2 * pearl.c: Nikoli's `Masyu' puzzle. Currently this is a blank
3 * puzzle file with nothing but a test solver-generator.
9 * - The generation method appears to be fundamentally flawed. I
10 * think generating a random loop and then choosing a clue set
11 * is simply not a viable approach, because on a test run of
12 * 10,000 attempts, it generated _six_ viable puzzles. All the
13 * rest of the randomly generated loops failed to be soluble
14 * even given a maximal clue set. Also, the vast majority of the
15 * clues were white circles (straight clues); black circles
16 * (corners) seem very uncommon.
17 * + So what can we do? One possible approach would be to
18 * adjust the random loop generation so that it created loops
19 * which were in some heuristic sense more likely to be
20 * viable Masyu puzzles. Certainly a good start on that would
21 * be to arrange that black clues actually _came up_ slightly
22 * more often, but I have no idea whether that would be
24 * + A second option would be to throw the entire mechanism out
25 * and instead write a different generator from scratch which
26 * evolves the solution along with the puzzle: place a few
27 * clues, nail down a bit of the loop, place another clue,
28 * nail down some more, etc. It's unclear whether this can
29 * sensibly be done, though.
31 * - Puzzle playing UI and everything else apart from the
53 #define DX(d) ( ((d)==R) - ((d)==L) )
54 #define DY(d) ( ((d)==D) - ((d)==U) )
56 #define F(d) (((d << 2) | (d >> 2)) & 0xF)
57 #define C(d) (((d << 3) | (d >> 1)) & 0xF)
58 #define A(d) (((d << 1) | (d >> 3)) & 0xF)
87 #define bBLANK (1 << BLANK)
102 static game_params *default_params(void)
104 game_params *ret = snew(game_params);
111 static int game_fetch_preset(int i, char **name, game_params **params)
116 static void free_params(game_params *params)
121 static game_params *dup_params(game_params *params)
123 game_params *ret = snew(game_params);
124 *ret = *params; /* structure copy */
128 static void decode_params(game_params *params, char const *string)
132 static char *encode_params(game_params *params, int full)
134 return dupstr("FIXME");
137 static config_item *game_configure(game_params *params)
142 static game_params *custom_params(config_item *cfg)
147 static char *validate_params(game_params *params, int full)
152 /* ----------------------------------------------------------------------
156 int pearl_solve(int w, int h, char *clues, char *result)
158 int W = 2*w+1, H = 2*h+1;
165 * workspace[(2*y+1)*W+(2*x+1)] indicates the possible nature
166 * of the square (x,y), as a logical OR of bitfields.
168 * workspace[(2*y)*W+(2*x+1)], for x odd and y even, indicates
169 * whether the horizontal edge between (x,y) and (x+1,y) is
170 * connected (1), disconnected (2) or unknown (3).
172 * workspace[(2*y+1)*W+(2*x)], indicates the same about the
173 * vertical edge between (x,y) and (x,y+1).
175 * Initially, every square is considered capable of being in
176 * any of the seven possible states (two straights, four
177 * corners and empty), except those corresponding to clue
178 * squares which are more restricted.
180 * Initially, all edges are unknown, except the ones around the
181 * grid border which are known to be disconnected.
183 workspace = snewn(W*H, short);
184 for (x = 0; x < W*H; x++)
187 for (y = 0; y < h; y++)
188 for (x = 0; x < w; x++)
189 switch (clues[y*w+x]) {
191 workspace[(2*y+1)*W+(2*x+1)] = bLU|bLD|bRU|bRD;
194 workspace[(2*y+1)*W+(2*x+1)] = bLR|bUD;
197 workspace[(2*y+1)*W+(2*x+1)] = bLR|bUD|bLU|bLD|bRU|bRD|bBLANK;
200 /* Horizontal edges */
201 for (y = 0; y <= h; y++)
202 for (x = 0; x < w; x++)
203 workspace[(2*y)*W+(2*x+1)] = (y==0 || y==h ? 2 : 3);
205 for (y = 0; y < h; y++)
206 for (x = 0; x <= w; x++)
207 workspace[(2*y+1)*W+(2*x)] = (x==0 || x==w ? 2 : 3);
210 * We maintain a dsf of connected squares, together with a
211 * count of the size of each equivalence class.
