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1/*
2 * group.c: a Latin-square puzzle, but played with groups' Cayley
3 * tables. That is, you are given a Cayley table of a group with
4 * most elements blank and a few clues, and you must fill it in
5 * so as to preserve the group axioms.
6 *
7 * This is a perfectly playable and fully working puzzle, but I'm
8 * leaving it for the moment in the 'unfinished' directory because
9 * it's just too esoteric (not to mention _hard_) for me to be
10 * comfortable presenting it to the general public as something they
11 * might (implicitly) actually want to play.
12 *
13 * TODO:
14 *
15 * - more solver techniques?
16 * * Inverses: once we know that gh = e, we can immediately
17 * deduce hg = e as well; then for any gx=y we can deduce
18 * hy=x, and for any xg=y we have yh=x.
19 * * Hard-mode associativity: we currently deduce based on
20 * definite numbers in the grid, but we could also winnow
21 * based on _possible_ numbers.
22 * * My overambitious original thoughts included wondering if we
23 * could infer that there must be elements of certain orders
24 * (e.g. a group of order divisible by 5 must contain an
25 * element of order 5), but I think in fact this is probably
26 * silly.
27 */
28
29#include <stdio.h>
30#include <stdlib.h>
31#include <string.h>
32#include <assert.h>
33#include <ctype.h>
34#ifdef NO_TGMATH_H
35# include <math.h>
36#else
37# include <tgmath.h>
38#endif
39
40#include "puzzles.h"
41#include "latin.h"
42
43/*
44 * Difficulty levels. I do some macro ickery here to ensure that my
45 * enum and the various forms of my name list always match up.
46 */
47#define DIFFLIST(A) \
48 A(TRIVIAL,Trivial,NULL,t) \
49 A(NORMAL,Normal,solver_normal,n) \
50 A(HARD,Hard,solver_hard,h) \
51 A(EXTREME,Extreme,NULL,x) \
52 A(UNREASONABLE,Unreasonable,NULL,u)
53#define ENUM(upper,title,func,lower) DIFF_ ## upper,
54#define TITLE(upper,title,func,lower) #title,
55#define ENCODE(upper,title,func,lower) #lower
56#define CONFIG(upper,title,func,lower) ":" #title
57enum { DIFFLIST(ENUM) DIFFCOUNT };
58static char const *const group_diffnames[] = { DIFFLIST(TITLE) };
59static char const group_diffchars[] = DIFFLIST(ENCODE);
60#define DIFFCONFIG DIFFLIST(CONFIG)
61
62enum {
63 COL_BACKGROUND,
64 COL_GRID,
65 COL_USER,
66 COL_HIGHLIGHT,
67 COL_ERROR,
68 COL_PENCIL,
69 COL_DIAGONAL,
70 NCOLOURS
71};
72
73/*
74 * In identity mode, we number the elements e,a,b,c,d,f,g,h,...
75 * Otherwise, they're a,b,c,d,e,f,g,h,... in the obvious way.
76 */
77#define E_TO_FRONT(c,id) ( (id) && (c)<=5 ? (c) % 5 + 1 : (c) )
78#define E_FROM_FRONT(c,id) ( (id) && (c)<=5 ? ((c) + 3) % 5 + 1 : (c) )
79
80#define FROMCHAR(c,id) E_TO_FRONT((((c)-('A'-1)) & ~0x20), id)
81#define ISCHAR(c) (((c)>='A'&&(c)<='Z') || ((c)>='a'&&(c)<='z'))
82#define TOCHAR(c,id) (E_FROM_FRONT(c,id) + ('a'-1))
83
84struct game_params {
85 int w, diff;
86 bool id;
87};
88
89typedef struct group_common {
90 int refcount;
91 bool *immutable;
92} group_common;
93
94struct game_state {
95 game_params par;
96 digit *grid;
97 int *pencil; /* bitmaps using bits 1<<1..1<<n */
98 group_common *common;
99 bool completed, cheated;
100 digit *sequence; /* sequence of group elements shown */
101
102 /*
103 * This array indicates thick lines separating rows and columns
104 * placed and unplaced manually by the user as a visual aid, e.g.
105 * to delineate a subgroup and its cosets.
106 *
107 * When a line is placed, it's deemed to be between the two
108 * particular group elements that are on either side of it at the
109 * time; dragging those two away from each other automatically
110 * gets rid of the line. Hence, for a given element i, dividers[i]
111 * is either -1 (indicating no divider to the right of i), or some
112 * other element (indicating a divider to the right of i iff that
113 * element is the one right of it). These are eagerly cleared
114 * during drags.
115 */
116 int *dividers; /* thick lines between rows/cols */
117};
118
119static game_params *default_params(void)
120{
121 game_params *ret = snew(game_params);
122
123 ret->w = 6;
124 ret->diff = DIFF_NORMAL;
125 ret->id = true;
126
127 return ret;
128}
129
130static const struct game_params group_presets[] = {
131 { 6, DIFF_NORMAL, true },
132 { 6, DIFF_NORMAL, false },
133 { 8, DIFF_NORMAL, true },
134 { 8, DIFF_NORMAL, false },
135 { 8, DIFF_HARD, true },
136 { 8, DIFF_HARD, false },
137 { 12, DIFF_NORMAL, true },
138};
139
140static bool game_fetch_preset(int i, char **name, game_params **params)
141{
142 game_params *ret;
143 char buf[80];
144
145 if (i < 0 || i >= lenof(group_presets))
146 return false;
147
148 ret = snew(game_params);
149 *ret = group_presets[i]; /* structure copy */
150
151 sprintf(buf, "%dx%d %s%s", ret->w, ret->w, group_diffnames[ret->diff],
152 ret->id ? "" : ", identity hidden");
153
154 *name = dupstr(buf);
155 *params = ret;
156 return true;
157}
158
159static void free_params(game_params *params)
160{
161 sfree(params);
162}
163
164static game_params *dup_params(const game_params *params)
165{
166 game_params *ret = snew(game_params);
167 *ret = *params; /* structure copy */
168 return ret;
169}
170
171static void decode_params(game_params *params, char const *string)
172{
173 char const *p = string;
174
175 params->w = atoi(p);
176 while (*p && isdigit((unsigned char)*p)) p++;
177 params->diff = DIFF_NORMAL;
178 params->id = true;
179
180 while (*p) {
181 if (*p == 'd') {
182 int i;
183 p++;
184 params->diff = DIFFCOUNT+1; /* ...which is invalid */
185 if (*p) {
186 for (i = 0; i < DIFFCOUNT; i++) {
187 if (*p == group_diffchars[i])
188 params->diff = i;
189 }
190 p++;
191 }
192 } else if (*p == 'i') {
193 params->id = false;
194 p++;
195 } else {
196 /* unrecognised character */
197 p++;
198 }
199 }
200}
201
202static char *encode_params(const game_params *params, bool full)
203{
204 char ret[80];
205
206 sprintf(ret, "%d", params->w);
207 if (full)
208 sprintf(ret + strlen(ret), "d%c", group_diffchars[params->diff]);
209 if (!params->id)
210 sprintf(ret + strlen(ret), "i");
211
212 return dupstr(ret);
213}
214
215static config_item *game_configure(const game_params *params)
216{
217 config_item *ret;
218 char buf[80];
219
220 ret = snewn(4, config_item);
221
222 ret[0].name = "Grid size";
223 ret[0].type = C_STRING;
224 sprintf(buf, "%d", params->w);
225 ret[0].u.string.sval = dupstr(buf);
226
227 ret[1].name = "Difficulty";
228 ret[1].type = C_CHOICES;
229 ret[1].u.choices.choicenames = DIFFCONFIG;
230 ret[1].u.choices.selected = params->diff;
231
232 ret[2].name = "Show identity";
233 ret[2].type = C_BOOLEAN;
234 ret[2].u.boolean.bval = params->id;
235
236 ret[3].name = NULL;
237 ret[3].type = C_END;
238
239 return ret;
240}
241
242static game_params *custom_params(const config_item *cfg)
243{
244 game_params *ret = snew(game_params);
245
246 ret->w = atoi(cfg[0].u.string.sval);
247 ret->diff = cfg[1].u.choices.selected;
248 ret->id = cfg[2].u.boolean.bval;
249
250 return ret;
251}
252
253static const char *validate_params(const game_params *params, bool full)
254{
255 if (params->w < 3 || params->w > 26)
256 return "Grid size must be between 3 and 26";
257 if (params->diff >= DIFFCOUNT)
258 return "Unknown difficulty rating";
259 if (!params->id && params->diff == DIFF_TRIVIAL) {
260 /*
261 * We can't have a Trivial-difficulty puzzle (i.e. latin
262 * square deductions only) without a clear identity, because
263 * identityless puzzles always have two rows and two columns
264 * entirely blank, and no latin-square deduction permits the
265 * distinguishing of two such rows.
266 */
267 return "Trivial puzzles must have an identity";
268 }
269 if (!params->id && params->w == 3) {
270 /*
271 * We can't have a 3x3 puzzle without an identity either,
272 * because 3x3 puzzles can't ever be harder than Trivial
273 * (there are no 3x3 latin squares which aren't also valid
274 * group tables, so enabling group-based deductions doesn't
275 * rule out any possible solutions) and - as above - Trivial
276 * puzzles can't not have an identity.
277 */
278 return "3x3 puzzles must have an identity";
279 }
280 return NULL;
281}
282
283/* ----------------------------------------------------------------------
284 * Solver.
285 */
286
287static int find_identity(struct latin_solver *solver)
288{
289 int w = solver->o;
290 digit *grid = solver->grid;
291 int i, j;
292
293 for (i = 0; i < w; i++)
294 for (j = 0; j < w; j++) {
295 if (grid[i*w+j] == i+1)
296 return j+1;
297 if (grid[i*w+j] == j+1)
298 return i+1;
299 }
300
301 return 0;
302}
303
304static int solver_normal(struct latin_solver *solver, void *vctx)
305{
306 int w = solver->o;
307#ifdef STANDALONE_SOLVER
308 char **names = solver->names;
309#endif
310 digit *grid = solver->grid;
311 int i, j, k;
312
313 /*
314 * Deduce using associativity: (ab)c = a(bc).
315 *
316 * So we pick any a,b,c we like; then if we know ab, bc, and
317 * (ab)c we can fill in a(bc).
