2 * solo.c: the number-placing puzzle most popularly known as `Sudoku'.
6 * - reports from users are that `Trivial'-mode puzzles are still
7 * rather hard compared to newspapers' easy ones, so some better
8 * low-end difficulty grading would be nice
9 * + it's possible that really easy puzzles always have
10 * _several_ things you can do, so don't make you hunt too
11 * hard for the one deduction you can currently make
12 * + it's also possible that easy puzzles require fewer
13 * cross-eliminations: perhaps there's a higher incidence of
14 * things you can deduce by looking only at (say) rows,
15 * rather than things you have to check both rows and columns
17 * + but really, what I need to do is find some really easy
18 * puzzles and _play_ them, to see what's actually easy about
20 * + while I'm revamping this area, filling in the _last_
21 * number in a nearly-full row or column should certainly be
22 * permitted even at the lowest difficulty level.
23 * + also Owen noticed that `Basic' grids requiring numeric
24 * elimination are actually very hard, so I wonder if a
25 * difficulty gradation between that and positional-
26 * elimination-only might be in order
27 * + but it's not good to have _too_ many difficulty levels, or
28 * it'll take too long to randomly generate a given level.
30 * - it might still be nice to do some prioritisation on the
31 * removal of numbers from the grid
32 * + one possibility is to try to minimise the maximum number
33 * of filled squares in any block, which in particular ought
34 * to enforce never leaving a completely filled block in the
35 * puzzle as presented.
37 * - alternative interface modes
38 * + sudoku.com's Windows program has a palette of possible
39 * entries; you select a palette entry first and then click
40 * on the square you want it to go in, thus enabling
41 * mouse-only play. Useful for PDAs! I don't think it's
42 * actually incompatible with the current highlight-then-type
43 * approach: you _either_ highlight a palette entry and then
44 * click, _or_ you highlight a square and then type. At most
45 * one thing is ever highlighted at a time, so there's no way
47 * + then again, I don't actually like sudoku.com's interface;
48 * it's too much like a paint package whereas I prefer to
49 * think of Solo as a text editor.
50 * + another PDA-friendly possibility is a drag interface:
51 * _drag_ numbers from the palette into the grid squares.
52 * Thought experiments suggest I'd prefer that to the
53 * sudoku.com approach, but I haven't actually tried it.
57 * Solo puzzles need to be square overall (since each row and each
58 * column must contain one of every digit), but they need not be
59 * subdivided the same way internally. I am going to adopt a
60 * convention whereby I _always_ refer to `r' as the number of rows
61 * of _big_ divisions, and `c' as the number of columns of _big_
62 * divisions. Thus, a 2c by 3r puzzle looks something like this:
66 * ------+------ (Of course, you can't subdivide it the other way
67 * 1 4 5 | 6 3 2 or you'll get clashes; observe that the 4 in the
68 * 3 2 6 | 4 1 5 top left would conflict with the 4 in the second
69 * ------+------ box down on the left-hand side.)
73 * The need for a strong naming convention should now be clear:
74 * each small box is two rows of digits by three columns, while the
75 * overall puzzle has three rows of small boxes by two columns. So
76 * I will (hopefully) consistently use `r' to denote the number of
77 * rows _of small boxes_ (here 3), which is also the number of
78 * columns of digits in each small box; and `c' vice versa (here
81 * I'm also going to choose arbitrarily to list c first wherever
82 * possible: the above is a 2x3 puzzle, not a 3x2 one.
92 #ifdef STANDALONE_SOLVER
94 int solver_show_working
, solver_recurse_depth
;
100 * To save space, I store digits internally as unsigned char. This
101 * imposes a hard limit of 255 on the order of the puzzle. Since
102 * even a 5x5 takes unacceptably long to generate, I don't see this
103 * as a serious limitation unless something _really_ impressive
104 * happens in computing technology; but here's a typedef anyway for
105 * general good practice.
107 typedef unsigned char digit
;
108 #define ORDER_MAX 255
110 #define PREFERRED_TILE_SIZE 32
111 #define TILE_SIZE (ds->tilesize)
112 #define BORDER (TILE_SIZE / 2)
114 #define FLASH_TIME 0.4F
116 enum { SYMM_NONE
, SYMM_ROT2
, SYMM_ROT4
, SYMM_REF2
, SYMM_REF2D
, SYMM_REF4
,
117 SYMM_REF4D
, SYMM_REF8
};
119 enum { DIFF_BLOCK
, DIFF_SIMPLE
, DIFF_INTERSECT
,
120 DIFF_SET
, DIFF_RECURSIVE
, DIFF_AMBIGUOUS
, DIFF_IMPOSSIBLE
};
134 int c
, r
, symm
, diff
;
140 unsigned char *pencil
; /* c*r*c*r elements */
141 unsigned char *immutable
; /* marks which digits are clues */
142 int completed
, cheated
;
145 static game_params
*default_params(void)
147 game_params
*ret
= snew(game_params
);
150 ret
->symm
= SYMM_ROT2
; /* a plausible default */
151 ret
->diff
= DIFF_BLOCK
; /* so is this */
156 static void free_params(game_params
*params
)
161 static game_params
*dup_params(game_params
*params
)
163 game_params
*ret
= snew(game_params
);
164 *ret
= *params
; /* structure copy */
168 static int game_fetch_preset(int i
, char **name
, game_params
**params
)
174 { "2x2 Trivial", { 2, 2, SYMM_ROT2
, DIFF_BLOCK
} },
175 { "2x3 Basic", { 2, 3, SYMM_ROT2
, DIFF_SIMPLE
} },
176 { "3x3 Trivial", { 3, 3, SYMM_ROT2
, DIFF_BLOCK
} },
177 { "3x3 Basic", { 3, 3, SYMM_ROT2
, DIFF_SIMPLE
} },
178 { "3x3 Intermediate", { 3, 3, SYMM_ROT2
, DIFF_INTERSECT
} },
179 { "3x3 Advanced", { 3, 3, SYMM_ROT2
, DIFF_SET
} },
180 { "3x3 Unreasonable", { 3, 3, SYMM_ROT2
, DIFF_RECURSIVE
} },
182 { "3x4 Basic", { 3, 4, SYMM_ROT2
, DIFF_SIMPLE
} },
183 { "4x4 Basic", { 4, 4, SYMM_ROT2
, DIFF_SIMPLE
} },
187 if (i
< 0 || i
>= lenof(presets
))
190 *name
= dupstr(presets
[i
].title
);
191 *params
= dup_params(&presets
[i
].params
);
196 static void decode_params(game_params
*ret
, char const *string
)
198 ret
->c
= ret
->r
= atoi(string
);
199 while (*string
&& isdigit((unsigned char)*string
)) string
++;
200 if (*string
== 'x') {
202 ret
->r
= atoi(string
);
203 while (*string
&& isdigit((unsigned char)*string
)) string
++;
206 if (*string
== 'r' || *string
== 'm' || *string
== 'a') {
209 if (*string
== 'd') {
216 while (*string
&& isdigit((unsigned char)*string
)) string
++;
217 if (sc
== 'm' && sn
== 8)
218 ret
->symm
= SYMM_REF8
;
219 if (sc
== 'm' && sn
== 4)
220 ret
->symm
= sd ? SYMM_REF4D
: SYMM_REF4
;
221 if (sc
== 'm' && sn
== 2)
222 ret
->symm
= sd ? SYMM_REF2D
: SYMM_REF2
;
223 if (sc
== 'r' && sn
== 4)
224 ret
->symm
= SYMM_ROT4
;
225 if (sc
== 'r' && sn
== 2)
226 ret
->symm
= SYMM_ROT2
;
228 ret
->symm
= SYMM_NONE
;
229 } else if (*string
== 'd') {
231 if (*string
== 't') /* trivial */
232 string
++, ret
->diff
= DIFF_BLOCK
;
233 else if (*string
== 'b') /* basic */
234 string
++, ret
->diff
= DIFF_SIMPLE
;
235 else if (*string
== 'i') /* intermediate */
236 string
++, ret
->diff
= DIFF_INTERSECT
;
237 else if (*string
== 'a') /* advanced */
238 string
++, ret
->diff
= DIFF_SET
;
239 else if (*string
== 'u') /* unreasonable */
240 string
++, ret
->diff
= DIFF_RECURSIVE
;
242 string
++; /* eat unknown character */
246 static char *encode_params(game_params
*params
, int full
)
250 sprintf(str
, "%dx%d", params
->c
, params
->r
);
252 switch (params
->symm
) {
253 case SYMM_REF8
: strcat(str
, "m8"); break;
254 case SYMM_REF4
: strcat(str
, "m4"); break;
255 case SYMM_REF4D
: strcat(str
, "md4"); break;
256 case SYMM_REF2
: strcat(str
, "m2"); break;
257 case SYMM_REF2D
: strcat(str
, "md2"); break;
258 case SYMM_ROT4
: strcat(str
, "r4"); break;
259 /* case SYMM_ROT2: strcat(str, "r2"); break; [default] */
260 case SYMM_NONE
: strcat(str
, "a"); break;
262 switch (params
->diff
) {
263 /* case DIFF_BLOCK: strcat(str, "dt"); break; [default] */
264 case DIFF_SIMPLE
: strcat(str
, "db"); break;
265 case DIFF_INTERSECT
: strcat(str
, "di"); break;
266 case DIFF_SET
: strcat(str
, "da"); break;
267 case DIFF_RECURSIVE
: strcat(str
, "du"); break;
273 static config_item
*game_configure(game_params
*params
)
278 ret
= snewn(5, config_item
);
280 ret
[0].name
= "Columns of sub-blocks";
281 ret
[0].type
= C_STRING
;
282 sprintf(buf
, "%d", params
->c
);
283 ret
[0].sval
= dupstr(buf
);
286 ret
[1].name
= "Rows of sub-blocks";
287 ret
[1].type
= C_STRING
;
288 sprintf(buf
, "%d", params
->r
);
289 ret
[1].sval
= dupstr(buf
);
292 ret
[2].name
= "Symmetry";
293 ret
[2].type
= C_CHOICES
;
294 ret
[2].sval
= ":None:2-way rotation:4-way rotation:2-way mirror:"
295 "2-way diagonal mirror:4-way mirror:4-way diagonal mirror:"
297 ret
[2].ival
= params
->symm
;
299 ret
[3].name
= "Difficulty";
300 ret
[3].type
= C_CHOICES
;
301 ret
[3].sval
= ":Trivial:Basic:Intermediate:Advanced:Unreasonable";
302 ret
[3].ival
= params
->diff
;
312 static game_params
*custom_params(config_item
*cfg
)
314 game_params
*ret
= snew(game_params
);
316 ret
->c
= atoi(cfg
[0].sval
);
317 ret
->r
= atoi(cfg
[1].sval
);
318 ret
->symm
= cfg
[2].ival
;
319 ret
->diff
= cfg
[3].ival
;
324 static char *validate_params(game_params
*params
, int full
)
326 if (params
->c
< 2 || params
->r
< 2)
327 return "Both dimensions must be at least 2";
328 if (params
->c
> ORDER_MAX
|| params
->r
> ORDER_MAX
)
329 return "Dimensions greater than "STR(ORDER_MAX
)" are not supported";
330 if ((params
->c
* params
->r
) > 36)
331 return "Unable to support more than 36 distinct symbols in a puzzle";
335 /* ----------------------------------------------------------------------
338 * This solver is used for several purposes:
339 * + to generate filled grids as the basis for new puzzles (by
340 * supplying no clue squares at all)
341 * + to check solubility of a grid as we gradually remove numbers
343 * + to solve an externally generated puzzle when the user selects
346 * It supports a variety of specific modes of reasoning. By
347 * enabling or disabling subsets of these modes we can arrange a
348 * range of difficulty levels.