213 dsf = snewn(w*h, int);
214 dsfsize = snewn(w*h, int);
217 * Now repeatedly try to find something we can do.
221 #ifdef SOLVER_DIAGNOSTICS
222 for (y = 0; y < H; y++) {
223 for (x = 0; x < W; x++)
224 printf("%*x", (x&1) ? 5 : 2, workspace[y*W+x]);
229 int done_something = FALSE;
232 * Go through the square state words, and discard any
233 * square state which is inconsistent with known facts
234 * about the edges around the square.
236 for (y = 0; y < h; y++)
237 for (x = 0; x < w; x++) {
238 for (b = 0; b < 0xD; b++)
239 if (workspace[(2*y+1)*W+(2*x+1)] & (1<<b)) {
241 * If any edge of this square is known to
242 * be connected when state b would require
243 * it disconnected, or vice versa, discard
246 for (d = 1; d <= 8; d += d) {
247 int ex = 2*x+1 + DX(d), ey = 2*y+1 + DY(d);
248 if (workspace[ey*W+ex] ==
250 workspace[(2*y+1)*W+(2*x+1)] &= ~(1<<b);
251 #ifdef SOLVER_DIAGNOSTICS
252 printf("edge (%d,%d)-(%d,%d) rules out state"
253 " %d for square (%d,%d)\n",
254 ex/2, ey/2, (ex+1)/2, (ey+1)/2,
257 done_something = TRUE;
264 * Consistency check: each square must have at
265 * least one state left!
267 if (!workspace[(2*y+1)*W+(2*x+1)]) {
268 #ifdef SOLVER_DIAGNOSTICS
269 printf("edge check at (%d,%d): inconsistency\n", x, y);
277 * Now go through the states array again, and nail down any
278 * unknown edge if one of its neighbouring squares makes it
281 for (y = 0; y < h; y++)
282 for (x = 0; x < w; x++) {
283 int edgeor = 0, edgeand = 15;
285 for (b = 0; b < 0xD; b++)
286 if (workspace[(2*y+1)*W+(2*x+1)] & (1<<b)) {
292 * Now any bit clear in edgeor marks a disconnected
293 * edge, and any bit set in edgeand marks a
297 /* First check consistency: neither bit is both! */
298 if (edgeand & ~edgeor) {
299 #ifdef SOLVER_DIAGNOSTICS
300 printf("square check at (%d,%d): inconsistency\n", x, y);
306 for (d = 1; d <= 8; d += d) {
307 int ex = 2*x+1 + DX(d), ey = 2*y+1 + DY(d);
309 if (!(edgeor & d) && workspace[ey*W+ex] == 3) {
310 workspace[ey*W+ex] = 2;
311 done_something = TRUE;
312 #ifdef SOLVER_DIAGNOSTICS
313 printf("possible states of square (%d,%d) force edge"
314 " (%d,%d)-(%d,%d) to be disconnected\n",
315 x, y, ex/2, ey/2, (ex+1)/2, (ey+1)/2);
317 } else if ((edgeand & d) && workspace[ey*W+ex] == 3) {
318 workspace[ey*W+ex] = 1;
319 done_something = TRUE;
320 #ifdef SOLVER_DIAGNOSTICS
321 printf("possible states of square (%d,%d) force edge"
322 " (%d,%d)-(%d,%d) to be connected\n",
323 x, y, ex/2, ey/2, (ex+1)/2, (ey+1)/2);
333 * Now for longer-range clue-based deductions (using the
334 * rules that a corner clue must connect to two straight
335 * squares, and a straight clue must connect to at least
336 * one corner square).