318 */
319 for (i = 0; i < w; i++)
320 for (j = 0; j < w; j++)
321 for (k = 0; k < w; k++) {
322 if (!grid[i*w+j] || !grid[j*w+k])
323 continue;
324 if (grid[(grid[i*w+j]-1)*w+k] &&
325 !grid[i*w+(grid[j*w+k]-1)]) {
326 int x = grid[j*w+k]-1, y = i;
327 int n = grid[(grid[i*w+j]-1)*w+k];
328#ifdef STANDALONE_SOLVER
329 if (solver_show_working) {
330 printf("%*sassociativity on %s,%s,%s: %s*%s = %s*%s\n",
331 solver_recurse_depth*4, "",
332 names[i], names[j], names[k],
333 names[grid[i*w+j]-1], names[k],
334 names[i], names[grid[j*w+k]-1]);
335 printf("%*s placing %s at (%d,%d)\n",
336 solver_recurse_depth*4, "",
337 names[n-1], x+1, y+1);
338 }
339#endif
340 if (solver->cube[(x*w+y)*w+n-1]) {
341 latin_solver_place(solver, x, y, n);
342 return 1;
343 } else {
344#ifdef STANDALONE_SOLVER
345 if (solver_show_working)
346 printf("%*s contradiction!\n",
347 solver_recurse_depth*4, "");
348 return -1;
349#endif
350 }
351 }
352 if (!grid[(grid[i*w+j]-1)*w+k] &&
353 grid[i*w+(grid[j*w+k]-1)]) {
354 int x = k, y = grid[i*w+j]-1;
355 int n = grid[i*w+(grid[j*w+k]-1)];
356#ifdef STANDALONE_SOLVER
357 if (solver_show_working) {
358 printf("%*sassociativity on %s,%s,%s: %s*%s = %s*%s\n",
359 solver_recurse_depth*4, "",
360 names[i], names[j], names[k],
361 names[grid[i*w+j]-1], names[k],
362 names[i], names[grid[j*w+k]-1]);
363 printf("%*s placing %s at (%d,%d)\n",
364 solver_recurse_depth*4, "",
365 names[n-1], x+1, y+1);
366 }
367#endif
368 if (solver->cube[(x*w+y)*w+n-1]) {
369 latin_solver_place(solver, x, y, n);
370 return 1;
371 } else {
372#ifdef STANDALONE_SOLVER
373 if (solver_show_working)
374 printf("%*s contradiction!\n",
375 solver_recurse_depth*4, "");
376 return -1;
377#endif
378 }
379 }
380 }
381
382 /*
383 * Fill in the row and column for the group identity, if it's not
384 * already known and if we've just found out what it is.
385 */
386 i = find_identity(solver);
387 if (i) {
388 bool done_something = false;
389 for (j = 1; j <= w; j++) {
390 if (!grid[(i-1)*w+(j-1)] || !grid[(j-1)*w+(i-1)]) {
391 done_something = true;
392 }
393 }
394 if (done_something) {
395#ifdef STANDALONE_SOLVER
396 if (solver_show_working) {
397 printf("%*s%s is the group identity\n",
398 solver_recurse_depth*4, "", names[i-1]);
399 }
400#endif
401 for (j = 1; j <= w; j++) {
402 if (!grid[(j-1)*w+(i-1)]) {
403 if (!cube(i-1, j-1, j)) {
404#ifdef STANDALONE_SOLVER
405 if (solver_show_working) {
406 printf("%*s but %s cannot go at (%d,%d) - "
407 "contradiction!\n",
408 solver_recurse_depth*4, "",
409 names[j-1], i, j);
410 }
411#endif
412 return -1;
413 }
414#ifdef STANDALONE_SOLVER
415 if (solver_show_working) {
416 printf("%*s placing %s at (%d,%d)\n",
417 solver_recurse_depth*4, "",
418 names[j-1], i, j);
419 }
420#endif
421 latin_solver_place(solver, i-1, j-1, j);
422 }
423 if (!grid[(i-1)*w+(j-1)]) {
424 if (!cube(j-1, i-1, j)) {
425#ifdef STANDALONE_SOLVER
426 if (solver_show_working) {
427 printf("%*s but %s cannot go at (%d,%d) - "
428 "contradiction!\n",
429 solver_recurse_depth*4, "",
430 names[j-1], j, i);
431 }
432#endif
433 return -1;
434 }
435#ifdef STANDALONE_SOLVER
436 if (solver_show_working) {
437 printf("%*s placing %s at (%d,%d)\n",
438 solver_recurse_depth*4, "",
439 names[j-1], j, i);
440 }
441#endif
442 latin_solver_place(solver, j-1, i-1, j);
443 }
444 }
445 return 1;
446 }
447 }
448
449 return 0;
450}
451
452static int solver_hard(struct latin_solver *solver, void *vctx)
453{
454 bool done_something = false;
455 int w = solver->o;
456#ifdef STANDALONE_SOLVER
457 char **names = solver->names;
458#endif
459 int i, j;
460
461 /*
462 * In identity-hidden mode, systematically rule out possibilities
463 * for the group identity.
464 *
465 * In solver_normal, we used the fact that any filled square in
466 * the grid whose contents _does_ match one of the elements it's
467 * the product of - that is, ab=a or ab=b - tells you immediately
468 * that the other element is the identity.
469 *
470 * Here, we use the flip side of that: any filled square in the
471 * grid whose contents does _not_ match either its row or column -
472 * that is, if ab is neither a nor b - tells you immediately that
473 * _neither_ of those elements is the identity. And if that's
474 * true, then we can also immediately rule out the possibility
475 * that it acts as the identity on any element at all.
476 */
477 for (i = 0; i < w; i++) {
478 bool i_can_be_id = true;
479#ifdef STANDALONE_SOLVER
480 char title[80];
481#endif
482
483 for (j = 0; j < w; j++) {
484 if (grid(i,j) && grid(i,j) != j+1) {
485#ifdef STANDALONE_SOLVER
486 if (solver_show_working)
487 sprintf(title, "%s cannot be the identity: "
488 "%s%s = %s =/= %s", names[i], names[i], names[j],
489 names[grid(i,j)-1], names[j]);
490#endif
491 i_can_be_id = false;
492 break;
493 }
494 if (grid(j,i) && grid(j,i) != j+1) {
495#ifdef STANDALONE_SOLVER
496 if (solver_show_working)
497 sprintf(title, "%s cannot be the identity: "
498 "%s%s = %s =/= %s", names[i], names[j], names[i],
499 names[grid(j,i)-1], names[j]);
500#endif
501 i_can_be_id = false;
502 break;
503 }
504 }
505
506 if (!i_can_be_id) {
507 /* Now rule out ij=j or ji=j for all j. */
508 for (j = 0; j < w; j++) {
509 if (cube(i, j, j+1)) {
510#ifdef STANDALONE_SOLVER
511 if (solver_show_working) {
512 if (title[0]) {
513 printf("%*s%s\n", solver_recurse_depth*4, "",
514 title);
515 title[0] = '\0';
516 }
517 printf("%*s ruling out %s at (%d,%d)\n",
518 solver_recurse_depth*4, "", names[j], i, j);
519 }
520#endif
521 cube(i, j, j+1) = false;
522 }
523 if (cube(j, i, j+1)) {
524#ifdef STANDALONE_SOLVER
525 if (solver_show_working) {
526 if (title[0]) {
527 printf("%*s%s\n", solver_recurse_depth*4, "",
528 title);
529 title[0] = '\0';
530 }
531 printf("%*s ruling out %s at (%d,%d)\n",
532 solver_recurse_depth*4, "", names[j], j, i);
533 }
534#endif
535 cube(j, i, j+1) = false;
536 }
537 }
538 }
539 }
540
541 return done_something;
542}
543
544#define SOLVER(upper,title,func,lower) func,
545static usersolver_t const group_solvers[] = { DIFFLIST(SOLVER) };
546
547static bool group_valid(struct latin_solver *solver, void *ctx)
548{
549 int w = solver->o;
550#ifdef STANDALONE_SOLVER
551 char **names = solver->names;
552#endif
553 int i, j, k;
554
555 for (i = 0; i < w; i++)
556 for (j = 0; j < w; j++)
557 for (k = 0; k < w; k++) {
558 int ij = grid(i, j) - 1;
559 int jk = grid(j, k) - 1;
560 int ij_k = grid(ij, k) - 1;
561 int i_jk = grid(i, jk) - 1;
562 if (ij_k != i_jk) {
563#ifdef STANDALONE_SOLVER
564 if (solver_show_working) {
565 printf("%*sfailure of associativity: "
566 "(%s%s)%s = %s%s = %s but "
567 "%s(%s%s) = %s%s = %s\n",
568 solver_recurse_depth*4, "",
569 names[i], names[j], names[k],
570 names[ij], names[k], names[ij_k],
571 names[i], names[j], names[k],
572 names[i], names[jk], names[i_jk]);
573 }
574#endif
575 return false;
576 }
577 }
578
579 return true;
580}
581
582static int solver(const game_params *params, digit *grid, int maxdiff)
583{
584 int w = params->w;
585 int ret;
586 struct latin_solver solver;
587
588#ifdef STANDALONE_SOLVER
589 char *p, text[100], *names[50];
590 int i;
591
592 for (i = 0, p = text; i < w; i++) {
593 names[i] = p;
594 *p++ = TOCHAR(i+1, params->id);
595 *p++ = '\0';
596 }
597 solver.names = names;
598#endif
599
600 if (latin_solver_alloc(&solver, grid, w))
601 ret = latin_solver_main(&solver, maxdiff,
602 DIFF_TRIVIAL, DIFF_HARD, DIFF_EXTREME,
603 DIFF_EXTREME, DIFF_UNREASONABLE,
604 group_solvers, group_valid, NULL, NULL, NULL);
605 else
606 ret = diff_impossible;
607
608 latin_solver_free(&solver);
609
610 return ret;
611}
612
613/* ----------------------------------------------------------------------
614 * Grid generation.
615 */
616
617static char *encode_grid(char *desc, digit *grid, int area)
618{
619 int run, i;
620 char *p = desc;
621
622 run = 0;
623 for (i = 0; i <= area; i++) {
624 int n = (i < area ? grid[i] : -1);
625
626 if (!n)
627 run++;
628 else {
629 if (run) {
630 while (run > 0) {
631 int c = 'a' - 1 + run;
632 if (run > 26)
633 c = 'z';
634 *p++ = c;
635 run -= c - ('a' - 1);
636 }
637 } else {
638 /*
639 * If there's a number in the very top left or
640 * bottom right, there's no point putting an
641 * unnecessary _ before or after it.