352 * Modes of reasoning currently supported:
354 * - Positional elimination: a number must go in a particular
355 * square because all the other empty squares in a given
356 * row/col/blk are ruled out.
358 * - Numeric elimination: a square must have a particular number
359 * in because all the other numbers that could go in it are
362 * - Intersectional analysis: given two domains which overlap
363 * (hence one must be a block, and the other can be a row or
364 * col), if the possible locations for a particular number in
365 * one of the domains can be narrowed down to the overlap, then
366 * that number can be ruled out everywhere but the overlap in
367 * the other domain too.
369 * - Set elimination: if there is a subset of the empty squares
370 * within a domain such that the union of the possible numbers
371 * in that subset has the same size as the subset itself, then
372 * those numbers can be ruled out everywhere else in the domain.
373 * (For example, if there are five empty squares and the
374 * possible numbers in each are 12, 23, 13, 134 and 1345, then
375 * the first three empty squares form such a subset: the numbers
376 * 1, 2 and 3 _must_ be in those three squares in some
377 * permutation, and hence we can deduce none of them can be in
378 * the fourth or fifth squares.)
379 * + You can also see this the other way round, concentrating
380 * on numbers rather than squares: if there is a subset of
381 * the unplaced numbers within a domain such that the union
382 * of all their possible positions has the same size as the
383 * subset itself, then all other numbers can be ruled out for
384 * those positions. However, it turns out that this is
385 * exactly equivalent to the first formulation at all times:
386 * there is a 1-1 correspondence between suitable subsets of
387 * the unplaced numbers and suitable subsets of the unfilled
388 * places, found by taking the _complement_ of the union of
389 * the numbers' possible positions (or the spaces' possible
392 * - Recursion. If all else fails, we pick one of the currently
393 * most constrained empty squares and take a random guess at its
394 * contents, then continue solving on that basis and see if we
399 * Within this solver, I'm going to transform all y-coordinates by
400 * inverting the significance of the block number and the position
401 * within the block. That is, we will start with the top row of
402 * each block in order, then the second row of each block in order,
405 * This transformation has the enormous advantage that it means
406 * every row, column _and_ block is described by an arithmetic
407 * progression of coordinates within the cubic array, so that I can
408 * use the same very simple function to do blockwise, row-wise and
409 * column-wise elimination.
411 #define YTRANS(y) (((y)%c)*r+(y)/c)
412 #define YUNTRANS(y) (((y)%r)*c+(y)/r)
414 struct solver_usage
{
417 * We set up a cubic array, indexed by x, y and digit; each
418 * element of this array is TRUE or FALSE according to whether
419 * or not that digit _could_ in principle go in that position.
421 * The way to index this array is cube[(x*cr+y)*cr+n-1].
422 * y-coordinates in here are transformed.
426 * This is the grid in which we write down our final
427 * deductions. y-coordinates in here are _not_ transformed.
431 * Now we keep track, at a slightly higher level, of what we
432 * have yet to work out, to prevent doing the same deduction
435 /* row[y*cr+n-1] TRUE if digit n has been placed in row y */
437 /* col[x*cr+n-1] TRUE if digit n has been placed in row x */
439 /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */
442 #define cubepos(x,y,n) (((x)*usage->cr+(y))*usage->cr+(n)-1)
443 #define cube(x,y,n) (usage->cube[cubepos(x,y,n)])
446 * Function called when we are certain that a particular square has
447 * a particular number in it. The y-coordinate passed in here is
450 static void solver_place(struct solver_usage
*usage
, int x
, int y
, int n
)
452 int c
= usage
->c
, r
= usage
->r
, cr
= usage
->cr
;
458 * Rule out all other numbers in this square.
460 for (i
= 1; i
<= cr
; i
++)
465 * Rule out this number in all other positions in the row.
467 for (i
= 0; i
< cr
; i
++)
472 * Rule out this number in all other positions in the column.
474 for (i
= 0; i
< cr
; i
++)
479 * Rule out this number in all other positions in the block.
483 for (i
= 0; i
< r
; i
++)
484 for (j
= 0; j
< c
; j
++)
485 if (bx
+i
!= x
|| by
+j
*r
!= y
)
486 cube(bx
+i
,by
+j
*r
,n
) = FALSE
;
489 * Enter the number in the result grid.
491 usage
->grid
[YUNTRANS(y
)*cr
+x
] = n
;
494 * Cross out this number from the list of numbers left to place
495 * in its row, its column and its block.
497 usage
->row
[y
*cr
+n
-1] = usage
->col
[x
*cr
+n
-1] =
498 usage
->blk
[((y
%r
)*c
+(x
/r
))*cr
+n
-1] = TRUE
;
501 static int solver_elim(struct solver_usage
*usage
, int start
, int step
502 #ifdef STANDALONE_SOLVER
507 int c
= usage
->c
, r
= usage
->r
, cr
= c
*r
;
511 * Count the number of set bits within this section of the
516 for (i
= 0; i
< cr
; i
++)
517 if (usage
->cube
[start
+i
*step
]) {
531 if (!usage
->grid
[YUNTRANS(y
)*cr
+x
]) {
532 #ifdef STANDALONE_SOLVER
533 if (solver_show_working
) {
535 printf("%*s", solver_recurse_depth
*4, "");
539 printf(":\n%*s placing %d at (%d,%d)\n",
540 solver_recurse_depth
*4, "", n
, 1+x
, 1+YUNTRANS(y
));
543 solver_place(usage
, x
, y
, n
);
547 #ifdef STANDALONE_SOLVER
548 if (solver_show_working
) {
550 printf("%*s", solver_recurse_depth
*4, "");
554 printf(":\n%*s no possibilities available\n",
555 solver_recurse_depth
*4, "");
564 static int solver_intersect(struct solver_usage
*usage
,
565 int start1
, int step1
, int start2
, int step2
566 #ifdef STANDALONE_SOLVER
571 int c
= usage
->c
, r
= usage
->r
, cr
= c
*r
;
575 * Loop over the first domain and see if there's any set bit
576 * not also in the second.
578 for (i
= 0; i
< cr
; i
++) {
579 int p
= start1
+i
*step1
;
580 if (usage
->cube
[p
] &&
581 !(p
>= start2
&& p
< start2
+cr
*step2
&&
582 (p
- start2
) % step2
== 0))
583 return 0; /* there is, so we can't deduce */
587 * We have determined that all set bits in the first domain are
588 * within its overlap with the second. So loop over the second
589 * domain and remove all set bits that aren't also in that
590 * overlap; return +1 iff we actually _did_ anything.
593 for (i
= 0; i
< cr
; i
++) {
594 int p
= start2
+i
*step2
;
595 if (usage
->cube
[p
] &&
596 !(p
>= start1
&& p
< start1
+cr
*step1
&& (p
- start1
) % step1
== 0))
598 #ifdef STANDALONE_SOLVER
599 if (solver_show_working
) {
604 printf("%*s", solver_recurse_depth
*4, "");
616 printf("%*s ruling out %d at (%d,%d)\n",
617 solver_recurse_depth
*4, "", pn
, 1+px
, 1+YUNTRANS(py
));
620 ret
= +1; /* we did something */
628 struct solver_scratch
{
629 unsigned char *grid
, *rowidx
, *colidx
, *set
;
632 static int solver_set(struct solver_usage
*usage
,
633 struct solver_scratch
*scratch
,
634 int start
, int step1
, int step2
635 #ifdef STANDALONE_SOLVER
640 int c
= usage
->c
, r
= usage
->r
, cr
= c
*r
;
642 unsigned char *grid
= scratch
->grid
;
643 unsigned char *rowidx
= scratch
->rowidx
;
644 unsigned char *colidx
= scratch
->colidx
;
645 unsigned char *set
= scratch
->set
;
648 * We are passed a cr-by-cr matrix of booleans. Our first job
649 * is to winnow it by finding any definite placements - i.e.
650 * any row with a solitary 1 - and discarding that row and the
651 * column containing the 1.