338 for (y = 0; y < h; y++)
339 for (x = 0; x < w; x++)
340 switch (clues[y*w+x]) {
342 for (d = 1; d <= 8; d += d) {
343 int ex = 2*x+1 + DX(d), ey = 2*y+1 + DY(d);
344 int fx = ex + DX(d), fy = ey + DY(d);
347 if (workspace[ey*W+ex] == 1) {
349 * If a corner clue is connected on any
350 * edge, then we can immediately nail
351 * down the square beyond that edge as
352 * being a straight in the appropriate
355 if (workspace[fy*W+fx] != (1<<type)) {
356 workspace[fy*W+fx] = (1<<type);
357 done_something = TRUE;
358 #ifdef SOLVER_DIAGNOSTICS
359 printf("corner clue at (%d,%d) forces square "
360 "(%d,%d) into state %d\n", x, y,
365 } else if (workspace[ey*W+ex] == 3) {
367 * Conversely, if a corner clue is
368 * separated by an unknown edge from a
369 * square which _cannot_ be a straight
370 * in the appropriate direction, we can
371 * mark that edge as disconnected.
373 if (!(workspace[fy*W+fx] & (1<<type))) {
374 workspace[ey*W+ex] = 2;
375 done_something = TRUE;
376 #ifdef SOLVER_DIAGNOSTICS
377 printf("corner clue at (%d,%d), plus square "
378 "(%d,%d) not being state %d, "
379 "disconnects edge (%d,%d)-(%d,%d)\n",
380 x, y, fx/2, fy/2, type,
381 ex/2, ey/2, (ex+1)/2, (ey+1)/2);
392 * If a straight clue is between two squares
393 * neither of which is capable of being a
394 * corner connected to it, then the straight
395 * clue cannot point in that direction.
397 for (d = 1; d <= 2; d += d) {
398 int fx = 2*x+1 + 2*DX(d), fy = 2*y+1 + 2*DY(d);
399 int gx = 2*x+1 - 2*DX(d), gy = 2*y+1 - 2*DY(d);
402 if (!(workspace[(2*y+1)*W+(2*x+1)] & (1<<type)))
405 if (!(workspace[fy*W+fx] & ((1<<(F(d)|A(d))) |
406 (1<<(F(d)|C(d))))) &&
407 !(workspace[gy*W+gx] & ((1<<( d |A(d))) |
409 workspace[(2*y+1)*W+(2*x+1)] &= ~(1<<type);
410 done_something = TRUE;
411 #ifdef SOLVER_DIAGNOSTICS
412 printf("straight clue at (%d,%d) cannot corner at "
413 "(%d,%d) or (%d,%d) so is not state %d\n",
414 x, y, fx/2, fy/2, gx/2, gy/2, type);
421 * If a straight clue with known direction is
422 * connected on one side to a known straight,
423 * then on the other side it must be a corner.
425 for (d = 1; d <= 8; d += d) {
426 int fx = 2*x+1 + 2*DX(d), fy = 2*y+1 + 2*DY(d);
427 int gx = 2*x+1 - 2*DX(d), gy = 2*y+1 - 2*DY(d);
430 if (workspace[(2*y+1)*W+(2*x+1)] != (1<<type))
433 if (!(workspace[fy*W+fx] &~ (bLR|bUD)) &&
434 (workspace[gy*W+gx] &~ (bLU|bLD|bRU|bRD))) {
435 workspace[gy*W+gx] &= (bLU|bLD|bRU|bRD);
436 done_something = TRUE;
437 #ifdef SOLVER_DIAGNOSTICS
438 printf("straight clue at (%d,%d) connecting to "
439 "straight at (%d,%d) makes (%d,%d) a "
440 "corner\n", x, y, fx/2, fy/2, gx/2, gy/2);
452 * Now detect shortcut loops.
456 int nonblanks, loopclass;
459 for (x = 0; x < w*h; x++)
463 * First go through the edge entries and update the dsf
464 * of which squares are connected to which others. We
465 * also track the number of squares in each equivalence
466 * class, and count the overall number of
467 * known-non-blank squares.
469 * In the process of doing this, we must notice if a
470 * loop has already been formed. If it has, we blank
471 * out any square which isn't part of that loop
472 * (failing a consistency check if any such square does
473 * not have BLANK as one of its remaining options) and
474 * exit the deduction loop with success.
478 for (y = 1; y < H-1; y++)
479 for (x = 1; x < W-1; x++)
482 * (x,y) are the workspace coordinates of
483 * an edge field. Compute the normal-space
484 * coordinates of the squares it connects.