642 */
643 if (p > desc && n > 0)
644 *p++ = '_';
645 }
646 if (n > 0)
647 p += sprintf(p, "%d", n);
648 run = 0;
649 }
650 }
651 return p;
652}
653
654/* ----- data generated by group.gap begins ----- */
655
656struct group {
657 unsigned long autosize;
658 int order, ngens;
659 const char *gens;
660};
661struct groups {
662 int ngroups;
663 const struct group *groups;
664};
665
666static const struct group groupdata[] = {
667 /* order 2 */
668 {1L, 2, 1, "BA"},
669 /* order 3 */
670 {2L, 3, 1, "BCA"},
671 /* order 4 */
672 {2L, 4, 1, "BCDA"},
673 {6L, 4, 2, "BADC" "CDAB"},
674 /* order 5 */
675 {4L, 5, 1, "BCDEA"},
676 /* order 6 */
677 {6L, 6, 2, "CFEBAD" "BADCFE"},
678 {2L, 6, 1, "DCFEBA"},
679 /* order 7 */
680 {6L, 7, 1, "BCDEFGA"},
681 /* order 8 */
682 {4L, 8, 1, "BCEFDGHA"},
683 {8L, 8, 2, "BDEFGAHC" "EGBHDCFA"},
684 {8L, 8, 2, "EGBHDCFA" "BAEFCDHG"},
685 {24L, 8, 2, "BDEFGAHC" "CHDGBEAF"},
686 {168L, 8, 3, "BAEFCDHG" "CEAGBHDF" "DFGAHBCE"},
687 /* order 9 */
688 {6L, 9, 1, "BDECGHFIA"},
689 {48L, 9, 2, "BDEAGHCIF" "CEFGHAIBD"},
690 /* order 10 */
691 {20L, 10, 2, "CJEBGDIFAH" "BADCFEHGJI"},
692 {4L, 10, 1, "DCFEHGJIBA"},
693 /* order 11 */
694 {10L, 11, 1, "BCDEFGHIJKA"},
695 /* order 12 */
696 {12L, 12, 2, "GLDKJEHCBIAF" "BCEFAGIJDKLH"},
697 {4L, 12, 1, "EHIJKCBLDGFA"},
698 {24L, 12, 2, "BEFGAIJKCDLH" "FJBKHLEGDCIA"},
699 {12L, 12, 2, "GLDKJEHCBIAF" "BAEFCDIJGHLK"},
700 {12L, 12, 2, "FDIJGHLBKAEC" "GIDKFLHCJEAB"},
701 /* order 13 */
702 {12L, 13, 1, "BCDEFGHIJKLMA"},
703 /* order 14 */
704 {42L, 14, 2, "ELGNIBKDMFAHCJ" "BADCFEHGJILKNM"},
705 {6L, 14, 1, "FEHGJILKNMBADC"},
706 /* order 15 */
707 {8L, 15, 1, "EGHCJKFMNIOBLDA"},
708 /* order 16 */
709 {8L, 16, 1, "MKNPFOADBGLCIEHJ"},
710 {96L, 16, 2, "ILKCONFPEDJHGMAB" "BDFGHIAKLMNCOEPJ"},
711 {32L, 16, 2, "MIHPFDCONBLAKJGE" "BEFGHJKALMNOCDPI"},
712 {32L, 16, 2, "IFACOGLMDEJBNPKH" "BEFGHJKALMNOCDPI"},
713 {16L, 16, 2, "MOHPFKCINBLADJGE" "BDFGHIEKLMNJOAPC"},
714 {16L, 16, 2, "MIHPFDJONBLEKCGA" "BDFGHIEKLMNJOAPC"},
715 {32L, 16, 2, "MOHPFDCINBLEKJGA" "BAFGHCDELMNIJKPO"},
716 {16L, 16, 2, "MIHPFKJONBLADCGE" "GDPHNOEKFLBCIAMJ"},
717 {32L, 16, 2, "MIBPFDJOGHLEKCNA" "CLEIJGMPKAOHNFDB"},
718 {192L, 16, 3,
719 "MCHPFAIJNBLDEOGK" "BEFGHJKALMNOCDPI" "GKLBNOEDFPHJIAMC"},
720 {64L, 16, 3, "MCHPFAIJNBLDEOGK" "LOGFPKJIBNMEDCHA" "CMAIJHPFDEONBLKG"},
721 {192L, 16, 3,
722 "IPKCOGMLEDJBNFAH" "BEFGHJKALMNOCDPI" "CMEIJBPFKAOGHLDN"},
723 {48L, 16, 3, "IPDJONFLEKCBGMAH" "FJBLMEOCGHPKAIND" "DGIEKLHNJOAMPBCF"},
724 {20160L, 16, 4,
725 "EHJKAMNBOCDPFGIL" "BAFGHCDELMNIJKPO" "CFAIJBLMDEOGHPKN"
726 "DGIAKLBNCOEFPHJM"},
727 /* order 17 */
728 {16L, 17, 1, "EFGHIJKLMNOPQABCD"},
729 /* order 18 */
730 {54L, 18, 2, "MKIQOPNAGLRECDBJHF" "BAEFCDJKLGHIOPMNRQ"},
731 {6L, 18, 1, "ECJKGHFOPDMNLRIQBA"},
732 {12L, 18, 2, "ECJKGHBOPAMNFRDQLI" "KNOPQCFREIGHLJAMBD"},
733 {432L, 18, 3,
734 "IFNAKLQCDOPBGHREMJ" "NOQCFRIGHKLJAMPBDE" "BAEFCDJKLGHIOPMNRQ"},
735 {48L, 18, 2, "ECJKGHBOPAMNFRDQLI" "FDKLHIOPBMNAREQCJG"},
736 /* order 19 */
737 {18L, 19, 1, "EFGHIJKLMNOPQRSABCD"},
738 /* order 20 */
739 {40L, 20, 2, "GTDKREHOBILSFMPCJQAN" "EABICDFMGHJQKLNTOPRS"},
740 {8L, 20, 1, "EHIJLCMNPGQRSKBTDOFA"},
741 {20L, 20, 2, "DJSHQNCLTRGPEBKAIFOM" "EABICDFMGHJQKLNTOPRS"},
742 {40L, 20, 2, "GTDKREHOBILSFMPCJQAN" "ECBIAGFMDKJQHONTLSRP"},
743 {24L, 20, 2, "IGFMDKJQHONTLSREPCBA" "FDIJGHMNKLQROPTBSAEC"},
744 /* order 21 */
745 {42L, 21, 2, "ITLSBOUERDHAGKCJNFMQP" "EJHLMKOPNRSQAUTCDBFGI"},
746 {12L, 21, 1, "EGHCJKFMNIPQLSTOUBRDA"},
747 /* order 22 */
748 {110L, 22, 2, "ETGVIBKDMFOHQJSLUNAPCR" "BADCFEHGJILKNMPORQTSVU"},
749 {10L, 22, 1, "FEHGJILKNMPORQTSVUBADC"},
750 /* order 23 */
751 {22L, 23, 1, "EFGHIJKLMNOPQRSTUVWABCD"},
752 /* order 24 */
753 {24L, 24, 2, "QXEJWPUMKLRIVBFTSACGHNDO" "HRNOPSWCTUVBLDIJXFGAKQME"},
754 {8L, 24, 1, "MQBTUDRWFGHXJELINOPKSAVC"},
755 {24L, 24, 2, "IOQRBEUVFWGHKLAXMNPSCDTJ" "NJXOVGDKSMTFIPQELCURBWAH"},
756 {48L, 24, 2, "QUEJWVXFKLRIPGMNSACBOTDH" "HSNOPWLDTUVBRIAKXFGCQEMJ"},
757 {24L, 24, 2, "QXEJWPUMKLRIVBFTSACGHNDO" "TWHNXLRIOPUMSACQVBFDEJGK"},
758 {48L, 24, 2, "QUEJWVXFKLRIPGMNSACBOTDH" "BAFGHCDEMNOPIJKLTUVQRSXW"},
759 {48L, 24, 3,
760 "QXKJWVUMESRIPGFTLDCBONAH" "JUEQRPXFKLWCVBMNSAIGHTDO"
761 "HSNOPWLDTUVBRIAKXFGCQEMJ"},
762 {24L, 24, 3,
763 "QUKJWPXFESRIVBMNLDCGHTAO" "JXEQRVUMKLWCPGFTSAIBONDH"
764 "TRONXLWCHVUMSAIJPGFDEQBK"},
765 {16L, 24, 2, "MRGTULWIOPFXSDJQBVNEKCHA" "VKXHOQASNTPBCWDEUFGIJLMR"},
766 {16L, 24, 2, "MRGTULWIOPFXSDJQBVNEKCHA" "RMLWIGTUSDJQOPFXEKCBVNAH"},
767 {48L, 24, 2, "IULQRGXMSDCWOPNTEKJBVFAH" "GLMOPRSDTUBVWIEKFXHJQANC"},
768 {24L, 24, 2, "UJPXMRCSNHGTLWIKFVBEDQOA" "NRUFVLWIPXMOJEDQHGTCSABK"},
769 {24L, 24, 2, "MIBTUAQRFGHXCDEWNOPJKLVS" "OKXVFWSCGUTNDRQJBPMALIHE"},
770 {144L, 24, 3,
771 "QXKJWVUMESRIPGFTLDCBONAH" "JUEQRPXFKLWCVBMNSAIGHTDO"
772 "BAFGHCDEMNOPIJKLTUVQRSXW"},
773 {336L, 24, 3,
774 "QTKJWONXESRIHVUMLDCPGFAB" "JNEQRHTUKLWCOPXFSAIVBMDG"
775 "HENOPJKLTUVBQRSAXFGWCDMI"},
776 /* order 25 */
777 {20L, 25, 1, "EHILMNPQRSFTUVBJWXDOYGAKC"},
778 {480L, 25, 2, "EHILMNPQRSCTUVBFWXDJYGOKA" "BDEGHIKLMNAPQRSCTUVFWXJYO"},
779 /* order 26 */
780 {156L, 26, 2,
781 "EXGZIBKDMFOHQJSLUNWPYRATCV" "BADCFEHGJILKNMPORQTSVUXWZY"},
782 {12L, 26, 1, "FEHGJILKNMPORQTSVUXWZYBADC"},
783};
784
785static const struct groups groups[] = {
786 {0, NULL}, /* trivial case: 0 */
787 {0, NULL}, /* trivial case: 1 */
788 {1, groupdata + 0}, /* 2 */
789 {1, groupdata + 1}, /* 3 */
790 {2, groupdata + 2}, /* 4 */
791 {1, groupdata + 4}, /* 5 */
792 {2, groupdata + 5}, /* 6 */
793 {1, groupdata + 7}, /* 7 */
794 {5, groupdata + 8}, /* 8 */
795 {2, groupdata + 13}, /* 9 */
796 {2, groupdata + 15}, /* 10 */
797 {1, groupdata + 17}, /* 11 */
798 {5, groupdata + 18}, /* 12 */
799 {1, groupdata + 23}, /* 13 */
800 {2, groupdata + 24}, /* 14 */
801 {1, groupdata + 26}, /* 15 */
802 {14, groupdata + 27}, /* 16 */
803 {1, groupdata + 41}, /* 17 */
804 {5, groupdata + 42}, /* 18 */
805 {1, groupdata + 47}, /* 19 */
806 {5, groupdata + 48}, /* 20 */
807 {2, groupdata + 53}, /* 21 */
808 {2, groupdata + 55}, /* 22 */
809 {1, groupdata + 57}, /* 23 */
810 {15, groupdata + 58}, /* 24 */
811 {2, groupdata + 73}, /* 25 */
812 {2, groupdata + 75}, /* 26 */
813};
814
815/* ----- data generated by group.gap ends ----- */
816
817static char *new_game_desc(const game_params *params, random_state *rs,
818 char **aux, bool interactive)
819{
820 int w = params->w, a = w*w;
821 digit *grid, *soln, *soln2;
822 int *indices;
823 int i, j, k, qh, qt;
824 int diff = params->diff;
825 const struct group *group;
826 char *desc, *p;
827
828 /*
829 * Difficulty exceptions: some combinations of size and
830 * difficulty cannot be satisfied, because all puzzles of at
831 * most that difficulty are actually even easier.
