2 * solo.c: the number-placing puzzle most popularly known as `Sudoku'.
8 * - can we do anything about nasty centring of text in GTK? It
9 * seems to be taking ascenders/descenders into account when
12 * - implement stronger modes of reasoning in nsolve, thus
13 * enabling harder puzzles
15 * - configurable difficulty levels
17 * - vary the symmetry (rotational or none)?
19 * - try for cleverer ways of reducing the solved grid; they seem
20 * to be coming out a bit full for the most part, and in
21 * particular it's inexcusable to leave a grid with an entire
22 * block (or presumably row or column) filled! I _hope_ we can
23 * do this simply by better prioritising (somehow) the possible
25 * + one simple option might be to work the other way: start
26 * with an empty grid and gradually _add_ numbers until it
27 * becomes solvable? Perhaps there might be some heuristic
28 * which enables us to pinpoint the most critical clues and
29 * thus add as few as possible.
31 * - alternative interface modes
32 * + sudoku.com's Windows program has a palette of possible
33 * entries; you select a palette entry first and then click
34 * on the square you want it to go in, thus enabling
35 * mouse-only play. Useful for PDAs! I don't think it's
36 * actually incompatible with the current highlight-then-type
37 * approach: you _either_ highlight a palette entry and then
38 * click, _or_ you highlight a square and then type. At most
39 * one thing is ever highlighted at a time, so there's no way
41 * + `pencil marks' might be useful for more subtle forms of
42 * deduction, once we implement creation of puzzles that
47 * Solo puzzles need to be square overall (since each row and each
48 * column must contain one of every digit), but they need not be
49 * subdivided the same way internally. I am going to adopt a
50 * convention whereby I _always_ refer to `r' as the number of rows
51 * of _big_ divisions, and `c' as the number of columns of _big_
52 * divisions. Thus, a 2c by 3r puzzle looks something like this:
56 * ------+------ (Of course, you can't subdivide it the other way
57 * 1 4 5 | 6 3 2 or you'll get clashes; observe that the 4 in the
58 * 3 2 6 | 4 1 5 top left would conflict with the 4 in the second
59 * ------+------ box down on the left-hand side.)
63 * The need for a strong naming convention should now be clear:
64 * each small box is two rows of digits by three columns, while the
65 * overall puzzle has three rows of small boxes by two columns. So
66 * I will (hopefully) consistently use `r' to denote the number of
67 * rows _of small boxes_ (here 3), which is also the number of
68 * columns of digits in each small box; and `c' vice versa (here
71 * I'm also going to choose arbitrarily to list c first wherever
72 * possible: the above is a 2x3 puzzle, not a 3x2 one.
85 * To save space, I store digits internally as unsigned char. This
86 * imposes a hard limit of 255 on the order of the puzzle. Since
87 * even a 5x5 takes unacceptably long to generate, I don't see this
88 * as a serious limitation unless something _really_ impressive
89 * happens in computing technology; but here's a typedef anyway for
90 * general good practice.
92 typedef unsigned char digit
;
98 #define FLASH_TIME 0.4F
116 unsigned char *immutable
; /* marks which digits are clues */
120 static game_params
*default_params(void)
122 game_params
*ret
= snew(game_params
);
129 static int game_fetch_preset(int i
, char **name
, game_params
**params
)
136 case 0: c
= 2, r
= 2; break;
137 case 1: c
= 2, r
= 3; break;
138 case 2: c
= 3, r
= 3; break;
139 case 3: c
= 3, r
= 4; break;
140 case 4: c
= 4, r
= 4; break;
141 default: return FALSE
;
144 sprintf(buf
, "%dx%d", c
, r
);
146 *params
= ret
= snew(game_params
);
149 /* FIXME: difficulty presets? */
153 static void free_params(game_params
*params
)
158 static game_params
*dup_params(game_params
*params
)
160 game_params
*ret
= snew(game_params
);
161 *ret
= *params
; /* structure copy */
165 static game_params
*decode_params(char const *string
)
167 game_params
*ret
= default_params();
169 ret
->c
= ret
->r
= atoi(string
);
170 while (*string
&& isdigit((unsigned char)*string
)) string
++;
171 if (*string
== 'x') {
173 ret
->r
= atoi(string
);
174 while (*string
&& isdigit((unsigned char)*string
)) string
++;
176 /* FIXME: difficulty levels */
181 static char *encode_params(game_params
*params
)
185 sprintf(str
, "%dx%d", params
->c
, params
->r
);
189 static config_item
*game_configure(game_params
*params
)
194 ret
= snewn(5, config_item
);
196 ret
[0].name
= "Columns of sub-blocks";
197 ret
[0].type
= C_STRING
;
198 sprintf(buf
, "%d", params
->c
);
199 ret
[0].sval
= dupstr(buf
);
202 ret
[1].name
= "Rows of sub-blocks";
203 ret
[1].type
= C_STRING
;
204 sprintf(buf
, "%d", params
->r
);
205 ret
[1].sval
= dupstr(buf
);
209 * FIXME: difficulty level.