653 memset(rowidx
, TRUE
, cr
);
654 memset(colidx
, TRUE
, cr
);
655 for (i
= 0; i
< cr
; i
++) {
656 int count
= 0, first
= -1;
657 for (j
= 0; j
< cr
; j
++)
658 if (usage
->cube
[start
+i
*step1
+j
*step2
])
662 * If count == 0, then there's a row with no 1s at all and
663 * the puzzle is internally inconsistent. However, we ought
664 * to have caught this already during the simpler reasoning
665 * methods, so we can safely fail an assertion if we reach
670 rowidx
[i
] = colidx
[first
] = FALSE
;
674 * Convert each of rowidx/colidx from a list of 0s and 1s to a
675 * list of the indices of the 1s.
677 for (i
= j
= 0; i
< cr
; i
++)
681 for (i
= j
= 0; i
< cr
; i
++)
687 * And create the smaller matrix.
689 for (i
= 0; i
< n
; i
++)
690 for (j
= 0; j
< n
; j
++)
691 grid
[i
*cr
+j
] = usage
->cube
[start
+rowidx
[i
]*step1
+colidx
[j
]*step2
];
694 * Having done that, we now have a matrix in which every row
695 * has at least two 1s in. Now we search to see if we can find
696 * a rectangle of zeroes (in the set-theoretic sense of
697 * `rectangle', i.e. a subset of rows crossed with a subset of
698 * columns) whose width and height add up to n.
705 * We have a candidate set. If its size is <=1 or >=n-1
706 * then we move on immediately.
708 if (count
> 1 && count
< n
-1) {
710 * The number of rows we need is n-count. See if we can
711 * find that many rows which each have a zero in all
712 * the positions listed in `set'.
715 for (i
= 0; i
< n
; i
++) {
717 for (j
= 0; j
< n
; j
++)
718 if (set
[j
] && grid
[i
*cr
+j
]) {
727 * We expect never to be able to get _more_ than
728 * n-count suitable rows: this would imply that (for
729 * example) there are four numbers which between them
730 * have at most three possible positions, and hence it
731 * indicates a faulty deduction before this point or
734 if (rows
> n
- count
) {
735 #ifdef STANDALONE_SOLVER
736 if (solver_show_working
) {
738 printf("%*s", solver_recurse_depth
*4,
743 printf(":\n%*s contradiction reached\n",
744 solver_recurse_depth
*4, "");
750 if (rows
>= n
- count
) {
751 int progress
= FALSE
;
754 * We've got one! Now, for each row which _doesn't_
755 * satisfy the criterion, eliminate all its set
756 * bits in the positions _not_ listed in `set'.
757 * Return +1 (meaning progress has been made) if we
758 * successfully eliminated anything at all.
760 * This involves referring back through
761 * rowidx/colidx in order to work out which actual
762 * positions in the cube to meddle with.
764 for (i
= 0; i
< n
; i
++) {
766 for (j
= 0; j
< n
; j
++)
767 if (set
[j
] && grid
[i
*cr
+j
]) {
772 for (j
= 0; j
< n
; j
++)
773 if (!set
[j
] && grid
[i
*cr
+j
]) {
774 int fpos
= (start
+rowidx
[i
]*step1
+
776 #ifdef STANDALONE_SOLVER
777 if (solver_show_working
) {
782 printf("%*s", solver_recurse_depth
*4,
795 printf("%*s ruling out %d at (%d,%d)\n",
796 solver_recurse_depth
*4, "",
797 pn
, 1+px
, 1+YUNTRANS(py
));
801 usage
->cube
[fpos
] = FALSE
;
813 * Binary increment: change the rightmost 0 to a 1, and
814 * change all 1s to the right of it to 0s.
817 while (i
> 0 && set
[i
-1])
818 set
[--i
] = 0, count
--;
820 set
[--i
] = 1, count
++;
828 static struct solver_scratch
*solver_new_scratch(struct solver_usage
*usage
)
830 struct solver_scratch
*scratch
= snew(struct solver_scratch
);
832 scratch
->grid
= snewn(cr
*cr
, unsigned char);
833 scratch
->rowidx
= snewn(cr
, unsigned char);
834 scratch
->colidx
= snewn(cr
, unsigned char);
835 scratch
->set
= snewn(cr
, unsigned char);
839 static void solver_free_scratch(struct solver_scratch
*scratch
)
842 sfree(scratch
->colidx
);
843 sfree(scratch
->rowidx
);
844 sfree(scratch
->grid
);
848 static int solver(int c
, int r
, digit
*grid
, int maxdiff
)
850 struct solver_usage
*usage
;
851 struct solver_scratch
*scratch
;
854 int diff
= DIFF_BLOCK
;
857 * Set up a usage structure as a clean slate (everything
860 usage
= snew(struct solver_usage
);
864 usage
->cube
= snewn(cr
*cr
*cr
, unsigned char);
865 usage
->grid
= grid
; /* write straight back to the input */
866 memset(usage
->cube
, TRUE
, cr
*cr
*cr
);
868 usage
->row
= snewn(cr
* cr
, unsigned char);
869 usage
->col
= snewn(cr
* cr
, unsigned char);
870 usage
->blk
= snewn(cr
* cr
, unsigned char);
871 memset(usage
->row
, FALSE
, cr
* cr
);
872 memset(usage
->col
, FALSE
, cr
* cr
);
873 memset(usage
->blk
, FALSE
, cr
* cr
);
875 scratch
= solver_new_scratch(usage
);
878 * Place all the clue numbers we are given.
880 for (x
= 0; x
< cr
; x
++)
881 for (y
= 0; y
< cr
; y
++)
883 solver_place(usage
, x
, YTRANS(y
), grid
[y
*cr
+x
]);
886 * Now loop over the grid repeatedly trying all permitted modes
887 * of reasoning. The loop terminates if we complete an
888 * iteration without making any progress; we then return
889 * failure or success depending on whether the grid is full or
894 * I'd like to write `continue;' inside each of the
895 * following loops, so that the solver returns here after
896 * making some progress. However, I can't specify that I
897 * want to continue an outer loop rather than the innermost
898 * one, so I'm apologetically resorting to a goto.
903 * Blockwise positional elimination.
905 for (x
= 0; x
< cr
; x
+= r
)
906 for (y
= 0; y
< r
; y
++)
907 for (n
= 1; n
<= cr
; n
++)
908 if (!usage
->blk
[(y
*c
+(x
/r
))*cr
+n
-1]) {
909 ret
= solver_elim(usage
, cubepos(x
,y
,n
), r
*cr
910 #ifdef STANDALONE_SOLVER
911 , "positional elimination,"
912 " %d in block (%d,%d)", n
, 1+x
/r
, 1+y
916 diff
= DIFF_IMPOSSIBLE
;
918 } else if (ret
> 0) {
919 diff
= max(diff
, DIFF_BLOCK
);
924 if (maxdiff
<= DIFF_BLOCK
)
928 * Row-wise positional elimination.
930 for (y
= 0; y
< cr
; y
++)
931 for (n
= 1; n
<= cr
; n
++)
932 if (!usage
->row
[y
*cr
+n
-1]) {
933 ret
= solver_elim(usage
, cubepos(0,y
,n
), cr
*cr
934 #ifdef STANDALONE_SOLVER
935 , "positional elimination,"
936 " %d in row %d", n
, 1+YUNTRANS(y
)
940 diff
= DIFF_IMPOSSIBLE
;
942 } else if (ret
> 0) {
943 diff
= max(diff
, DIFF_SIMPLE
);
948 * Column-wise positional elimination.
950 for (x
= 0; x
< cr
; x
++)
951 for (n
= 1; n
<= cr
; n
++)
952 if (!usage
->col
[x
*cr
+n
-1]) {
953 ret
= solver_elim(usage
, cubepos(x
,0,n
), cr
954 #ifdef STANDALONE_SOLVER
955 , "positional elimination,"
956 " %d in column %d", n
, 1+x
960 diff
= DIFF_IMPOSSIBLE
;
962 } else if (ret
> 0) {
963 diff
= max(diff
, DIFF_SIMPLE
);
969 * Numeric elimination.
971 for (x
= 0; x
< cr
; x
++)
972 for (y
= 0; y
< cr
; y
++)
973 if (!usage
->grid
[YUNTRANS(y
)*cr
+x
]) {
974 ret
= solver_elim(usage
, cubepos(x
,y
,1), 1
975 #ifdef STANDALONE_SOLVER
976 , "numeric elimination at (%d,%d)", 1+x
,
981 diff
= DIFF_IMPOSSIBLE
;
983 } else if (ret
> 0) {
984 diff
= max(diff
, DIFF_SIMPLE
);
989 if (maxdiff
<= DIFF_SIMPLE
)
993 * Intersectional analysis, rows vs blocks.
995 for (y
= 0; y
< cr
; y
++)
996 for (x
= 0; x
< cr
; x
+= r
)
997 for (n
= 1; n
<= cr
; n
++)
999 * solver_intersect() never returns -1.
1001 if (!usage
->row
[y
*cr
+n
-1] &&
1002 !usage
->blk
[((y
%r
)*c
+(x
/r
))*cr
+n
-1] &&
1003 (solver_intersect(usage
, cubepos(0,y
,n
), cr
*cr
,
1004 cubepos(x
,y
%r
,n
), r
*cr
1005 #ifdef STANDALONE_SOLVER
1006 , "intersectional analysis,"
1007 " %d in row %d vs block (%d,%d)",
1008 n
, 1+YUNTRANS(y
), 1+x
/r
, 1+y
%r
1011 solver_intersect(usage
, cubepos(x
,y
%r
,n
), r
*cr
,
1012 cubepos(0,y
,n
), cr
*cr
1013 #ifdef STANDALONE_SOLVER
1014 , "intersectional analysis,"
1015 " %d in block (%d,%d) vs row %d",
1016 n
, 1+x
/r
, 1+y
%r
, 1+YUNTRANS(y
)
1019 diff
= max(diff
, DIFF_INTERSECT
);
1024 * Intersectional analysis, columns vs blocks.