832 *
833 * Remember to re-test this whenever a change is made to the
834 * solver logic!
835 *
836 * I tested it using the following shell command:
837
838for d in t n h x u; do
839 for id in '' i; do
840 for i in {3..9}; do
841 echo -n "./group --generate 1 ${i}d${d}${id}: "
842 perl -e 'alarm 30; exec @ARGV' \
843 ./group --generate 1 ${i}d${d}${id} >/dev/null && echo ok
844 done
845 done
846done
847
848 * Of course, it's better to do that after taking the exceptions
849 * _out_, so as to detect exceptions that should be removed as
850 * well as those which should be added.
851 */
852 if (w < 5 && diff == DIFF_UNREASONABLE)
853 diff--;
854 if ((w < 5 || ((w == 6 || w == 8) && params->id)) && diff == DIFF_EXTREME)
855 diff--;
856 if ((w < 6 || (w == 6 && params->id)) && diff == DIFF_HARD)
857 diff--;
858 if ((w < 4 || (w == 4 && params->id)) && diff == DIFF_NORMAL)
859 diff--;
860
861 grid = snewn(a, digit);
862 soln = snewn(a, digit);
863 soln2 = snewn(a, digit);
864 indices = snewn(a, int);
865
866 while (1) {
867 /*
868 * Construct a valid group table, by picking a group from
869 * the above data table, decompressing it into a full
870 * representation by BFS, and then randomly permuting its
871 * non-identity elements.
872 *
873 * We build the canonical table in 'soln' (and use 'grid' as
874 * our BFS queue), then transfer the table into 'grid'
875 * having shuffled the rows.
876 */
877 assert(w >= 2);
878 assert(w < lenof(groups));
879 group = groups[w].groups + random_upto(rs, groups[w].ngroups);
880 assert(group->order == w);
881 memset(soln, 0, a);
882 for (i = 0; i < w; i++)
883 soln[i] = i+1;
884 qh = qt = 0;
885 grid[qt++] = 1;
886 while (qh < qt) {
887 digit *row, *newrow;
888
889 i = grid[qh++];
890 row = soln + (i-1)*w;
891
892 for (j = 0; j < group->ngens; j++) {
893 int nri;
894 const char *gen = group->gens + j*w;
895
896 /*
897 * Apply each group generator to row, constructing a
898 * new row.
899 */
900 nri = gen[row[0]-1] - 'A' + 1; /* which row is it? */
901 newrow = soln + (nri-1)*w;
902 if (!newrow[0]) { /* not done yet */
903 for (k = 0; k < w; k++)
904 newrow[k] = gen[row[k]-1] - 'A' + 1;
905 grid[qt++] = nri;
906 }
907 }
908 }
909 /* That's got the canonical table. Now shuffle it. */
910 for (i = 0; i < w; i++)
911 soln2[i] = i;
912 if (params->id) /* do we shuffle in the identity? */
913 shuffle(soln2+1, w-1, sizeof(*soln2), rs);
914 else
915 shuffle(soln2, w, sizeof(*soln2), rs);
916 for (i = 0; i < w; i++)
917 for (j = 0; j < w; j++)
918 grid[(soln2[i])*w+(soln2[j])] = soln2[soln[i*w+j]-1]+1;
919
920 /*
921 * Remove entries one by one while the puzzle is still
922 * soluble at the appropriate difficulty level.
923 */
924 memcpy(soln, grid, a);
925 if (!params->id) {
926 /*
927 * Start by blanking the entire identity row and column,
928 * and also another row and column so that the player
929 * can't trivially determine which element is the
930 * identity.
931 */
932
933 j = 1 + random_upto(rs, w-1); /* pick a second row/col to blank */
934 for (i = 0; i < w; i++) {
935 grid[(soln2[0])*w+i] = grid[i*w+(soln2[0])] = 0;
936 grid[(soln2[j])*w+i] = grid[i*w+(soln2[j])] = 0;
937 }
938
939 memcpy(soln2, grid, a);
940 if (solver(params, soln2, diff) > diff)
941 continue; /* go round again if that didn't work */
942 }
943
944 k = 0;
945 for (i = (params->id ? 1 : 0); i < w; i++)
946 for (j = (params->id ? 1 : 0); j < w; j++)
947 if (grid[i*w+j])
948 indices[k++] = i*w+j;
949 shuffle(indices, k, sizeof(*indices), rs);
950
951 for (i = 0; i < k; i++) {
952 memcpy(soln2, grid, a);
953 soln2[indices[i]] = 0;
954 if (solver(params, soln2, diff) <= diff)
955 grid[indices[i]] = 0;
956 }
957
958 /*
959 * Make sure the puzzle isn't too easy.
960 */
961 if (diff > 0) {
962 memcpy(soln2, grid, a);
963 if (solver(params, soln2, diff-1) < diff)
964 continue; /* go round and try again */
965 }
966
967 /*
968 * Done.
969 */
970 break;
971 }
972
973 /*
974 * Encode the puzzle description.
975 */
976 desc = snewn(a*20, char);
977 p = encode_grid(desc, grid, a);
978 *p++ = '\0';
979 desc = sresize(desc, p - desc, char);
980
981 /*
982 * Encode the solution.
983 */
984 *aux = snewn(a+2, char);
985 (*aux)[0] = 'S';
986 for (i = 0; i < a; i++)
987 (*aux)[i+1] = TOCHAR(soln[i], params->id);
988 (*aux)[a+1] = '\0';
989
990 sfree(grid);
991 sfree(soln);
992 sfree(soln2);
993 sfree(indices);
994
995 return desc;
996}
997
998/* ----------------------------------------------------------------------
999 * Gameplay.