220 static game_params
*custom_params(config_item
*cfg
)
222 game_params
*ret
= snew(game_params
);
224 ret
->c
= atof(cfg
[0].sval
);
225 ret
->r
= atof(cfg
[1].sval
);
230 static char *validate_params(game_params
*params
)
232 if (params
->c
< 2 || params
->r
< 2)
233 return "Both dimensions must be at least 2";
234 if (params
->c
> ORDER_MAX
|| params
->r
> ORDER_MAX
)
235 return "Dimensions greater than "STR(ORDER_MAX
)" are not supported";
239 /* ----------------------------------------------------------------------
240 * Full recursive Solo solver.
242 * The algorithm for this solver is shamelessly copied from a
243 * Python solver written by Andrew Wilkinson (which is GPLed, but
244 * I've reused only ideas and no code). It mostly just does the
245 * obvious recursive thing: pick an empty square, put one of the
246 * possible digits in it, recurse until all squares are filled,
247 * backtrack and change some choices if necessary.
249 * The clever bit is that every time it chooses which square to
250 * fill in next, it does so by counting the number of _possible_
251 * numbers that can go in each square, and it prioritises so that
252 * it picks a square with the _lowest_ number of possibilities. The
253 * idea is that filling in lots of the obvious bits (particularly
254 * any squares with only one possibility) will cut down on the list
255 * of possibilities for other squares and hence reduce the enormous
256 * search space as much as possible as early as possible.
258 * In practice the algorithm appeared to work very well; run on
259 * sample problems from the Times it completed in well under a
260 * second on my G5 even when written in Python, and given an empty
261 * grid (so that in principle it would enumerate _all_ solved
262 * grids!) it found the first valid solution just as quickly. So
263 * with a bit more randomisation I see no reason not to use this as
268 * Internal data structure used in solver to keep track of
271 struct rsolve_coord
{ int x
, y
, r
; };
272 struct rsolve_usage
{
273 int c
, r
, cr
; /* cr == c*r */
274 /* grid is a copy of the input grid, modified as we go along */
276 /* row[y*cr+n-1] TRUE if digit n has been placed in row y */
278 /* col[x*cr+n-1] TRUE if digit n has been placed in row x */
280 /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */
282 /* This lists all the empty spaces remaining in the grid. */
283 struct rsolve_coord
*spaces
;
285 /* If we need randomisation in the solve, this is our random state. */
287 /* Number of solutions so far found, and maximum number we care about. */
292 * The real recursive step in the solving function.
294 static void rsolve_real(struct rsolve_usage
*usage
, digit
*grid
)
296 int c
= usage
->c
, r
= usage
->r
, cr
= usage
->cr
;
297 int i
, j
, n
, sx
, sy
, bestm
, bestr
;
301 * Firstly, check for completion! If there are no spaces left
302 * in the grid, we have a solution.
304 if (usage
->nspaces
== 0) {
307 * This is our first solution, so fill in the output grid.
309 memcpy(grid
, usage
->grid
, cr
* cr
);
316 * Otherwise, there must be at least one space. Find the most
317 * constrained space, using the `r' field as a tie-breaker.
319 bestm
= cr
+1; /* so that any space will beat it */
322 for (j
= 0; j
< usage
->nspaces
; j
++) {
323 int x
= usage
->spaces
[j
].x
, y
= usage
->spaces
[j
].y
;
327 * Find the number of digits that could go in this space.
330 for (n
= 0; n
< cr
; n
++)
331 if (!usage
->row
[y
*cr
+n
] && !usage
->col
[x
*cr
+n
] &&
332 !usage
->blk
[((y
/c
)*c
+(x
/r
))*cr
+n
])
335 if (m
< bestm
|| (m
== bestm
&& usage
->spaces
[j
].r
< bestr
)) {
337 bestr
= usage
->spaces
[j
].r
;
345 * Swap that square into the final place in the spaces array,
346 * so that decrementing nspaces will remove it from the list.
348 if (i
!= usage
->nspaces
-1) {
349 struct rsolve_coord t
;
350 t
= usage
->spaces
[usage
->nspaces
-1];
351 usage
->spaces
[usage
->nspaces
-1] = usage
->spaces
[i
];
352 usage
->spaces
[i
] = t
;
356 * Now we've decided which square to start our recursion at,
357 * simply go through all possible values, shuffling them
358 * randomly first if necessary.
