const game_state
*state
)
645 char *description
= snewn(SQUARE_COUNT(state
) + 1, char);
646 char *dp
= description
;
650 FORALL_SQUARES(state
, i
, j
) {
651 if (CLUE_AT(state
, i
, j
) < 0) {
652 if (empty_count
> 25) {
653 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
659 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
662 dp
+= sprintf(dp
, "%c", (int)CLUE2CHAR(CLUE_AT(state
, i
, j
)));
667 dp
+= sprintf(dp
, "%c", (int)(empty_count
+ 'a' - 1));
669 retval
= dupstr(description
);
675 /* We require that the params pass the test in validate_params and that the
676 * description fills the entire game area */
677 static char *validate_desc(game_params
*params
, char *desc
)
681 for (; *desc
; ++desc
) {
682 if (*desc
>= '0' && *desc
<= '9') {
687 count
+= *desc
- 'a' + 1;
690 return "Unknown character in description";
693 if (count
< SQUARE_COUNT(params
))
694 return "Description too short for board size";
695 if (count
> SQUARE_COUNT(params
))
696 return "Description too long for board size";
701 /* Sums the lengths of the numbers in range [0,n) */
702 /* See equivalent function in solo.c for justification of this. */
703 static int len_0_to_n(int n
)
705 int len
= 1; /* Counting 0 as a bit of a special case */
708 for (i
= 1; i
< n
; i
*= 10) {
709 len
+= max(n
- i
, 0);
715 static char *encode_solve_move(const game_state
*state
)
719 /* This is going to return a string representing the moves needed to set
720 * every line in a grid to be the same as the ones in 'state'. The exact
721 * length of this string is predictable. */
723 len
= 1; /* Count the 'S' prefix */
724 /* Numbers in horizontal lines */
725 /* Horizontal lines, x position */
726 len
+= len_0_to_n(state
->w
) * (state
->h
+ 1);
727 /* Horizontal lines, y position */
728 len
+= len_0_to_n(state
->h
+ 1) * (state
->w
);
729 /* Vertical lines, y position */
730 len
+= len_0_to_n(state
->h
) * (state
->w
+ 1);
731 /* Vertical lines, x position */
732 len
+= len_0_to_n(state
->w
+ 1) * (state
->h
);
733 /* For each line we also have two letters and a comma */
734 len
+= 3 * (LINE_COUNT(state
));
736 ret
= snewn(len
+ 1, char);
739 p
+= sprintf(p
, "S");
741 FORALL_HL(state
, i
, j
) {
742 switch (RIGHTOF_DOT(state
, i
, j
)) {
744 p
+= sprintf(p
, "%d,%dhy", i
, j
);
747 p
+= sprintf(p
, "%d,%dhn", i
, j
);
752 FORALL_VL(state
, i
, j
) {
753 switch (BELOW_DOT(state
, i
, j
)) {
755 p
+= sprintf(p
, "%d,%dvy", i
, j
);
758 p
+= sprintf(p
, "%d,%dvn", i
, j
);
763 /* No point in doing sums like that if they're going to be wrong */
764 assert(strlen(ret
) <= (size_t)len
);
768 static game_ui
*new_ui(game_state
*state
)
773 static void free_ui(game_ui
*ui
)
777 static char *encode_ui(game_ui
*ui
)
782 static void decode_ui(game_ui
*ui
, char *encoding
)
786 static void game_changed_state(game_ui
*ui
, game_state
*oldstate
,
787 game_state
*newstate
)
791 #define SIZE(d) ((d) * TILE_SIZE + 2 * BORDER + 1)
793 static void game_compute_size(game_params
*params
, int tilesize
,
796 struct { int tilesize
; } ads
, *ds
= &ads
;
797 ads
.tilesize
= tilesize
;
799 *x
= SIZE(params
->w
);
800 *y
= SIZE(params
->h
);
803 static void game_set_size(drawing
*dr
, game_drawstate
*ds
,
804 game_params
*params
, int tilesize
)
806 ds
->tilesize
= tilesize
;
807 ds
->linewidth
= max(1,tilesize
/16);
810 static float *game_colours(frontend
*fe
, int *ncolours
)
812 float *ret
= snewn(4 * NCOLOURS
, float);
814 frontend_default_colour(fe
, &ret
[COL_BACKGROUND
* 3]);
816 ret
[COL_FOREGROUND
* 3 + 0] = 0.0F
;
817 ret
[COL_FOREGROUND
* 3 + 1] = 0.0F
;
818 ret
[COL_FOREGROUND
* 3 + 2] = 0.0F
;
820 ret
[COL_HIGHLIGHT
* 3 + 0] = 1.0F
;
821 ret
[COL_HIGHLIGHT
* 3 + 1] = 1.0F
;
822 ret
[COL_HIGHLIGHT
* 3 + 2] = 1.0F
;
824 ret
[COL_MISTAKE
* 3 + 0] = 1.0F
;
825 ret
[COL_MISTAKE
* 3 + 1] = 0.0F
;
826 ret
[COL_MISTAKE
* 3 + 2] = 0.0F
;
828 *ncolours
= NCOLOURS
;
832 static game_drawstate
*game_new_drawstate(drawing
*dr
, game_state
*state
)
834 struct game_drawstate
*ds
= snew(struct game_drawstate
);
836 ds
->tilesize
= ds
->linewidth
= 0;
838 ds
->hl
= snewn(HL_COUNT(state
), char);
839 ds
->vl
= snewn(VL_COUNT(state
), char);
840 ds
->clue_error
= snewn(SQUARE_COUNT(state
), char);
843 memset(ds
->hl
, LINE_UNKNOWN
, HL_COUNT(state
));
844 memset(ds
->vl
, LINE_UNKNOWN
, VL_COUNT(state
));
845 memset(ds
->clue_error
, 0, SQUARE_COUNT(state
));
850 static void game_free_drawstate(drawing
*dr
, game_drawstate
*ds
)
852 sfree(ds
->clue_error
);
858 static int game_timing_state(game_state
*state
, game_ui
*ui
)
863 static float game_anim_length(game_state
*oldstate
, game_state
*newstate
,
864 int dir
, game_ui
*ui
)
869 static char *game_text_format(game_state
*state
)
875 len
= (2 * state
->w
+ 2) * (2 * state
->h
+ 1);
876 rp
= ret
= snewn(len
+ 1, char);
879 switch (ABOVE_SQUARE(state, i, j)) { \
881 rp += sprintf(rp, " -"); \
884 rp += sprintf(rp, " x"); \
887 rp += sprintf(rp, " "); \
890 assert(!"Illegal line state for HL"); \
894 switch (LEFTOF_SQUARE(state, i, j)) { \
896 rp += sprintf(rp, "|"); \
899 rp += sprintf(rp, "x"); \
902 rp += sprintf(rp, " "); \
905 assert(!"Illegal line state for VL"); \
908 for (j
= 0; j
< state
->h
; ++j
) {
909 for (i
= 0; i
< state
->w
; ++i
) {
912 rp
+= sprintf(rp
, " \n");
913 for (i
= 0; i
< state
->w
; ++i
) {
915 rp
+= sprintf(rp
, "%c", (int)CLUE2CHAR(CLUE_AT(state
, i
, j
)));
918 rp
+= sprintf(rp
, "\n");
920 for (i
= 0; i
< state
->w
; ++i
) {
923 rp
+= sprintf(rp
, " \n");
925 assert(strlen(ret
) == len
);
929 /* ----------------------------------------------------------------------
934 static void check_caches(const solver_state
* sstate
)
937 const game_state
*state
= sstate
->state
;
939 FORALL_DOTS(state
, i
, j
) {
941 fprintf(stderr
, "dot [%d,%d] y: %d %d n: %d %d\n", i
, j
,
942 dot_order(state
, i
, j
, LINE_YES
),
943 sstate
->dot_yescount
[i
+ (state
->w
+ 1) * j
],
944 dot_order(state
, i
, j
, LINE_NO
),
945 sstate
->dot_nocount
[i
+ (state
->w
+ 1) * j
]);
948 assert(dot_order(state
, i
, j
, LINE_YES
) ==
949 DOT_YES_COUNT(sstate
, i
, j
));
950 assert(dot_order(state
, i
, j
, LINE_NO
) ==
951 DOT_NO_COUNT(sstate
, i
, j
));
954 FORALL_SQUARES(state
, i
, j
) {
956 fprintf(stderr
, "square [%d,%d] y: %d %d n: %d %d\n", i
, j
,
957 square_order(state
, i
, j
, LINE_YES
),
958 sstate
->square_yescount
[i
+ state
->w
* j
],
959 square_order(state
, i
, j
, LINE_NO
),
960 sstate
->square_nocount
[i
+ state
->w
* j
]);
963 assert(square_order(state
, i
, j
, LINE_YES
) ==
964 SQUARE_YES_COUNT(sstate
, i
, j
));
965 assert(square_order(state
, i
, j
, LINE_NO
) ==
966 SQUARE_NO_COUNT(sstate
, i
, j
));
971 #define check_caches(s) \
973 fprintf(stderr, "check_caches at line %d\n", __LINE__); \
977 #endif /* DEBUG_CACHES */
979 /* ----------------------------------------------------------------------
980 * Solver utility functions
983 static int set_line_bydot(solver_state
*sstate
, int x
, int y
, enum direction d
,
984 enum line_state line_new
990 game_state
*state
= sstate
->state
;
992 /* This line borders at most two squares in our board. We figure out the
993 * x and y positions of those squares so we can record that their yes or no
994 * counts have been changed */
995 int sq1_x
=-1, sq1_y
=-1, sq2_x
=-1, sq2_y
=-1;
996 int otherdot_x
=-1, otherdot_y
=-1;
998 int progress
= FALSE
;
1001 fprintf(stderr
, "set_line_bydot [%d,%d], %s, %d\n",
1002 x
, y
, DIR2STR(d
), line_new
);
1005 assert(line_new
!= LINE_UNKNOWN
);
1007 check_caches(sstate
);
1013 if (LEFTOF_DOT(state
, x
, y
) != line_new
) {
1014 LV_LEFTOF_DOT(state
, x
, y
) = line_new
;
1028 assert(x
< state
->w
);
1029 if (RIGHTOF_DOT(state
, x
, y
) != line_new
) {
1030 LV_RIGHTOF_DOT(state
, x
, y
) = line_new
;
1045 if (ABOVE_DOT(state
, x
, y
) != line_new
) {
1046 LV_ABOVE_DOT(state
, x
, y
) = line_new
;
1060 assert(y
< state
->h
);
1061 if (BELOW_DOT(state
, x
, y
) != line_new
) {
1062 LV_BELOW_DOT(state
, x
, y
) = line_new
;
1081 fprintf(stderr
, "set line [%d,%d] -> [%d,%d] to %s (%s)\n",
1082 x
, y
, otherdot_x
, otherdot_y
, line_new
== LINE_YES ?
"YES" : "NO",
1086 /* Above we updated the cache for the dot that the line in question reaches
1087 * from the dot we've been told about. Here we update that for the dot
1088 * named in our arguments. */
1089 if (line_new
== LINE_YES
) {
1090 if (sq1_x
>= 0 && sq1_y
>= 0)
1091 ++SQUARE_YES_COUNT(sstate
, sq1_x
, sq1_y
);
1092 if (sq2_x
< state
->w
&& sq2_y
< state
->h
)
1093 ++SQUARE_YES_COUNT(sstate
, sq2_x
, sq2_y
);
1094 ++DOT_YES_COUNT(sstate
, x
, y
);
1095 ++DOT_YES_COUNT(sstate
, otherdot_x
, otherdot_y
);
1097 if (sq1_x
>= 0 && sq1_y
>= 0)
1098 ++SQUARE_NO_COUNT(sstate
, sq1_x
, sq1_y
);
1099 if (sq2_x
< state
->w
&& sq2_y
< state
->h
)
1100 ++SQUARE_NO_COUNT(sstate
, sq2_x
, sq2_y
);
1101 ++DOT_NO_COUNT(sstate
, x
, y
);
1102 ++DOT_NO_COUNT(sstate
, otherdot_x
, otherdot_y
);
1105 check_caches(sstate
);
1110 #define set_line_bydot(a, b, c, d, e) \
1111 set_line_bydot(a, b, c, d, e, __FUNCTION__)
1115 * Merge two dots due to the existence of an edge between them.
1116 * Updates the dsf tracking equivalence classes, and keeps track of
1117 * the length of path each dot is currently a part of.
1118 * Returns TRUE if the dots were already linked, ie if they are part of a
1119 * closed loop, and false otherwise.