1000 */
1001
1002static const char *validate_grid_desc(const char **pdesc, int range, int area)
1003{
1004 const char *desc = *pdesc;
1005 int squares = 0;
1006 while (*desc && *desc != ',') {
1007 int n = *desc++;
1008 if (n >= 'a' && n <= 'z') {
1009 squares += n - 'a' + 1;
1010 } else if (n == '_') {
1011 /* do nothing */;
1012 } else if (n > '0' && n <= '9') {
1013 int val = atoi(desc-1);
1014 if (val < 1 || val > range)
1015 return "Out-of-range number in game description";
1016 squares++;
1017 while (*desc >= '0' && *desc <= '9')
1018 desc++;
1019 } else
1020 return "Invalid character in game description";
1021 }
1022
1023 if (squares < area)
1024 return "Not enough data to fill grid";
1025
1026 if (squares > area)
1027 return "Too much data to fit in grid";
1028 *pdesc = desc;
1029 return NULL;
1030}
1031
1032static const char *validate_desc(const game_params *params, const char *desc)
1033{
1034 int w = params->w, a = w*w;
1035 const char *p = desc;
1036
1037 return validate_grid_desc(&p, w, a);
1038}
1039
1040static const char *spec_to_grid(const char *desc, digit *grid, int area)
1041{
1042 int i = 0;
1043 while (*desc && *desc != ',') {
1044 int n = *desc++;
1045 if (n >= 'a' && n <= 'z') {
1046 int run = n - 'a' + 1;
1047 assert(i + run <= area);
1048 while (run-- > 0)
1049 grid[i++] = 0;
1050 } else if (n == '_') {
1051 /* do nothing */;
1052 } else if (n > '0' && n <= '9') {
1053 assert(i < area);
1054 grid[i++] = atoi(desc-1);
1055 while (*desc >= '0' && *desc <= '9')
1056 desc++;
1057 } else {
1058 assert(!"We can't get here");
1059 }
1060 }
1061 assert(i == area);
1062 return desc;
1063}
1064
1065static game_state *new_game(midend *me, const game_params *params,
1066 const char *desc)
1067{
1068 int w = params->w, a = w*w;
1069 game_state *state = snew(game_state);
1070 int i;
1071
1072 state->par = *params; /* structure copy */
1073 state->grid = snewn(a, digit);
1074 state->common = snew(group_common);
1075 state->common->refcount = 1;
1076 state->common->immutable = snewn(a, bool);
1077 state->pencil = snewn(a, int);
1078 for (i = 0; i < a; i++) {
1079 state->grid[i] = 0;
1080 state->common->immutable[i] = false;
1081 state->pencil[i] = 0;
1082 }
1083 state->sequence = snewn(w, digit);
1084 state->dividers = snewn(w, int);
1085 for (i = 0; i < w; i++) {
1086 state->sequence[i] = i;
1087 state->dividers[i] = -1;
1088 }
1089
1090 desc = spec_to_grid(desc, state->grid, a);
1091 for (i = 0; i < a; i++)
1092 if (state->grid[i] != 0)
1093 state->common->immutable[i] = true;
1094
1095 state->completed = false;
1096 state->cheated = false;
1097
1098 return state;
1099}
1100
1101static game_state *dup_game(const game_state *state)
1102{
1103 int w = state->par.w, a = w*w;
1104 game_state *ret = snew(game_state);
1105
1106 ret->par = state->par; /* structure copy */
1107
1108 ret->grid = snewn(a, digit);
1109 ret->common = state->common;
1110 ret->common->refcount++;
1111 ret->pencil = snewn(a, int);
1112 ret->sequence = snewn(w, digit);
1113 ret->dividers = snewn(w, int);
1114 memcpy(ret->grid, state->grid, a*sizeof(digit));
1115 memcpy(ret->pencil, state->pencil, a*sizeof(int));
1116 memcpy(ret->sequence, state->sequence, w*sizeof(digit));
1117 memcpy(ret->dividers, state->dividers, w*sizeof(int));
1118
1119 ret->completed = state->completed;
1120 ret->cheated = state->cheated;
1121
1122 return ret;
1123}
1124
1125static void free_game(game_state *state)
1126{
1127 sfree(state->grid);
1128 if (--state->common->refcount == 0) {
1129 sfree(state->common->immutable);
1130 sfree(state->common);
1131 }
1132 sfree(state->pencil);
1133 sfree(state->sequence);
1134 sfree(state);
1135}
1136
1137static char *solve_game(const game_state *state, const game_state *currstate,
1138 const char *aux, const char **error)
1139{
1140 int w = state->par.w, a = w*w;
1141 int i, ret;
1142 digit *soln;
1143 char *out;
1144
1145 if (aux)
1146 return dupstr(aux);
1147
1148 soln = snewn(a, digit);
1149 memcpy(soln, state->grid, a*sizeof(digit));
1150
1151 ret = solver(&state->par, soln, DIFFCOUNT-1);
1152
1153 if (ret == diff_impossible) {
1154 *error = "No solution exists for this puzzle";
1155 out = NULL;
1156 } else if (ret == diff_ambiguous) {
1157 *error = "Multiple solutions exist for this puzzle";
1158 out = NULL;
1159 } else {
1160 out = snewn(a+2, char);
1161 out[0] = 'S';
1162 for (i = 0; i < a; i++)
1163 out[i+1] = TOCHAR(soln[i], state->par.id);
1164 out[a+1] = '\0';
1165 }
1166
1167 sfree(soln);
1168 return out;
1169}
1170
1171static bool game_can_format_as_text_now(const game_params *params)
1172{
1173 return true;
1174}
1175
1176static char *game_text_format(const game_state *state)
1177{
1178 int w = state->par.w;
1179 int x, y;
1180 char *ret, *p, ch;
1181
1182 ret = snewn(2*w*w+1, char); /* leave room for terminating NUL */
1183
1184 p = ret;
1185 for (y = 0; y < w; y++) {
1186 for (x = 0; x < w; x++) {
1187 digit d = state->grid[y*w+x];
1188
1189 if (d == 0) {
1190 ch = '.';
1191 } else {
1192 ch = TOCHAR(d, state->par.id);
1193 }
1194
1195 *p++ = ch;
1196 if (x == w-1) {
1197 *p++ = '\n';
1198 } else {
1199 *p++ = ' ';
1200 }
1201 }
1202 }
1203
1204 assert(p - ret == 2*w*w);
1205 *p = '\0';
1206 return ret;
1207}
1208
1209struct game_ui {
1210 /*
1211 * These are the coordinates of the primary highlighted square on
1212 * the grid, if hshow = 1.
1213 */
1214 int hx, hy;
1215 /*
1216 * These are the coordinates hx,hy _before_ they go through
1217 * state->sequence.
1218 */
1219 int ohx, ohy;
1220 /*
1221 * These variables give the length and displacement of a diagonal
1222 * sequence of highlighted squares starting at ohx,ohy (still if
1223 * hshow = 1). To find the squares' real coordinates, for 0<=i<dn,
1224 * compute ohx+i*odx and ohy+i*ody and then map through
1225 * state->sequence.
1226 */
1227 int odx, ody, odn;
1228 /*
1229 * This indicates whether the current highlight is a
1230 * pencil-mark one or a real one.
1231 */
1232 bool hpencil;
1233 /*
1234 * This indicates whether or not we're showing the highlight
1235 * (used to be hx = hy = -1); important so that when we're
1236 * using the cursor keys it doesn't keep coming back at a
1237 * fixed position. When hshow = 1, pressing a valid number
1238 * or letter key or Space will enter that number or letter in the grid.
1239 */
1240 bool hshow;
1241 /*
1242 * This indicates whether we're using the highlight as a cursor;
1243 * it means that it doesn't vanish on a keypress, and that it is
1244 * allowed on immutable squares.
1245 */
1246 bool hcursor;
1247 /*
1248 * This indicates whether we're dragging a table header to
1249 * reposition an entire row or column.
1250 */
1251 int drag; /* 0=none 1=row 2=col */
1252 int dragnum; /* element being dragged */
1253 int dragpos; /* its current position */
1254 int edgepos;
1255
1256 /*
1257 * User preference option: if the user right-clicks in a square
1258 * and presses a letter key to add/remove a pencil mark, do we
1259 * hide the mouse highlight again afterwards?
1260 *
1261 * Historically our answer was yes. The Android port prefers no.
1262 * There are advantages both ways, depending how much you dislike
1263 * the highlight cluttering your view. So it's a preference.
1264 */
1265 bool pencil_keep_highlight;
1266};
1267
1268static game_ui *new_ui(const game_state *state)
1269{
1270 game_ui *ui = snew(game_ui);
1271
1272 ui->hx = ui->hy = 0;
1273 ui->hpencil = false;
1274 ui->hshow = false;
1275 ui->hcursor = false;
1276 ui->drag = 0;
1277
1278 ui->pencil_keep_highlight = false;
1279
1280 return ui;
1281}
1282
1283static void free_ui(game_ui *ui)
1284{
1285 sfree(ui);
1286}
1287
1288static config_item *get_prefs(game_ui *ui)
1289{
1290 config_item *ret;
1291
1292 ret = snewn(2, config_item);
1293
1294 ret[0].name = "Keep mouse highlight after changing a pencil mark";
1295 ret[0].kw = "pencil-keep-highlight";
1296 ret[0].type = C_BOOLEAN;
1297 ret[0].u.boolean.bval = ui->pencil_keep_highlight;
1298
1299 ret[1].name = NULL;
1300 ret[1].type = C_END;
1301
1302 return ret;
1303}
1304
1305static void set_prefs(game_ui *ui, const config_item *cfg)
1306{
1307 ui->pencil_keep_highlight = cfg[0].u.boolean.bval;
1308}
1309
1310static void game_changed_state(game_ui *ui, const game_state *oldstate,
1311 const game_state *newstate)
1312{
1313 int w = newstate->par.w;
1314 /*
1315 * We prevent pencil-mode highlighting of a filled square, unless
1316 * we're using the cursor keys. So if the user has just filled in
1317 * a square which we had a pencil-mode highlight in (by Undo, or
1318 * by Redo, or by Solve), then we cancel the highlight.
1319 */
1320 if (ui->hshow && ui->hpencil && !ui->hcursor &&
1321 newstate->grid[ui->hy * w + ui->hx] != 0) {
1322 ui->hshow = false;
1323 }
1324 if (ui->hshow && ui->odn > 1) {
1325 /*
1326 * Reordering of rows or columns within the range of a
1327 * multifill selection cancels the multifill and deselects
1328 * everything.
1329 */
1330 int i;
1331 for (i = 0; i < ui->odn; i++) {
1332 if (oldstate->sequence[ui->ohx + i*ui->odx] !=
1333 newstate->sequence[ui->ohx + i*ui->odx]) {
1334 ui->hshow = false;
1335 break;
1336 }
1337 if (oldstate->sequence[ui->ohy + i*ui->ody] !=
1338 newstate->sequence[ui->ohy + i*ui->ody]) {
1339 ui->hshow = false;
1340 break;
1341 }
1342 }
1343 } else if (ui->hshow &&
1344 (newstate->sequence[ui->ohx] != ui->hx ||
1345 newstate->sequence[ui->ohy] != ui->hy)) {
1346 /*
1347 * Otherwise, reordering of the row or column containing the
1348 * selection causes the selection to move with it.