360 digits
= snewn(bestm
, int);
362 for (n
= 0; n
< cr
; n
++)
363 if (!usage
->row
[sy
*cr
+n
] && !usage
->col
[sx
*cr
+n
] &&
364 !usage
->blk
[((sy
/c
)*c
+(sx
/r
))*cr
+n
]) {
370 for (i
= j
; i
> 1; i
--) {
371 int p
= random_upto(usage
->rs
, i
);
374 digits
[p
] = digits
[i
-1];
380 /* And finally, go through the digit list and actually recurse. */
381 for (i
= 0; i
< j
; i
++) {
384 /* Update the usage structure to reflect the placing of this digit. */
385 usage
->row
[sy
*cr
+n
-1] = usage
->col
[sx
*cr
+n
-1] =
386 usage
->blk
[((sy
/c
)*c
+(sx
/r
))*cr
+n
-1] = TRUE
;
387 usage
->grid
[sy
*cr
+sx
] = n
;
390 /* Call the solver recursively. */
391 rsolve_real(usage
, grid
);
394 * If we have seen as many solutions as we need, terminate
395 * all processing immediately.
397 if (usage
->solns
>= usage
->maxsolns
)
400 /* Revert the usage structure. */
401 usage
->row
[sy
*cr
+n
-1] = usage
->col
[sx
*cr
+n
-1] =
402 usage
->blk
[((sy
/c
)*c
+(sx
/r
))*cr
+n
-1] = FALSE
;
403 usage
->grid
[sy
*cr
+sx
] = 0;
411 * Entry point to solver. You give it dimensions and a starting
412 * grid, which is simply an array of N^4 digits. In that array, 0
413 * means an empty square, and 1..N mean a clue square.
415 * Return value is the number of solutions found; searching will
416 * stop after the provided `max'. (Thus, you can pass max==1 to
417 * indicate that you only care about finding _one_ solution, or
418 * max==2 to indicate that you want to know the difference between
419 * a unique and non-unique solution.) The input parameter `grid' is
420 * also filled in with the _first_ (or only) solution found by the
423 static int rsolve(int c
, int r
, digit
*grid
, random_state
*rs
, int max
)
425 struct rsolve_usage
*usage
;
430 * Create an rsolve_usage structure.
432 usage
= snew(struct rsolve_usage
);
438 usage
->grid
= snewn(cr
* cr
, digit
);
439 memcpy(usage
->grid
, grid
, cr
* cr
);
441 usage
->row
= snewn(cr
* cr
, unsigned char);
442 usage
->col
= snewn(cr
* cr
, unsigned char);
443 usage
->blk
= snewn(cr
* cr
, unsigned char);
444 memset(usage
->row
, FALSE
, cr
* cr
);
445 memset(usage
->col
, FALSE
, cr
* cr
);
446 memset(usage
->blk
, FALSE
, cr
* cr
);
448 usage
->spaces
= snewn(cr
* cr
, struct rsolve_coord
);
452 usage
->maxsolns
= max
;
457 * Now fill it in with data from the input grid.
459 for (y
= 0; y
< cr
; y
++) {
460 for (x
= 0; x
< cr
; x
++) {
461 int v
= grid
[y
*cr
+x
];
463 usage
->spaces
[usage
->nspaces
].x
= x
;
464 usage
->spaces
[usage
->nspaces
].y
= y
;
466 usage
->spaces
[usage
->nspaces
].r
= random_bits(rs
, 31);
468 usage
->spaces
[usage
->nspaces
].r
= usage
->nspaces
;
471 usage
->row
[y
*cr
+v
-1] = TRUE
;
472 usage
->col
[x
*cr
+v
-1] = TRUE
;
473 usage
->blk
[((y
/c
)*c
+(x
/r
))*cr
+v
-1] = TRUE
;
479 * Run the real recursive solving function.
481 rsolve_real(usage
, grid
);
485 * Clean up the usage structure now we have our answer.
487 sfree(usage
->spaces
);
500 /* ----------------------------------------------------------------------
501 * End of recursive solver code.
504 /* ----------------------------------------------------------------------
505 * Less capable non-recursive solver. This one is used to check
506 * solubility of a grid as we gradually remove numbers from it: by
507 * verifying a grid using this solver we can ensure it isn't _too_
508 * hard (e.g. does not actually require guessing and backtracking).
510 * It supports a variety of specific modes of reasoning. By
511 * enabling or disabling subsets of these modes we can arrange a
512 * range of difficulty levels.
516 * Modes of reasoning currently supported:
518 * - Positional elimination: a number must go in a particular
519 * square because all the other empty squares in a given
520 * row/col/blk are ruled out.