1121 static int merge_dots(solver_state
*sstate
, int x1
, int y1
, int x2
, int y2
)
1125 i
= y1
* (sstate
->state
->w
+ 1) + x1
;
1126 j
= y2
* (sstate
->state
->w
+ 1) + x2
;
1128 i
= dsf_canonify(sstate
->dotdsf
, i
);
1129 j
= dsf_canonify(sstate
->dotdsf
, j
);
1134 len
= sstate
->looplen
[i
] + sstate
->looplen
[j
];
1135 dsf_merge(sstate
->dotdsf
, i
, j
);
1136 i
= dsf_canonify(sstate
->dotdsf
, i
);
1137 sstate
->looplen
[i
] = len
;
1142 /* Seriously, these should be functions */
1144 #define LINEDSF_INDEX(state, x, y, d) \
1145 ((d == UP) ? ((y-1) * (state->w + 1) + x) : \
1146 (d == DOWN) ? ((y) * (state->w + 1) + x) : \
1147 (d == LEFT) ? ((y) * (state->w) + x-1 + VL_COUNT(state)) : \
1148 (d == RIGHT) ? ((y) * (state->w) + x + VL_COUNT(state)) : \
1149 (assert(!"bad direction value"), 0))
1151 static void linedsf_deindex(const game_state
*state
, int i
,
1152 int *px
, int *py
, enum direction
*pd
)
1155 if (i
< VL_COUNT(state
)) {
1157 *(px
) = (i
) % (state
->w
+1);
1158 *(py
) = (i
) / (state
->w
+1);
1160 i_mod
= i
- VL_COUNT(state
);
1162 *(px
) = (i_mod
) % (state
->w
);
1163 *(py
) = (i_mod
) / (state
->w
);
1167 /* Merge two lines because the solver has deduced that they must be either
1168 * identical or opposite. Returns TRUE if this is new information, otherwise
1170 static int merge_lines(solver_state
*sstate
,
1171 int x1
, int y1
, enum direction d1
,
1172 int x2
, int y2
, enum direction d2
,
1175 , const char *reason
1181 i
= LINEDSF_INDEX(sstate
->state
, x1
, y1
, d1
);
1182 j
= LINEDSF_INDEX(sstate
->state
, x2
, y2
, d2
);
1184 assert(i
< LINE_COUNT(sstate
->state
));
1185 assert(j
< LINE_COUNT(sstate
->state
));
1187 i
= edsf_canonify(sstate
->hard
->linedsf
, i
, &inv_tmp
);
1189 j
= edsf_canonify(sstate
->hard
->linedsf
, j
, &inv_tmp
);
1192 edsf_merge(sstate
->hard
->linedsf
, i
, j
, inverse
);
1196 fprintf(stderr
, "%s [%d,%d,%s] [%d,%d,%s] %s(%s)\n",
1198 x1
, y1
, DIR2STR(d1
),
1199 x2
, y2
, DIR2STR(d2
),
1200 inverse ?
"inverse " : "", reason
);
1207 #define merge_lines(a, b, c, d, e, f, g, h) \
1208 merge_lines(a, b, c, d, e, f, g, h, __FUNCTION__)
1211 /* Return 0 if the given lines are not in the same equivalence class, 1 if they
1212 * are known identical, or 2 if they are known opposite */
1214 static int lines_related(solver_state
*sstate
,
1215 int x1
, int y1
, enum direction d1
,
1216 int x2
, int y2
, enum direction d2
)
1218 int i
, j
, inv1
, inv2
;
1220 i
= LINEDSF_INDEX(sstate
->state
, x1
, y1
, d1
);
1221 j
= LINEDSF_INDEX(sstate
->state
, x2
, y2
, d2
);
1223 i
= edsf_canonify(sstate
->hard
->linedsf
, i
, &inv1
);
1224 j
= edsf_canonify(sstate
->hard
->linedsf
, j
, &inv2
);
1227 return (inv1
== inv2
) ?
1 : 2;
1233 /* Count the number of lines of a particular type currently going into the
1234 * given dot. Lines going off the edge of the board are assumed fixed no. */
1235 static int dot_order(const game_state
* state
, int i
, int j
, char line_type
)
1240 if (line_type
== LV_LEFTOF_DOT(state
, i
, j
))
1243 if (line_type
== LINE_NO
)
1247 if (line_type
== LV_RIGHTOF_DOT(state
, i
, j
))
1250 if (line_type
== LINE_NO
)
1254 if (line_type
== LV_ABOVE_DOT(state
, i
, j
))
1257 if (line_type
== LINE_NO
)
1261 if (line_type
== LV_BELOW_DOT(state
, i
, j
))
1264 if (line_type
== LINE_NO
)
1271 /* Count the number of lines of a particular type currently surrounding the
1273 static int square_order(const game_state
* state
, int i
, int j
, char line_type
)
1277 if (ABOVE_SQUARE(state
, i
, j
) == line_type
)
1279 if (BELOW_SQUARE(state
, i
, j
) == line_type
)
1281 if (LEFTOF_SQUARE(state
, i
, j
) == line_type
)
1283 if (RIGHTOF_SQUARE(state
, i
, j
) == line_type
)
1289 /* Set all lines bordering a dot of type old_type to type new_type
1290 * Return value tells caller whether this function actually did anything */
1291 static int dot_setall(solver_state
*sstate
, int i
, int j
,
1292 char old_type
, char new_type
)
1294 int retval
= FALSE
, r
;
1295 game_state
*state
= sstate
->state
;
1297 if (old_type
== new_type
)
1300 if (i
> 0 && LEFTOF_DOT(state
, i
, j
) == old_type
) {
1301 r
= set_line_bydot(sstate
, i
, j
, LEFT
, new_type
);
1306 if (i
< state
->w
&& RIGHTOF_DOT(state
, i
, j
) == old_type
) {
1307 r
= set_line_bydot(sstate
, i
, j
, RIGHT
, new_type
);
1312 if (j
> 0 && ABOVE_DOT(state
, i
, j
) == old_type
) {
1313 r
= set_line_bydot(sstate
, i
, j
, UP
, new_type
);
1318 if (j
< state
->h
&& BELOW_DOT(state
, i
, j
) == old_type
) {
1319 r
= set_line_bydot(sstate
, i
, j
, DOWN
, new_type
);
1327 /* Set all lines bordering a square of type old_type to type new_type */
1328 static int square_setall(solver_state
*sstate
, int i
, int j
,
1329 char old_type
, char new_type
)
1332 game_state
*state
= sstate
->state
;
1335 fprintf(stderr
, "square_setall [%d,%d] from %d to %d\n", i
, j
,
1336 old_type
, new_type
);
1338 if (ABOVE_SQUARE(state
, i
, j
) == old_type
) {
1339 r
= set_line_bydot(sstate
, i
, j
, RIGHT
, new_type
);
1342 if (BELOW_SQUARE(state
, i
, j
) == old_type
) {
1343 r
= set_line_bydot(sstate
, i
, j
+1, RIGHT
, new_type
);
1346 if (LEFTOF_SQUARE(state
, i
, j
) == old_type
) {
1347 r
= set_line_bydot(sstate
, i
, j
, DOWN
, new_type
);
1350 if (RIGHTOF_SQUARE(state
, i
, j
) == old_type
) {
1351 r
= set_line_bydot(sstate
, i
+1, j
, DOWN
, new_type
);
1358 /* ----------------------------------------------------------------------
1359 * Loop generation and clue removal
1362 /* We're going to store a list of current candidate squares for lighting.
1363 * Each square gets a 'score', which tells us how adding that square right
1364 * now would affect the length of the solution loop. We're trying to
1365 * maximise that quantity so will bias our random selection of squares to
1366 * light towards those with high scores */
1369 unsigned long random
;
1373 static int get_square_cmpfn(void *v1
, void *v2
)
1375 struct square
*s1
= v1
;
1376 struct square
*s2
= v2
;
1390 static int square_sort_cmpfn(void *v1
, void *v2
)
1392 struct square
*s1
= v1
;
1393 struct square
*s2
= v2
;
1396 r
= s2
->score
- s1
->score
;
1401 if (s1
->random
< s2
->random
)
1403 else if (s1
->random
> s2
->random
)
1407 * It's _just_ possible that two squares might have been given
1408 * the same random value. In that situation, fall back to
1409 * comparing based on the coordinates. This introduces a tiny
1410 * directional bias, but not a significant one.
1412 return get_square_cmpfn(v1
, v2
);
1415 enum { SQUARE_LIT
, SQUARE_UNLIT
};
1417 #define SQUARE_STATE(i, j) \
1418 ( LEGAL_SQUARE(state, i, j) ? \
1419 LV_SQUARE_STATE(i,j) : \
1422 #define LV_SQUARE_STATE(i, j) board[SQUARE_INDEX(state, i, j)]
1424 /* Generate a new complete set of clues for the given game_state (respecting
1425 * the dimensions provided by said game_state) */
1426 static void add_full_clues(game_state
*state
, random_state
*rs
)
1431 int board_area
= SQUARE_COUNT(state
);
1434 struct square
*square
, *tmpsquare
, *sq
;
1435 struct square square_pos
;
1437 /* These will contain exactly the same information, sorted into different
1439 tree234
*lightable_squares_sorted
, *lightable_squares_gettable
;
1441 #define SQUARE_REACHABLE(i,j) \
1442 (t = (SQUARE_STATE(i-1, j) == SQUARE_LIT || \
1443 SQUARE_STATE(i+1, j) == SQUARE_LIT || \
1444 SQUARE_STATE(i, j-1) == SQUARE_LIT || \
1445 SQUARE_STATE(i, j+1) == SQUARE_LIT), \
1448 /* One situation in which we may not light a square is if that'll leave one
1449 * square above/below and one left/right of us unlit, separated by a lit
1450 * square diagnonal from us */
1451 #define SQUARE_DIAGONAL_VIOLATION(i, j, h, v) \
1452 (t = (SQUARE_STATE((i)+(h), (j)) == SQUARE_UNLIT && \
1453 SQUARE_STATE((i), (j)+(v)) == SQUARE_UNLIT && \
1454 SQUARE_STATE((i)+(h), (j)+(v)) == SQUARE_LIT), \
1457 /* We also may not light a square if it will form a loop of lit squares
1458 * around some unlit squares, as then the game soln won't have a single
1460 #define SQUARE_LOOP_VIOLATION(i, j, lit1, lit2) \
1461 (SQUARE_STATE((i)+1, (j)) == lit1 && \
1462 SQUARE_STATE((i)-1, (j)) == lit1 && \
1463 SQUARE_STATE((i), (j)+1) == lit2 && \
1464 SQUARE_STATE((i), (j)-1) == lit2)
1466 #define CAN_LIGHT_SQUARE(i, j) \
1467 (SQUARE_REACHABLE(i, j) && \
1468 !SQUARE_DIAGONAL_VIOLATION(i, j, -1, -1) && \
1469 !SQUARE_DIAGONAL_VIOLATION(i, j, +1, -1) && \
1470 !SQUARE_DIAGONAL_VIOLATION(i, j, -1, +1) && \
1471 !SQUARE_DIAGONAL_VIOLATION(i, j, +1, +1) && \
1472 !SQUARE_LOOP_VIOLATION(i, j, SQUARE_LIT, SQUARE_UNLIT) && \
1473 !SQUARE_LOOP_VIOLATION(i, j, SQUARE_UNLIT, SQUARE_LIT))
1475 #define IS_LIGHTING_CANDIDATE(i, j) \
1476 (SQUARE_STATE(i, j) == SQUARE_UNLIT && \
1477 CAN_LIGHT_SQUARE(i,j))
1479 /* The 'score' of a square reflects its current desirability for selection
1480 * as the next square to light. We want to encourage moving into uncharted
1481 * areas so we give scores according to how many of the square's neighbours
1482 * are currently unlit. */
1489 #define SQUARE_SCORE(i,j) \
1490 (2*((SQUARE_STATE(i-1, j) == SQUARE_UNLIT) + \
1491 (SQUARE_STATE(i+1, j) == SQUARE_UNLIT) + \
1492 (SQUARE_STATE(i, j-1) == SQUARE_UNLIT) + \
1493 (SQUARE_STATE(i, j+1) == SQUARE_UNLIT)) - 4)
1495 /* When a square gets lit, this defines how far away from that square we
1496 * need to go recomputing scores */
1497 #define SCORE_DISTANCE 1
1499 board
= snewn(board_area
, char);
1500 clues
= state
->clues
;
1503 memset(board
, SQUARE_UNLIT
, board_area
);
1505 /* Seed the board with a single lit square near the middle */
1508 if (state
->w
& 1 && random_bits(rs
, 1))
1510 if (state
->h
& 1 && random_bits(rs
, 1))
1513 LV_SQUARE_STATE(i
, j
) = SQUARE_LIT
;
1515 /* We need a way of favouring squares that will increase our loopiness.