1349 */
1350 int i;
1351 for (i = 0; i < w; i++) {
1352 if (newstate->sequence[i] == ui->hx)
1353 ui->ohx = i;
1354 if (newstate->sequence[i] == ui->hy)
1355 ui->ohy = i;
1356 }
1357 }
1358}
1359
1360static const char *current_key_label(const game_ui *ui,
1361 const game_state *state, int button)
1362{
1363 if (ui->hshow && button == CURSOR_SELECT)
1364 return ui->hpencil ? "Ink" : "Pencil";
1365 if (ui->hshow && button == CURSOR_SELECT2) {
1366 int w = state->par.w;
1367 int i;
1368 for (i = 0; i < ui->odn; i++) {
1369 int x = state->sequence[ui->ohx + i*ui->odx];
1370 int y = state->sequence[ui->ohy + i*ui->ody];
1371 int index = y*w+x;
1372 if (ui->hpencil && state->grid[index]) return "";
1373 if (state->common->immutable[index]) return "";
1374 }
1375 return "Clear";
1376 }
1377 return "";
1378}
1379
1380#define PREFERRED_TILESIZE 48
1381#define TILESIZE (ds->tilesize)
1382#define BORDER (TILESIZE / 2)
1383#define LEGEND (TILESIZE)
1384#define GRIDEXTRA max((TILESIZE / 32),1)
1385#define COORD(x) ((x)*TILESIZE + BORDER + LEGEND)
1386#define FROMCOORD(x) (((x)+(TILESIZE-BORDER-LEGEND)) / TILESIZE - 1)
1387
1388#define FLASH_TIME 0.4F
1389
1390#define DF_DIVIDER_TOP 0x1000
1391#define DF_DIVIDER_BOT 0x2000
1392#define DF_DIVIDER_LEFT 0x4000
1393#define DF_DIVIDER_RIGHT 0x8000
1394#define DF_HIGHLIGHT 0x0400
1395#define DF_HIGHLIGHT_PENCIL 0x0200
1396#define DF_IMMUTABLE 0x0100
1397#define DF_LEGEND 0x0080
1398#define DF_DIGIT_MASK 0x001F
1399
1400#define EF_DIGIT_SHIFT 5
1401#define EF_DIGIT_MASK ((1 << EF_DIGIT_SHIFT) - 1)
1402#define EF_LEFT_SHIFT 0
1403#define EF_RIGHT_SHIFT (3*EF_DIGIT_SHIFT)
1404#define EF_LEFT_MASK ((1UL << (3*EF_DIGIT_SHIFT)) - 1UL)
1405#define EF_RIGHT_MASK (EF_LEFT_MASK << EF_RIGHT_SHIFT)
1406#define EF_LATIN (1UL << (6*EF_DIGIT_SHIFT))
1407
1408struct game_drawstate {
1409 game_params par;
1410 int w, tilesize;
1411 bool started;
1412 long *tiles, *legend, *pencil, *errors;
1413 long *errtmp;
1414 digit *sequence;
1415};
1416
1417static bool check_errors(const game_state *state, long *errors)
1418{
1419 int w = state->par.w, a = w*w;
1420 digit *grid = state->grid;
1421 int i, j, k, x, y;
1422 bool errs = false;
1423
1424 /*
1425 * To verify that we have a valid group table, it suffices to
1426 * test latin-square-hood and associativity only. All the other
1427 * group axioms follow from those two.
1428 *
1429 * Proof:
1430 *
1431 * Associativity is given; closure is obvious from latin-
1432 * square-hood. We need to show that an identity exists and that
1433 * every element has an inverse.
1434 *
1435 * Identity: take any element a. There will be some element e
1436 * such that ea=a (in a latin square, every element occurs in
1437 * every row and column, so a must occur somewhere in the a
1438 * column, say on row e). For any other element b, there must
1439 * exist x such that ax=b (same argument from latin-square-hood
1440 * again), and then associativity gives us eb = e(ax) = (ea)x =
1441 * ax = b. Hence eb=b for all b, i.e. e is a left-identity. A
1442 * similar argument tells us that there must be some f which is
1443 * a right-identity, and then we show they are the same element
1444 * by observing that ef must simultaneously equal e and equal f.
1445 *
1446 * Inverses: given any a, by the latin-square argument again,
1447 * there must exist p and q such that pa=e and aq=e (i.e. left-
1448 * and right-inverses). We can show these are equal by
1449 * associativity: p = pe = p(aq) = (pa)q = eq = q. []
1450 */
1451
1452 if (errors)
1453 for (i = 0; i < a; i++)
1454 errors[i] = 0;
1455
1456 for (y = 0; y < w; y++) {
1457 unsigned long mask = 0, errmask = 0;
1458 for (x = 0; x < w; x++) {
1459 unsigned long bit = 1UL << grid[y*w+x];
1460 errmask |= (mask & bit);
1461 mask |= bit;
1462 }
1463
1464 if (mask != (1 << (w+1)) - (1 << 1)) {
1465 errs = true;
1466 errmask &= ~1UL;
1467 if (errors) {
1468 for (x = 0; x < w; x++)
1469 if (errmask & (1UL << grid[y*w+x]))
1470 errors[y*w+x] |= EF_LATIN;
1471 }
1472 }
1473 }
1474
1475 for (x = 0; x < w; x++) {
1476 unsigned long mask = 0, errmask = 0;
1477 for (y = 0; y < w; y++) {
1478 unsigned long bit = 1UL << grid[y*w+x];
1479 errmask |= (mask & bit);
1480 mask |= bit;
1481 }
1482
1483 if (mask != (1 << (w+1)) - (1 << 1)) {
1484 errs = true;
1485 errmask &= ~1UL;
1486 if (errors) {
1487 for (y = 0; y < w; y++)
1488 if (errmask & (1UL << grid[y*w+x]))
1489 errors[y*w+x] |= EF_LATIN;
1490 }
1491 }
1492 }
1493
1494 for (i = 1; i < w; i++)
1495 for (j = 1; j < w; j++)
1496 for (k = 1; k < w; k++)
1497 if (grid[i*w+j] && grid[j*w+k] &&
1498 grid[(grid[i*w+j]-1)*w+k] &&
1499 grid[i*w+(grid[j*w+k]-1)] &&
1500 grid[(grid[i*w+j]-1)*w+k] != grid[i*w+(grid[j*w+k]-1)]) {
1501 if (errors) {
1502 int a = i+1, b = j+1, c = k+1;
1503 int ab = grid[i*w+j], bc = grid[j*w+k];
1504 int left = (ab-1)*w+(c-1), right = (a-1)*w+(bc-1);
1505 /*
1506 * If the appropriate error slot is already
1507 * used for one of the squares, we don't
1508 * fill either of them.
1509 */
1510 if (!(errors[left] & EF_LEFT_MASK) &&
1511 !(errors[right] & EF_RIGHT_MASK)) {
1512 long err;
1513 err = a;
1514 err = (err << EF_DIGIT_SHIFT) | b;
1515 err = (err << EF_DIGIT_SHIFT) | c;
1516 errors[left] |= err << EF_LEFT_SHIFT;
1517 errors[right] |= err << EF_RIGHT_SHIFT;
1518 }
1519 }
1520 errs = true;
1521 }
1522
1523 return errs;
1524}
1525
1526static int find_in_sequence(digit *seq, int len, digit n)
1527{
1528 int i;
1529
1530 for (i = 0; i < len; i++)
1531 if (seq[i] == n)
1532 return i;
1533
1534 assert(!"Should never get here");
1535 return -1;
1536}
1537
1538static char *interpret_move(const game_state *state, game_ui *ui,
1539 const game_drawstate *ds,
1540 int x, int y, int button)
1541{
1542 int w = state->par.w;
1543 int tx, ty;
1544 char buf[80];
1545
1546 button = STRIP_BUTTON_MODIFIERS(button);
1547
1548 tx = FROMCOORD(x);
1549 ty = FROMCOORD(y);
1550
1551 if (ui->drag) {
1552 if (IS_MOUSE_DRAG(button)) {
1553 int tcoord = ((ui->drag &~ 4) == 1 ? ty : tx);
1554 ui->drag |= 4; /* some movement has happened */
1555 if (tcoord >= 0 && tcoord < w) {
1556 ui->dragpos = tcoord;
1557 return MOVE_UI_UPDATE;
1558 }
1559 } else if (IS_MOUSE_RELEASE(button)) {
1560 if (ui->drag & 4) {
1561 ui->drag = 0; /* end drag */
1562 if (state->sequence[ui->dragpos] == ui->dragnum)
1563 return MOVE_UI_UPDATE; /* drag was a no-op overall */
1564 sprintf(buf, "D%d,%d", ui->dragnum, ui->dragpos);
1565 return dupstr(buf);
1566 } else {
1567 ui->drag = 0; /* end 'drag' */
1568 if (ui->edgepos > 0 && ui->edgepos < w) {
1569 sprintf(buf, "V%d,%d",
1570 state->sequence[ui->edgepos-1],
1571 state->sequence[ui->edgepos]);
1572 return dupstr(buf);
1573 } else
1574 return MOVE_UI_UPDATE; /* no-op */
1575 }
1576 }
1577 } else if (IS_MOUSE_DOWN(button)) {
1578 if (tx >= 0 && tx < w && ty >= 0 && ty < w) {
1579 int otx = tx, oty = ty;
1580 tx = state->sequence[tx];
1581 ty = state->sequence[ty];
1582 if (button == LEFT_BUTTON) {
1583 if (tx == ui->hx && ty == ui->hy &&
1584 ui->hshow && !ui->hpencil) {
1585 ui->hshow = false;
1586 } else {
1587 ui->hx = tx;
1588 ui->hy = ty;
1589 ui->ohx = otx;
1590 ui->ohy = oty;
1591 ui->odx = ui->ody = 0;
1592 ui->odn = 1;
1593 ui->hshow = !state->common->immutable[ty*w+tx];
1594 ui->hpencil = false;
1595 }
1596 ui->hcursor = false;
1597 return MOVE_UI_UPDATE;
1598 }
1599 if (button == RIGHT_BUTTON) {
1600 /*
1601 * Pencil-mode highlighting for non filled squares.
