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.
220 int done_something = FALSE;
222 #ifdef SOLVER_DIAGNOSTICS
223 for (y = 0; y < H; y++) {
224 for (x = 0; x < W; x++)
225 printf("%*x", (x&1) ? 5 : 2, workspace[y*W+x]);
231 * Go through the square state words, and discard any
232 * square state which is inconsistent with known facts
233 * about the edges around the square.
235 for (y = 0; y < h; y++)
236 for (x = 0; x < w; x++) {
237 for (b = 0; b < 0xD; b++)
238 if (workspace[(2*y+1)*W+(2*x+1)] & (1<<b)) {
240 * If any edge of this square is known to
241 * be connected when state b would require
242 * it disconnected, or vice versa, discard
245 for (d = 1; d <= 8; d += d) {
246 int ex = 2*x+1 + DX(d), ey = 2*y+1 + DY(d);
247 if (workspace[ey*W+ex] ==
249 workspace[(2*y+1)*W+(2*x+1)] &= ~(1<<b);
250 #ifdef SOLVER_DIAGNOSTICS
251 printf("edge (%d,%d)-(%d,%d) rules out state"
252 " %d for square (%d,%d)\n",
253 ex/2, ey/2, (ex+1)/2, (ey+1)/2,
256 done_something = TRUE;
263 * Consistency check: each square must have at
264 * least one state left!
266 if (!workspace[(2*y+1)*W+(2*x+1)]) {
267 #ifdef SOLVER_DIAGNOSTICS
268 printf("edge check at (%d,%d): inconsistency\n", x, y);
276 * Now go through the states array again, and nail down any
277 * unknown edge if one of its neighbouring squares makes it
280 for (y = 0; y < h; y++)
281 for (x = 0; x < w; x++) {
282 int edgeor = 0, edgeand = 15;
284 for (b = 0; b < 0xD; b++)
285 if (workspace[(2*y+1)*W+(2*x+1)] & (1<<b)) {
291 * Now any bit clear in edgeor marks a disconnected
292 * edge, and any bit set in edgeand marks a
296 /* First check consistency: neither bit is both! */
297 if (edgeand & ~edgeor) {
298 #ifdef SOLVER_DIAGNOSTICS
299 printf("square check at (%d,%d): inconsistency\n", x, y);
305 for (d = 1; d <= 8; d += d) {
306 int ex = 2*x+1 + DX(d), ey = 2*y+1 + DY(d);
308 if (!(edgeor & d) && workspace[ey*W+ex] == 3) {
309 workspace[ey*W+ex] = 2;
310 done_something = TRUE;
311 #ifdef SOLVER_DIAGNOSTICS
312 printf("possible states of square (%d,%d) force edge"
313 " (%d,%d)-(%d,%d) to be disconnected\n",
314 x, y, ex/2, ey/2, (ex+1)/2, (ey+1)/2);
316 } else if ((edgeand & d) && workspace[ey*W+ex] == 3) {
317 workspace[ey*W+ex] = 1;
318 done_something = TRUE;
319 #ifdef SOLVER_DIAGNOSTICS
320 printf("possible states of square (%d,%d) force edge"
321 " (%d,%d)-(%d,%d) to be connected\n",
322 x, y, ex/2, ey/2, (ex+1)/2, (ey+1)/2);
332 * Now for longer-range clue-based deductions (using the
333 * rules that a corner clue must connect to two straight
334 * squares, and a straight clue must connect to at least
335 * one corner square).
337 for (y = 0; y < h; y++)
338 for (x = 0; x < w; x++)
339 switch (clues[y*w+x]) {
341 for (d = 1; d <= 8; d += d) {
342 int ex = 2*x+1 + DX(d), ey = 2*y+1 + DY(d);
343 int fx = ex + DX(d), fy = ey + DY(d);
346 if (workspace[ey*W+ex] == 1) {
348 * If a corner clue is connected on any
349 * edge, then we can immediately nail
350 * down the square beyond that edge as
351 * being a straight in the appropriate
354 if (workspace[fy*W+fx] != (1<<type)) {
355 workspace[fy*W+fx] = (1<<type);
356 done_something = TRUE;
357 #ifdef SOLVER_DIAGNOSTICS
358 printf("corner clue at (%d,%d) forces square "
359 "(%d,%d) into state %d\n", x, y,
364 } else if (workspace[ey*W+ex] == 3) {
366 * Conversely, if a corner clue is
367 * separated by an unknown edge from a
368 * square which _cannot_ be a straight
369 * in the appropriate direction, we can
370 * mark that edge as disconnected.