1516 * We do this by maintaining a list of all candidate squares sorted by
1517 * their score and choose randomly from that with appropriate skew.
1518 * In order to avoid consistently biasing towards particular squares, we
1519 * need the sort order _within_ each group of scores to be completely
1520 * random. But it would be abusing the hospitality of the tree234 data
1521 * structure if our comparison function were nondeterministic :-). So with
1522 * each square we associate a random number that does not change during a
1523 * particular run of the generator, and use that as a secondary sort key.
1524 * Yes, this means we will be biased towards particular random squares in
1525 * any one run but that doesn't actually matter. */
1527 lightable_squares_sorted
= newtree234(square_sort_cmpfn
);
1528 lightable_squares_gettable
= newtree234(get_square_cmpfn
);
1529 #define ADD_SQUARE(s) \
1531 sq = add234(lightable_squares_sorted, s); \
1533 sq = add234(lightable_squares_gettable, s); \
1537 #define REMOVE_SQUARE(s) \
1539 sq = del234(lightable_squares_sorted, s); \
1541 sq = del234(lightable_squares_gettable, s); \
1545 #define HANDLE_DIR(a, b) \
1546 square = snew(struct square); \
1547 square->x = (i)+(a); \
1548 square->y = (j)+(b); \
1549 square->score = 2; \
1550 square->random = random_bits(rs, 31); \
1558 /* Light squares one at a time until the board is interesting enough */
1561 /* We have count234(lightable_squares) possibilities, and in
1562 * lightable_squares_sorted they are sorted with the most desirable
1564 c
= count234(lightable_squares_sorted
);
1567 assert(c
== count234(lightable_squares_gettable
));
1569 /* Check that the best square available is any good */
1570 square
= (struct square
*)index234(lightable_squares_sorted
, 0);
1574 * We never want to _decrease_ the loop's perimeter. Making
1575 * moves that leave the perimeter the same is occasionally
1576 * useful: if it were _never_ done then the user would be
1577 * able to deduce illicitly that any degree-zero vertex was
1578 * on the outside of the loop. So we do it sometimes but
1581 if (square
->score
< 0 || (square
->score
== 0 &&
1582 random_upto(rs
, 2) == 0)) {
1586 assert(square
->score
== SQUARE_SCORE(square
->x
, square
->y
));
1587 assert(SQUARE_STATE(square
->x
, square
->y
) == SQUARE_UNLIT
);
1588 assert(square
->x
>= 0 && square
->x
< state
->w
);
1589 assert(square
->y
>= 0 && square
->y
< state
->h
);
1591 /* Update data structures */
1592 LV_SQUARE_STATE(square
->x
, square
->y
) = SQUARE_LIT
;
1593 REMOVE_SQUARE(square
);
1595 /* We might have changed the score of any squares up to 2 units away in
1597 for (b
= -SCORE_DISTANCE
; b
<= SCORE_DISTANCE
; b
++) {
1598 for (a
= -SCORE_DISTANCE
; a
<= SCORE_DISTANCE
; a
++) {
1601 square_pos
.x
= square
->x
+ a
;
1602 square_pos
.y
= square
->y
+ b
;
1603 if (square_pos
.x
< 0 || square_pos
.x
>= state
->w
||
1604 square_pos
.y
< 0 || square_pos
.y
>= state
->h
) {
1607 tmpsquare
= find234(lightable_squares_gettable
, &square_pos
,
1610 assert(tmpsquare
->x
== square_pos
.x
);
1611 assert(tmpsquare
->y
== square_pos
.y
);
1612 assert(SQUARE_STATE(tmpsquare
->x
, tmpsquare
->y
) ==
1614 REMOVE_SQUARE(tmpsquare
);
1616 tmpsquare
= snew(struct square
);
1617 tmpsquare
->x
= square_pos
.x
;
1618 tmpsquare
->y
= square_pos
.y
;
1619 tmpsquare
->random
= random_bits(rs
, 31);
1621 tmpsquare
->score
= SQUARE_SCORE(tmpsquare
->x
, tmpsquare
->y
);
1623 if (IS_LIGHTING_CANDIDATE(tmpsquare
->x
, tmpsquare
->y
)) {
1624 ADD_SQUARE(tmpsquare
);
1634 while ((square
= delpos234(lightable_squares_gettable
, 0)) != NULL
)
1636 freetree234(lightable_squares_gettable
);
1637 freetree234(lightable_squares_sorted
);
1639 /* Copy out all the clues */
1640 FORALL_SQUARES(state
, i
, j
) {
1641 c
= SQUARE_STATE(i
, j
);
1642 LV_CLUE_AT(state
, i
, j
) = 0;
1643 if (SQUARE_STATE(i
-1, j
) != c
) ++LV_CLUE_AT(state
, i
, j
);
1644 if (SQUARE_STATE(i
+1, j
) != c
) ++LV_CLUE_AT(state
, i
, j
);
1645 if (SQUARE_STATE(i
, j
-1) != c
) ++LV_CLUE_AT(state
, i
, j
);
1646 if (SQUARE_STATE(i
, j
+1) != c
) ++LV_CLUE_AT(state
, i
, j
);
1652 static int game_has_unique_soln(const game_state
*state
, int diff
)
1655 solver_state
*sstate_new
;
1656 solver_state
*sstate
= new_solver_state((game_state
*)state
, diff
);
1658 sstate_new
= solve_game_rec(sstate
, diff
);
1660 assert(sstate_new
->solver_status
!= SOLVER_MISTAKE
);
1661 ret
= (sstate_new
->solver_status
== SOLVER_SOLVED
);
1663 free_solver_state(sstate_new
);
1664 free_solver_state(sstate
);
1669 /* Remove clues one at a time at random. */
1670 static game_state
*remove_clues(game_state
*state
, random_state
*rs
,
1673 int *square_list
, squares
;
1674 game_state
*ret
= dup_game(state
), *saved_ret
;
1680 /* We need to remove some clues. We'll do this by forming a list of all
1681 * available clues, shuffling it, then going along one at a
1682 * time clearing each clue in turn for which doing so doesn't render the
1683 * board unsolvable. */
1684 squares
= state
->w
* state
->h
;
1685 square_list
= snewn(squares
, int);
1686 for (n
= 0; n
< squares
; ++n
) {
1690 shuffle(square_list
, squares
, sizeof(int), rs
);
1692 for (n
= 0; n
< squares
; ++n
) {
1693 saved_ret
= dup_game(ret
);
1694 LV_CLUE_AT(ret
, square_list
[n
] % state
->w
,
1695 square_list
[n
] / state
->w
) = -1;
1698 desc
= state_to_text(ret
);
1699 fprintf(stderr
, "%dx%d:%s\n", state
->w
, state
->h
, desc
);
1703 if (game_has_unique_soln(ret
, diff
)) {
1704 free_game(saved_ret
);
1715 static char *new_game_desc(game_params
*params
, random_state
*rs
,
1716 char **aux
, int interactive
)
1718 /* solution and description both use run-length encoding in obvious ways */
1720 game_state
*state
= snew(game_state
), *state_new
;
1722 state
->h
= params
->h
;
1723 state
->w
= params
->w
;
1725 state
->clues
= snewn(SQUARE_COUNT(params
), char);
1726 state
->hl
= snewn(HL_COUNT(params
), char);
1727 state
->vl
= snewn(VL_COUNT(params
), char);
1730 memset(state
->hl
, LINE_UNKNOWN
, HL_COUNT(params
));
1731 memset(state
->vl
, LINE_UNKNOWN
, VL_COUNT(params
));
1733 state
->solved
= state
->cheated
= FALSE
;
1734 state
->recursion_depth
= params
->rec
;
1736 /* Get a new random solvable board with all its clues filled in. Yes, this
1737 * can loop for ever if the params are suitably unfavourable, but
1738 * preventing games smaller than 4x4 seems to stop this happening */
1741 add_full_clues(state
, rs
);
1742 } while (!game_has_unique_soln(state
, params
->diff
));
1744 state_new
= remove_clues(state
, rs
, params
->diff
);
1748 if (params
->diff
> 0 && game_has_unique_soln(state
, params
->diff
-1)) {
1750 fprintf(stderr
, "Rejecting board, it is too easy\n");
1752 goto newboard_please
;
1755 retval
= state_to_text(state
);
1759 assert(!validate_desc(params
, retval
));
1764 static game_state
*new_game(midend
*me
, game_params
*params
, char *desc
)
1767 game_state
*state
= snew(game_state
);
1768 int empties_to_make
= 0;
1770 const char *dp
= desc
;
1772 state
->recursion_depth
= 0; /* XXX pending removal, probably */
1774 state
->h
= params
->h
;
1775 state
->w
= params
->w
;
1777 state
->clues
= snewn(SQUARE_COUNT(params
), char);
1778 state
->hl
= snewn(HL_COUNT(params
), char);
1779 state
->vl
= snewn(VL_COUNT(params
), char);
1781 state
->solved
= state
->cheated
= FALSE
;
1783 FORALL_SQUARES(params
, i
, j
) {
1784 if (empties_to_make
) {
1786 LV_CLUE_AT(state
, i
, j
) = -1;
1792 if (n
>= 0 && n
< 10) {
1793 LV_CLUE_AT(state
, i
, j
) = n
;
1797 LV_CLUE_AT(state
, i
, j
) = -1;
1798 empties_to_make
= n
- 1;
1803 memset(state
->hl
, LINE_UNKNOWN
, HL_COUNT(params
));
1804 memset(state
->vl
, LINE_UNKNOWN
, VL_COUNT(params
));
1809 enum { LOOP_NONE
=0, LOOP_SOLN
, LOOP_NOT_SOLN
};
1811 /* ----------------------------------------------------------------------
1814 * Our solver modes operate as follows. Each mode also uses the modes above it.
1817 * Just implement the rules of the game.
1820 * For each pair of lines through each dot we store a bit for whether
1821 * at least one of them is on and whether at most one is on. (If we know
1822 * both or neither is on that's already stored more directly.) That's six
1823 * bits per dot. Bit number n represents the lines shown in dline_desc.
1826 * Use edsf data structure to make equivalence classes of lines that are
1827 * known identical to or opposite to one another.
1830 /* The order the following are defined in is very important, see below.