522 * - Numeric elimination: a square must have a particular number
523 * in because all the other numbers that could go in it are
526 * More advanced modes of reasoning I'd like to support in future:
528 * - Intersectional elimination: given two domains which overlap
529 * (hence one must be a block, and the other can be a row or
530 * col), if the possible locations for a particular number in
531 * one of the domains can be narrowed down to the overlap, then
532 * that number can be ruled out everywhere but the overlap in
533 * the other domain too.
535 * - Setwise numeric elimination: if there is a subset of the
536 * empty squares within a domain such that the union of the
537 * possible numbers in that subset has the same size as the
538 * subset itself, then those numbers can be ruled out everywhere
539 * else in the domain. (For example, if there are five empty
540 * squares and the possible numbers in each are 12, 23, 13, 134
541 * and 1345, then the first three empty squares form such a
542 * subset: the numbers 1, 2 and 3 _must_ be in those three
543 * squares in some permutation, and hence we can deduce none of
544 * them can be in the fourth or fifth squares.)
547 struct nsolve_usage
{
550 * We set up a cubic array, indexed by x, y and digit; each
551 * element of this array is TRUE or FALSE according to whether
552 * or not that digit _could_ in principle go in that position.
554 * The way to index this array is cube[(x*cr+y)*cr+n-1].
558 * This is the grid in which we write down our final
563 * Now we keep track, at a slightly higher level, of what we
564 * have yet to work out, to prevent doing the same deduction
567 /* row[y*cr+n-1] TRUE if digit n has been placed in row y */
569 /* col[x*cr+n-1] TRUE if digit n has been placed in row x */
571 /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */
574 #define cube(x,y,n) (usage->cube[((x)*usage->cr+(y))*usage->cr+(n)-1])
577 * Function called when we are certain that a particular square has
578 * a particular number in it.
580 static void nsolve_place(struct nsolve_usage
*usage
, int x
, int y
, int n
)
582 int c
= usage
->c
, r
= usage
->r
, cr
= usage
->cr
;
588 * Rule out all other numbers in this square.
590 for (i
= 1; i
<= cr
; i
++)
595 * Rule out this number in all other positions in the row.
597 for (i
= 0; i
< cr
; i
++)
602 * Rule out this number in all other positions in the column.
604 for (i
= 0; i
< cr
; i
++)
609 * Rule out this number in all other positions in the block.
613 for (i
= 0; i
< r
; i
++)
614 for (j
= 0; j
< c
; j
++)
615 if (bx
+i
!= x
|| by
+j
!= y
)
616 cube(bx
+i
,by
+j
,n
) = FALSE
;
619 * Enter the number in the result grid.
621 usage
->grid
[y
*cr
+x
] = n
;
624 * Cross out this number from the list of numbers left to place
625 * in its row, its column and its block.
627 usage
->row
[y
*cr
+n
-1] = usage
->col
[x
*cr
+n
-1] =
628 usage
->blk
[((y
/c
)*c
+(x
/r
))*cr
+n
-1] = TRUE
;
631 static int nsolve_blk_pos_elim(struct nsolve_usage
*usage
,
634 int c
= usage
->c
, r
= usage
->r
;
641 * Count the possible positions within this block where this
642 * number could appear.
646 for (i
= 0; i
< r
; i
++)
647 for (j
= 0; j
< c
; j
++)
648 if (cube(x
+i
,y
+j
,n
)) {
655 assert(fx
>= 0 && fy
>= 0);
656 nsolve_place(usage
, fx
, fy
, n
);
663 static int nsolve_row_pos_elim(struct nsolve_usage
*usage
,
670 * Count the possible positions within this row where this
671 * number could appear.
675 for (x
= 0; x
< cr
; x
++)
683 nsolve_place(usage
, fx
, y
, n
);
690 static int nsolve_col_pos_elim(struct nsolve_usage
*usage
,
697 * Count the possible positions within this column where this
698 * number could appear.
702 for (y
= 0; y
< cr
; y
++)
710 nsolve_place(usage
, x
, fy
, n
);
717 static int nsolve_num_elim(struct nsolve_usage
*usage
,
724 * Count the possible numbers that could appear in this square.
728 for (n
= 1; n
<= cr
; n
++)
736 nsolve_place(usage
, x
, y
, fn
);
743 static int nsolve(int c
, int r
, digit
*grid
)
745 struct nsolve_usage
*usage
;
750 * Set up a usage structure as a clean slate (everything
753 usage
= snew(struct nsolve_usage
);
757 usage
->cube
= snewn(cr
*cr
*cr
, unsigned char);
758 usage
->grid
= grid
; /* write straight back to the input */
759 memset(usage
->cube
, TRUE
, cr
*cr
*cr
);
761 usage
->row
= snewn(cr
* cr
, unsigned char);
762 usage
->col
= snewn(cr
* cr
, unsigned char);
763 usage
->blk
= snewn(cr
* cr
, unsigned char);
764 memset(usage
->row
, FALSE
, cr
* cr
);
765 memset(usage
->col
, FALSE
, cr
* cr
);
766 memset(usage
->blk
, FALSE
, cr
* cr
);
769 * Place all the clue numbers we are given.