372 if (!(workspace[fy*W+fx] & (1<<type))) {
373 workspace[ey*W+ex] = 2;
374 done_something = TRUE;
375 #ifdef SOLVER_DIAGNOSTICS
376 printf("corner clue at (%d,%d), plus square "
377 "(%d,%d) not being state %d, "
378 "disconnects edge (%d,%d)-(%d,%d)\n",
379 x, y, fx/2, fy/2, type,
380 ex/2, ey/2, (ex+1)/2, (ey+1)/2);
390 * If a straight clue is between two squares
391 * neither of which is capable of being a
392 * corner connected to it, then the straight
393 * clue cannot point in that direction.
395 for (d = 1; d <= 2; d += d) {
396 int fx = 2*x+1 + 2*DX(d), fy = 2*y+1 + 2*DY(d);
397 int gx = 2*x+1 - 2*DX(d), gy = 2*y+1 - 2*DY(d);
400 if (!(workspace[(2*y+1)*W+(2*x+1)] & (1<<type)))
403 if (!(workspace[fy*W+fx] & ((1<<(F(d)|A(d))) |
404 (1<<(F(d)|C(d))))) &&
405 !(workspace[gy*W+gx] & ((1<<( d |A(d))) |
407 workspace[(2*y+1)*W+(2*x+1)] &= ~(1<<type);
408 done_something = TRUE;
409 #ifdef SOLVER_DIAGNOSTICS
410 printf("straight clue at (%d,%d) cannot corner at "
411 "(%d,%d) or (%d,%d) so is not state %d\n",
412 x, y, fx/2, fy/2, gx/2, gy/2, type);
419 * If a straight clue with known direction is
420 * connected on one side to a known straight,
421 * then on the other side it must be a corner.
423 for (d = 1; d <= 8; d += d) {
424 int fx = 2*x+1 + 2*DX(d), fy = 2*y+1 + 2*DY(d);
425 int gx = 2*x+1 - 2*DX(d), gy = 2*y+1 - 2*DY(d);
428 if (workspace[(2*y+1)*W+(2*x+1)] != (1<<type))
431 if (!(workspace[fy*W+fx] &~ (bLR|bUD)) &&
432 (workspace[gy*W+gx] &~ (bLU|bLD|bRU|bRD))) {
433 workspace[gy*W+gx] &= (bLU|bLD|bRU|bRD);
434 done_something = TRUE;
435 #ifdef SOLVER_DIAGNOSTICS
436 printf("straight clue at (%d,%d) connecting to "
437 "straight at (%d,%d) makes (%d,%d) a "
438 "corner\n", x, y, fx/2, fy/2, gx/2, gy/2);
450 * Now detect shortcut loops.
454 int nonblanks, loopclass;
457 for (x = 0; x < w*h; x++)
461 * First go through the edge entries and update the dsf
462 * of which squares are connected to which others. We
463 * also track the number of squares in each equivalence
464 * class, and count the overall number of
465 * known-non-blank squares.
467 * In the process of doing this, we must notice if a
468 * loop has already been formed. If it has, we blank
469 * out any square which isn't part of that loop
470 * (failing a consistency check if any such square does
471 * not have BLANK as one of its remaining options) and
472 * exit the deduction loop with success.
476 for (y = 1; y < H-1; y++)
477 for (x = 1; x < W-1; x++)
480 * (x,y) are the workspace coordinates of
481 * an edge field. Compute the normal-space
482 * coordinates of the squares it connects.