1831 * The last two fields may seem non-obvious: they specify that when talking
1832 * about a square the dx and dy offsets should be added to the square coords to
1833 * get to the right dot. Where dx and dy are -1 this means that the dline
1834 * doesn't make sense for a square. */
1835 /* XXX can this be done with a struct instead? */
1837 DLINE(DLINE_UD, UP, DOWN, -1, -1) \
1838 DLINE(DLINE_LR, LEFT, RIGHT, -1, -1) \
1839 DLINE(DLINE_UR, UP, RIGHT, 0, 1) \
1840 DLINE(DLINE_DL, DOWN, LEFT, 1, 0) \
1841 DLINE(DLINE_UL, UP, LEFT, 1, 1) \
1842 DLINE(DLINE_DR, DOWN, RIGHT, 0, 0)
1844 #define OPP_DLINE(dline_desc) ((dline_desc) ^ 1)
1847 #define DLINE(desc, dir1, dir2, dx, dy) \
1854 enum dline_desc desc
;
1855 enum direction dir1
, dir2
;
1859 const static struct dline dlines
[] = {
1860 #define DLINE(desc, dir1, dir2, dx, dy) \
1861 { desc, dir1, dir2, dx, dy },
1866 #define FORALL_DOT_DLINES(dl_iter) \
1867 for (dl_iter = 0; dl_iter < lenof(dlines); ++dl_iter)
1869 #define FORALL_SQUARE_DLINES(dl_iter) \
1870 for (dl_iter = 2; dl_iter < lenof(dlines); ++dl_iter)
1873 ((d==DLINE_UD) ? "DLINE_UD": \
1874 (d==DLINE_LR) ? "DLINE_LR": \
1875 (d==DLINE_UR) ? "DLINE_UR": \
1876 (d==DLINE_DL) ? "DLINE_DL": \
1877 (d==DLINE_UL) ? "DLINE_UL": \
1878 (d==DLINE_DR) ? "DLINE_DR": \
1881 #define CHECK_DLINE_SENSIBLE(d) assert(dlines[(d)].dx != -1 && dlines[(d)].dy != -1)
1883 /* This will fail an assertion if the directions handed to it are the same, as
1884 * no dline corresponds to that */
1885 static enum dline_desc
dline_desc_from_dirs(enum direction dir1
,
1886 enum direction dir2
)
1890 assert (dir1
!= dir2
);
1892 for (i
= 0; i
< lenof(dlines
); ++i
) {
1893 if ((dir1
== dlines
[i
].dir1
&& dir2
== dlines
[i
].dir2
) ||
1894 (dir1
== dlines
[i
].dir2
&& dir2
== dlines
[i
].dir1
)) {
1895 return dlines
[i
].desc
;
1899 assert(!"dline not found");
1900 return DLINE_UD
; /* placate compiler */
1903 /* The following functions allow you to get or set info about the selected
1904 * dline corresponding to the dot or square at [i,j]. You'll get an assertion
1905 * failure if you talk about a dline that doesn't exist, ie if you ask about
1906 * non-touching lines around a square. */
1907 static int get_dot_dline(const game_state
*state
, const char *dline_array
,
1908 int i
, int j
, enum dline_desc desc
)
1910 /* fprintf(stderr, "get_dot_dline %p [%d,%d] %s\n", dline_array, i, j, DL2STR(desc)); */
1911 return BIT_SET(dline_array
[i
+ (state
->w
+ 1) * j
], desc
);
1914 static int set_dot_dline(game_state
*state
, char *dline_array
,
1915 int i
, int j
, enum dline_desc desc
1917 , const char *reason
1922 ret
= SET_BIT(dline_array
[i
+ (state
->w
+ 1) * j
], desc
);
1926 fprintf(stderr
, "set_dot_dline %p [%d,%d] %s (%s)\n", dline_array
, i
, j
, DL2STR(desc
), reason
);
1931 static int get_square_dline(game_state
*state
, char *dline_array
,
1932 int i
, int j
, enum dline_desc desc
)
1934 CHECK_DLINE_SENSIBLE(desc
);
1935 /* fprintf(stderr, "get_square_dline %p [%d,%d] %s\n", dline_array, i, j, DL2STR(desc)); */
1936 return BIT_SET(dline_array
[(i
+dlines
[desc
].dx
) + (state
->w
+ 1) * (j
+dlines
[desc
].dy
)],
1940 static int set_square_dline(game_state
*state
, char *dline_array
,
1941 int i
, int j
, enum dline_desc desc
1943 , const char *reason
1948 CHECK_DLINE_SENSIBLE(desc
);
1949 ret
= SET_BIT(dline_array
[(i
+dlines
[desc
].dx
) + (state
->w
+ 1) * (j
+dlines
[desc
].dy
)], desc
);
1952 fprintf(stderr
, "set_square_dline %p [%d,%d] %s (%s)\n", dline_array
, i
, j
, DL2STR(desc
), reason
);
1958 #define set_dot_dline(a, b, c, d, e) \
1959 set_dot_dline(a, b, c, d, e, __FUNCTION__)
1960 #define set_square_dline(a, b, c, d, e) \
1961 set_square_dline(a, b, c, d, e, __FUNCTION__)
1964 static int set_dot_opp_dline(game_state
*state
, char *dline_array
,
1965 int i
, int j
, enum dline_desc desc
)
1967 return set_dot_dline(state
, dline_array
, i
, j
, OPP_DLINE(desc
));
1970 static int set_square_opp_dline(game_state
*state
, char *dline_array
,
1971 int i
, int j
, enum dline_desc desc
)
1973 return set_square_dline(state
, dline_array
, i
, j
, OPP_DLINE(desc
));
1976 /* Find out if both the lines in the given dline are UNKNOWN */
1977 static int dline_both_unknown(const game_state
*state
, int i
, int j
,
1978 enum dline_desc desc
)
1981 (get_line_status_from_point(state
, i
, j
, dlines
[desc
].dir1
) == LINE_UNKNOWN
) &&
1982 (get_line_status_from_point(state
, i
, j
, dlines
[desc
].dir2
) == LINE_UNKNOWN
);
1985 #define SQUARE_DLINES \
1986 HANDLE_DLINE(DLINE_UL, RIGHTOF_SQUARE, BELOW_SQUARE, 1, 1); \
1987 HANDLE_DLINE(DLINE_UR, LEFTOF_SQUARE, BELOW_SQUARE, 0, 1); \
1988 HANDLE_DLINE(DLINE_DL, RIGHTOF_SQUARE, ABOVE_SQUARE, 1, 0); \
1989 HANDLE_DLINE(DLINE_DR, LEFTOF_SQUARE, ABOVE_SQUARE, 0, 0);
1991 #define DOT_DLINES \
1992 HANDLE_DLINE(DLINE_UD, ABOVE_DOT, BELOW_DOT); \
1993 HANDLE_DLINE(DLINE_LR, LEFTOF_DOT, RIGHTOF_DOT); \
1994 HANDLE_DLINE(DLINE_UL, ABOVE_DOT, LEFTOF_DOT); \
1995 HANDLE_DLINE(DLINE_UR, ABOVE_DOT, RIGHTOF_DOT); \
1996 HANDLE_DLINE(DLINE_DL, BELOW_DOT, LEFTOF_DOT); \
1997 HANDLE_DLINE(DLINE_DR, BELOW_DOT, RIGHTOF_DOT);
1999 static void array_setall(char *array
, char from
, char to
, int len
)
2001 char *p
= array
, *p_old
= p
;
2002 int len_remaining
= len
;
2004 while ((p
= memchr(p
, from
, len_remaining
))) {
2006 len_remaining
-= p
- p_old
;
2013 static int get_line_status_from_point(const game_state
*state
,
2014 int x
, int y
, enum direction d
)
2018 return LEFTOF_DOT(state
, x
, y
);
2020 return RIGHTOF_DOT(state
, x
, y
);
2022 return ABOVE_DOT(state
, x
, y
);
2024 return BELOW_DOT(state
, x
, y
);
2030 /* First and second args are coord offset from top left of square to one end
2031 * of line in question, third and fourth args are the direction from the first
2032 * end of the line to the second. Fifth arg is the direction of the line from
2033 * the coord offset position.
2036 #define SQUARE_LINES \
2037 SQUARE_LINE( 0, 0, RIGHT, RIGHTOF_DOT, UP); \
2038 SQUARE_LINE( 0, +1, RIGHT, RIGHTOF_DOT, DOWN); \
2039 SQUARE_LINE( 0, 0, DOWN, BELOW_DOT, LEFT); \
2040 SQUARE_LINE(+1, 0, DOWN, BELOW_DOT, RIGHT);
2042 /* Set pairs of lines around this square which are known to be identical to
2043 * the given line_state */
2044 static int square_setall_identical(solver_state
*sstate
, int x
, int y
,
2045 enum line_state line_new
)
2047 /* can[dir] contains the canonical line associated with the line in
2048 * direction dir from the square in question. Similarly inv[dir] is
2049 * whether or not the line in question is inverse to its canonical
2051 int can
[4], inv
[4], i
, j
;
2057 fprintf(stderr
, "Setting all identical unknown lines around square "
2058 "[%d,%d] to %d:\n", x
, y
, line_new
);
2061 #define SQUARE_LINE(dx, dy, linedir, dir_dot, sqdir) \
2063 edsf_canonify(sstate->hard->linedsf, \
2064 LINEDSF_INDEX(sstate->state, x+(dx), y+(dy), linedir), \
2071 for (j
= 0; j
< 4; ++j
) {
2072 for (i
= 0; i
< 4; ++i
) {
2076 if (can
[i
] == can
[j
] && inv
[i
] == inv
[j
]) {
2078 /* Lines in directions i and j are identical.
2079 * Only do j now, we'll do i when the loop causes us to
2080 * consider {i,j} in the opposite order. */
2081 #define SQUARE_LINE(dx, dy, dir, c, sqdir) \
2083 retval = set_line_bydot(sstate, x+(dx), y+(dy), dir, line_new); \
2100 /* Set all identical lines passing through the current dot to the chosen line
2101 * state. (implicitly this only looks at UNKNOWN lines) */
2102 static int dot_setall_identical(solver_state
*sstate
, int x
, int y
,
2103 enum line_state line_new
)
2105 /* The implementation of this is a little naughty but I can't see how to do
2106 * it elegantly any other way */
2107 int can
[4], inv
[4], i
, j
;
2111 for (d
= 0; d
< 4; ++d
) {
2112 can
[d
] = edsf_canonify(sstate
->hard
->linedsf
,
2113 LINEDSF_INDEX(sstate
->state
, x
, y
, d
),
2117 for (j
= 0; j
< 4; ++j
) {
2119 for (i
= 0; i
< j
; ++i
) {
2120 if (can
[i
] == can
[j
] && inv
[i
] == inv
[j
]) {
2121 /* Lines in directions i and j are identical */
2122 if (get_line_status_from_point(sstate
->state
, x
, y
, j
) ==
2124 set_line_bydot(sstate
->state
, x
, y
, j
,
2138 static int square_setboth_in_dline(solver_state
*sstate
, enum dline_desc dd
,
2139 int i
, int j
, enum line_state line_new
)
2142 const struct dline dll
= dlines
[dd
], *dl
= &dll
;
2145 fprintf(stderr
, "square_setboth_in_dline %s [%d,%d] to %d\n",
2146 DL2STR(dd
), i
, j
, line_new
);
2149 CHECK_DLINE_SENSIBLE(dd
);
2152 set_line_bydot(sstate
, i
+dl
->dx
, j
+dl
->dy
, dl
->dir1
, line_new
);
2154 set_line_bydot(sstate
, i
+dl
->dx
, j
+dl
->dy
, dl
->dir2
, line_new
);
2159 /* Call this function to register that the two unknown lines going into the dot
2160 * [x,y] are identical or opposite (depending on the value of 'inverse'). This
2161 * function will cause an assertion failure if anything other than exactly two
2162 * lines into the dot are unknown.
2163 * As usual returns TRUE if any progress was made, otherwise FALSE. */
2164 static int dot_relate_2_unknowns(solver_state
*sstate
, int x
, int y
, int inverse
)
2166 enum direction d1
=DOWN
, d2
=DOWN
; /* Just to keep compiler quiet */
2169 #define TRY_DIR(d) \
2170 if (get_line_status_from_point(sstate->state, x, y, d) == \
2172 if (dirs_set == 0) \
2175 assert(dirs_set == 1); \
2187 assert(dirs_set
== 2);
2191 fprintf(stderr
, "Lines in direction %s and %s from dot [%d,%d] are %s\n",
2192 DIR2STR(d1
), DIR2STR(d2
), x
, y
, inverse?
"opposite":"the same");
2195 return merge_lines(sstate
, x
, y
, d1
, x
, y
, d2
, inverse
);
2198 /* Very similar to dot_relate_2_unknowns. */
2199 static int square_relate_2_unknowns(solver_state
*sstate
, int x
, int y
, int inverse
)
2201 enum direction d1
=DOWN
, d2
=DOWN
;
2202 int x1
=-1, y1
=-1, x2
=-1, y2
=-1;
2206 fprintf(stderr
, "2 unknowns around square [%d,%d] are %s\n",
2207 x
, y
, inverse?
"opposite":"the same");
2210 #define TRY_DIR(i, j, d, dir_sq) \
2212 if (dir_sq(sstate->state, x, y) == LINE_UNKNOWN) { \
2213 if (dirs_set == 0) { \
2214 d1 = d; x1 = i; y1 = j; \
2216 assert(dirs_set == 1); \
2217 d2 = d; x2 = i; y2 = j; \
2223 TRY_DIR(x
, y
, RIGHT
, ABOVE_SQUARE
);
2224 TRY_DIR(x
, y
, DOWN
, LEFTOF_SQUARE
);
2225 TRY_DIR(x
+1, y
, DOWN
, RIGHTOF_SQUARE
);
2226 TRY_DIR(x
, y
+1, RIGHT
, BELOW_SQUARE
);
2229 assert(dirs_set
== 2);
2232 fprintf(stderr
, "Line in direction %s from dot [%d,%d] and line in direction %s from dot [%2d,%2d] are %s\n",
2233 DIR2STR(d1
), x1
, y1
, DIR2STR(d2
), x2
, y2
, inverse?