486 int ax = (x-1)/2, ay = (y-1)/2, ac = ay*w+ax;
487 int bx = x/2, by = y/2, bc = by*w+bx;
490 * If the edge is connected, do the dsf
493 if (workspace[y*W+x] == 1) {
496 ae = dsf_canonify(dsf, ac);
497 be = dsf_canonify(dsf, bc);
503 if (loopclass != -1) {
505 * In fact, we have two
506 * separate loops, which is
509 #ifdef SOLVER_DIAGNOSTICS
510 printf("two loops found in grid!\n");
518 * Merge the two equivalence
521 int size = dsfsize[ae] + dsfsize[be];
522 dsf_merge(dsf, ac, bc);
523 ae = dsf_canonify(dsf, ac);
527 } else if ((y & x) & 1) {
529 * (x,y) are the workspace coordinates of a
530 * square field. If the square is
531 * definitely not blank, count it.
533 if (!(workspace[y*W+x] & bBLANK))
538 * If we discovered an existing loop above, we must now
539 * blank every square not part of it, and exit the main
542 if (loopclass != -1) {
543 #ifdef SOLVER_DIAGNOSTICS
544 printf("loop found in grid!\n");
546 for (y = 0; y < h; y++)
547 for (x = 0; x < w; x++)
548 if (dsf_canonify(dsf, y*w+x) != loopclass) {
549 if (workspace[(y*2+1)*W+(x*2+1)] & bBLANK) {
550 workspace[(y*2+1)*W+(x*2+1)] = bBLANK;
553 * This square is not part of the
554 * loop, but is known non-blank. We
557 #ifdef SOLVER_DIAGNOSTICS
558 printf("non-blank square (%d,%d) found outside"
573 * Now go through the workspace again and mark any edge
574 * which would cause a shortcut loop (i.e. would
575 * connect together two squares in the same equivalence
576 * class, and that equivalence class does not contain
577 * _all_ the known-non-blank squares currently in the
578 * grid) as disconnected. Also, mark any _square state_
579 * which would cause a shortcut loop as disconnected.
581 for (y = 1; y < H-1; y++)
582 for (x = 1; x < W-1; x++)
585 * (x,y) are the workspace coordinates of
586 * an edge field. Compute the normal-space
587 * coordinates of the squares it connects.
589 int ax = (x-1)/2, ay = (y-1)/2, ac = ay*w+ax;
590 int bx = x/2, by = y/2, bc = by*w+bx;
593 * If the edge is currently unknown, and
594 * sits between two squares in the same
595 * equivalence class, and the size of that
596 * class is less than nonblanks, then
597 * connecting this edge would be a shortcut
598 * loop and so we must not do so.
600 if (workspace[y*W+x] == 3) {
603 ae = dsf_canonify(dsf, ac);
604 be = dsf_canonify(dsf, bc);
608 * We have a loop. Is it a shortcut?
610 if (dsfsize[ae] < nonblanks) {
612 * Yes! Mark this edge disconnected.
614 workspace[y*W+x] = 2;
615 done_something = TRUE;
616 #ifdef SOLVER_DIAGNOSTICS
617 printf("edge (%d,%d)-(%d,%d) would create"
618 " a shortcut loop, hence must be"
619 " disconnected\n", x/2, y/2,
625 } else if ((y & x) & 1) {
627 * (x,y) are the workspace coordinates of a
628 * square field. Go through its possible
629 * (non-blank) states and see if any gives
630 * rise to a shortcut loop.
632 * This is slightly fiddly, because we have
633 * to check whether this square is already
634 * part of the same equivalence class as
635 * the things it's joining.
637 int ae = dsf_canonify(dsf, (y/2)*w+(x/2));
639 for (b = 2; b < 0xD; b++)
640 if (workspace[y*W+x] & (1<<b)) {
642 * Find the equivalence classes of
643 * the two squares this one would
644 * connect if it were in this
649 for (d = 1; d <= 8; d += d) if (b & d) {
650 int xx = x/2 + DX(d), yy = y/2 + DY(d);
651 int ee = dsf_canonify(dsf, yy*w+xx);
661 * This square state would form
662 * a loop on equivalence class
663 * e. Measure the size of that
664 * loop, and see if it's a
667 int loopsize = dsfsize[e];
669 loopsize++;/* add the square itself */
670 if (loopsize < nonblanks) {
672 * It is! Mark this square
675 workspace[y*W+x] &= ~(1<<b);
676 done_something = TRUE;
677 #ifdef SOLVER_DIAGNOSTICS
678 printf("square (%d,%d) would create a "
679 "shortcut loop in state %d, "
693 * If we reach here, there is nothing left we can do.