484 int ax = (x-1)/2, ay = (y-1)/2, ac = ay*w+ax;
485 int bx = x/2, by = y/2, bc = by*w+bx;
488 * If the edge is connected, do the dsf
491 if (workspace[y*W+x] == 1) {
494 ae = dsf_canonify(dsf, ac);
495 be = dsf_canonify(dsf, bc);
501 if (loopclass != -1) {
503 * In fact, we have two
504 * separate loops, which is
507 #ifdef SOLVER_DIAGNOSTICS
508 printf("two loops found in grid!\n");
516 * Merge the two equivalence
519 int size = dsfsize[ae] + dsfsize[be];
520 dsf_merge(dsf, ac, bc);
521 ae = dsf_canonify(dsf, ac);
525 } else if ((y & x) & 1) {
527 * (x,y) are the workspace coordinates of a
528 * square field. If the square is
529 * definitely not blank, count it.
531 if (!(workspace[y*W+x] & bBLANK))
536 * If we discovered an existing loop above, we must now
537 * blank every square not part of it, and exit the main
540 if (loopclass != -1) {
541 #ifdef SOLVER_DIAGNOSTICS
542 printf("loop found in grid!\n");
544 for (y = 0; y < h; y++)
545 for (x = 0; x < w; x++)
546 if (dsf_canonify(dsf, y*w+x) != loopclass) {
547 if (workspace[(y*2+1)*W+(x*2+1)] & bBLANK) {
548 workspace[(y*2+1)*W+(x*2+1)] = bBLANK;
551 * This square is not part of the
552 * loop, but is known non-blank. We
555 #ifdef SOLVER_DIAGNOSTICS
556 printf("non-blank square (%d,%d) found outside"
571 * Now go through the workspace again and mark any edge
572 * which would cause a shortcut loop (i.e. would
573 * connect together two squares in the same equivalence
574 * class, and that equivalence class does not contain
575 * _all_ the known-non-blank squares currently in the
576 * grid) as disconnected. Also, mark any _square state_
577 * which would cause a shortcut loop as disconnected.
579 for (y = 1; y < H-1; y++)
580 for (x = 1; x < W-1; x++)
583 * (x,y) are the workspace coordinates of
584 * an edge field. Compute the normal-space
585 * coordinates of the squares it connects.
587 int ax = (x-1)/2, ay = (y-1)/2, ac = ay*w+ax;
588 int bx = x/2, by = y/2, bc = by*w+bx;
591 * If the edge is currently unknown, and
592 * sits between two squares in the same
593 * equivalence class, and the size of that
594 * class is less than nonblanks, then
595 * connecting this edge would be a shortcut
596 * loop and so we must not do so.
598 if (workspace[y*W+x] == 3) {
601 ae = dsf_canonify(dsf, ac);
602 be = dsf_canonify(dsf, bc);
606 * We have a loop. Is it a shortcut?
608 if (dsfsize[ae] < nonblanks) {
610 * Yes! Mark this edge disconnected.
612 workspace[y*W+x] = 2;
613 done_something = TRUE;
614 #ifdef SOLVER_DIAGNOSTICS
615 printf("edge (%d,%d)-(%d,%d) would create"
616 " a shortcut loop, hence must be"
617 " disconnected\n", x/2, y/2,
623 } else if ((y & x) & 1) {
625 * (x,y) are the workspace coordinates of a
626 * square field. Go through its possible
627 * (non-blank) states and see if any gives
628 * rise to a shortcut loop.
630 * This is slightly fiddly, because we have
631 * to check whether this square is already
632 * part of the same equivalence class as
633 * the things it's joining.
635 int ae = dsf_canonify(dsf, (y/2)*w+(x/2));
637 for (b = 2; b < 0xD; b++)
638 if (workspace[y*W+x] & (1<<b)) {
640 * Find the equivalence classes of
641 * the two squares this one would
642 * connect if it were in this
647 for (d = 1; d <= 8; d += d) if (b & d) {
648 int xx = x/2 + DX(d), yy = y/2 + DY(d);
649 int ee = dsf_canonify(dsf, yy*w+xx);
659 * This square state would form
660 * a loop on equivalence class
661 * e. Measure the size of that
662 * loop, and see if it's a
665 int loopsize = dsfsize[e];
667 loopsize++;/* add the square itself */
668 if (loopsize < nonblanks) {
670 * It is! Mark this square
673 workspace[y*W+x] &= ~(1<<b);
674 done_something = TRUE;
675 #ifdef SOLVER_DIAGNOSTICS
676 printf("square (%d,%d) would create a "
677 "shortcut loop in state %d, "
691 * If we reach here, there is nothing left we can do.