"opposite":"the same");
2236 return merge_lines(sstate
, x1
, y1
, d1
, x2
, y2
, d2
, inverse
);
2239 /* Figure out if any dlines can be 'collapsed' (and do so if they can). This
2240 * can happen if one of the lines is known and due to the dline status this
2241 * tells us state of the other, or if there's an interaction with the linedsf
2242 * (ie if atmostone is set for a dline and the lines are known identical they
2243 * must both be LINE_NO, etc). XXX at the moment only the former is
2244 * implemented, and indeed the latter should be implemented in the hard mode
2247 static int dot_collapse_dlines(solver_state
*sstate
, int i
, int j
)
2249 int progress
= FALSE
;
2250 enum direction dir1
, dir2
;
2253 game_state
*state
= sstate
->state
;
2256 for (dir1
= 0; dir1
< 4; dir1
++) {
2257 dir1st
= get_line_status_from_point(state
, i
, j
, dir1
);
2258 if (dir1st
== LINE_UNKNOWN
)
2260 /* dir2 iterates over the whole range rather than starting at dir1+1
2261 * because test below is asymmetric */
2262 for (dir2
= 0; dir2
< 4; dir2
++) {
2266 if ((i
== 0 && (dir1
== LEFT
|| dir2
== LEFT
)) ||
2267 (j
== 0 && (dir1
== UP
|| dir2
== UP
)) ||
2268 (i
== state
->w
&& (dir1
== RIGHT
|| dir2
== RIGHT
)) ||
2269 (j
== state
->h
&& (dir1
== DOWN
|| dir2
== DOWN
))) {
2274 fprintf(stderr
, "dot_collapse_dlines [%d,%d], %s %s\n", i
, j
,
2275 DIR2STR(dir1
), DIR2STR(dir2
));
2278 if (get_line_status_from_point(state
, i
, j
, dir2
) ==
2280 dd
= dline_desc_from_dirs(dir1
, dir2
);
2282 dlset
= get_dot_dline(state
, sstate
->normal
->dot_atmostone
, i
, j
, dd
);
2283 if (dlset
&& dir1st
== LINE_YES
) {
2284 /* fprintf(stderr, "setting %s to NO\n", DIR2STR(dir2)); */
2286 set_line_bydot(sstate
, i
, j
, dir2
, LINE_NO
);
2289 dlset
= get_dot_dline(state
, sstate
->normal
->dot_atleastone
, i
, j
, dd
);
2290 if (dlset
&& dir1st
== LINE_NO
) {
2291 /* fprintf(stderr, "setting %s to YES\n", DIR2STR(dir2)); */
2293 set_line_bydot(sstate
, i
, j
, dir2
, LINE_YES
);
2303 * These are the main solver functions.
2305 * Their return values are diff values corresponding to the lowest mode solver
2306 * that would notice the work that they have done. For example if the normal
2307 * mode solver adds actual lines or crosses, it will return DIFF_EASY as the
2308 * easy mode solver might be able to make progress using that. It doesn't make
2309 * sense for one of them to return a diff value higher than that of the
2312 * Each function returns the lowest value it can, as early as possible, in
2313 * order to try and pass as much work as possible back to the lower level
2314 * solvers which progress more quickly.
2317 /* PROPOSED NEW DESIGN:
2318 * We have a work queue consisting of 'events' notifying us that something has
2319 * happened that a particular solver mode might be interested in. For example
2320 * the hard mode solver might do something that helps the normal mode solver at
2321 * dot [x,y] in which case it will enqueue an event recording this fact. Then
2322 * we pull events off the work queue, and hand each in turn to the solver that
2323 * is interested in them. If a solver reports that it failed we pass the same
2324 * event on to progressively more advanced solvers and the loop detector. Once
2325 * we've exhausted an event, or it has helped us progress, we drop it and
2326 * continue to the next one. The events are sorted first in order of solver
2327 * complexity (easy first) then order of insertion (oldest first).
2328 * Once we run out of events we loop over each permitted solver in turn
2329 * (easiest first) until either a deduction is made (and an event therefore
2330 * emerges) or no further deductions can be made (in which case we've failed).
2333 * * How do we 'loop over' a solver when both dots and squares are concerned.
2334 * Answer: first all squares then all dots.
2337 static int easy_mode_deductions(solver_state
*sstate
)
2339 int i
, j
, h
, w
, current_yes
, current_no
;
2341 int diff
= DIFF_MAX
;
2343 state
= sstate
->state
;
2347 /* Per-square deductions */
2348 FORALL_SQUARES(state
, i
, j
) {
2349 if (sstate
->square_solved
[SQUARE_INDEX(state
, i
, j
)])
2352 current_yes
= SQUARE_YES_COUNT(sstate
, i
, j
);
2353 current_no
= SQUARE_NO_COUNT(sstate
, i
, j
);
2355 if (current_yes
+ current_no
== 4) {
2356 sstate
->square_solved
[SQUARE_INDEX(state
, i
, j
)] = TRUE
;
2357 /* diff = min(diff, DIFF_EASY); */
2361 if (CLUE_AT(state
, i
, j
) < 0)
2364 if (CLUE_AT(state
, i
, j
) < current_yes
) {
2366 fprintf(stderr
, "detected error [%d,%d] in %s at line %d\n", i
, j
, __FUNCTION__
, __LINE__
);
2368 sstate
->solver_status
= SOLVER_MISTAKE
;
2371 if (CLUE_AT(state
, i
, j
) == current_yes
) {
2372 if (square_setall(sstate
, i
, j
, LINE_UNKNOWN
, LINE_NO
))
2373 diff
= min(diff
, DIFF_EASY
);
2374 sstate
->square_solved
[SQUARE_INDEX(state
, i
, j
)] = TRUE
;
2378 if (4 - CLUE_AT(state
, i
, j
) < current_no
) {
2380 fprintf(stderr
, "detected error [%d,%d] in %s at line %d\n", i
, j
, __FUNCTION__
, __LINE__
);
2382 sstate
->solver_status
= SOLVER_MISTAKE
;
2385 if (4 - CLUE_AT(state
, i
, j
) == current_no
) {
2386 if (square_setall(sstate
, i
, j
, LINE_UNKNOWN
, LINE_YES
))
2387 diff
= min(diff
, DIFF_EASY
);
2388 sstate
->square_solved
[SQUARE_INDEX(state
, i
, j
)] = TRUE
;
2393 check_caches(sstate
);
2395 /* Per-dot deductions */
2396 FORALL_DOTS(state
, i
, j
) {
2397 if (sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)])
2400 switch (DOT_YES_COUNT(sstate
, i
, j
)) {
2402 switch (DOT_NO_COUNT(sstate
, i
, j
)) {
2405 fprintf(stderr
, "dot [%d,%d]: 0 yes, 3 no\n", i
, j
);
2407 dot_setall(sstate
, i
, j
, LINE_UNKNOWN
, LINE_NO
);
2408 diff
= min(diff
, DIFF_EASY
);
2411 sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)] = TRUE
;
2416 switch (DOT_NO_COUNT(sstate
, i
, j
)) {
2417 case 2: /* 1 yes, 2 no */
2419 fprintf(stderr
, "dot [%d,%d]: 1 yes, 2 no\n", i
, j
);
2421 dot_setall(sstate
, i
, j
, LINE_UNKNOWN
, LINE_YES
);
2422 diff
= min(diff
, DIFF_EASY
);
2423 sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)] = TRUE
;
2425 case 3: /* 1 yes, 3 no */
2427 fprintf(stderr
, "detected error [%d,%d] in %s at line %d\n", i
, j
, __FUNCTION__
, __LINE__
);
2429 sstate
->solver_status
= SOLVER_MISTAKE
;
2435 fprintf(stderr
, "dot [%d,%d]: 2 yes\n", i
, j
);
2437 dot_setall(sstate
, i
, j
, LINE_UNKNOWN
, LINE_NO
);
2438 diff
= min(diff
, DIFF_EASY
);
2439 sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)] = TRUE
;
2444 fprintf(stderr
, "detected error [%d,%d] in %s at line %d\n", i
, j
, __FUNCTION__
, __LINE__
);
2446 sstate
->solver_status
= SOLVER_MISTAKE
;
2451 check_caches(sstate
);
2456 static int normal_mode_deductions(solver_state
*sstate
)
2459 game_state
*state
= sstate
->state
;
2461 int diff
= DIFF_MAX
;
2463 FORALL_SQUARES(state
, i
, j
) {
2464 if (sstate
->square_solved
[SQUARE_INDEX(state
, i
, j
)])
2467 if (CLUE_AT(state
, i
, j
) < 0)
2470 switch (CLUE_AT(state
, i
, j
)) {
2473 fprintf(stderr
, "clue [%d,%d] is 1, doing dline ops\n",
2476 FORALL_SQUARE_DLINES(dd
) {
2477 /* At most one of any DLINE can be set */
2478 if (set_square_dline(state
,
2479 sstate
->normal
->dot_atmostone
,
2481 diff
= min(diff
, DIFF_NORMAL
);
2484 if (get_square_dline(state
,
2485 sstate
->normal
->dot_atleastone
,
2487 /* This DLINE provides enough YESes to solve the clue */
2488 if (square_setboth_in_dline(sstate
, OPP_DLINE(dd
),
2490 diff
= min(diff
, DIFF_EASY
);
2497 /* If at least one of one DLINE is set, at most one
2498 * of the opposing one is and vice versa */
2500 fprintf(stderr
, "clue [%d,%d] is 2, doing dline ops\n",
2503 FORALL_SQUARE_DLINES(dd
) {
2504 if (get_square_dline(state
,
2505 sstate
->normal
->dot_atmostone
,
2507 if (set_square_opp_dline(state
,
2508 sstate
->normal
->dot_atleastone
,
2510 diff
= min(diff
, DIFF_NORMAL
);
2513 if (get_square_dline(state
,
2514 sstate
->normal
->dot_atleastone
,
2516 if (set_square_opp_dline(state
,
2517 sstate
->normal
->dot_atmostone
,
2519 diff
= min(diff
, DIFF_NORMAL
);
2526 fprintf(stderr
, "clue [%d,%d] is 3, doing dline ops\n",
2529 FORALL_SQUARE_DLINES(dd
) {
2530 /* At least one of any DLINE must be set */
2531 if (set_square_dline(state
,
2532 sstate
->normal
->dot_atleastone
,
2534 diff
= min(diff
, DIFF_NORMAL
);
2537 if (get_square_dline(state
,
2538 sstate
->normal
->dot_atmostone
,
2540 /* This DLINE provides enough NOs to solve the clue */
2541 if (square_setboth_in_dline(sstate
, OPP_DLINE(dd
),
2543 diff
= min(diff
, DIFF_EASY
);
2551 check_caches(sstate
);
2553 if (diff
< DIFF_NORMAL
)
2556 FORALL_DOTS(state
, i
, j
) {
2557 if (sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)])
2561 text
= game_text_format(state
);
2562 fprintf(stderr
, "-----------------\n%s", text
);
2566 switch (DOT_YES_COUNT(sstate
, i
, j
)) {
2568 switch (DOT_NO_COUNT(sstate
, i
, j
)) {
2570 /* Make note that at most one of each unknown DLINE
2577 switch (DOT_NO_COUNT(sstate
, i
, j
)) {
2579 /* 1 yes, 1 no, so exactly one of unknowns is
2582 fprintf(stderr
, "dot [%d,%d]: 1 yes, 1 no\n", i
, j
);
2584 FORALL_DOT_DLINES(dd
) {
2585 if (dline_both_unknown(state
,
2587 if (set_dot_dline(state
,
2588 sstate
->normal
->dot_atleastone
,
2590 diff
= min(diff
, DIFF_NORMAL
);
2598 fprintf(stderr
, "dot [%d,%d]: 1 yes, 0 or 1 no\n", i
, j
);
2600 /* 1 yes, fewer than 2 no, so at most one of
2601 * unknowns is yes */
2602 FORALL_DOT_DLINES(dd
) {
2603 if (dline_both_unknown(state
,
2605 if (set_dot_dline(state
,
2606 sstate
->normal
->dot_atmostone
,
2608 diff
= min(diff
, DIFF_NORMAL
);
2617 /* DLINE deductions that don't depend on the exact number of
2618 * LINE_YESs or LINE_NOs */
2620 /* If at least one of a dline in a dot is YES, at most one
2621 * of the opposite dline to that dot must be YES. */
2622 FORALL_DOT_DLINES(dd
) {
2623 if (get_dot_dline(state
,
2624 sstate
->normal
->dot_atleastone
,
2626 if (set_dot_opp_dline(state
,
2627 sstate
->normal
->dot_atmostone
,
2629 diff
= min(diff
, DIFF_NORMAL
);
2634 if (dot_collapse_dlines(sstate
, i
, j
))
2635 diff
= min(diff
, DIFF_EASY
);
2637 check_caches(sstate
);
2642 static int hard_mode_deductions(solver_state
*sstate
)
2645 game_state
*state
= sstate
->state
;
2646 const int h
=state
->h
, w
=state
->w
;
2647 enum direction dir1
, dir2
;
2648 int can1
, can2
, inv1
, inv2
;
2649 int diff
= DIFF_MAX
;
2652 FORALL_SQUARES(state
, i
, j
) {
2653 if (sstate
->square_solved
[SQUARE_INDEX(state
, i
, j
)])
2656 switch (CLUE_AT(state
, i
, j
)) {
2661 if (square_setall_identical(sstate
, i
, j
, LINE_NO
))
2662 diff
= min(diff
, DIFF_EASY
);
2665 if (square_setall_identical(sstate
, i
, j
, LINE_YES
))
2666 diff
= min(diff
, DIFF_EASY
);
2670 if (SQUARE_YES_COUNT(sstate
, i
, j
) +
2671 SQUARE_NO_COUNT(sstate
, i
, j
) == 2) {
2672 /* There are exactly two unknown lines bordering this
2674 if (SQUARE_YES_COUNT(sstate
, i
, j
) + 1 ==
2675 CLUE_AT(state
, i
, j
)) {
2676 /* They must be different */
2677 if (square_relate_2_unknowns(sstate
, i
, j
, TRUE
))
2678 diff
= min(diff
, DIFF_HARD
);
2683 check_caches(sstate
);
2685 FORALL_DOTS(state
, i
, j
) {
2686 if (DOT_YES_COUNT(sstate
, i
, j
) == 1 &&
2687 DOT_NO_COUNT(sstate
, i
, j
) == 1) {
2688 if (dot_relate_2_unknowns(sstate
, i
, j
, TRUE
))
2689 diff
= min(diff
, DIFF_HARD
);
2693 if (DOT_YES_COUNT(sstate
, i
, j
) == 0 &&
2694 DOT_NO_COUNT(sstate
, i
, j
) == 2) {
2695 if (dot_relate_2_unknowns(sstate
, i
, j
, FALSE
))
2696 diff
= min(diff
, DIFF_HARD
);
2701 /* If two lines into a dot are related, the other two lines into that dot
2702 * are related in the same way. */
2704 /* iter over points that aren't on edges */
2705 for (i
= 1; i
< w
; ++i
) {
2706 for (j
= 1; j
< h
; ++j
) {
2707 if (sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)])
2710 /* iter over directions */
2711 for (dir1
= 0; dir1
< 4; ++dir1
) {
2712 for (dir2
= dir1
+1; dir2
< 4; ++dir2
) {
2713 /* canonify both lines */
2714 can1
= edsf_canonify
2715 (sstate
->hard
->linedsf
,
2716 LINEDSF_INDEX(state
, i
, j
, dir1
),
2718 can2
= edsf_canonify
2719 (sstate
->hard
->linedsf
,
2720 LINEDSF_INDEX(state
, i
, j
, dir2
),
2722 /* merge opposite lines */
2724 if (merge_lines(sstate
,
2725 i
, j
, OPP_DIR(dir1
),
2726 i
, j
, OPP_DIR(dir2
),
2728 diff
= min(diff
, DIFF_HARD
);
2736 /* If the state of a line is known, deduce the state of its canonical line
2738 FORALL_DOTS(state
, i
, j
) {
2739 /* Do this even if the dot we're on is solved */
2741 can1
= edsf_canonify(sstate
->hard
->linedsf
,
2742 LINEDSF_INDEX(state
, i
, j
, RIGHT
),
2744 linedsf_deindex(state
, can1
, &a
, &b
, &dir1
);
2745 s
= RIGHTOF_DOT(state
, i
, j
);
2746 if (s
!= LINE_UNKNOWN
)
2748 if (set_line_bydot(sstate
, a
, b
, dir1
, inv1 ?