1026 for (x
= 0; x
< cr
; x
++)
1027 for (y
= 0; y
< r
; y
++)
1028 for (n
= 1; n
<= cr
; n
++)
1029 if (!usage
->col
[x
*cr
+n
-1] &&
1030 !usage
->blk
[(y
*c
+(x
/r
))*cr
+n
-1] &&
1031 (solver_intersect(usage
, cubepos(x
,0,n
), cr
,
1032 cubepos((x
/r
)*r
,y
,n
), r
*cr
1033 #ifdef STANDALONE_SOLVER
1034 , "intersectional analysis,"
1035 " %d in column %d vs block (%d,%d)",
1039 solver_intersect(usage
, cubepos((x
/r
)*r
,y
,n
), r
*cr
,
1041 #ifdef STANDALONE_SOLVER
1042 , "intersectional analysis,"
1043 " %d in block (%d,%d) vs column %d",
1047 diff
= max(diff
, DIFF_INTERSECT
);
1051 if (maxdiff
<= DIFF_INTERSECT
)
1055 * Blockwise set elimination.
1057 for (x
= 0; x
< cr
; x
+= r
)
1058 for (y
= 0; y
< r
; y
++) {
1059 ret
= solver_set(usage
, scratch
, cubepos(x
,y
,1), r
*cr
, 1
1060 #ifdef STANDALONE_SOLVER
1061 , "set elimination, block (%d,%d)", 1+x
/r
, 1+y
1065 diff
= DIFF_IMPOSSIBLE
;
1067 } else if (ret
> 0) {
1068 diff
= max(diff
, DIFF_SET
);
1074 * Row-wise set elimination.
1076 for (y
= 0; y
< cr
; y
++) {
1077 ret
= solver_set(usage
, scratch
, cubepos(0,y
,1), cr
*cr
, 1
1078 #ifdef STANDALONE_SOLVER
1079 , "set elimination, row %d", 1+YUNTRANS(y
)
1083 diff
= DIFF_IMPOSSIBLE
;
1085 } else if (ret
> 0) {
1086 diff
= max(diff
, DIFF_SET
);
1092 * Column-wise set elimination.
1094 for (x
= 0; x
< cr
; x
++) {
1095 ret
= solver_set(usage
, scratch
, cubepos(x
,0,1), cr
, 1
1096 #ifdef STANDALONE_SOLVER
1097 , "set elimination, column %d", 1+x
1101 diff
= DIFF_IMPOSSIBLE
;
1103 } else if (ret
> 0) {
1104 diff
= max(diff
, DIFF_SET
);
1110 * If we reach here, we have made no deductions in this
1111 * iteration, so the algorithm terminates.
1117 * Last chance: if we haven't fully solved the puzzle yet, try
1118 * recursing based on guesses for a particular square. We pick
1119 * one of the most constrained empty squares we can find, which
1120 * has the effect of pruning the search tree as much as
1123 if (maxdiff
>= DIFF_RECURSIVE
) {
1124 int best
, bestcount
;
1129 for (y
= 0; y
< cr
; y
++)
1130 for (x
= 0; x
< cr
; x
++)
1131 if (!grid
[y
*cr
+x
]) {
1135 * An unfilled square. Count the number of
1136 * possible digits in it.
1139 for (n
= 1; n
<= cr
; n
++)
1140 if (cube(x
,YTRANS(y
),n
))
1144 * We should have found any impossibilities
1145 * already, so this can safely be an assert.
1149 if (count
< bestcount
) {
1157 digit
*list
, *ingrid
, *outgrid
;
1159 diff
= DIFF_IMPOSSIBLE
; /* no solution found yet */
1162 * Attempt recursion.
1167 list
= snewn(cr
, digit
);
1168 ingrid
= snewn(cr
* cr
, digit
);
1169 outgrid
= snewn(cr
* cr
, digit
);
1170 memcpy(ingrid
, grid
, cr
* cr
);
1172 /* Make a list of the possible digits. */
1173 for (j
= 0, n
= 1; n
<= cr
; n
++)
1174 if (cube(x
,YTRANS(y
),n
))
1177 #ifdef STANDALONE_SOLVER
1178 if (solver_show_working
) {
1180 printf("%*srecursing on (%d,%d) [",
1181 solver_recurse_depth
*4, "", x
, y
);
1182 for (i
= 0; i
< j
; i
++) {
1183 printf("%s%d", sep
, list
[i
]);
1191 * And step along the list, recursing back into the
1192 * main solver at every stage.
1194 for (i
= 0; i
< j
; i
++) {
1197 memcpy(outgrid
, ingrid
, cr
* cr
);
1198 outgrid
[y
*cr
+x
] = list
[i
];
1200 #ifdef STANDALONE_SOLVER
1201 if (solver_show_working
)
1202 printf("%*sguessing %d at (%d,%d)\n",
1203 solver_recurse_depth
*4, "", list
[i
], x
, y
);
1204 solver_recurse_depth
++;
1207 ret
= solver(c
, r
, outgrid
, maxdiff
);
1209 #ifdef STANDALONE_SOLVER
1210 solver_recurse_depth
--;
1211 if (solver_show_working
) {
1212 printf("%*sretracting %d at (%d,%d)\n",
1213 solver_recurse_depth
*4, "", list
[i
], x
, y
);
1218 * If we have our first solution, copy it into the
1219 * grid we will return.
1221 if (diff
== DIFF_IMPOSSIBLE
&& ret
!= DIFF_IMPOSSIBLE
)
1222 memcpy(grid
, outgrid
, cr
*cr
);
1224 if (ret
== DIFF_AMBIGUOUS
)
1225 diff
= DIFF_AMBIGUOUS
;
1226 else if (ret
== DIFF_IMPOSSIBLE
)
1227 /* do not change our return value */;
1229 /* the recursion turned up exactly one solution */
1230 if (diff
== DIFF_IMPOSSIBLE
)
1231 diff
= DIFF_RECURSIVE
;
1233 diff
= DIFF_AMBIGUOUS
;
1237 * As soon as we've found more than one solution,
1238 * give up immediately.
1240 if (diff
== DIFF_AMBIGUOUS
)
1251 * We're forbidden to use recursion, so we just see whether
1252 * our grid is fully solved, and return DIFF_IMPOSSIBLE
1255 for (y
= 0; y
< cr
; y
++)
1256 for (x
= 0; x
< cr
; x
++)
1258 diff
= DIFF_IMPOSSIBLE
;
1263 #ifdef STANDALONE_SOLVER
1264 if (solver_show_working
)
1265 printf("%*s%s found\n",
1266 solver_recurse_depth
*4, "",
1267 diff
== DIFF_IMPOSSIBLE ?
"no solution" :
1268 diff
== DIFF_AMBIGUOUS ?
"multiple solutions" :
1278 solver_free_scratch(scratch
);
1283 /* ----------------------------------------------------------------------
1284 * End of solver code.
1287 /* ----------------------------------------------------------------------
1288 * Solo filled-grid generator.
1290 * This grid generator works by essentially trying to solve a grid
1291 * starting from no clues, and not worrying that there's more than
1292 * one possible solution. Unfortunately, it isn't computationally
1293 * feasible to do this by calling the above solver with an empty
1294 * grid, because that one needs to allocate a lot of scratch space
1295 * at every recursion level. Instead, I have a much simpler
1296 * algorithm which I shamelessly copied from a Python solver
1297 * written by Andrew Wilkinson (which is GPLed, but I've reused
1298 * only ideas and no code). It mostly just does the obvious
1299 * recursive thing: pick an empty square, put one of the possible
1300 * digits in it, recurse until all squares are filled, backtrack
1301 * and change some choices if necessary.
1303 * The clever bit is that every time it chooses which square to
1304 * fill in next, it does so by counting the number of _possible_
1305 * numbers that can go in each square, and it prioritises so that
1306 * it picks a square with the _lowest_ number of possibilities. The
1307 * idea is that filling in lots of the obvious bits (particularly
1308 * any squares with only one possibility) will cut down on the list
1309 * of possibilities for other squares and hence reduce the enormous
1310 * search space as much as possible as early as possible.
1314 * Internal data structure used in gridgen to keep track of
1317 struct gridgen_coord
{ int x
, y
, r
; };
1318 struct gridgen_usage
{
1319 int c
, r
, cr
; /* cr == c*r */
1320 /* grid is a copy of the input grid, modified as we go along */
1322 /* row[y*cr+n-1] TRUE if digit n has been placed in row y */
1324 /* col[x*cr+n-1] TRUE if digit n has been placed in row x */
1326 /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */
1328 /* This lists all the empty spaces remaining in the grid. */
1329 struct gridgen_coord
*spaces
;
1331 /* If we need randomisation in the solve, this is our random state. */
1336 * The real recursive step in the generating function.
1338 static int gridgen_real(struct gridgen_usage
*usage
, digit
*grid
)
1340 int c
= usage
->c
, r
= usage
->r
, cr
= usage
->cr
;
1341 int i
, j
, n
, sx
, sy
, bestm
, bestr
, ret
;
1345 * Firstly, check for completion! If there are no spaces left
1346 * in the grid, we have a solution.
1348 if (usage
->nspaces
== 0) {
1349 memcpy(grid
, usage
->grid
, cr
* cr
);
1354 * Otherwise, there must be at least one space. Find the most
1355 * constrained space, using the `r' field as a tie-breaker.
1357 bestm
= cr
+1; /* so that any space will beat it */
1360 for (j
= 0; j
< usage
->nspaces
; j
++) {
1361 int x
= usage
->spaces
[j
].x
, y
= usage
->spaces
[j
].y
;
1365 * Find the number of digits that could go in this space.
1368 for (n
= 0; n
< cr
; n
++)
1369 if (!usage
->row
[y
*cr
+n
] && !usage
->col
[x
*cr
+n
] &&
1370 !usage
->blk
[((y
/c
)*c
+(x
/r
))*cr
+n
])
1373 if (m
< bestm
|| (m
== bestm
&& usage
->spaces
[j
].r
< bestr
)) {
1375 bestr
= usage
->spaces
[j
].r
;
1383 * Swap that square into the final place in the spaces array,
1384 * so that decrementing nspaces will remove it from the list.