692 * Return 2 for ambiguous puzzle.
699 * If we reach _here_, it's by `break' out of the main loop,
700 * which means we've successfully achieved a solution. This
701 * means that we expect every square to be nailed down to
702 * exactly one possibility. Transcribe those possibilities into
705 for (y = 0; y < h; y++)
706 for (x = 0; x < w; x++) {
707 for (b = 0; b < 0xD; b++)
708 if (workspace[(2*y+1)*W+(2*x+1)] == (1<<b)) {
712 assert(b < 0xD); /* we should have had a break by now */
723 /* ----------------------------------------------------------------------
727 void pearl_loopgen(int w, int h, char *grid, random_state *rs)
729 int *options, *mindist, *maxdist, *list;
730 int x, y, d, total, n, area, limit;
733 * We're eventually going to have to return a w-by-h array
734 * containing line segment data. However, it's more convenient
735 * while actually generating the loop to consider the problem
736 * as a (w-1) by (h-1) array in which some squares are `inside'
737 * and some `outside'.
739 * I'm going to use the top left corner of my return array in
740 * the latter manner until the end of the function.
744 * To begin with, all squares are outside (0), except for one
745 * randomly selected one which is inside (1).
747 memset(grid, 0, w*h);
748 x = random_upto(rs, w-1);
749 y = random_upto(rs, h-1);
753 * I'm also going to need an array to store the possible
754 * options for the next extension of the grid.
756 options = snewn(w*h, int);
757 for (x = 0; x < w*h; x++)
761 * And some arrays and a list for breadth-first searching.
763 mindist = snewn(w*h, int);
764 maxdist = snewn(w*h, int);
765 list = snewn(w*h, int);
768 * Now we repeatedly scan the grid for feasible squares into
769 * which we can extend our loop, pick one, and do it.
774 #ifdef LOOPGEN_DIAGNOSTICS
775 for (y = 0; y < h; y++) {
776 for (x = 0; x < w; x++)
777 printf("%d", grid[y*w+x]);
784 * Our primary aim in growing this loop is to make it
785 * reasonably _dense_ in the target rectangle. That is, we
786 * want the maximum over all squares of the minimum
787 * distance from that square to the loop to be small.
789 * Therefore, we start with a breadth-first search of the
790 * grid to find those minimum distances.
793 int head = 0, tail = 0;
796 for (i = 0; i < w*h; i++) {
804 while (head < tail) {
808 for (d = 1; d <= 8; d += d) {
809 int xx = x + DX(d), yy = y + DY(d);
810 if (xx >= 0 && xx < w && yy >= 0 && yy < h &&
811 mindist[yy*w+xx] < 0) {
812 mindist[yy*w+xx] = mindist[i] + 1;
813 list[tail++] = yy*w+xx;
819 * Having done the BFS, we now backtrack along its path
820 * to determine the most distant square that each
821 * square is on the shortest path to. This tells us
822 * which of the loop extension candidates (all of which
823 * are squares marked 1) is most desirable to extend
824 * into in terms of minimising the maximum distance
825 * from any empty square to the nearest loop square.
827 for (head = tail; head-- > 0 ;) {
836 for (d = 1; d <= 8; d += d) {
837 int xx = x + DX(d), yy = y + DY(d);
838 if (xx >= 0 && xx < w && yy >= 0 && yy < h &&
839 mindist[yy*w+xx] > mindist[i] &&
840 maxdist[yy*w+xx] > max) {
841 max = maxdist[yy*w+xx];
850 * A square is a viable candidate for extension of our loop
851 * if and only if the following conditions are all met:
852 * - It is currently labelled 0.