OPP(s
) : s
))
2749 diff
= min(diff
, DIFF_EASY
);
2753 can1
= edsf_canonify(sstate
->hard
->linedsf
,
2754 LINEDSF_INDEX(state
, i
, j
, DOWN
),
2756 linedsf_deindex(state
, can1
, &a
, &b
, &dir1
);
2757 s
= BELOW_DOT(state
, i
, j
);
2758 if (s
!= LINE_UNKNOWN
)
2760 if (set_line_bydot(sstate
, a
, b
, dir1
, inv1 ?
OPP(s
) : s
))
2761 diff
= min(diff
, DIFF_EASY
);
2766 /* Interactions between dline and linedsf */
2767 FORALL_DOTS(state
, i
, j
) {
2768 if (sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)])
2771 FORALL_DOT_DLINES(dd
) {
2772 const struct dline dll
= dlines
[dd
], *dl
= &dll
;
2773 if (i
== 0 && (dl
->dir1
== LEFT
|| dl
->dir2
== LEFT
))
2775 if (i
== w
&& (dl
->dir1
== RIGHT
|| dl
->dir2
== RIGHT
))
2777 if (j
== 0 && (dl
->dir1
== UP
|| dl
->dir2
== UP
))
2779 if (j
== h
&& (dl
->dir1
== DOWN
|| dl
->dir2
== DOWN
))
2782 if (get_dot_dline(state
, sstate
->normal
->dot_atleastone
,
2784 get_dot_dline(state
, sstate
->normal
->dot_atmostone
,
2786 /* atleastone && atmostone => inverse */
2787 if (merge_lines(sstate
, i
, j
, dl
->dir1
, i
, j
, dl
->dir2
, 1)) {
2788 diff
= min(diff
, DIFF_HARD
);
2791 /* don't have atleastone and atmostone for this dline */
2792 can1
= edsf_canonify(sstate
->hard
->linedsf
,
2793 LINEDSF_INDEX(state
, i
, j
, dl
->dir1
),
2795 can2
= edsf_canonify(sstate
->hard
->linedsf
,
2796 LINEDSF_INDEX(state
, i
, j
, dl
->dir2
),
2800 /* identical => collapse dline */
2801 if (get_dot_dline(state
,
2802 sstate
->normal
->dot_atleastone
,
2804 if (set_line_bydot(sstate
, i
, j
,
2805 dl
->dir1
, LINE_YES
)) {
2806 diff
= min(diff
, DIFF_EASY
);
2808 if (set_line_bydot(sstate
, i
, j
,
2809 dl
->dir2
, LINE_YES
)) {
2810 diff
= min(diff
, DIFF_EASY
);
2812 } else if (get_dot_dline(state
,
2813 sstate
->normal
->dot_atmostone
,
2815 if (set_line_bydot(sstate
, i
, j
,
2816 dl
->dir1
, LINE_NO
)) {
2817 diff
= min(diff
, DIFF_EASY
);
2819 if (set_line_bydot(sstate
, i
, j
,
2820 dl
->dir2
, LINE_NO
)) {
2821 diff
= min(diff
, DIFF_EASY
);
2825 /* inverse => atleastone && atmostone */
2826 if (set_dot_dline(state
,
2827 sstate
->normal
->dot_atleastone
,
2829 diff
= min(diff
, DIFF_NORMAL
);
2831 if (set_dot_dline(state
,
2832 sstate
->normal
->dot_atmostone
,
2834 diff
= min(diff
, DIFF_NORMAL
);
2842 /* If the state of the canonical line for line 'l' is known, deduce the
2844 FORALL_DOTS(state
, i
, j
) {
2845 if (sstate
->dot_solved
[DOT_INDEX(state
, i
, j
)])
2849 can1
= edsf_canonify(sstate
->hard
->linedsf
,
2850 LINEDSF_INDEX(state
, i
, j
, RIGHT
),
2852 linedsf_deindex(state
, can1
, &a
, &b
, &dir1
);
2853 s
= get_line_status_from_point(state
, a
, b
, dir1
);
2854 if (s
!= LINE_UNKNOWN
)
2856 if (set_line_bydot(sstate
, i
, j
, RIGHT
, inv1 ?
OPP(s
) : s
))
2857 diff
= min(diff
, DIFF_EASY
);
2861 can1
= edsf_canonify(sstate
->hard
->linedsf
,
2862 LINEDSF_INDEX(state
, i
, j
, DOWN
),
2864 linedsf_deindex(state
, can1
, &a
, &b
, &dir1
);
2865 s
= get_line_status_from_point(state
, a
, b
, dir1
);
2866 if (s
!= LINE_UNKNOWN
)
2868 if (set_line_bydot(sstate
, i
, j
, DOWN
, inv1 ?
OPP(s
) : s
))
2869 diff
= min(diff
, DIFF_EASY
);
2877 static int loop_deductions(solver_state
*sstate
)
2879 int edgecount
= 0, clues
= 0, satclues
= 0, sm1clues
= 0;
2880 game_state
*state
= sstate
->state
;
2881 int shortest_chainlen
= DOT_COUNT(state
);
2882 int loop_found
= FALSE
;
2885 int progress
= FALSE
;
2889 * Go through the grid and update for all the new edges.
2890 * Since merge_dots() is idempotent, the simplest way to
2891 * do this is just to update for _all_ the edges.
2893 * Also, while we're here, we count the edges, count the
2894 * clues, count the satisfied clues, and count the
2895 * satisfied-minus-one clues.
2897 FORALL_DOTS(state
, i
, j
) {
2898 if (RIGHTOF_DOT(state
, i
, j
) == LINE_YES
) {
2899 loop_found
|= merge_dots(sstate
, i
, j
, i
+1, j
);
2902 if (BELOW_DOT(state
, i
, j
) == LINE_YES
) {
2903 loop_found
|= merge_dots(sstate
, i
, j
, i
, j
+1);
2907 if (CLUE_AT(state
, i
, j
) >= 0) {
2908 int c
= CLUE_AT(state
, i
, j
);
2909 int o
= SQUARE_YES_COUNT(sstate
, i
, j
);
2918 for (i
= 0; i
< DOT_COUNT(state
); ++i
) {
2920 sstate
->looplen
[dsf_canonify(sstate
->dotdsf
, i
)];
2921 if (dots_connected
> 1)
2922 shortest_chainlen
= min(shortest_chainlen
, dots_connected
);
2925 assert(sstate
->solver_status
== SOLVER_INCOMPLETE
);
2927 if (satclues
== clues
&& shortest_chainlen
== edgecount
) {
2928 sstate
->solver_status
= SOLVER_SOLVED
;
2929 /* This discovery clearly counts as progress, even if we haven't
2930 * just added any lines or anything */
2932 goto finished_loop_deductionsing
;
2936 * Now go through looking for LINE_UNKNOWN edges which
2937 * connect two dots that are already in the same
2938 * equivalence class. If we find one, test to see if the
2939 * loop it would create is a solution.
2941 FORALL_DOTS(state
, i
, j
) {
2942 for (d
= 0; d
< 2; d
++) {
2943 int i2
, j2
, eqclass
, val
;
2946 if (RIGHTOF_DOT(state
, i
, j
) !=
2952 if (BELOW_DOT(state
, i
, j
) !=
2960 eqclass
= dsf_canonify(sstate
->dotdsf
, j
* (state
->w
+1) + i
);
2961 if (eqclass
!= dsf_canonify(sstate
->dotdsf
,
2962 j2
* (state
->w
+1) + i2
)) {
2966 val
= LINE_NO
; /* loop is bad until proven otherwise */
2969 * This edge would form a loop. Next
2970 * question: how long would the loop be?
2971 * Would it equal the total number of edges
2972 * (plus the one we'd be adding if we added
2975 if (sstate
->looplen
[eqclass
] == edgecount
+ 1) {
2980 * This edge would form a loop which
2981 * took in all the edges in the entire
2982 * grid. So now we need to work out
2983 * whether it would be a valid solution
2984 * to the puzzle, which means we have to
2985 * check if it satisfies all the clues.
2986 * This means that every clue must be
2987 * either satisfied or satisfied-minus-
2988 * 1, and also that the number of
2989 * satisfied-minus-1 clues must be at
2990 * most two and they must lie on either
2991 * side of this edge.