694 * Return 2 for ambiguous puzzle.
701 * If we reach _here_, it's by `break' out of the main loop,
702 * which means we've successfully achieved a solution. This
703 * means that we expect every square to be nailed down to
704 * exactly one possibility. Transcribe those possibilities into
707 for (y = 0; y < h; y++)
708 for (x = 0; x < w; x++) {
709 for (b = 0; b < 0xD; b++)
710 if (workspace[(2*y+1)*W+(2*x+1)] == (1<<b)) {
714 assert(b < 0xD); /* we should have had a break by now */
725 /* ----------------------------------------------------------------------
729 void pearl_loopgen(int w, int h, char *grid, random_state *rs)
731 int *options, *mindist, *maxdist, *list;
732 int x, y, d, total, n, area, limit;
735 * We're eventually going to have to return a w-by-h array
736 * containing line segment data. However, it's more convenient
737 * while actually generating the loop to consider the problem
738 * as a (w-1) by (h-1) array in which some squares are `inside'
739 * and some `outside'.
741 * I'm going to use the top left corner of my return array in
742 * the latter manner until the end of the function.
746 * To begin with, all squares are outside (0), except for one
747 * randomly selected one which is inside (1).
749 memset(grid, 0, w*h);
750 x = random_upto(rs, w-1);
751 y = random_upto(rs, h-1);
755 * I'm also going to need an array to store the possible
756 * options for the next extension of the grid.
758 options = snewn(w*h, int);
759 for (x = 0; x < w*h; x++)
763 * And some arrays and a list for breadth-first searching.
765 mindist = snewn(w*h, int);
766 maxdist = snewn(w*h, int);
767 list = snewn(w*h, int);
770 * Now we repeatedly scan the grid for feasible squares into
771 * which we can extend our loop, pick one, and do it.
776 #ifdef LOOPGEN_DIAGNOSTICS
777 for (y = 0; y < h; y++) {
778 for (x = 0; x < w; x++)
779 printf("%d", grid[y*w+x]);
786 * Our primary aim in growing this loop is to make it
787 * reasonably _dense_ in the target rectangle. That is, we
788 * want the maximum over all squares of the minimum
789 * distance from that square to the loop to be small.
791 * Therefore, we start with a breadth-first search of the
792 * grid to find those minimum distances.
795 int head = 0, tail = 0;
798 for (i = 0; i < w*h; i++) {
806 while (head < tail) {
810 for (d = 1; d <= 8; d += d) {
811 int xx = x + DX(d), yy = y + DY(d);
812 if (xx >= 0 && xx < w && yy >= 0 && yy < h &&
813 mindist[yy*w+xx] < 0) {
814 mindist[yy*w+xx] = mindist[i] + 1;
815 list[tail++] = yy*w+xx;
821 * Having done the BFS, we now backtrack along its path
822 * to determine the most distant square that each
823 * square is on the shortest path to. This tells us
824 * which of the loop extension candidates (all of which
825 * are squares marked 1) is most desirable to extend
826 * into in terms of minimising the maximum distance
827 * from any empty square to the nearest loop square.
829 for (head = tail; head-- > 0 ;) {
838 for (d = 1; d <= 8; d += d) {
839 int xx = x + DX(d), yy = y + DY(d);
840 if (xx >= 0 && xx < w && yy >= 0 && yy < h &&
841 mindist[yy*w+xx] > mindist[i] &&
842 maxdist[yy*w+xx] > max) {
843 max = maxdist[yy*w+xx];
852 * A square is a viable candidate for extension of our loop
853 * if and only if the following conditions are all met:
854 * - It is currently labelled 0.