1386 if (i
!= usage
->nspaces
-1) {
1387 struct gridgen_coord t
;
1388 t
= usage
->spaces
[usage
->nspaces
-1];
1389 usage
->spaces
[usage
->nspaces
-1] = usage
->spaces
[i
];
1390 usage
->spaces
[i
] = t
;
1394 * Now we've decided which square to start our recursion at,
1395 * simply go through all possible values, shuffling them
1396 * randomly first if necessary.
1398 digits
= snewn(bestm
, int);
1400 for (n
= 0; n
< cr
; n
++)
1401 if (!usage
->row
[sy
*cr
+n
] && !usage
->col
[sx
*cr
+n
] &&
1402 !usage
->blk
[((sy
/c
)*c
+(sx
/r
))*cr
+n
]) {
1407 shuffle(digits
, j
, sizeof(*digits
), usage
->rs
);
1409 /* And finally, go through the digit list and actually recurse. */
1411 for (i
= 0; i
< j
; i
++) {
1414 /* Update the usage structure to reflect the placing of this digit. */
1415 usage
->row
[sy
*cr
+n
-1] = usage
->col
[sx
*cr
+n
-1] =
1416 usage
->blk
[((sy
/c
)*c
+(sx
/r
))*cr
+n
-1] = TRUE
;
1417 usage
->grid
[sy
*cr
+sx
] = n
;
1420 /* Call the solver recursively. Stop when we find a solution. */
1421 if (gridgen_real(usage
, grid
))
1424 /* Revert the usage structure. */
1425 usage
->row
[sy
*cr
+n
-1] = usage
->col
[sx
*cr
+n
-1] =
1426 usage
->blk
[((sy
/c
)*c
+(sx
/r
))*cr
+n
-1] = FALSE
;
1427 usage
->grid
[sy
*cr
+sx
] = 0;
1439 * Entry point to generator. You give it dimensions and a starting
1440 * grid, which is simply an array of cr*cr digits.
1442 static void gridgen(int c
, int r
, digit
*grid
, random_state
*rs
)
1444 struct gridgen_usage
*usage
;
1448 * Clear the grid to start with.
1450 memset(grid
, 0, cr
*cr
);
1453 * Create a gridgen_usage structure.
1455 usage
= snew(struct gridgen_usage
);
1461 usage
->grid
= snewn(cr
* cr
, digit
);
1462 memcpy(usage
->grid
, grid
, cr
* cr
);
1464 usage
->row
= snewn(cr
* cr
, unsigned char);
1465 usage
->col
= snewn(cr
* cr
, unsigned char);
1466 usage
->blk
= snewn(cr
* cr
, unsigned char);
1467 memset(usage
->row
, FALSE
, cr
* cr
);
1468 memset(usage
->col
, FALSE
, cr
* cr
);
1469 memset(usage
->blk
, FALSE
, cr
* cr
);
1471 usage
->spaces
= snewn(cr
* cr
, struct gridgen_coord
);
1477 * Initialise the list of grid spaces.
1479 for (y
= 0; y
< cr
; y
++) {
1480 for (x
= 0; x
< cr
; x
++) {
1481 usage
->spaces
[usage
->nspaces
].x
= x
;
1482 usage
->spaces
[usage
->nspaces
].y
= y
;
1483 usage
->spaces
[usage
->nspaces
].r
= random_bits(rs
, 31);
1489 * Run the real generator function.
1491 gridgen_real(usage
, grid
);
1494 * Clean up the usage structure now we have our answer.
1496 sfree(usage
->spaces
);
1504 /* ----------------------------------------------------------------------
1505 * End of grid generator code.
1509 * Check whether a grid contains a valid complete puzzle.
1511 static int check_valid(int c
, int r
, digit
*grid
)
1514 unsigned char *used
;
1517 used
= snewn(cr
, unsigned char);
1520 * Check that each row contains precisely one of everything.
1522 for (y
= 0; y
< cr
; y
++) {
1523 memset(used
, FALSE
, cr
);
1524 for (x
= 0; x
< cr
; x
++)
1525 if (grid
[y
*cr
+x
] > 0 && grid
[y
*cr
+x
] <= cr
)
1526 used
[grid
[y
*cr
+x
]-1] = TRUE
;
1527 for (n
= 0; n
< cr
; n
++)
1535 * Check that each column contains precisely one of everything.
1537 for (x
= 0; x
< cr
; x
++) {
1538 memset(used
, FALSE
, cr
);
1539 for (y
= 0; y
< cr
; y
++)
1540 if (grid
[y
*cr
+x
] > 0 && grid
[y
*cr
+x
] <= cr
)
1541 used
[grid
[y
*cr
+x
]-1] = TRUE
;
1542 for (n
= 0; n
< cr
; n
++)
1550 * Check that each block contains precisely one of everything.
1552 for (x
= 0; x
< cr
; x
+= r
) {
1553 for (y
= 0; y
< cr
; y
+= c
) {
1555 memset(used
, FALSE
, cr
);
1556 for (xx
= x
; xx
< x
+r
; xx
++)
1557 for (yy
= 0; yy
< y
+c
; yy
++)
1558 if (grid
[yy
*cr
+xx
] > 0 && grid
[yy
*cr
+xx
] <= cr
)
1559 used
[grid
[yy
*cr
+xx
]-1] = TRUE
;
1560 for (n
= 0; n
< cr
; n
++)
1572 static int symmetries(game_params
*params
, int x
, int y
, int *output
, int s
)
1574 int c
= params
->c
, r
= params
->r
, cr
= c
*r
;
1577 #define ADD(x,y) (*output++ = (x), *output++ = (y), i++)
1583 break; /* just x,y is all we need */
1585 ADD(cr
- 1 - x
, cr
- 1 - y
);
1590 ADD(cr
- 1 - x
, cr
- 1 - y
);
1601 ADD(cr
- 1 - x
, cr
- 1 - y
);
1605 ADD(cr
- 1 - x
, cr
- 1 - y
);
1606 ADD(cr
- 1 - y
, cr
- 1 - x
);
1611 ADD(cr
- 1 - x
, cr
- 1 - y
);
1615 ADD(cr
- 1 - y
, cr
- 1 - x
);
1624 static char *encode_solve_move(int cr
, digit
*grid
)
1627 char *ret
, *p
, *sep
;
1630 * It's surprisingly easy to work out _exactly_ how long this
1631 * string needs to be. To decimal-encode all the numbers from 1
1634 * - every number has a units digit; total is n.
1635 * - all numbers above 9 have a tens digit; total is max(n-9,0).
1636 * - all numbers above 99 have a hundreds digit; total is max(n-99,0).
1640 for (i
= 1; i
<= cr
; i
*= 10)
1641 len
+= max(cr
- i
+ 1, 0);
1642 len
+= cr
; /* don't forget the commas */
1643 len
*= cr
; /* there are cr rows of these */
1646 * Now len is one bigger than the total size of the
1647 * comma-separated numbers (because we counted an
1648 * additional leading comma). We need to have a leading S
1649 * and a trailing NUL, so we're off by one in total.
1653 ret
= snewn(len
, char);
1657 for (i
= 0; i
< cr
*cr
; i
++) {
1658 p
+= sprintf(p
, "%s%d", sep
, grid
[i
]);
1662 assert(p
- ret
== len
);
1667 static char *new_game_desc(game_params
*params
, random_state
*rs
,
1668 char **aux
, int interactive
)
1670 int c
= params
->c
, r
= params
->r
, cr
= c
*r
;
1672 digit
*grid
, *grid2
;
1673 struct xy
{ int x
, y
; } *locs
;
1676 int coords
[16], ncoords
;
1681 * Adjust the maximum difficulty level to be consistent with
1682 * the puzzle size: all 2x2 puzzles appear to be Trivial
1683 * (DIFF_BLOCK) so we cannot hold out for even a Basic
1684 * (DIFF_SIMPLE) one.
1686 maxdiff
= params
->diff
;
1687 if (c
== 2 && r
== 2)
1688 maxdiff
= DIFF_BLOCK
;
1690 grid
= snewn(area
, digit
);
1691 locs
= snewn(area
, struct xy
);
1692 grid2
= snewn(area
, digit
);
1695 * Loop until we get a grid of the required difficulty. This is
1696 * nasty, but it seems to be unpleasantly hard to generate
1697 * difficult grids otherwise.
1701 * Generate a random solved state.
1703 gridgen(c
, r
, grid
, rs
);
1704 assert(check_valid(c
, r
, grid
));
1707 * Save the solved grid in aux.
1711 * We might already have written *aux the last time we
1712 * went round this loop, in which case we should free
1713 * the old aux before overwriting it with the new one.
1719 *aux
= encode_solve_move(cr
, grid
);
1723 * Now we have a solved grid, start removing things from it
1724 * while preserving solubility.
1728 * Find the set of equivalence classes of squares permitted
1729 * by the selected symmetry. We do this by enumerating all
1730 * the grid squares which have no symmetric companion
1731 * sorting lower than themselves.
1734 for (y
= 0; y
< cr
; y
++)
1735 for (x
= 0; x
< cr
; x
++) {
1739 ncoords
= symmetries(params
, x
, y
, coords
, params
->symm
);
1740 for (j
= 0; j
< ncoords
; j
++)
1741 if (coords
[2*j
+1]*cr
+coords
[2*j
] < i
)
1751 * Now shuffle that list.
1753 shuffle(locs
, nlocs
, sizeof(*locs
), rs
);
1756 * Now loop over the shuffled list and, for each element,
1757 * see whether removing that element (and its reflections)
1758 * from the grid will still leave the grid soluble.