771 for (x
= 0; x
< cr
; x
++)
772 for (y
= 0; y
< cr
; y
++)
774 nsolve_place(usage
, x
, y
, grid
[y
*cr
+x
]);
777 * Now loop over the grid repeatedly trying all permitted modes
778 * of reasoning. The loop terminates if we complete an
779 * iteration without making any progress; we then return
780 * failure or success depending on whether the grid is full or
785 * Blockwise positional elimination.
787 for (x
= 0; x
< c
; x
++)
788 for (y
= 0; y
< r
; y
++)
789 for (n
= 1; n
<= cr
; n
++)
790 if (!usage
->blk
[((y
/c
)*c
+(x
/r
))*cr
+n
-1] &&
791 nsolve_blk_pos_elim(usage
, x
, y
, n
))
795 * Row-wise positional elimination.
797 for (y
= 0; y
< cr
; y
++)
798 for (n
= 1; n
<= cr
; n
++)
799 if (!usage
->row
[y
*cr
+n
-1] &&
800 nsolve_row_pos_elim(usage
, y
, n
))
803 * Column-wise positional elimination.
805 for (x
= 0; x
< cr
; x
++)
806 for (n
= 1; n
<= cr
; n
++)
807 if (!usage
->col
[x
*cr
+n
-1] &&
808 nsolve_col_pos_elim(usage
, x
, n
))
812 * Numeric elimination.
814 for (x
= 0; x
< cr
; x
++)
815 for (y
= 0; y
< cr
; y
++)
816 if (!usage
->grid
[y
*cr
+x
] &&
817 nsolve_num_elim(usage
, x
, y
))
821 * If we reach here, we have made no deductions in this
822 * iteration, so the algorithm terminates.
833 for (x
= 0; x
< cr
; x
++)
834 for (y
= 0; y
< cr
; y
++)
840 /* ----------------------------------------------------------------------
841 * End of non-recursive solver code.
845 * Check whether a grid contains a valid complete puzzle.
847 static int check_valid(int c
, int r
, digit
*grid
)
853 used
= snewn(cr
, unsigned char);
856 * Check that each row contains precisely one of everything.
858 for (y
= 0; y
< cr
; y
++) {
859 memset(used
, FALSE
, cr
);
860 for (x
= 0; x
< cr
; x
++)
861 if (grid
[y
*cr
+x
] > 0 && grid
[y
*cr
+x
] <= cr
)
862 used
[grid
[y
*cr
+x
]-1] = TRUE
;
863 for (n
= 0; n
< cr
; n
++)
871 * Check that each column contains precisely one of everything.
873 for (x
= 0; x
< cr
; x
++) {
874 memset(used
, FALSE
, cr
);
875 for (y
= 0; y
< cr
; y
++)
876 if (grid
[y
*cr
+x
] > 0 && grid
[y
*cr
+x
] <= cr
)
877 used
[grid
[y
*cr
+x
]-1] = TRUE
;
878 for (n
= 0; n
< cr
; n
++)
886 * Check that each block contains precisely one of everything.
888 for (x
= 0; x
< cr
; x
+= r
) {
889 for (y
= 0; y
< cr
; y
+= c
) {
891 memset(used
, FALSE
, cr
);
892 for (xx
= x
; xx
< x
+r
; xx
++)
893 for (yy
= 0; yy
< y
+c
; yy
++)
894 if (grid
[yy
*cr
+xx
] > 0 && grid
[yy
*cr
+xx
] <= cr
)
895 used
[grid
[yy
*cr
+xx
]-1] = TRUE
;
896 for (n
= 0; n
< cr
; n
++)
908 static char *new_game_seed(game_params
*params
, random_state
*rs
)
910 int c
= params
->c
, r
= params
->r
, cr
= c
*r
;
913 struct xy
{ int x
, y
; } *locs
;
919 * Start the recursive solver with an empty grid to generate a
920 * random solved state.