1602 */
1603 if (state->grid[ty*w+tx] == 0) {
1604 if (tx == ui->hx && ty == ui->hy &&
1605 ui->hshow && ui->hpencil) {
1606 ui->hshow = false;
1607 } else {
1608 ui->hpencil = true;
1609 ui->hx = tx;
1610 ui->hy = ty;
1611 ui->ohx = otx;
1612 ui->ohy = oty;
1613 ui->odx = ui->ody = 0;
1614 ui->odn = 1;
1615 ui->hshow = true;
1616 }
1617 } else {
1618 ui->hshow = false;
1619 }
1620 ui->hcursor = false;
1621 return MOVE_UI_UPDATE;
1622 }
1623 } else if (tx >= 0 && tx < w && ty == -1) {
1624 ui->drag = 2;
1625 ui->dragnum = state->sequence[tx];
1626 ui->dragpos = tx;
1627 ui->edgepos = FROMCOORD(x + TILESIZE/2);
1628 return MOVE_UI_UPDATE;
1629 } else if (ty >= 0 && ty < w && tx == -1) {
1630 ui->drag = 1;
1631 ui->dragnum = state->sequence[ty];
1632 ui->dragpos = ty;
1633 ui->edgepos = FROMCOORD(y + TILESIZE/2);
1634 return MOVE_UI_UPDATE;
1635 }
1636 } else if (IS_MOUSE_DRAG(button)) {
1637 if (!ui->hpencil &&
1638 tx >= 0 && tx < w && ty >= 0 && ty < w &&
1639 abs(tx - ui->ohx) == abs(ty - ui->ohy)) {
1640 ui->odn = abs(tx - ui->ohx) + 1;
1641 ui->odx = (tx < ui->ohx ? -1 : +1);
1642 ui->ody = (ty < ui->ohy ? -1 : +1);
1643 } else {
1644 ui->odx = ui->ody = 0;
1645 ui->odn = 1;
1646 }
1647 return MOVE_UI_UPDATE;
1648 }
1649
1650 if (IS_CURSOR_MOVE(button)) {
1651 int cx = find_in_sequence(state->sequence, w, ui->hx);
1652 int cy = find_in_sequence(state->sequence, w, ui->hy);
1653 move_cursor(button, &cx, &cy, w, w, false, NULL);
1654 ui->hx = state->sequence[cx];
1655 ui->hy = state->sequence[cy];
1656 ui->hshow = true;
1657 ui->hcursor = true;
1658 ui->ohx = cx;
1659 ui->ohy = cy;
1660 ui->odx = ui->ody = 0;
1661 ui->odn = 1;
1662 return MOVE_UI_UPDATE;
1663 }
1664 if (ui->hshow &&
1665 (button == CURSOR_SELECT)) {
1666 ui->hpencil = !ui->hpencil;
1667 ui->hcursor = true;
1668 return MOVE_UI_UPDATE;
1669 }
1670
1671 if (ui->hshow &&
1672 ((ISCHAR(button) && FROMCHAR(button, state->par.id) <= w) ||
1673 button == CURSOR_SELECT2 || button == '\b')) {
1674 int n = FROMCHAR(button, state->par.id);
1675 int i, buflen;
1676 char *movebuf;
1677
1678 if (button == CURSOR_SELECT2 || button == '\b')
1679 n = 0;
1680
1681 for (i = 0; i < ui->odn; i++) {
1682 int x = state->sequence[ui->ohx + i*ui->odx];
1683 int y = state->sequence[ui->ohy + i*ui->ody];
1684 int index = y*w+x;
1685
1686 /*
1687 * Can't make pencil marks in a filled square. This can only
1688 * become highlighted if we're using cursor keys.
1689 */
1690 if (ui->hpencil && state->grid[index])
1691 return NULL;
1692
1693 /*
1694 * Can't do anything to an immutable square. Exception:
1695 * trying to set it to what it already was is OK (so that
1696 * multifilling can set a whole diagonal to a without
1697 * having to detour round the one immutable square in the
1698 * middle that already said a).
1699 */
1700 if (!ui->hpencil && state->grid[index] == n)
1701 /* OK even if it is immutable */;
1702 else if (state->common->immutable[index])
1703 return NULL;
1704 }
1705
1706 movebuf = snewn(80 * ui->odn, char);
1707 buflen = sprintf(movebuf, "%c%d,%d,%d",
1708 (char)(ui->hpencil && n > 0 ? 'P' : 'R'),
1709 ui->hx, ui->hy, n);
1710 for (i = 1; i < ui->odn; i++) {
1711 assert(buflen < i*80);
1712 buflen += sprintf(movebuf + buflen, "+%d,%d",
1713 state->sequence[ui->ohx + i*ui->odx],
1714 state->sequence[ui->ohy + i*ui->ody]);
1715 }
1716 movebuf = sresize(movebuf, buflen+1, char);
1717
1718 /*
1719 * Hide the highlight after a keypress, if it was mouse-
1720 * generated. Also, don't hide it if this move has changed
1721 * pencil marks and the user preference says not to hide the
1722 * highlight in that situation.
1723 */
1724 if (!ui->hcursor && !(ui->hpencil && ui->pencil_keep_highlight))
1725 ui->hshow = false;
1726
1727 return movebuf;
1728 }
1729
1730 if (button == 'M' || button == 'm')
1731 return dupstr("M");
1732
1733 return NULL;
1734}
1735
1736static game_state *execute_move(const game_state *from, const char *move)
1737{
1738 int w = from->par.w, a = w*w;
1739 game_state *ret;
1740 int x, y, i, j, n, pos;
1741
1742 if (move[0] == 'S') {
1743 ret = dup_game(from);
1744 ret->completed = ret->cheated = true;
1745
1746 for (i = 0; i < a; i++) {
1747 if (!ISCHAR(move[i+1]) || FROMCHAR(move[i+1], from->par.id) > w) {
1748 free_game(ret);
1749 return NULL;
1750 }
1751 ret->grid[i] = FROMCHAR(move[i+1], from->par.id);
1752 ret->pencil[i] = 0;
1753 }
1754
1755 if (move[a+1] != '\0') {
1756 free_game(ret);
1757 return NULL;
1758 }
1759
1760 return ret;
1761 } else if ((move[0] == 'P' || move[0] == 'R') &&
1762 sscanf(move+1, "%d,%d,%d%n", &x, &y, &n, &pos) == 3 &&
1763 n >= 0 && n <= w) {
1764 const char *mp = move + 1 + pos;
1765 bool pencil = (move[0] == 'P');
1766 ret = dup_game(from);
1767
1768 while (1) {
1769 if (x < 0 || x >= w || y < 0 || y >= w) {
1770 free_game(ret);
1771 return NULL;
1772 }
1773 if (from->common->immutable[y*w+x] &&
1774 !(!pencil && from->grid[y*w+x] == n))
1775 return NULL;
1776
1777 if (move[0] == 'P' && n > 0) {
1778 ret->pencil[y*w+x] ^= 1 << n;
1779 } else {
1780 ret->grid[y*w+x] = n;
1781 ret->pencil[y*w+x] = 0;
1782 }
1783
1784 if (!*mp)
1785 break;
1786
1787 if (*mp != '+')
1788 return NULL;
1789 if (sscanf(mp, "+%d,%d%n", &x, &y, &pos) < 2)
1790 return NULL;
1791 mp += pos;
1792 }
1793
1794 if (!ret->completed && !check_errors(ret, NULL))
1795 ret->completed = true;
1796
1797 return ret;
1798 } else if (move[0] == 'M') {
1799 /*
1800 * Fill in absolutely all pencil marks everywhere. (I
1801 * wouldn't use this for actual play, but it's a handy
1802 * starting point when following through a set of
1803 * diagnostics output by the standalone solver.)
1804 */
1805 ret = dup_game(from);
1806 for (i = 0; i < a; i++) {
1807 if (!ret->grid[i])
1808 ret->pencil[i] = (1 << (w+1)) - (1 << 1);
1809 }
1810 return ret;
1811 } else if (move[0] == 'D' &&
1812 sscanf(move+1, "%d,%d", &x, &y) == 2) {
1813 /*
1814 * Reorder the rows and columns so that digit x is in position
1815 * y.
1816 */
1817 ret = dup_game(from);
1818 for (i = j = 0; i < w; i++) {
1819 if (i == y) {
1820 ret->sequence[i] = x;
1821 } else {
1822 if (from->sequence[j] == x)
1823 j++;
1824 ret->sequence[i] = from->sequence[j++];
1825 }
1826 }
1827 /*
1828 * Eliminate any obsoleted dividers.
1829 */
1830 for (x = 0; x < w; x++) {
1831 int i = ret->sequence[x];
1832 int j = (x+1 < w ? ret->sequence[x+1] : -1);
1833 if (ret->dividers[i] != j)
1834 ret->dividers[i] = -1;
1835 }
1836 return ret;
1837 } else if (move[0] == 'V' &&
1838 sscanf(move+1, "%d,%d", &i, &j) == 2) {
1839 ret = dup_game(from);
1840 if (ret->dividers[i] == j)
1841 ret->dividers[i] = -1;
1842 else
1843 ret->dividers[i] = j;
1844 return ret;
1845 } else
1846 return NULL; /* couldn't parse move string */
1847}
1848
1849/* ----------------------------------------------------------------------
1850 * Drawing routines.