1760 for (i
= 0; i
< nlocs
; i
++) {
1766 memcpy(grid2
, grid
, area
);
1767 ncoords
= symmetries(params
, x
, y
, coords
, params
->symm
);
1768 for (j
= 0; j
< ncoords
; j
++)
1769 grid2
[coords
[2*j
+1]*cr
+coords
[2*j
]] = 0;
1771 ret
= solver(c
, r
, grid2
, maxdiff
);
1772 if (ret
!= DIFF_IMPOSSIBLE
&& ret
!= DIFF_AMBIGUOUS
) {
1773 for (j
= 0; j
< ncoords
; j
++)
1774 grid
[coords
[2*j
+1]*cr
+coords
[2*j
]] = 0;
1778 memcpy(grid2
, grid
, area
);
1779 } while (solver(c
, r
, grid2
, maxdiff
) < maxdiff
);
1785 * Now we have the grid as it will be presented to the user.
1786 * Encode it in a game desc.
1792 desc
= snewn(5 * area
, char);
1795 for (i
= 0; i
<= area
; i
++) {
1796 int n
= (i
< area ? grid
[i
] : -1);
1803 int c
= 'a' - 1 + run
;
1807 run
-= c
- ('a' - 1);
1811 * If there's a number in the very top left or
1812 * bottom right, there's no point putting an
1813 * unnecessary _ before or after it.
1815 if (p
> desc
&& n
> 0)
1819 p
+= sprintf(p
, "%d", n
);
1823 assert(p
- desc
< 5 * area
);
1825 desc
= sresize(desc
, p
- desc
, char);
1833 static char *validate_desc(game_params
*params
, char *desc
)
1835 int area
= params
->r
* params
->r
* params
->c
* params
->c
;
1840 if (n
>= 'a' && n
<= 'z') {
1841 squares
+= n
- 'a' + 1;
1842 } else if (n
== '_') {
1844 } else if (n
> '0' && n
<= '9') {
1846 while (*desc
>= '0' && *desc
<= '9')
1849 return "Invalid character in game description";
1853 return "Not enough data to fill grid";
1856 return "Too much data to fit in grid";
1861 static game_state
*new_game(midend
*me
, game_params
*params
, char *desc
)
1863 game_state
*state
= snew(game_state
);
1864 int c
= params
->c
, r
= params
->r
, cr
= c
*r
, area
= cr
* cr
;
1867 state
->c
= params
->c
;
1868 state
->r
= params
->r
;
1870 state
->grid
= snewn(area
, digit
);
1871 state
->pencil
= snewn(area
* cr
, unsigned char);
1872 memset(state
->pencil
, 0, area
* cr
);
1873 state
->immutable
= snewn(area
, unsigned char);
1874 memset(state
->immutable
, FALSE
, area
);
1876 state
->completed
= state
->cheated
= FALSE
;
1881 if (n
>= 'a' && n
<= 'z') {
1882 int run
= n
- 'a' + 1;
1883 assert(i
+ run
<= area
);
1885 state
->grid
[i
++] = 0;
1886 } else if (n
== '_') {
1888 } else if (n
> '0' && n
<= '9') {
1890 state
->immutable
[i
] = TRUE
;
1891 state
->grid
[i
++] = atoi(desc
-1);
1892 while (*desc
>= '0' && *desc
<= '9')
1895 assert(!"We can't get here");
1903 static game_state
*dup_game(game_state
*state
)
1905 game_state
*ret
= snew(game_state
);
1906 int c
= state
->c
, r
= state
->r
, cr
= c
*r
, area
= cr
* cr
;
1911 ret
->grid
= snewn(area
, digit
);
1912 memcpy(ret
->grid
, state
->grid
, area
);
1914 ret
->pencil
= snewn(area
* cr
, unsigned char);
1915 memcpy(ret
->pencil
, state
->pencil
, area
* cr
);
1917 ret
->immutable
= snewn(area
, unsigned char);
1918 memcpy(ret
->immutable
, state
->immutable
, area
);
1920 ret
->completed
= state
->completed
;
1921 ret
->cheated
= state
->cheated
;
1926 static void free_game(game_state
*state
)
1928 sfree(state
->immutable
);
1929 sfree(state
->pencil
);
1934 static char *solve_game(game_state
*state
, game_state
*currstate
,
1935 char *ai
, char **error
)
1937 int c
= state
->c
, r
= state
->r
, cr
= c
*r
;
1943 * If we already have the solution in ai, save ourselves some
1949 grid
= snewn(cr
*cr
, digit
);
1950 memcpy(grid
, state
->grid
, cr
*cr
);
1951 solve_ret
= solver(c
, r
, grid
, DIFF_RECURSIVE
);
1955 if (solve_ret
== DIFF_IMPOSSIBLE
)
1956 *error
= "No solution exists for this puzzle";
1957 else if (solve_ret
== DIFF_AMBIGUOUS
)
1958 *error
= "Multiple solutions exist for this puzzle";
1965 ret
= encode_solve_move(cr
, grid
);
1972 static char *grid_text_format(int c
, int r
, digit
*grid
)
1980 * There are cr lines of digits, plus r-1 lines of block
1981 * separators. Each line contains cr digits, cr-1 separating
1982 * spaces, and c-1 two-character block separators. Thus, the
1983 * total length of a line is 2*cr+2*c-3 (not counting the
1984 * newline), and there are cr+r-1 of them.
1986 maxlen
= (cr
+r
-1) * (2*cr
+2*c
-2);
1987 ret
= snewn(maxlen
+1, char);
1990 for (y
= 0; y
< cr
; y
++) {
1991 for (x
= 0; x
< cr
; x
++) {
1992 int ch
= grid
[y
* cr
+ x
];
2002 if ((x
+1) % r
== 0) {
2009 if (y
+1 < cr
&& (y
+1) % c
== 0) {
2010 for (x
= 0; x
< cr
; x
++) {
2014 if ((x
+1) % r
== 0) {
2024 assert(p
- ret
== maxlen
);
2029 static char *game_text_format(game_state
*state
)
2031 return grid_text_format(state
->c
, state
->r
, state
->grid
);
2036 * These are the coordinates of the currently highlighted
2037 * square on the grid, or -1,-1 if there isn't one. When there
2038 * is, pressing a valid number or letter key or Space will
2039 * enter that number or letter in the grid.
2043 * This indicates whether the current highlight is a
2044 * pencil-mark one or a real one.
2049 static game_ui
*new_ui(game_state
*state
)
2051 game_ui
*ui
= snew(game_ui
);
2053 ui
->hx
= ui
->hy
= -1;
2059 static void free_ui(game_ui
*ui
)
2064 static char *encode_ui(game_ui
*ui
)
2069 static void decode_ui(game_ui
*ui
, char *encoding
)
2073 static void game_changed_state(game_ui
*ui
, game_state
*oldstate
,
2074 game_state
*newstate
)
2076 int c
= newstate
->c
, r
= newstate
->r
, cr
= c
*r
;
2078 * We prevent pencil-mode highlighting of a filled square. So
2079 * if the user has just filled in a square which we had a
2080 * pencil-mode highlight in (by Undo, or by Redo, or by Solve),
2081 * then we cancel the highlight.
2083 if (ui
->hx
>= 0 && ui
->hy
>= 0 && ui
->hpencil
&&
2084 newstate
->grid
[ui
->hy
* cr
+ ui
->hx
] != 0) {
2085 ui
->hx
= ui
->hy
= -1;
2089 struct game_drawstate
{
2094 unsigned char *pencil
;
2096 /* This is scratch space used within a single call to game_redraw. */
2100 static char *interpret_move(game_state
*state
, game_ui
*ui
, game_drawstate
*ds
,
2101 int x
, int y
, int button
)
2103 int c
= state
->c
, r
= state
->r
, cr
= c
*r
;
2107 button
&= ~MOD_MASK
;
2109 tx
= (x
+ TILE_SIZE
- BORDER
) / TILE_SIZE
- 1;
2110 ty
= (y
+ TILE_SIZE
- BORDER
) / TILE_SIZE
- 1;
2112 if (tx
>= 0 && tx
< cr
&& ty
>= 0 && ty
< cr
) {
2113 if (button
== LEFT_BUTTON
) {
2114 if (state
->immutable
[ty
*cr
+tx
]) {
2115 ui
->hx
= ui
->hy
= -1;
2116 } else if (tx
== ui
->hx
&& ty
== ui
->hy
&& ui
->hpencil
== 0) {
2117 ui
->hx
= ui
->hy
= -1;
2123 return ""; /* UI activity occurred */
2125 if (button
== RIGHT_BUTTON
) {
2127 * Pencil-mode highlighting for non filled squares.
2129 if (state
->grid
[ty
*cr
+tx
] == 0) {
2130 if (tx
== ui
->hx
&& ty
== ui
->hy
&& ui
->hpencil
) {
2131 ui
->hx
= ui
->hy
= -1;
2138 ui
->hx
= ui
->hy
= -1;
2140 return ""; /* UI activity occurred */
2144 if (ui
->hx
!= -1 && ui
->hy
!= -1 &&
2145 ((button
>= '1' && button
<= '9' && button
- '0' <= cr
) ||
2146 (button
>= 'a' && button
<= 'z' && button
- 'a' + 10 <= cr
) ||
2147 (button
>= 'A' && button
<= 'Z' && button
- 'A' + 10 <= cr
) ||
2149 int n
= button
- '0';
2150 if (button
>= 'A' && button
<= 'Z')
2151 n
= button
- 'A' + 10;
2152 if (button
>= 'a' && button
<= 'z')
2153 n
= button
- 'a' + 10;
2158 * Can't overwrite this square. In principle this shouldn't
2159 * happen anyway because we should never have even been
2160 * able to highlight the square, but it never hurts to be
2163 if (state
->immutable
[ui
->hy
*cr
+ui
->hx
])
2167 * Can't make pencil marks in a filled square. In principle
2168 * this shouldn't happen anyway because we should never
2169 * have even been able to pencil-highlight the square, but
2170 * it never hurts to be careful.
2172 if (ui
->hpencil
&& state
->grid
[ui
->hy
*cr
+ui
->hx
])
2175 sprintf(buf
, "%c%d,%d,%d",
2176 (char)(ui
->hpencil
&& n
> 0 ?