922 grid
= snewn(area
, digit
);
923 memset(grid
, 0, area
);
924 ret
= rsolve(c
, r
, grid
, rs
, 1);
926 assert(check_valid(c
, r
, grid
));
930 "\x0\x1\x0\x0\x6\x0\x0\x0\x0"
931 "\x5\x0\x0\x7\x0\x4\x0\x2\x0"
932 "\x0\x0\x6\x1\x0\x0\x0\x0\x0"
933 "\x8\x9\x7\x0\x0\x0\x0\x0\x0"
934 "\x0\x0\x3\x0\x4\x0\x9\x0\x0"
935 "\x0\x0\x0\x0\x0\x0\x8\x7\x6"
936 "\x0\x0\x0\x0\x0\x9\x1\x0\x0"
937 "\x0\x3\x0\x6\x0\x5\x0\x0\x7"
938 "\x0\x0\x0\x0\x8\x0\x0\x5\x0"
943 for (y
= 0; y
< cr
; y
++) {
944 for (x
= 0; x
< cr
; x
++) {
945 printf("%2.0d", grid
[y
*cr
+x
]);
956 for (y
= 0; y
< cr
; y
++) {
957 for (x
= 0; x
< cr
; x
++) {
958 printf("%2.0d", grid
[y
*cr
+x
]);
967 * Now we have a solved grid, start removing things from it
968 * while preserving solubility.
970 locs
= snewn((cr
+1)/2 * (cr
+1)/2, struct xy
);
971 grid2
= snewn(area
, digit
);
976 * Iterate over the top left corner of the grid and
977 * enumerate all the filled squares we could empty.
981 for (x
= 0; 2*x
< cr
; x
++)
982 for (y
= 0; 2*y
< cr
; y
++)
990 * Now shuffle that list.
992 for (i
= nlocs
; i
> 1; i
--) {
993 int p
= random_upto(rs
, i
);
995 struct xy t
= locs
[p
];
1002 * Now loop over the shuffled list and, for each element,
1003 * see whether removing that element (and its reflections)
1004 * from the grid will still leave the grid soluble by
1007 for (i
= 0; i
< nlocs
; i
++) {
1011 memcpy(grid2
, grid
, area
);
1013 grid2
[y
*cr
+cr
-1-x
] = 0;
1014 grid2
[(cr
-1-y
)*cr
+x
] = 0;
1015 grid2
[(cr
-1-y
)*cr
+cr
-1-x
] = 0;
1017 if (nsolve(c
, r
, grid2
)) {
1019 grid
[y
*cr
+cr
-1-x
] = 0;
1020 grid
[(cr
-1-y
)*cr
+x
] = 0;
1021 grid
[(cr
-1-y
)*cr
+cr
-1-x
] = 0;
1028 * There was nothing we could remove without destroying
1040 for (y
= 0; y
< cr
; y
++) {
1041 for (x
= 0; x
< cr
; x
++) {
1042 printf("%2.0d", grid
[y
*cr
+x
]);
1051 * Now we have the grid as it will be presented to the user.
1052 * Encode it in a game seed.
1058 seed
= snewn(5 * area
, char);
1061 for (i
= 0; i
<= area
; i
++) {
1062 int n
= (i
< area ? grid
[i
] : -1);
1069 int c
= 'a' - 1 + run
;
1073 run
-= c
- ('a' - 1);
1077 * If there's a number in the very top left or
1078 * bottom right, there's no point putting an
1079 * unnecessary _ before or after it.
1081 if (p
> seed
&& n
> 0)
1085 p
+= sprintf(p
, "%d", n
);
1089 assert(p
- seed
< 5 * area
);
1091 seed
= sresize(seed
, p
- seed
, char);
1099 static char *validate_seed(game_params
*params
, char *seed
)
1101 int area
= params
->r
* params
->r
* params
->c
* params
->c
;
1106 if (n
>= 'a' && n
<= 'z') {
1107 squares
+= n
- 'a' + 1;
1108 } else if (n
== '_') {
1110 } else if (n
> '0' && n
<= '9') {
1112 while (*seed
>= '0' && *seed
<= '9')
1115 return "Invalid character in game specification";
1119 return "Not enough data to fill grid";
1122 return "Too much data to fit in grid";
1127 static game_state
*new_game(game_params
*params
, char *seed
)
1129 game_state
*state
= snew(game_state
);
1130 int c
= params
->c
, r
= params
->r
, cr
= c
*r
, area
= cr
* cr
;
1133 state
->c
= params
->c
;
1134 state
->r
= params
->r
;
1136 state
->grid
= snewn(area
, digit
);
1137 state
->immutable
= snewn(area
, unsigned char);
1138 memset(state
->immutable
, FALSE
, area
);
1140 state
->completed
= FALSE
;
1145 if (n
>= 'a' && n
<= 'z') {
1146 int run
= n
- 'a' + 1;
1147 assert(i
+ run
<= area
);
1149 state
->grid
[i
++] = 0;
1150 } else if (n
== '_') {
1152 } else if (n
> '0' && n
<= '9') {
1154 state
->immutable
[i
] = TRUE
;
1155 state
->grid
[i
++] = atoi(seed
-1);
1156 while (*seed
>= '0' && *seed
<= '9')
1159 assert(!"We can't get here");
1167 static game_state
*dup_game(game_state
*state
)
1169 game_state
*ret
= snew(game_state
);
1170 int c
= state
->c
, r
= state
->r
, cr
= c
*r
, area
= cr
* cr
;
1175 ret
->grid
= snewn(area
, digit
);
1176 memcpy(ret
->grid
, state
->grid
, area
);
1178 ret
->immutable
= snewn(area
, unsigned char);
1179 memcpy(ret
->immutable
, state
->immutable
, area
);
1181 ret
->completed
= state
->completed
;
1186 static void free_game(game_state
*state
)
1188 sfree(state
->immutable
);
1195 * These are the coordinates of the currently highlighted
1196 * square on the grid, or -1,-1 if there isn't one. When there
1197 * is, pressing a valid number or letter key or Space will
1198 * enter that number or letter in the grid.