855 * - At least one of its four orthogonal neighbours is
857 * - If you consider its eight orthogonal and diagonal
858 * neighbours to form a ring, that ring contains at most
859 * one contiguous run of 1s. (It must also contain at
860 * _least_ one, of course, but that's already guaranteed
861 * by the previous condition so there's no need to test
865 for (y = 0; y < h-1; y++)
866 for (x = 0; x < w-1; x++) {
868 int rx, neighbours, runs, dist;
870 dist = maxdist[y*w+x];
874 continue; /* it isn't labelled 0 */
877 for (rx = 0, d = 1; d <= 8; rx += 2, d += d) {
878 int x2 = x + DX(d), y2 = y + DY(d);
879 int x3 = x2 + DX(A(d)), y3 = y2 + DY(A(d));
880 int g2 = (x2 >= 0 && x2 < w && y2 >= 0 && y2 < h ?
882 int g3 = (x3 >= 0 && x3 < w && y3 >= 0 && y3 < h ?
891 continue; /* it doesn't have a 1 neighbour */
894 for (rx = 0; rx < 8; rx++)
895 if (ring[rx] && !ring[(rx+1) & 7])
899 continue; /* too many runs of 1s */
902 * Now we know this square is a viable extension
903 * candidate. Mark it.
905 * FIXME: probabilistic prioritisation based on
906 * perimeter perturbation? (Wow, must keep that
909 options[y*w+x] = dist * (4-neighbours) * (4-neighbours);
910 total += options[y*w+x];
914 break; /* nowhere to go! */
917 * Now pick a random one of the viable extension squares,
918 * and extend into it.
920 n = random_upto(rs, total);
921 for (y = 0; y < h-1; y++)
922 for (x = 0; x < w-1; x++) {
924 if (options[y*w+x] > n)
925 goto found; /* two-level break */
928 assert(!"We shouldn't ever get here");
934 * We terminate the loop when around 7/12 of the grid area
935 * is full, but we also require that the loop has reached
938 limit = random_upto(rs, (w-1)*(h-1)) + 13*(w-1)*(h-1);
939 if (24 * area > limit) {
940 int l = FALSE, r = FALSE, u = FALSE, d = FALSE;
941 for (x = 0; x < w; x++) {
947 for (y = 0; y < h; y++) {
953 if (l && r && u && d)
963 #ifdef LOOPGEN_DIAGNOSTICS
964 printf("final loop:\n");
965 for (y = 0; y < h; y++) {
966 for (x = 0; x < w; x++)
967 printf("%d", grid[y*w+x]);
974 * Now convert this array of 0s and 1s into an array of path
977 for (y = h; y-- > 0 ;) {
978 for (x = w; x-- > 0 ;) {
980 * Examine the four grid squares of which (x,y) are in
981 * the bottom right, to determine the output for this
984 int ul = (x > 0 && y > 0 ? grid[(y-1)*w+(x-1)] : 0);
985 int ur = (y > 0 ? grid[(y-1)*w+x] : 0);
986 int dl = (x > 0 ? grid[y*w+(x-1)] : 0);
987 int dr = grid[y*w+x];
990 if (ul != ur) type |= U;
991 if (dl != dr) type |= D;
992 if (ul != dl) type |= L;
993 if (ur != dr) type |= R;
995 assert((bLR|bUD|bLU|bLD|bRU|bRD|bBLANK) & (1 << type));
1002 #if defined LOOPGEN_DIAGNOSTICS && !defined GENERATION_DIAGNOSTICS
1003 printf("as returned:\n");
1004 for (y = 0; y < h; y++) {
1005 for (x = 0; x < w; x++) {
1006 int type = grid[y*w+x];
1008 if (type & L) *p++ = 'L';
1009 if (type & R) *p++ = 'R';