853 * - At least one of its four orthogonal neighbours is
855 * - If you consider its eight orthogonal and diagonal
856 * neighbours to form a ring, that ring contains at most
857 * one contiguous run of 1s. (It must also contain at
858 * _least_ one, of course, but that's already guaranteed
859 * by the previous condition so there's no need to test
863 for (y = 0; y < h-1; y++)
864 for (x = 0; x < w-1; x++) {
866 int rx, neighbours, runs, dist;
868 dist = maxdist[y*w+x];
872 continue; /* it isn't labelled 0 */
875 for (rx = 0, d = 1; d <= 8; rx += 2, d += d) {
876 int x2 = x + DX(d), y2 = y + DY(d);
877 int x3 = x2 + DX(A(d)), y3 = y2 + DY(A(d));
878 int g2 = (x2 >= 0 && x2 < w && y2 >= 0 && y2 < h ?
880 int g3 = (x3 >= 0 && x3 < w && y3 >= 0 && y3 < h ?
889 continue; /* it doesn't have a 1 neighbour */
892 for (rx = 0; rx < 8; rx++)
893 if (ring[rx] && !ring[(rx+1) & 7])
897 continue; /* too many runs of 1s */
900 * Now we know this square is a viable extension
901 * candidate. Mark it.
903 * FIXME: probabilistic prioritisation based on
904 * perimeter perturbation? (Wow, must keep that
907 options[y*w+x] = dist * (4-neighbours) * (4-neighbours);
908 total += options[y*w+x];
912 break; /* nowhere to go! */
915 * Now pick a random one of the viable extension squares,
916 * and extend into it.
918 n = random_upto(rs, total);
919 for (y = 0; y < h-1; y++)
920 for (x = 0; x < w-1; x++) {
922 if (options[y*w+x] > n)
923 goto found; /* two-level break */
926 assert(!"We shouldn't ever get here");
932 * We terminate the loop when around 7/12 of the grid area
933 * is full, but we also require that the loop has reached
936 limit = random_upto(rs, (w-1)*(h-1)) + 13*(w-1)*(h-1);
937 if (24 * area > limit) {
938 int l = FALSE, r = FALSE, u = FALSE, d = FALSE;
939 for (x = 0; x < w; x++) {
945 for (y = 0; y < h; y++) {
951 if (l && r && u && d)
961 #ifdef LOOPGEN_DIAGNOSTICS
962 printf("final loop:\n");
963 for (y = 0; y < h; y++) {
964 for (x = 0; x < w; x++)
965 printf("%d", grid[y*w+x]);
972 * Now convert this array of 0s and 1s into an array of path
975 for (y = h; y-- > 0 ;) {
976 for (x = w; x-- > 0 ;) {
978 * Examine the four grid squares of which (x,y) are in
979 * the bottom right, to determine the output for this
982 int ul = (x > 0 && y > 0 ? grid[(y-1)*w+(x-1)] : 0);
983 int ur = (y > 0 ? grid[(y-1)*w+x] : 0);
984 int dl = (x > 0 ? grid[y*w+(x-1)] : 0);
985 int dr = grid[y*w+x];
988 if (ul != ur) type |= U;
989 if (dl != dr) type |= D;
990 if (ul != dl) type |= L;
991 if (ur != dr) type |= R;
993 assert((bLR|bUD|bLU|bLD|bRU|bRD|bBLANK) & (1 << type));
1000 #if defined LOOPGEN_DIAGNOSTICS && !defined GENERATION_DIAGNOSTICS
1001 printf("as returned:\n");
1002 for (y = 0; y < h; y++) {
1003 for (x = 0; x < w; x++) {
1004 int type = grid[y*w+x];
1006 if (type & L) *p++ = 'L';
1007 if (type & R) *p++ = 'R';