1203 static game_ui
*new_ui(game_state
*state
)
1205 game_ui
*ui
= snew(game_ui
);
1207 ui
->hx
= ui
->hy
= -1;
1212 static void free_ui(game_ui
*ui
)
1217 static game_state
*make_move(game_state
*from
, game_ui
*ui
, int x
, int y
,
1220 int c
= from
->c
, r
= from
->r
, cr
= c
*r
;
1224 tx
= (x
- BORDER
) / TILE_SIZE
;
1225 ty
= (y
- BORDER
) / TILE_SIZE
;
1227 if (tx
>= 0 && tx
< cr
&& ty
>= 0 && ty
< cr
&& button
== LEFT_BUTTON
) {
1228 if (tx
== ui
->hx
&& ty
== ui
->hy
) {
1229 ui
->hx
= ui
->hy
= -1;
1234 return from
; /* UI activity occurred */
1237 if (ui
->hx
!= -1 && ui
->hy
!= -1 &&
1238 ((button
>= '1' && button
<= '9' && button
- '0' <= cr
) ||
1239 (button
>= 'a' && button
<= 'z' && button
- 'a' + 10 <= cr
) ||
1240 (button
>= 'A' && button
<= 'Z' && button
- 'A' + 10 <= cr
) ||
1242 int n
= button
- '0';
1243 if (button
>= 'A' && button
<= 'Z')
1244 n
= button
- 'A' + 10;
1245 if (button
>= 'a' && button
<= 'z')
1246 n
= button
- 'a' + 10;
1250 if (from
->immutable
[ui
->hy
*cr
+ui
->hx
])
1251 return NULL
; /* can't overwrite this square */
1253 ret
= dup_game(from
);
1254 ret
->grid
[ui
->hy
*cr
+ui
->hx
] = n
;
1255 ui
->hx
= ui
->hy
= -1;
1258 * We've made a real change to the grid. Check to see
1259 * if the game has been completed.
1261 if (!ret
->completed
&& check_valid(c
, r
, ret
->grid
)) {
1262 ret
->completed
= TRUE
;
1265 return ret
; /* made a valid move */
1271 /* ----------------------------------------------------------------------
1275 struct game_drawstate
{
1282 #define XSIZE(cr) ((cr) * TILE_SIZE + 2*BORDER + 1)
1283 #define YSIZE(cr) ((cr) * TILE_SIZE + 2*BORDER + 1)
1285 static void game_size(game_params
*params
, int *x
, int *y
)
1287 int c
= params
->c
, r
= params
->r
, cr
= c
*r
;
1293 static float *game_colours(frontend
*fe
, game_state
*state
, int *ncolours
)
1295 float *ret
= snewn(3 * NCOLOURS
, float);
1297 frontend_default_colour(fe
, &ret
[COL_BACKGROUND
* 3]);
1299 ret
[COL_GRID
* 3 + 0] = 0.0F
;
1300 ret
[COL_GRID
* 3 + 1] = 0.0F
;
1301 ret
[COL_GRID
* 3 + 2] = 0.0F
;
1303 ret
[COL_CLUE
* 3 + 0] = 0.0F
;
1304 ret
[COL_CLUE
* 3 + 1] = 0.0F
;
1305 ret
[COL_CLUE
* 3 + 2] = 0.0F
;
1307 ret
[COL_USER
* 3 + 0] = 0.0F
;
1308 ret
[COL_USER
* 3 + 1] = 0.6F
* ret
[COL_BACKGROUND
* 3 + 1];
1309 ret
[COL_USER
* 3 + 2] = 0.0F
;
1311 ret
[COL_HIGHLIGHT
* 3 + 0] = 0.85F
* ret
[COL_BACKGROUND
* 3 + 0];
1312 ret
[COL_HIGHLIGHT
* 3 + 1] = 0.85F
* ret
[COL_BACKGROUND
* 3 + 1];
1313 ret
[COL_HIGHLIGHT
* 3 + 2] = 0.85F
* ret
[COL_BACKGROUND
* 3 + 2];
1315 *ncolours
= NCOLOURS
;
1319 static game_drawstate
*game_new_drawstate(game_state
*state
)
1321 struct game_drawstate
*ds
= snew(struct game_drawstate
);
1322 int c
= state
->c
, r
= state
->r
, cr
= c
*r
;
1324 ds
->started
= FALSE
;
1328 ds
->grid
= snewn(cr
*cr
, digit
);
1329 memset(ds
->grid
, 0, cr
*cr
);
1330 ds