'P' : 'R'), ui
->hx
, ui
->hy
, n
);
2178 ui
->hx
= ui
->hy
= -1;
2186 static game_state
*execute_move(game_state
*from
, char *move
)
2188 int c
= from
->c
, r
= from
->r
, cr
= c
*r
;
2192 if (move
[0] == 'S') {
2195 ret
= dup_game(from
);
2196 ret
->completed
= ret
->cheated
= TRUE
;
2199 for (n
= 0; n
< cr
*cr
; n
++) {
2200 ret
->grid
[n
] = atoi(p
);
2202 if (!*p
|| ret
->grid
[n
] < 1 || ret
->grid
[n
] > cr
) {
2207 while (*p
&& isdigit((unsigned char)*p
)) p
++;
2212 } else if ((move
[0] == 'P' || move
[0] == 'R') &&
2213 sscanf(move
+1, "%d,%d,%d", &x
, &y
, &n
) == 3 &&
2214 x
>= 0 && x
< cr
&& y
>= 0 && y
< cr
&& n
>= 0 && n
<= cr
) {
2216 ret
= dup_game(from
);
2217 if (move
[0] == 'P' && n
> 0) {
2218 int index
= (y
*cr
+x
) * cr
+ (n
-1);
2219 ret
->pencil
[index
] = !ret
->pencil
[index
];
2221 ret
->grid
[y
*cr
+x
] = n
;
2222 memset(ret
->pencil
+ (y
*cr
+x
)*cr
, 0, cr
);
2225 * We've made a real change to the grid. Check to see
2226 * if the game has been completed.
2228 if (!ret
->completed
&& check_valid(c
, r
, ret
->grid
)) {
2229 ret
->completed
= TRUE
;
2234 return NULL
; /* couldn't parse move string */
2237 /* ----------------------------------------------------------------------
2241 #define SIZE(cr) ((cr) * TILE_SIZE + 2*BORDER + 1)
2242 #define GETTILESIZE(cr, w) ( (double)(w-1) / (double)(cr+1) )
2244 static void game_compute_size(game_params
*params
, int tilesize
,
2247 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2248 struct { int tilesize
; } ads
, *ds
= &ads
;
2249 ads
.tilesize
= tilesize
;
2251 *x
= SIZE(params
->c
* params
->r
);
2252 *y
= SIZE(params
->c
* params
->r
);
2255 static void game_set_size(drawing
*dr
, game_drawstate
*ds
,
2256 game_params
*params
, int tilesize
)
2258 ds
->tilesize
= tilesize
;
2261 static float *game_colours(frontend
*fe
, game_state
*state
, int *ncolours
)
2263 float *ret
= snewn(3 * NCOLOURS
, float);
2265 frontend_default_colour(fe
, &ret
[COL_BACKGROUND
* 3]);
2267 ret
[COL_GRID
* 3 + 0] = 0.0F
;
2268 ret
[COL_GRID
* 3 + 1] = 0.0F
;
2269 ret
[COL_GRID
* 3 + 2] = 0.0F
;
2271 ret
[COL_CLUE
* 3 + 0] = 0.0F
;
2272 ret
[COL_CLUE
* 3 + 1] = 0.0F
;
2273 ret
[COL_CLUE
* 3 + 2] = 0.0F
;
2275 ret
[COL_USER
* 3 + 0] = 0.0F
;
2276 ret
[COL_USER
* 3 + 1] = 0.6F
* ret
[COL_BACKGROUND
* 3 + 1];
2277 ret
[COL_USER
* 3 + 2] = 0.0F
;
2279 ret
[COL_HIGHLIGHT
* 3 + 0] = 0.85F
* ret
[COL_BACKGROUND
* 3 + 0];
2280 ret
[COL_HIGHLIGHT
* 3 + 1] = 0.85F
* ret
[COL_BACKGROUND
* 3 + 1];
2281 ret
[COL_HIGHLIGHT
* 3 + 2] = 0.85F
* ret
[COL_BACKGROUND
* 3 + 2];
2283 ret
[COL_ERROR
* 3 + 0] = 1.0F
;
2284 ret
[COL_ERROR
* 3 + 1] = 0.0F
;
2285 ret
[COL_ERROR
* 3 + 2] = 0.0F
;
2287 ret
[COL_PENCIL
* 3 + 0] = 0.5F
* ret
[COL_BACKGROUND
* 3 + 0];
2288 ret
[COL_PENCIL
* 3 + 1] = 0.5F
* ret
[COL_BACKGROUND
* 3 + 1];
2289 ret
[COL_PENCIL
* 3 + 2] = ret
[COL_BACKGROUND
* 3 + 2];
2291 *ncolours
= NCOLOURS
;
2295 static game_drawstate
*game_new_drawstate(drawing
*dr
, game_state
*state
)
2297 struct game_drawstate
*ds
= snew(struct game_drawstate
);
2298 int c
= state
->c
, r
= state
->r
, cr
= c
*r
;
2300 ds
->started
= FALSE
;
2304 ds
->grid
= snewn(cr
*cr
, digit
);
2305 memset(ds
->grid
, 0, cr
*cr
);
2306 ds
->pencil
= snewn(cr
*cr
*cr
, digit
);
2307 memset(ds
->pencil
, 0, cr
*cr
*cr
);
2308 ds
->hl
= snewn(cr
*cr
, unsigned char);
2309 memset(ds
->hl
, 0, cr
*cr
);
2310 ds
->entered_items
= snewn(cr
*cr
, int);
2311 ds
->tilesize
= 0; /* not decided yet */
2315 static void game_free_drawstate(drawing
*dr
, game_drawstate
*ds
)
2320 sfree(ds
->entered_items
);
2324 static void draw_number(drawing
*dr
, game_drawstate
*ds
, game_state
*state
,
2325 int x
, int y
, int hl
)
2327 int c
= state
->c
, r
= state
->r
, cr
= c
*r
;
2332 if (ds
->grid
[y
*cr
+x
] == state
->grid
[y
*cr
+x
] &&
2333 ds
->hl
[y
*cr
+x
] == hl
&&
2334 !memcmp(ds
->pencil
+(y
*cr
+x
)*cr
, state
->pencil
+(y
*cr
+x
)*cr
, cr
))
2335 return; /* no change required */
2337 tx
= BORDER
+ x
* TILE_SIZE
+ 2;
2338 ty
= BORDER
+ y
* TILE_SIZE
+ 2;
2354 clip(dr
, cx
, cy
, cw
, ch
);
2356 /* background needs erasing */
2357 draw_rect(dr
, cx
, cy
, cw
, ch
, (hl
& 15) == 1 ? COL_HIGHLIGHT
: COL_BACKGROUND
);
2359 /* pencil-mode highlight */
2360 if ((hl
& 15) == 2) {
2364 coords
[2] = cx
+cw
/2;
2367 coords
[5] = cy
+ch
/2;
2368 draw_polygon(dr
, coords
, 3, COL_HIGHLIGHT
, COL_HIGHLIGHT
);
2371 /* new number needs drawing? */
2372 if (state
->grid
[y
*cr
+x
]) {
2374 str
[0] = state
->grid
[y
*cr
+x
] + '0';
2376 str
[0] += 'a' - ('9'+1);
2377 draw_text(dr
, tx
+ TILE_SIZE
/2, ty
+ TILE_SIZE
/2,
2378 FONT_VARIABLE
, TILE_SIZE
/2, ALIGN_VCENTRE
| ALIGN_HCENTRE
,
2379 state
->immutable
[y
*cr
+x
] ? COL_CLUE
: (hl
& 16) ? COL_ERROR
: COL_USER
, str
);
2382 int pw
, ph
, pmax
, fontsize
;
2384 /* count the pencil marks required */
2385 for (i
= npencil
= 0; i
< cr
; i
++)
2386 if (state
->pencil
[(y
*cr
+x
)*cr
+i
])
2390 * It's not sensible to arrange pencil marks in the same
2391 * layout as the squares within a block, because this leads
2392 * to the font being too small. Instead, we arrange pencil
2393 * marks in the nearest thing we can to a square layout,
2394 * and we adjust the square layout depending on the number
2395 * of pencil marks in the square.
2397 for (pw
= 1; pw
* pw
< npencil
; pw
++);
2398 if (pw
< 3) pw
= 3; /* otherwise it just looks _silly_ */
2399 ph
= (npencil
+ pw
- 1) / pw
;
2400 if (ph
< 2) ph
= 2; /* likewise */
2402 fontsize
= TILE_SIZE
/(pmax
*(11-pmax
)/8);
2404 for (i
= j
= 0; i
< cr
; i
++)
2405 if (state
->pencil
[(y
*cr
+x
)*cr
+i
]) {
2406 int dx
= j
% pw
, dy
= j
/ pw
;
2411 str
[0] += 'a' - ('9'+1);
2412 draw_text(dr
, tx
+ (4*dx
+3) * TILE_SIZE
/ (4*pw
+2),
2413 ty
+ (4*dy
+3) * TILE_SIZE
/ (4*ph
+2),
2414 FONT_VARIABLE
, fontsize
,
2415 ALIGN_VCENTRE
| ALIGN_HCENTRE
, COL_PENCIL
, str
);
2422 draw_update(dr
, cx
, cy
, cw
, ch
);
2424 ds
->grid
[y
*cr
+x
] = state
->grid
[y
*cr
+x
];
2425 memcpy(ds
->pencil
+(y
*cr
+x
)*cr
, state
->pencil
+(y
*cr
+x
)*cr
, cr
);
2426 ds
->hl
[y
*cr
+x
] = hl
;
2429 static void game_redraw(drawing
*dr
, game_drawstate
*ds
, game_state
*oldstate
,
2430 game_state
*state
, int dir
, game_ui
*ui
,
2431 float animtime
, float flashtime
)
2433 int c
= state
->c
, r
= state
->r
, cr
= c
*r
;
2438 * The initial contents of the window are not guaranteed
2439 * and can vary with front ends. To be on the safe side,
2440 * all games should start by drawing a big
2441 * background-colour rectangle covering the whole window.