1008 if (type & U) *p++ = 'U';
1009 if (type & D) *p++ = 'D';
1019 static char *new_game_desc(game_params *params, random_state *rs,
1020 char **aux, int interactive)
1025 int x, y, d, ret, i;
1028 clues = snewn(7*7, char);
1036 "\0\0\2\0\0\0\0", 7*7);
1037 grid = snewn(7*7, char);
1038 printf("%d\n", pearl_solve(7, 7, clues, grid));
1040 clues = snewn(10*10, char);
1042 "\0\0\2\0\2\0\0\0\0\0"
1043 "\0\0\0\0\2\0\0\0\1\0"
1044 "\0\0\1\0\1\0\2\0\0\0"
1045 "\0\0\0\2\0\0\2\0\0\0"
1046 "\1\0\0\0\0\2\0\0\0\2"
1047 "\0\0\2\0\0\0\0\2\0\0"
1048 "\0\0\1\0\0\0\2\0\0\0"
1049 "\2\0\0\0\1\0\0\0\0\2"
1050 "\0\0\0\0\0\0\2\2\0\0"
1051 "\0\0\1\0\0\0\0\0\0\1", 10*10);
1052 grid = snewn(10*10, char);
1053 printf("%d\n", pearl_solve(10, 10, clues, grid));
1055 clues = snewn(10*10, char);
1057 "\0\0\0\0\0\0\1\0\0\0"
1058 "\0\1\0\1\2\0\0\0\0\2"
1059 "\0\0\0\0\0\0\0\0\0\1"
1060 "\2\0\0\1\2\2\1\0\0\0"
1061 "\1\0\0\0\0\0\0\1\0\0"
1062 "\0\0\2\0\0\0\0\0\0\2"
1063 "\0\0\0\2\1\2\1\0\0\2"
1064 "\2\0\0\0\0\0\0\0\0\0"
1065 "\2\0\0\0\0\1\1\0\2\0"
1066 "\0\0\0\2\0\0\0\0\0\0", 10*10);
1067 grid = snewn(10*10, char);
1068 printf("%d\n", pearl_solve(10, 10, clues, grid));
1071 grid = snewn(w*h, char);
1072 clues = snewn(w*h, char);
1073 clueorder = snewn(w*h, int);
1076 pearl_loopgen(w, h, grid, rs);
1078 #ifdef GENERATION_DIAGNOSTICS
1079 printf("grid array:\n");
1080 for (y = 0; y < h; y++) {
1081 for (x = 0; x < w; x++) {
1082 int type = grid[y*w+x];
1084 if (type & L) *p++ = 'L';
1085 if (type & R) *p++ = 'R';
1086 if (type & U) *p++ = 'U';
1087 if (type & D) *p++ = 'D';
1097 * Set up the maximal clue array.
1099 for (y = 0; y < h; y++)
1100 for (x = 0; x < w; x++) {
1101 int type = grid[y*w+x];
1103 clues[y*w+x] = NOCLUE;
1105 if ((bLR|bUD) & (1 << type)) {
1107 * This is a straight; see if it's a viable
1108 * candidate for a straight clue. It qualifies if
1109 * at least one of the squares it connects to is a
1112 for (d = 1; d <= 8; d += d) if (type & d) {
1113 int xx = x + DX(d), yy = y + DY(d);
1114 assert(xx >= 0 && xx < w && yy >= 0 && yy < h);
1115 if ((bLU|bLD|bRU|bRD) & (1 << grid[yy*w+xx]))
1118 if (d <= 8) /* we found one */
1119 clues[y*w+x] = STRAIGHT;
1120 } else if ((bLU|bLD|bRU|bRD) & (1 << type)) {
1122 * This is a corner; see if it's a viable candidate
1123 * for a corner clue. It qualifies if all the
1124 * squares it connects to are straights.
1126 for (d = 1; d <= 8; d += d) if (type & d) {
1127 int xx = x + DX(d), yy = y + DY(d);
1128 assert(xx >= 0 && xx < w && yy >= 0 && yy < h);
1129 if (!((bLR|bUD) & (1 << grid[yy*w+xx])))
1132 if (d > 8) /* we didn't find a counterexample */
1133 clues[y*w+x] = CORNER;
1137 #ifdef GENERATION_DIAGNOSTICS
1138 printf("clue array:\n");
1139 for (y = 0; y < h; y++) {
1140 for (x = 0; x < w; x++) {
1141 printf("%c", " *O"[(unsigned char)clues[y*w+x]]);
1149 * See if we can solve the puzzle just like this.