->hl
= snewn(cr
*cr
, unsigned char);
1331 memset(ds
->hl
, 0, cr
*cr
);
1336 static void game_free_drawstate(game_drawstate
*ds
)
1343 static void draw_number(frontend
*fe
, game_drawstate
*ds
, game_state
*state
,
1344 int x
, int y
, int hl
)
1346 int c
= state
->c
, r
= state
->r
, cr
= c
*r
;
1351 if (ds
->grid
[y
*cr
+x
] == state
->grid
[y
*cr
+x
] && ds
->hl
[y
*cr
+x
] == hl
)
1352 return; /* no change required */
1354 tx
= BORDER
+ x
* TILE_SIZE
+ 2;
1355 ty
= BORDER
+ y
* TILE_SIZE
+ 2;
1371 clip(fe
, cx
, cy
, cw
, ch
);
1373 /* background needs erasing? */
1374 if (ds
->grid
[y
*cr
+x
] || ds
->hl
[y
*cr
+x
] != hl
)
1375 draw_rect(fe
, cx
, cy
, cw
, ch
, hl ? COL_HIGHLIGHT
: COL_BACKGROUND
);
1377 /* new number needs drawing? */
1378 if (state
->grid
[y
*cr
+x
]) {
1380 str
[0] = state
->grid
[y
*cr
+x
] + '0';
1382 str
[0] += 'a' - ('9'+1);
1383 draw_text(fe
, tx
+ TILE_SIZE
/2, ty
+ TILE_SIZE
/2,
1384 FONT_VARIABLE
, TILE_SIZE
/2, ALIGN_VCENTRE
| ALIGN_HCENTRE
,
1385 state
->immutable
[y
*cr
+x
] ? COL_CLUE
: COL_USER
, str
);
1390 draw_update(fe
, cx
, cy
, cw
, ch
);
1392 ds
->grid
[y
*cr
+x
] = state
->grid
[y
*cr
+x
];
1393 ds
->hl
[y
*cr
+x
] = hl
;
1396 static void game_redraw(frontend
*fe
, game_drawstate
*ds
, game_state
*oldstate
,
1397 game_state
*state
, int dir
, game_ui
*ui
,
1398 float animtime
, float flashtime
)
1400 int c
= state
->c
, r
= state
->r
, cr
= c
*r
;
1405 * The initial contents of the window are not guaranteed
1406 * and can vary with front ends. To be on the safe side,
1407 * all games should start by drawing a big
1408 * background-colour rectangle covering the whole window.
1410 draw_rect(fe
, 0, 0, XSIZE(cr
), YSIZE(cr
), COL_BACKGROUND
);
1415 for (x
= 0; x
<= cr
; x
++) {
1416 int thick
= (x
% r ?
0 : 1);
1417 draw_rect(fe
, BORDER
+ x
*TILE_SIZE
- thick
, BORDER
-1,
1418 1+2*thick
, cr
*TILE_SIZE
+3, COL_GRID
);
1420 for (y
= 0; y
<= cr
; y
++) {
1421 int thick
= (y
% c ?
0 : 1);
1422 draw_rect(fe
, BORDER
-1, BORDER
+ y
*TILE_SIZE
- thick
,
1423 cr
*TILE_SIZE
+3, 1+2*thick
, COL_GRID
);
1428 * Draw any numbers which need redrawing.
1430 for (x
= 0; x
< cr
; x
++) {
1431 for (y
= 0; y
< cr
; y
++) {
1432 draw_number(fe
, ds
, state
, x
, y
,
1433 (x
== ui
->hx
&& y
== ui
->hy
) ||
1435 (flashtime
<= FLASH_TIME
/3 ||
1436 flashtime
>= FLASH_TIME
*2/3)));
1441 * Update the _entire_ grid if necessary.
1444 draw_update(fe
, 0, 0, XSIZE(cr
), YSIZE(cr
));
1449 static float game_anim_length(game_state
*oldstate
, game_state
*newstate
,
1455 static float game_flash_length(game_state
*oldstate
, game_state
*newstate
,
1458 if (!oldstate
->completed
&& newstate
->completed
)
1463 static int game_wants_statusbar(void)
1469 #define thegame solo
1472 const struct game thegame
= {
1473 "Solo", "games.solo", TRUE
,
1494 game_free_drawstate
,
1498 game_wants_statusbar
,