2996 if (CLUE_AT(state
, cx
,cy
) >= 0 &&
2997 square_order(state
, cx
,cy
, LINE_YES
) ==
2998 CLUE_AT(state
, cx
,cy
) - 1) {
3001 if (CLUE_AT(state
, i
, j
) >= 0 &&
3002 SQUARE_YES_COUNT(sstate
, i
, j
) ==
3003 CLUE_AT(state
, i
, j
) - 1) {
3006 if (sm1clues
== sm1_nearby
&&
3007 sm1clues
+ satclues
== clues
) {
3008 val
= LINE_YES
; /* loop is good! */
3013 * Right. Now we know that adding this edge
3014 * would form a loop, and we know whether
3015 * that loop would be a viable solution or
3018 * If adding this edge produces a solution,
3019 * then we know we've found _a_ solution but
3020 * we don't know that it's _the_ solution -
3021 * if it were provably the solution then
3022 * we'd have deduced this edge some time ago
3023 * without the need to do loop detection. So
3024 * in this state we return SOLVER_AMBIGUOUS,
3025 * which has the effect that hitting Solve
3026 * on a user-provided puzzle will fill in a
3027 * solution but using the solver to
3028 * construct new puzzles won't consider this
3029 * a reasonable deduction for the user to
3033 progress
= set_line_bydot(sstate
, i
, j
, RIGHT
, val
);
3034 assert(progress
== TRUE
);
3036 progress
= set_line_bydot(sstate
, i
, j
, DOWN
, val
);
3037 assert(progress
== TRUE
);
3039 if (val
== LINE_YES
) {
3040 sstate
->solver_status
= SOLVER_AMBIGUOUS
;
3041 goto finished_loop_deductionsing
;
3046 finished_loop_deductionsing
:
3047 return progress ? DIFF_EASY
: DIFF_MAX
;
3050 /* This will return a dynamically allocated solver_state containing the (more)
3052 static solver_state
*solve_game_rec(const solver_state
*sstate_start
,
3057 solver_state
*sstate
, *sstate_saved
, *sstate_tmp
;
3058 solver_state
*sstate_rec_solved
;
3059 int recursive_soln_count
;
3060 int solver_progress
;
3063 /* Indicates which solver we should call next. This is a sensible starting
3065 int current_solver
= DIFF_EASY
, next_solver
;
3071 printf("solve_game_rec: recursion_remaining = %d\n",
3072 sstate_start
->recursion_remaining
);
3075 sstate
= dup_solver_state(sstate_start
);
3077 /* Cache the values of some variables for readability */
3078 state
= sstate
->state
;
3082 sstate_saved
= NULL
;
3084 nonrecursive_solver
:
3085 solver_progress
= FALSE
;
3087 check_caches(sstate
);
3091 text
= game_text_format(state
);
3092 fprintf(stderr
, "-----------------\n%s", text
);
3096 if (sstate
->solver_status
== SOLVER_MISTAKE
)
3099 /* fprintf(stderr, "Invoking solver %d\n", current_solver); */
3100 next_solver
= solver_fns
[current_solver
](sstate
);
3102 if (next_solver
== DIFF_MAX
) {
3103 /* fprintf(stderr, "Current solver failed\n"); */
3104 if (current_solver
< diff
&& current_solver
+ 1 < DIFF_MAX
) {
3105 /* Try next beefier solver */
3106 next_solver
= current_solver
+ 1;
3108 /* fprintf(stderr, "Doing loop deductions\n"); */
3109 next_solver
= loop_deductions(sstate
);
3113 if (sstate
->solver_status
== SOLVER_SOLVED
||
3114 sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
3115 /* fprintf(stderr, "Solver completed\n"); */
3119 /* Once we've looped over all permitted solvers then the loop
3120 * deductions without making any progress, we'll exit this while loop */
3121 current_solver
= next_solver
;
3122 } while (current_solver
< DIFF_MAX
);
3124 if (sstate
->solver_status
== SOLVER_SOLVED
||
3125 sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
3126 /* s/LINE_UNKNOWN/LINE_NO/g */
3127 array_setall(sstate
->state
->hl
, LINE_UNKNOWN
, LINE_NO
,
3128 HL_COUNT(sstate
->state
));
3129 array_setall(sstate
->state
->vl
, LINE_UNKNOWN
, LINE_NO
,
3130 VL_COUNT(sstate
->state
));
3134 /* Perform recursive calls */
3135 if (sstate
->recursion_remaining
) {
3136 sstate_saved
= dup_solver_state(sstate
);
3138 sstate
->recursion_remaining
--;
3140 recursive_soln_count
= 0;
3141 sstate_rec_solved
= NULL
;
3143 /* Memory management:
3144 * sstate_saved won't be modified but needs to be freed when we have
3146 * sstate is expected to contain our 'best' solution by the time we
3147 * finish this section of code. It's the thing we'll try adding lines
3148 * to, seeing if they make it more solvable.
3149 * If sstate_rec_solved is non-NULL, it will supersede sstate
3150 * eventually. sstate_tmp should not hold a value persistently.
3153 /* NB SOLVER_AMBIGUOUS is like SOLVER_SOLVED except the solver is aware
3154 * of the possibility of additional solutions. So as soon as we have a
3155 * SOLVER_AMBIGUOUS we can safely propagate it back to our caller, but
3156 * if we get a SOLVER_SOLVED we want to keep trying in case we find
3157 * further solutions and have to mark it ambiguous.
3160 #define DO_RECURSIVE_CALL(dir_dot) \
3161 if (dir_dot(sstate->state, i, j) == LINE_UNKNOWN) { \
3162 debug(("Trying " #dir_dot " at [%d,%d]\n", i, j)); \
3163 LV_##dir_dot(sstate->state, i, j) = LINE_YES; \
3164 sstate_tmp = solve_game_rec(sstate, diff); \
3165 switch (sstate_tmp->solver_status) { \
3166 case SOLVER_AMBIGUOUS: \
3167 debug(("Solver ambiguous, returning\n")); \
3168 sstate_rec_solved = sstate_tmp; \
3169 goto finished_recursion; \
3170 case SOLVER_SOLVED: \
3171 switch (++recursive_soln_count) { \
3173 debug(("One solution found\n")); \
3174 sstate_rec_solved = sstate_tmp; \
3177 debug(("Ambiguous solutions found\n")); \
3178 free_solver_state(sstate_tmp); \
3179 sstate_rec_solved->solver_status = SOLVER_AMBIGUOUS; \
3180 goto finished_recursion; \
3182 assert(!"recursive_soln_count out of range"); \
3186 case SOLVER_MISTAKE: \
3187 debug(("Non-solution found\n")); \
3188 free_solver_state(sstate_tmp); \
3189 free_solver_state(sstate_saved); \
3190 LV_##dir_dot(sstate->state, i, j) = LINE_NO; \
3191 goto nonrecursive_solver; \
3192 case SOLVER_INCOMPLETE: \
3193 debug(("Recursive step inconclusive\n")); \
3194 free_solver_state(sstate_tmp); \
3197 free_solver_state(sstate); \
3198 sstate = dup_solver_state(sstate_saved); \
3201 FORALL_DOTS(state
, i
, j
) {
3202 /* Only perform recursive calls on 'loose ends' */
3203 if (DOT_YES_COUNT(sstate
, i
, j
) == 1) {
3204 DO_RECURSIVE_CALL(LEFTOF_DOT
);
3205 DO_RECURSIVE_CALL(RIGHTOF_DOT
);
3206 DO_RECURSIVE_CALL(ABOVE_DOT
);
3207 DO_RECURSIVE_CALL(BELOW_DOT
);
3213 if (sstate_rec_solved
) {
3214 free_solver_state(sstate
);
3215 sstate
= sstate_rec_solved
;
3223 #define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
3224 if (sstate->normal->dot_atmostone[i+a + (sstate->state->w + 1) * (j+b)] & \
3226 if (square_order(sstate->state, i, j, LINE_UNKNOWN) - 1 == \
3227 CLUE_AT(sstate->state, i, j) - '0') { \
3228 square_setall(sstate->state, i, j, LINE_UNKNOWN, LINE_YES); \
3229 /* XXX the following may overwrite known data! */ \
3230 dir1_sq(sstate->state, i, j) = LINE_UNKNOWN; \
3231 dir2_sq(sstate->state, i, j) = LINE_UNKNOWN; \
3238 static char *solve_game(game_state
*state
, game_state
*currstate
,
3239 char *aux
, char **error
)
3242 solver_state
*sstate
, *new_sstate
;
3244 sstate
= new_solver_state(state
, DIFF_MAX
);
3245 new_sstate
= solve_game_rec(sstate
, DIFF_MAX
);
3247 if (new_sstate
->solver_status
== SOLVER_SOLVED
) {
3248 soln
= encode_solve_move(new_sstate
->state
);
3249 } else if (new_sstate
->solver_status
== SOLVER_AMBIGUOUS
) {
3250 soln
= encode_solve_move(new_sstate
->state
);
3251 /**error = "Solver found ambiguous solutions"; */
3253 soln
= encode_solve_move(new_sstate
->state
);
3254 /**error = "Solver failed"; */
3257 free_solver_state(new_sstate
);
3258 free_solver_state(sstate
);
3263 /* ----------------------------------------------------------------------
3264 * Drawing and mouse-handling
3267 static char *interpret_move(game_state
*state
, game_ui
*ui
, game_drawstate
*ds
,
3268 int x
, int y
, int button
)
3273 char button_char
= ' ';
3274 enum line_state old_state
;
3276 button
&= ~MOD_MASK
;
3278 /* Around each line is a diamond-shaped region where points within that
3279 * region are closer to this line than any other. We assume any click
3280 * within a line's diamond was meant for that line. It would all be a lot
3281 * simpler if the / and % operators respected modulo arithmetic properly
3282 * for negative numbers. */
3287 /* Get the coordinates of the square the click was in */
3288 i
= (x
+ TILE_SIZE
) / TILE_SIZE
- 1;
3289 j
= (y
+ TILE_SIZE
) / TILE_SIZE
- 1;
3291 /* Get the precise position inside square [i,j] */
3292 p
= (x
+ TILE_SIZE
) % TILE_SIZE
;
3293 q
= (y
+ TILE_SIZE
) % TILE_SIZE
;
3295 /* After this bit of magic [i,j] will correspond to the point either above
3296 * or to the left of the line selected */
3298 if (TILE_SIZE
- p
> q
) {
3301 hl_selected
= FALSE
;
3305 if (TILE_SIZE
- q
> p
) {
3306 hl_selected
= FALSE
;
3317 if (i
>= state
->w
|| j
>= state
->h
+ 1)
3320 if (i
>= state
->w
+ 1 || j
>= state
->h
)
3324 /* I think it's only possible to play this game with mouse clicks, sorry */
3325 /* Maybe will add mouse drag support some time */
3327 old_state
= RIGHTOF_DOT(state
, i
, j
);
3329 old_state
= BELOW_DOT(state
, i
, j
);
3333 switch (old_state
) {
3347 switch (old_state
) {
3362 sprintf(buf
, "%d,%d%c%c", i
, j
, (int)(hl_selected ?
'h' : 'v'), (int)button_char
);
3368 static game_state
*execute_move(game_state
*state
, char *move
)
3371 game_state
*newstate
= dup_game(state
);
3373 if (move
[0] == 'S') {
3375 newstate
->cheated
= TRUE
;
3380 move
= strchr(move
, ',');
3384 move
+= strspn(move
, "1234567890");
3385 switch (*(move
++)) {
3387 if (i
>= newstate
->w
|| j
> newstate
->h
)
3389 switch (*(move
++)) {
3391 LV_RIGHTOF_DOT(newstate
, i
, j
) = LINE_YES
;
3394 LV_RIGHTOF_DOT(newstate
, i
, j
) = LINE_NO
;
3397 LV_RIGHTOF_DOT(newstate
, i
, j
) = LINE_UNKNOWN
;
3404 if (i
> newstate
->w
|| j
>= newstate
->h
)
3406 switch (*(move
++)) {
3408 LV_BELOW_DOT(newstate
, i
, j
) = LINE_YES
;
3411 LV_BELOW_DOT(newstate
, i
, j
) = LINE_NO
;
3414 LV_BELOW_DOT(newstate
, i
, j
) = LINE_UNKNOWN
;
3426 * Check for completion.
3428 i
= 0; /* placate optimiser */
3429 for (j
= 0; j
<= newstate
->h
; j
++) {
3430 for (i
= 0; i
< newstate
->w
; i
++)
3431 if (LV_RIGHTOF_DOT(newstate
, i
, j
) == LINE_YES
)
3433 if (i
< newstate
->w
)
3436 if (j
<= newstate
->h
) {
3442 * We've found a horizontal edge at (i,j). Follow it round
3443 * to see if it's part of a loop.
3447 int order
= dot_order(newstate
, x
, y
, LINE_YES
);
3449 goto completion_check_done
;
3451 if (LEFTOF_DOT(newstate
, x
, y
) == LINE_YES
&& prevdir
!= 'L') {
3454 } else if (RIGHTOF_DOT(newstate
, x
, y
) == LINE_YES
&&
3458 } else if (ABOVE_DOT(newstate
, x
, y
) == LINE_YES
&&
3462 } else if (BELOW_DOT(newstate
, x
, y
) == LINE_YES
&&
3467 assert(!"Can't happen"); /* dot_order guarantees success */
3472 if (x
== i
&& y
== j
)
3476 if (x
!= i
|| y
!= j
|| looplen
== 0)
3477 goto completion_check_done
;
3480 * We've traced our way round a loop, and we know how many
3481 * line segments were involved. Count _all_ the line
3482 * segments in the grid, to see if the loop includes them
3486 FORALL_DOTS(newstate
, i
, j
) {
3487 count
+= ((RIGHTOF_DOT(newstate
, i
, j
) == LINE_YES
) +
3488 (BELOW_DOT(newstate
, i
, j
) == LINE_YES
));
3490 assert(count
>= looplen
);
3491 if (count
!= looplen
)
3492 goto completion_check_done
;
3495 * The grid contains one closed loop and nothing else.