2443 draw_rect(dr
, 0, 0, SIZE(cr
), SIZE(cr
), COL_BACKGROUND
);
2448 for (x
= 0; x
<= cr
; x
++) {
2449 int thick
= (x
% r ?
0 : 1);
2450 draw_rect(dr
, BORDER
+ x
*TILE_SIZE
- thick
, BORDER
-1,
2451 1+2*thick
, cr
*TILE_SIZE
+3, COL_GRID
);
2453 for (y
= 0; y
<= cr
; y
++) {
2454 int thick
= (y
% c ?
0 : 1);
2455 draw_rect(dr
, BORDER
-1, BORDER
+ y
*TILE_SIZE
- thick
,
2456 cr
*TILE_SIZE
+3, 1+2*thick
, COL_GRID
);
2461 * This array is used to keep track of rows, columns and boxes
2462 * which contain a number more than once.
2464 for (x
= 0; x
< cr
* cr
; x
++)
2465 ds
->entered_items
[x
] = 0;
2466 for (x
= 0; x
< cr
; x
++)
2467 for (y
= 0; y
< cr
; y
++) {
2468 digit d
= state
->grid
[y
*cr
+x
];
2470 int box
= (x
/r
)+(y
/c
)*c
;
2471 ds
->entered_items
[x
*cr
+d
-1] |= ((ds
->entered_items
[x
*cr
+d
-1] & 1) << 1) | 1;
2472 ds
->entered_items
[y
*cr
+d
-1] |= ((ds
->entered_items
[y
*cr
+d
-1] & 4) << 1) | 4;
2473 ds
->entered_items
[box
*cr
+d
-1] |= ((ds
->entered_items
[box
*cr
+d
-1] & 16) << 1) | 16;
2478 * Draw any numbers which need redrawing.
2480 for (x
= 0; x
< cr
; x
++) {
2481 for (y
= 0; y
< cr
; y
++) {
2483 digit d
= state
->grid
[y
*cr
+x
];
2485 if (flashtime
> 0 &&
2486 (flashtime
<= FLASH_TIME
/3 ||
2487 flashtime
>= FLASH_TIME
*2/3))
2490 /* Highlight active input areas. */
2491 if (x
== ui
->hx
&& y
== ui
->hy
)
2492 highlight
= ui
->hpencil ?
2 : 1;
2494 /* Mark obvious errors (ie, numbers which occur more than once
2495 * in a single row, column, or box). */
2496 if (d
&& ((ds
->entered_items
[x
*cr
+d
-1] & 2) ||
2497 (ds
->entered_items
[y
*cr
+d
-1] & 8) ||
2498 (ds
->entered_items
[((x
/r
)+(y
/c
)*c
)*cr
+d
-1] & 32)))
2501 draw_number(dr
, ds
, state
, x
, y
, highlight
);
2506 * Update the _entire_ grid if necessary.
2509 draw_update(dr
, 0, 0, SIZE(cr
), SIZE(cr
));
2514 static float game_anim_length(game_state
*oldstate
, game_state
*newstate
,
2515 int dir
, game_ui
*ui
)
2520 static float game_flash_length(game_state
*oldstate
, game_state
*newstate
,
2521 int dir
, game_ui
*ui
)
2523 if (!oldstate
->completed
&& newstate
->completed
&&
2524 !oldstate
->cheated
&& !newstate
->cheated
)
2529 static int game_wants_statusbar(void)
2534 static int game_timing_state(game_state
*state
, game_ui
*ui
)
2539 static void game_print_size(game_params
*params
, float *x
, float *y
)
2544 * I'll use 9mm squares by default. They should be quite big
2545 * for this game, because players will want to jot down no end
2546 * of pencil marks in the squares.
2548 game_compute_size(params
, 900, &pw
, &ph
);
2553 static void game_print(drawing
*dr
, game_state
*state
, int tilesize
)
2555 int c
= state
->c
, r
= state
->r
, cr
= c
*r
;
2556 int ink
= print_mono_colour(dr
, 0);
2559 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2560 game_drawstate ads
, *ds
= &ads
;
2561 ads
.tilesize
= tilesize
;
2566 print_line_width(dr
, 3 * TILE_SIZE
/ 40);
2567 draw_rect_outline(dr
, BORDER
, BORDER
, cr
*TILE_SIZE
, cr
*TILE_SIZE
, ink
);
2572 for (x
= 1; x
< cr
; x
++) {
2573 print_line_width(dr
, (x
% r ?
1 : 3) * TILE_SIZE
/ 40);
2574 draw_line(dr
, BORDER
+x
*TILE_SIZE
, BORDER
,
2575 BORDER
+x
*TILE_SIZE
, BORDER
+cr
*TILE_SIZE
, ink
);
2577 for (y
= 1; y
< cr
; y
++) {
2578 print_line_width(dr
, (y
% c ?
1 : 3) * TILE_SIZE
/ 40);
2579 draw_line(dr
, BORDER
, BORDER
+y
*TILE_SIZE
,
2580 BORDER
+cr
*TILE_SIZE
, BORDER
+y
*TILE_SIZE
, ink
);
2586 for (y
= 0; y
< cr
; y
++)
2587 for (x
= 0; x
< cr
; x
++)
2588 if (state
->grid
[y
*cr
+x
]) {
2591 str
[0] = state
->grid
[y
*cr
+x
] + '0';
2593 str
[0] += 'a' - ('9'+1);
2594 draw_text(dr
, BORDER
+ x
*TILE_SIZE
+ TILE_SIZE
/2,
2595 BORDER
+ y
*TILE_SIZE
+ TILE_SIZE
/2,
2596 FONT_VARIABLE
, TILE_SIZE
/2,
2597 ALIGN_VCENTRE
| ALIGN_HCENTRE
, ink
, str
);
2602 #define thegame solo
2605 const struct game thegame
= {
2606 "Solo", "games.solo",
2613 TRUE
, game_configure
, custom_params
,
2621 TRUE
, game_text_format
,
2629 PREFERRED_TILE_SIZE
, game_compute_size
, game_set_size
,
2632 game_free_drawstate
,
2636 TRUE
, FALSE
, game_print_size
, game_print
,
2637 game_wants_statusbar
,
2638 FALSE
, game_timing_state
,
2639 0, /* mouse_priorities */
2642 #ifdef STANDALONE_SOLVER
2645 * gcc -DSTANDALONE_SOLVER -o solosolver solo.c malloc.c
2648 void frontend_default_colour(frontend
*fe
, float *output
) {}
2649 void draw_text(drawing
*dr
, int x
, int y
, int fonttype
, int fontsize
,
2650 int align
, int colour
, char *text
) {}
2651 void draw_rect(drawing
*dr
, int x
, int y
, int w
, int h
, int colour
) {}
2652 void draw_rect_outline(drawing
*dr
, int x
, int y
, int w
, int h
, int colour
) {}
2653 void draw_line(drawing
*dr
, int x1
, int y1
, int x2
, int y2
, int colour
) {}
2654 void draw_polygon(drawing
*dr
, int *coords
, int npoints
,
2655 int fillcolour
, int outlinecolour
) {}
2656 void clip(drawing
*dr
, int x
, int y
, int w
, int h
) {}
2657 void unclip(drawing
*dr
) {}
2658 void start_draw(drawing
*dr
) {}
2659 void draw_update(drawing
*dr
, int x
, int y
, int w
, int h
) {}
2660 void end_draw(drawing
*dr
) {}
2661 int print_mono_colour(drawing
*dr
, int grey
) { return 0; }
2662 void print_line_width(drawing
*dr
, int width
) {}
2663 unsigned long random_bits(random_state
*state
, int bits
)
2664 { assert(!"Shouldn't get randomness"); return 0; }
2665 unsigned long random_upto(random_state
*state
, unsigned long limit
)
2666 { assert(!"Shouldn't get randomness"); return 0; }
2667 void shuffle(void *array
, int nelts
, int eltsize
, random_state
*rs
)
2668 { assert(!"Shouldn't get randomness"); }
2670 void fatal(char *fmt
, ...)
2674 fprintf(stderr
, "fatal error: ");
2677 vfprintf(stderr
, fmt
, ap
);
2680 fprintf(stderr
, "\n");
2684 int main(int argc
, char **argv
)
2688 char *id
= NULL
, *desc
, *err
;
2692 while (--argc
> 0) {
2694 if (!strcmp(p
, "-v")) {
2695 solver_show_working
= TRUE
;
2696 } else if (!strcmp(p
, "-g")) {
2698 } else if (*p
== '-') {
2699 fprintf(stderr
, "%s: unrecognised option `%s'\n", argv
[0], p
);
2707 fprintf(stderr
, "usage: %s [-g | -v] <game_id>\n", argv
[0]);
2711 desc
= strchr(id
, ':');
2713 fprintf(stderr
, "%s: game id expects a colon in it\n", argv
[0]);
2718 p
= default_params();
2719 decode_params(p
, id
);
2720 err
= validate_desc(p
, desc
);
2722 fprintf(stderr
, "%s: %s\n", argv
[0], err
);
2725 s
= new_game(NULL
, p
, desc
);
2727 ret
= solver(p
->c
, p
->r
, s
->grid
, DIFF_RECURSIVE
);
2729 printf("Difficulty rating: %s\n",
2730 ret
==DIFF_BLOCK ?
"Trivial (blockwise positional elimination only)":
2731 ret
==DIFF_SIMPLE ?
"Basic (row/column/number elimination required)":
2732 ret
==DIFF_INTERSECT ?
"Intermediate (intersectional analysis required)":
2733 ret
==DIFF_SET ?
"Advanced (set elimination required)":
2734 ret
==DIFF_RECURSIVE ?
"Unreasonable (guesswork and backtracking required)":
2735 ret
==DIFF_AMBIGUOUS ?
"Ambiguous (multiple solutions exist)":
2736 ret
==DIFF_IMPOSSIBLE ?
"Impossible (no solution exists)":
2737 "INTERNAL ERROR: unrecognised difficulty code");
2739 printf("%s\n", grid_text_format(p
->c
, p
->r
, s
->grid
));