1010 if (type & U) *p++ = 'U';
1011 if (type & D) *p++ = 'D';
1021 static char *new_game_desc(game_params *params, random_state *rs,
1022 char **aux, int interactive)
1027 int x, y, d, ret, i;
1030 clues = snewn(7*7, char);
1038 "\0\0\2\0\0\0\0", 7*7);
1039 grid = snewn(7*7, char);
1040 printf("%d\n", pearl_solve(7, 7, clues, grid));
1042 clues = snewn(10*10, char);
1044 "\0\0\2\0\2\0\0\0\0\0"
1045 "\0\0\0\0\2\0\0\0\1\0"
1046 "\0\0\1\0\1\0\2\0\0\0"
1047 "\0\0\0\2\0\0\2\0\0\0"
1048 "\1\0\0\0\0\2\0\0\0\2"
1049 "\0\0\2\0\0\0\0\2\0\0"
1050 "\0\0\1\0\0\0\2\0\0\0"
1051 "\2\0\0\0\1\0\0\0\0\2"
1052 "\0\0\0\0\0\0\2\2\0\0"
1053 "\0\0\1\0\0\0\0\0\0\1", 10*10);
1054 grid = snewn(10*10, char);
1055 printf("%d\n", pearl_solve(10, 10, clues, grid));
1057 clues = snewn(10*10, char);
1059 "\0\0\0\0\0\0\1\0\0\0"
1060 "\0\1\0\1\2\0\0\0\0\2"
1061 "\0\0\0\0\0\0\0\0\0\1"
1062 "\2\0\0\1\2\2\1\0\0\0"
1063 "\1\0\0\0\0\0\0\1\0\0"
1064 "\0\0\2\0\0\0\0\0\0\2"
1065 "\0\0\0\2\1\2\1\0\0\2"
1066 "\2\0\0\0\0\0\0\0\0\0"
1067 "\2\0\0\0\0\1\1\0\2\0"
1068 "\0\0\0\2\0\0\0\0\0\0", 10*10);
1069 grid = snewn(10*10, char);
1070 printf("%d\n", pearl_solve(10, 10, clues, grid));
1073 grid = snewn(w*h, char);
1074 clues = snewn(w*h, char);
1075 clueorder = snewn(w*h, int);
1078 pearl_loopgen(w, h, grid, rs);
1080 #ifdef GENERATION_DIAGNOSTICS
1081 printf("grid array:\n");
1082 for (y = 0; y < h; y++) {
1083 for (x = 0; x < w; x++) {
1084 int type = grid[y*w+x];
1086 if (type & L) *p++ = 'L';
1087 if (type & R) *p++ = 'R';
1088 if (type & U) *p++ = 'U';
1089 if (type & D) *p++ = 'D';
1099 * Set up the maximal clue array.
1101 for (y = 0; y < h; y++)
1102 for (x = 0; x < w; x++) {
1103 int type = grid[y*w+x];
1105 clues[y*w+x] = NOCLUE;
1107 if ((bLR|bUD) & (1 << type)) {
1109 * This is a straight; see if it's a viable
1110 * candidate for a straight clue. It qualifies if
1111 * at least one of the squares it connects to is a
1114 for (d = 1; d <= 8; d += d) if (type & d) {
1115 int xx = x + DX(d), yy = y + DY(d);
1116 assert(xx >= 0 && xx < w && yy >= 0 && yy < h);
1117 if ((bLU|bLD|bRU|bRD) & (1 << grid[yy*w+xx]))
1120 if (d <= 8) /* we found one */
1121 clues[y*w+x] = STRAIGHT;
1122 } else if ((bLU|bLD|bRU|bRD) & (1 << type)) {
1124 * This is a corner; see if it's a viable candidate
1125 * for a corner clue. It qualifies if all the
1126 * squares it connects to are straights.
1128 for (d = 1; d <= 8; d += d) if (type & d) {
1129 int xx = x + DX(d), yy = y + DY(d);
1130 assert(xx >= 0 && xx < w && yy >= 0 && yy < h);
1131 if (!((bLR|bUD) & (1 << grid[yy*w+xx])))
1134 if (d > 8) /* we didn't find a counterexample */
1135 clues[y*w+x] = CORNER;
1139 #ifdef GENERATION_DIAGNOSTICS
1140 printf("clue array:\n");
1141 for (y = 0; y < h; y++) {
1142 for (x = 0; x < w; x++) {
1143 printf("%c", " *O"[(unsigned char)clues[y*w+x]]);
1151 * See if we can solve the puzzle just like this.