3496 * Check that all the clues are satisfied.
3498 FORALL_SQUARES(newstate
, i
, j
) {
3499 if (CLUE_AT(newstate
, i
, j
) >= 0) {
3500 if (square_order(newstate
, i
, j
, LINE_YES
) !=
3501 CLUE_AT(newstate
, i
, j
)) {
3502 goto completion_check_done
;
3510 newstate
->solved
= TRUE
;
3513 completion_check_done
:
3517 free_game(newstate
);
3521 /* ----------------------------------------------------------------------
3524 static void game_redraw(drawing
*dr
, game_drawstate
*ds
, game_state
*oldstate
,
3525 game_state
*state
, int dir
, game_ui
*ui
,
3526 float animtime
, float flashtime
)
3530 int line_colour
, flash_changed
;
3535 * The initial contents of the window are not guaranteed and
3536 * can vary with front ends. To be on the safe side, all games
3537 * should start by drawing a big background-colour rectangle
3538 * covering the whole window.
3540 draw_rect(dr
, 0, 0, SIZE(state
->w
), SIZE(state
->h
), COL_BACKGROUND
);
3543 FORALL_DOTS(state
, i
, j
) {
3545 BORDER
+ i
* TILE_SIZE
- LINEWIDTH
/2,
3546 BORDER
+ j
* TILE_SIZE
- LINEWIDTH
/2,
3547 LINEWIDTH
, LINEWIDTH
, COL_FOREGROUND
);
3551 FORALL_SQUARES(state
, i
, j
) {
3552 c
[0] = CLUE2CHAR(CLUE_AT(state
, i
, j
));
3555 BORDER
+ i
* TILE_SIZE
+ TILE_SIZE
/2,
3556 BORDER
+ j
* TILE_SIZE
+ TILE_SIZE
/2,
3557 FONT_VARIABLE
, TILE_SIZE
/2,
3558 ALIGN_VCENTRE
| ALIGN_HCENTRE
, COL_FOREGROUND
, c
);
3560 draw_update(dr
, 0, 0,
3561 state
->w
* TILE_SIZE
+ 2*BORDER
+ 1,
3562 state
->h
* TILE_SIZE
+ 2*BORDER
+ 1);
3566 if (flashtime
> 0 &&
3567 (flashtime
<= FLASH_TIME
/3 ||
3568 flashtime
>= FLASH_TIME
*2/3)) {
3569 flash_changed
= !ds
->flashing
;
3570 ds
->flashing
= TRUE
;
3571 line_colour
= COL_HIGHLIGHT
;
3573 flash_changed
= ds
->flashing
;
3574 ds
->flashing
= FALSE
;
3575 line_colour
= COL_FOREGROUND
;
3578 #define CROSS_SIZE (3 * LINEWIDTH / 2)
3580 /* Redraw clue colours if necessary */
3581 FORALL_SQUARES(state
, i
, j
) {
3582 n
= CLUE_AT(state
, i
, j
);
3586 assert(n
>= 0 && n
<= 4);
3588 c
[0] = CLUE2CHAR(CLUE_AT(state
, i
, j
));
3591 clue_mistake
= (square_order(state
, i
, j
, LINE_YES
) > n
||
3592 square_order(state
, i
, j
, LINE_NO
) > (4-n
));
3594 if (clue_mistake
!= ds
->clue_error
[SQUARE_INDEX(state
, i
, j
)]) {
3596 BORDER
+ i
* TILE_SIZE
+ CROSS_SIZE
,
3597 BORDER
+ j
* TILE_SIZE
+ CROSS_SIZE
,
3598 TILE_SIZE
- CROSS_SIZE
* 2, TILE_SIZE
- CROSS_SIZE
* 2,
3601 BORDER
+ i
* TILE_SIZE
+ TILE_SIZE
/2,
3602 BORDER
+ j
* TILE_SIZE
+ TILE_SIZE
/2,
3603 FONT_VARIABLE
, TILE_SIZE
/2,
3604 ALIGN_VCENTRE
| ALIGN_HCENTRE
,
3605 clue_mistake ? COL_MISTAKE
: COL_FOREGROUND
, c
);
3606 draw_update(dr
, i
* TILE_SIZE
+ BORDER
, j
* TILE_SIZE
+ BORDER
,
3607 TILE_SIZE
, TILE_SIZE
);
3609 ds
->clue_error
[SQUARE_INDEX(state
, i
, j
)] = clue_mistake
;
3613 /* I've also had a request to colour lines red if they make a non-solution
3614 * loop, or if more than two lines go into any point. I think that would
3615 * be good some time. */
3617 #define CLEAR_VL(i, j) \
3620 BORDER + i * TILE_SIZE - CROSS_SIZE, \
3621 BORDER + j * TILE_SIZE + LINEWIDTH - LINEWIDTH/2, \
3623 TILE_SIZE - LINEWIDTH, \
3626 BORDER + i * TILE_SIZE - CROSS_SIZE, \
3627 BORDER + j * TILE_SIZE - CROSS_SIZE, \
3629 TILE_SIZE + CROSS_SIZE*2); \
3632 #define CLEAR_HL(i, j) \
3635 BORDER + i * TILE_SIZE + LINEWIDTH - LINEWIDTH/2, \
3636 BORDER + j * TILE_SIZE - CROSS_SIZE, \
3637 TILE_SIZE - LINEWIDTH, \
3641 BORDER + i * TILE_SIZE - CROSS_SIZE, \
3642 BORDER + j * TILE_SIZE - CROSS_SIZE, \
3643 TILE_SIZE + CROSS_SIZE*2, \
3647 /* Vertical lines */
3648 FORALL_VL(state
, i
, j
) {
3649 switch (BELOW_DOT(state
, i
, j
)) {
3651 if (ds
->vl
[VL_INDEX(state
, i
, j
)] != BELOW_DOT(state
, i
, j
)) {
3656 if (ds
->vl
[VL_INDEX(state
, i
, j
)] != BELOW_DOT(state
, i
, j
) ||
3660 BORDER
+ i
* TILE_SIZE
- LINEWIDTH
/2,
3661 BORDER
+ j
* TILE_SIZE
+ LINEWIDTH
- LINEWIDTH
/2,
3662 LINEWIDTH
, TILE_SIZE
- LINEWIDTH
,
3667 if (ds
->vl
[VL_INDEX(state
, i
, j
)] != BELOW_DOT(state
, i
, j
)) {
3670 BORDER
+ i
* TILE_SIZE
- CROSS_SIZE
,
3671 BORDER
+ j
* TILE_SIZE
+ TILE_SIZE
/2 - CROSS_SIZE
,
3672 BORDER
+ i
* TILE_SIZE
+ CROSS_SIZE
- 1,
3673 BORDER
+ j
* TILE_SIZE
+ TILE_SIZE
/2 + CROSS_SIZE
- 1,
3676 BORDER
+ i
* TILE_SIZE
+ CROSS_SIZE
- 1,
3677 BORDER
+ j
* TILE_SIZE
+ TILE_SIZE
/2 - CROSS_SIZE
,
3678 BORDER
+ i
* TILE_SIZE
- CROSS_SIZE
,
3679 BORDER
+ j
* TILE_SIZE
+ TILE_SIZE
/2 + CROSS_SIZE
- 1,
3684 ds
->vl
[VL_INDEX(state
, i
, j
)] = BELOW_DOT(state
, i
, j
);
3687 /* Horizontal lines */
3688 FORALL_HL(state
, i
, j
) {
3689 switch (RIGHTOF_DOT(state
, i
, j
)) {
3691 if (ds
->hl
[HL_INDEX(state
, i
, j
)] != RIGHTOF_DOT(state
, i
, j
)) {
3696 if (ds
->hl
[HL_INDEX(state
, i
, j
)] != RIGHTOF_DOT(state
, i
, j
) ||
3700 BORDER
+ i
* TILE_SIZE
+ LINEWIDTH
- LINEWIDTH
/2,
3701 BORDER
+ j
* TILE_SIZE
- LINEWIDTH
/2,
3702 TILE_SIZE
- LINEWIDTH
, LINEWIDTH
,
3707 if (ds
->hl
[HL_INDEX(state
, i
, j
)] != RIGHTOF_DOT(state
, i
, j
)) {
3710 BORDER
+ i
* TILE_SIZE
+ TILE_SIZE
/2 - CROSS_SIZE
,
3711 BORDER
+ j
* TILE_SIZE
+ CROSS_SIZE
- 1,
3712 BORDER
+ i
* TILE_SIZE
+ TILE_SIZE
/2 + CROSS_SIZE
- 1,
3713 BORDER
+ j
* TILE_SIZE
- CROSS_SIZE
,
3716 BORDER
+ i
* TILE_SIZE
+ TILE_SIZE
/2 - CROSS_SIZE
,
3717 BORDER
+ j
* TILE_SIZE
- CROSS_SIZE
,
3718 BORDER
+ i
* TILE_SIZE
+ TILE_SIZE
/2 + CROSS_SIZE
- 1,
3719 BORDER
+ j
* TILE_SIZE
+ CROSS_SIZE
- 1,
3724 ds
->hl
[HL_INDEX(state
, i
, j
)] = RIGHTOF_DOT(state
, i
, j
);
3728 static float game_flash_length(game_state
*oldstate
, game_state
*newstate
,
3729 int dir
, game_ui
*ui
)
3731 if (!oldstate
->solved
&& newstate
->solved
&&
3732 !oldstate
->cheated
&& !newstate
->cheated
) {
3739 static void game_print_size(game_params
*params
, float *x
, float *y
)
3744 * I'll use 7mm squares by default.
3746 game_compute_size(params
, 700, &pw
, &ph
);
3751 static void game_print(drawing
*dr
, game_state
*state
, int tilesize
)
3753 int ink
= print_mono_colour(dr
, 0);
3755 game_drawstate ads
, *ds
= &ads
;
3757 game_set_size(dr
, ds
, NULL
, tilesize
);
3760 * Dots. I'll deliberately make the dots a bit wider than the
3761 * lines, so you can still see them. (And also because it's
3762 * annoyingly tricky to make them _exactly_ the same size...)
3764 FORALL_DOTS(state
, x
, y
) {
3765 draw_circle(dr
, BORDER
+ x
* TILE_SIZE
, BORDER
+ y
* TILE_SIZE
,
3766 LINEWIDTH
, ink
, ink
);
3772 FORALL_SQUARES(state
, x
, y
) {
3773 if (CLUE_AT(state
, x
, y
) >= 0) {
3776 c
[0] = CLUE2CHAR(CLUE_AT(state
, x
, y
));
3779 BORDER
+ x
* TILE_SIZE
+ TILE_SIZE
/2,
3780 BORDER
+ y
* TILE_SIZE
+ TILE_SIZE
/2,
3781 FONT_VARIABLE
, TILE_SIZE
/2,
3782 ALIGN_VCENTRE
| ALIGN_HCENTRE
, ink
, c
);
3787 * Lines. (At the moment, I'm not bothering with crosses.)
3789 FORALL_HL(state
, x
, y
) {
3790 if (RIGHTOF_DOT(state
, x
, y
) == LINE_YES
)
3791 draw_rect(dr
, BORDER
+ x
* TILE_SIZE
,
3792 BORDER
+ y
* TILE_SIZE
- LINEWIDTH
/2,
3793 TILE_SIZE
, (LINEWIDTH
/2) * 2 + 1, ink
);
3796 FORALL_VL(state
, x
, y
) {
3797 if (BELOW_DOT(state
, x
, y
) == LINE_YES
)
3798 draw_rect(dr
, BORDER
+ x
* TILE_SIZE
- LINEWIDTH
/2,
3799 BORDER
+ y
* TILE_SIZE
,
3800 (LINEWIDTH
/2) * 2 + 1, TILE_SIZE
, ink
);
3805 #define thegame loopy
3808 const struct game thegame
= {
3809 "Loopy", "games.loopy", "loopy",
3816 TRUE
, game_configure
, custom_params
,
3824 TRUE
, game_text_format
,
3832 PREFERRED_TILE_SIZE
, game_compute_size
, game_set_size
,
3835 game_free_drawstate
,
3839 TRUE
, FALSE
, game_print_size
, game_print
,
3840 FALSE
/* wants_statusbar */,
3841 FALSE
, game_timing_state
,
3842 0, /* mouse_priorities */