1151 ret = pearl_solve(w, h, clues, grid);
1152 assert(ret > 0); /* shouldn't be inconsistent! */
1154 continue; /* go round and try again */
1157 * Now shuffle the grid points and gradually remove the
1158 * clues to find a minimal set which still leaves the
1161 for (i = 0; i < w*h; i++)
1163 shuffle(clueorder, w*h, sizeof(*clueorder), rs);
1164 for (i = 0; i < w*h; i++) {
1167 y = clueorder[i] / w;
1168 x = clueorder[i] % w;
1170 if (clues[y*w+x] == 0)
1173 clue = clues[y*w+x];
1174 clues[y*w+x] = 0; /* try removing this clue */
1176 ret = pearl_solve(w, h, clues, grid);
1179 clues[y*w+x] = clue; /* oops, put it back again */
1182 #ifdef FINISHED_PUZZLE
1183 printf("clue array:\n");
1184 for (y = 0; y < h; y++) {
1185 for (x = 0; x < w; x++) {
1186 printf("%c", " *O"[(unsigned char)clues[y*w+x]]);
1200 return dupstr("FIXME");
1203 static char *validate_desc(game_params *params, char *desc)
1208 static game_state *new_game(midend *me, game_params *params, char *desc)
1210 game_state *state = snew(game_state);
1217 static game_state *dup_game(game_state *state)
1219 game_state *ret = snew(game_state);
1221 ret->FIXME = state->FIXME;
1226 static void free_game(game_state *state)
1231 static char *solve_game(game_state *state, game_state *currstate,
1232 char *aux, char **error)
1237 static int game_can_format_as_text_now(game_params *params)
1242 static char *game_text_format(game_state *state)
1247 static game_ui *new_ui(game_state *state)
1252 static void free_ui(game_ui *ui)
1256 static char *encode_ui(game_ui *ui)
1261 static void decode_ui(game_ui *ui, char *encoding)
1265 static void game_changed_state(game_ui *ui, game_state *oldstate,
1266 game_state *newstate)
1270 struct game_drawstate {
1275 static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
1276 int x, int y, int button)
1281 static game_state *execute_move(game_state *state, char *move)
1286 /* ----------------------------------------------------------------------
1290 static void game_compute_size(game_params *params, int tilesize,
1293 *x = *y = 10 * tilesize; /* FIXME */
1296 static void game_set_size(drawing *dr, game_drawstate *ds,
1297 game_params *params, int tilesize)
1299 ds->tilesize = tilesize;
1302 static float *game_colours(frontend *fe, int *ncolours)
1304 float *ret = snewn(3 * NCOLOURS, float);
1306 frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
1308 *ncolours = NCOLOURS;
1312 static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
1314 struct game_drawstate *ds = snew(struct game_drawstate);
1322 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
1327 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
1328 game_state *state, int dir, game_ui *ui,
1329 float animtime, float flashtime)
1332 * The initial contents of the window are not guaranteed and
1333 * can vary with front ends. To be on the safe side, all games
1334 * should start by drawing a big background-colour rectangle
1335 * covering the whole window.
1337 draw_rect(dr, 0, 0, 10*ds->tilesize, 10*ds->tilesize, COL_BACKGROUND);
1340 static float game_anim_length(game_state *oldstate, game_state *newstate,
1341 int dir, game_ui *ui)
1346 static float game_flash_length(game_state *oldstate, game_state *newstate,
1347 int dir, game_ui *ui)
1352 static int game_is_solved(game_state *state)
1357 static int game_timing_state(game_state *state, game_ui *ui)
1362 static void game_print_size(game_params *params, float *x, float *y)
1366 static void game_print(drawing *dr, game_state *state, int tilesize)
1371 #define thegame pearl
1374 const struct game thegame = {
1375 "Pearl", NULL, NULL,
1382 FALSE, game_configure, custom_params,
1390 FALSE, game_can_format_as_text_now, game_text_format,
1398 20 /* FIXME */, game_compute_size, game_set_size,
1401 game_free_drawstate,
1406 FALSE, FALSE, game_print_size, game_print,
1407 FALSE, /* wants_statusbar */
1408 FALSE, game_timing_state,