1153 ret = pearl_solve(w, h, clues, grid);
1154 assert(ret > 0); /* shouldn't be inconsistent! */
1156 continue; /* go round and try again */
1159 * Now shuffle the grid points and gradually remove the
1160 * clues to find a minimal set which still leaves the
1163 for (i = 0; i < w*h; i++)
1165 shuffle(clueorder, w*h, sizeof(*clueorder), rs);
1166 for (i = 0; i < w*h; i++) {
1169 y = clueorder[i] / w;
1170 x = clueorder[i] % w;
1172 if (clues[y*w+x] == 0)
1175 clue = clues[y*w+x];
1176 clues[y*w+x] = 0; /* try removing this clue */
1178 ret = pearl_solve(w, h, clues, grid);
1181 clues[y*w+x] = clue; /* oops, put it back again */
1184 #ifdef FINISHED_PUZZLE
1185 printf("clue array:\n");
1186 for (y = 0; y < h; y++) {
1187 for (x = 0; x < w; x++) {
1188 printf("%c", " *O"[(unsigned char)clues[y*w+x]]);
1202 return dupstr("FIXME");
1205 static char *validate_desc(game_params *params, char *desc)
1210 static game_state *new_game(midend *me, game_params *params, char *desc)
1212 game_state *state = snew(game_state);
1219 static game_state *dup_game(game_state *state)
1221 game_state *ret = snew(game_state);
1223 ret->FIXME = state->FIXME;
1228 static void free_game(game_state *state)
1233 static char *solve_game(game_state *state, game_state *currstate,
1234 char *aux, char **error)
1239 static int game_can_format_as_text_now(game_params *params)
1244 static char *game_text_format(game_state *state)
1249 static game_ui *new_ui(game_state *state)
1254 static void free_ui(game_ui *ui)
1258 static char *encode_ui(game_ui *ui)
1263 static void decode_ui(game_ui *ui, char *encoding)
1267 static void game_changed_state(game_ui *ui, game_state *oldstate,
1268 game_state *newstate)
1272 struct game_drawstate {
1277 static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
1278 int x, int y, int button)
1283 static game_state *execute_move(game_state *state, char *move)
1288 /* ----------------------------------------------------------------------
1292 static void game_compute_size(game_params *params, int tilesize,
1295 *x = *y = 10 * tilesize; /* FIXME */
1298 static void game_set_size(drawing *dr, game_drawstate *ds,
1299 game_params *params, int tilesize)
1301 ds->tilesize = tilesize;
1304 static float *game_colours(frontend *fe, int *ncolours)
1306 float *ret = snewn(3 * NCOLOURS, float);
1308 frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
1310 *ncolours = NCOLOURS;
1314 static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
1316 struct game_drawstate *ds = snew(struct game_drawstate);
1324 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
1329 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
1330 game_state *state, int dir, game_ui *ui,
1331 float animtime, float flashtime)
1334 * The initial contents of the window are not guaranteed and
1335 * can vary with front ends. To be on the safe side, all games
1336 * should start by drawing a big background-colour rectangle
1337 * covering the whole window.
1339 draw_rect(dr, 0, 0, 10*ds->tilesize, 10*ds->tilesize, COL_BACKGROUND);
1342 static float game_anim_length(game_state *oldstate, game_state *newstate,
1343 int dir, game_ui *ui)
1348 static float game_flash_length(game_state *oldstate, game_state *newstate,
1349 int dir, game_ui *ui)
1354 static int game_timing_state(game_state *state, game_ui *ui)
1359 static void game_print_size(game_params *params, float *x, float *y)
1363 static void game_print(drawing *dr, game_state *state, int tilesize)
1368 #define thegame pearl
1371 const struct game thegame = {
1372 "Pearl", NULL, NULL,
1379 FALSE, game_configure, custom_params,
1387 FALSE, game_can_format_as_text_now, game_text_format,
1395 20 /* FIXME */, game_compute_size, game_set_size,
1398 game_free_drawstate,
1402 FALSE, FALSE, game_print_size, game_print,
1403 FALSE, /* wants_statusbar */
1404 FALSE, game_timing_state,