1851 */
1852
1853#define SIZE(w) ((w) * TILESIZE + 2*BORDER + LEGEND)
1854
1855static void game_compute_size(const game_params *params, int tilesize,
1856 const game_ui *ui, int *x, int *y)
1857{
1858 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
1859 struct { int tilesize; } ads, *ds = &ads;
1860 ads.tilesize = tilesize;
1861
1862 *x = *y = SIZE(params->w);
1863}
1864
1865static void game_set_size(drawing *dr, game_drawstate *ds,
1866 const game_params *params, int tilesize)
1867{
1868 ds->tilesize = tilesize;
1869}
1870
1871static float *game_colours(frontend *fe, int *ncolours)
1872{
1873 float *ret = snewn(3 * NCOLOURS, float);
1874
1875 frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
1876
1877 ret[COL_GRID * 3 + 0] = 0.0F;
1878 ret[COL_GRID * 3 + 1] = 0.0F;
1879 ret[COL_GRID * 3 + 2] = 0.0F;
1880
1881 ret[COL_USER * 3 + 0] = 0.0F;
1882 ret[COL_USER * 3 + 1] = 0.6F * ret[COL_BACKGROUND * 3 + 1];
1883 ret[COL_USER * 3 + 2] = 0.0F;
1884
1885 ret[COL_HIGHLIGHT * 3 + 0] = 0.78F * ret[COL_BACKGROUND * 3 + 0];
1886 ret[COL_HIGHLIGHT * 3 + 1] = 0.78F * ret[COL_BACKGROUND * 3 + 1];
1887 ret[COL_HIGHLIGHT * 3 + 2] = 0.78F * ret[COL_BACKGROUND * 3 + 2];
1888
1889 ret[COL_ERROR * 3 + 0] = 1.0F;
1890 ret[COL_ERROR * 3 + 1] = 0.0F;
1891 ret[COL_ERROR * 3 + 2] = 0.0F;
1892
1893 ret[COL_PENCIL * 3 + 0] = 0.5F * ret[COL_BACKGROUND * 3 + 0];
1894 ret[COL_PENCIL * 3 + 1] = 0.5F * ret[COL_BACKGROUND * 3 + 1];
1895 ret[COL_PENCIL * 3 + 2] = ret[COL_BACKGROUND * 3 + 2];
1896
1897 ret[COL_DIAGONAL * 3 + 0] = 0.95F * ret[COL_BACKGROUND * 3 + 0];
1898 ret[COL_DIAGONAL * 3 + 1] = 0.95F * ret[COL_BACKGROUND * 3 + 1];
1899 ret[COL_DIAGONAL * 3 + 2] = 0.95F * ret[COL_BACKGROUND * 3 + 2];
1900
1901 *ncolours = NCOLOURS;
1902 return ret;
1903}
1904
1905static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
1906{
1907 int w = state->par.w, a = w*w;
1908 struct game_drawstate *ds = snew(struct game_drawstate);
1909 int i;
1910
1911 ds->w = w;
1912 ds->par = state->par; /* structure copy */
1913 ds->tilesize = 0;
1914 ds->started = false;
1915 ds->tiles = snewn(a, long);
1916 ds->legend = snewn(w, long);
1917 ds->pencil = snewn(a, long);
1918 ds->errors = snewn(a, long);
1919 ds->sequence = snewn(a, digit);
1920 for (i = 0; i < a; i++)
1921 ds->tiles[i] = ds->pencil[i] = -1;
1922 for (i = 0; i < w; i++)
1923 ds->legend[i] = -1;
1924 ds->errtmp = snewn(a, long);
1925
1926 return ds;
1927}
1928
1929static void game_free_drawstate(drawing *dr, game_drawstate *ds)
1930{
1931 sfree(ds->tiles);
1932 sfree(ds->pencil);
1933 sfree(ds->errors);
1934 sfree(ds->errtmp);
1935 sfree(ds->sequence);
1936 sfree(ds);
1937}
1938
1939static void draw_tile(drawing *dr, game_drawstate *ds, int x, int y, long tile,
1940 long pencil, long error)
1941{
1942 int w = ds->w /* , a = w*w */;
1943 int tx, ty, tw, th;
1944 int cx, cy, cw, ch;
1945 char str[64];
1946
1947 tx = BORDER + LEGEND + x * TILESIZE + 1;
1948 ty = BORDER + LEGEND + y * TILESIZE + 1;
1949
1950 cx = tx;
1951 cy = ty;
1952 cw = tw = TILESIZE-1;
1953 ch = th = TILESIZE-1;
1954
1955 if (tile & DF_LEGEND) {
1956 cx += TILESIZE/10;
1957 cy += TILESIZE/10;
1958 cw -= TILESIZE/5;
1959 ch -= TILESIZE/5;
1960 tile |= DF_IMMUTABLE;
1961 }
1962
1963 clip(dr, cx, cy, cw, ch);
1964
1965 /* background needs erasing */
1966 draw_rect(dr, cx, cy, cw, ch,
1967 (tile & DF_HIGHLIGHT) ? COL_HIGHLIGHT :
1968 (x == y) ? COL_DIAGONAL : COL_BACKGROUND);
1969
1970 /* dividers */
1971 if (tile & DF_DIVIDER_TOP)
1972 draw_rect(dr, cx, cy, cw, 1, COL_GRID);
1973 if (tile & DF_DIVIDER_BOT)
1974 draw_rect(dr, cx, cy+ch-1, cw, 1, COL_GRID);
1975 if (tile & DF_DIVIDER_LEFT)
1976 draw_rect(dr, cx, cy, 1, ch, COL_GRID);
1977 if (tile & DF_DIVIDER_RIGHT)
1978 draw_rect(dr, cx+cw-1, cy, 1, ch, COL_GRID);
1979
1980 /* pencil-mode highlight */
1981 if (tile & DF_HIGHLIGHT_PENCIL) {
1982 int coords[6];
1983 coords[0] = cx;
1984 coords[1] = cy;
1985 coords[2] = cx+cw/2;
1986 coords[3] = cy;
1987 coords[4] = cx;
1988 coords[5] = cy+ch/2;
1989 draw_polygon(dr, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT);
1990 }
1991
1992 /* new number needs drawing? */
1993 if (tile & DF_DIGIT_MASK) {
1994 str[1] = '\0';
1995 str[0] = TOCHAR(tile & DF_DIGIT_MASK, ds->par.id);
1996 draw_text(dr, tx + TILESIZE/2, ty + TILESIZE/2,
1997 FONT_VARIABLE, TILESIZE/2, ALIGN_VCENTRE | ALIGN_HCENTRE,
1998 (error & EF_LATIN) ? COL_ERROR :
1999 (tile & DF_IMMUTABLE) ? COL_GRID : COL_USER, str);
2000
2001 if (error & EF_LEFT_MASK) {
2002 int a = (error >> (EF_LEFT_SHIFT+2*EF_DIGIT_SHIFT))&EF_DIGIT_MASK;
2003 int b = (error >> (EF_LEFT_SHIFT+1*EF_DIGIT_SHIFT))&EF_DIGIT_MASK;
2004 int c = (error >> (EF_LEFT_SHIFT ))&EF_DIGIT_MASK;
2005 char buf[10];
2006 sprintf(buf, "(%c%c)%c", TOCHAR(a, ds->par.id),
2007 TOCHAR(b, ds->par.id), TOCHAR(c, ds->par.id));
2008 draw_text(dr, tx + TILESIZE/2, ty + TILESIZE/6,
2009 FONT_VARIABLE, TILESIZE/6, ALIGN_VCENTRE | ALIGN_HCENTRE,
2010 COL_ERROR, buf);
2011 }
2012 if (error & EF_RIGHT_MASK) {
2013 int a = (error >> (EF_RIGHT_SHIFT+2*EF_DIGIT_SHIFT))&EF_DIGIT_MASK;
2014 int b = (error >> (EF_RIGHT_SHIFT+1*EF_DIGIT_SHIFT))&EF_DIGIT_MASK;
2015 int c = (error >> (EF_RIGHT_SHIFT ))&EF_DIGIT_MASK;
2016 char buf[10];
2017 sprintf(buf, "%c(%c%c)", TOCHAR(a, ds->par.id),
2018 TOCHAR(b, ds->par.id), TOCHAR(c, ds->par.id));
2019 draw_text(dr, tx + TILESIZE/2, ty + TILESIZE - TILESIZE/6,
2020 FONT_VARIABLE, TILESIZE/6, ALIGN_VCENTRE | ALIGN_HCENTRE,
2021 COL_ERROR, buf);
2022 }
2023 } else {
2024 int i, j, npencil;
2025 int pl, pr, pt, pb;
2026 float bestsize;
2027 int pw, ph, minph, pbest, fontsize;
2028
2029 /* Count the pencil marks required. */
2030 for (i = 1, npencil = 0; i <= w; i++)
2031 if (pencil & (1 << i))
2032 npencil++;
2033 if (npencil) {
2034
2035 minph = 2;
2036
2037 /*
2038 * Determine the bounding rectangle within which we're going
2039 * to put the pencil marks.
2040 */
2041 /* Start with the whole square */
2042 pl = tx + GRIDEXTRA;
2043 pr = pl + TILESIZE - GRIDEXTRA;
2044 pt = ty + GRIDEXTRA;
2045 pb = pt + TILESIZE - GRIDEXTRA;
2046
2047 /*
2048 * We arrange our pencil marks in a grid layout, with
2049 * the number of rows and columns adjusted to allow the
2050 * maximum font size.
2051 *
2052 * So now we work out what the grid size ought to be.
2053 */
2054 bestsize = 0.0;
2055 pbest = 0;
2056 /* Minimum */
2057 for (pw = 3; pw < max(npencil,4); pw++) {
2058 float fw, fh, fs;
2059
2060 ph = (npencil + pw - 1) / pw;
2061 ph = max(ph, minph);
2062 fw = (pr - pl) / (float)pw;
2063 fh = (pb - pt) / (float)ph;
2064 fs = min(fw, fh);
2065 if (fs > bestsize) {
2066 bestsize = fs;
2067 pbest = pw;
2068 }
2069 }
2070 assert(pbest > 0);
2071 pw = pbest;
2072 ph = (npencil + pw - 1) / pw;
2073 ph = max(ph, minph);
2074
2075 /*
2076 * Now we've got our grid dimensions, work out the pixel
2077 * size of a grid element, and round it to the nearest
2078 * pixel. (We don't want rounding errors to make the
2079 * grid look uneven at low pixel sizes.)
2080 */
2081 fontsize = min((pr - pl) / pw, (pb - pt) / ph);
2082
2083 /*
2084 * Centre the resulting figure in the square.
2085 */
2086 pl = tx + (TILESIZE - fontsize * pw) / 2;
2087 pt = ty + (TILESIZE - fontsize * ph) / 2;
2088
2089 /*
2090 * Now actually draw the pencil marks.
2091 */
2092 for (i = 1, j = 0; i <= w; i++)
2093 if (pencil & (1 << i)) {
2094 int dx = j % pw, dy = j / pw;
2095
2096 str[1] = '\0';
2097 str[0] = TOCHAR(i, ds->par.id);
2098 draw_text(dr, pl + fontsize * (2*dx+1) / 2,
2099 pt + fontsize * (2*dy+1) / 2,
2100 FONT_VARIABLE, fontsize,
2101 ALIGN_VCENTRE | ALIGN_HCENTRE, COL_PENCIL, str);
2102 j++;
2103 }
2104 }
2105 }
2106
2107 unclip(dr);
2108
2109 draw_update(dr, cx, cy, cw, ch);
2110}
2111
2112static void game_redraw(drawing *dr, game_drawstate *ds,
2113 const game_state *oldstate, const game_state *state,
2114 int dir, const game_ui *ui,
2115 float animtime, float flashtime)
2116{
2117 int w = state->par.w /*, a = w*w */;
2118 int x, y, i, j;
2119
2120 if (!ds->started) {
2121 /*
2122 * Big containing rectangle.
2123 */
2124 draw_rect(dr, COORD(0) - GRIDEXTRA, COORD(0) - GRIDEXTRA,
2125 w*TILESIZE+1+GRIDEXTRA*2, w*TILESIZE+1+GRIDEXTRA*2,
2126 COL_GRID);
2127
2128 draw_update(dr, 0, 0, SIZE(w), SIZE(w));
2129
2130 ds->started = true;
2131 }
2132
2133 check_errors(state, ds->errtmp);
2134
2135 /*
2136 * Construct a modified version of state->sequence which takes
2137 * into account an unfinished drag operation.
2138 */
2139 if (ui->drag) {
2140 x = ui->dragnum;
2141 y = ui->dragpos;
2142 } else {
2143 x = y = -1;
2144 }
2145 for (i = j = 0; i < w; i++) {
2146 if (i == y) {
2147 ds->sequence[i] = x;
2148 } else {
2149 if (state->sequence[j] == x)
2150 j++;
2151 ds->sequence[i] = state->sequence[j++];
2152 }
2153 }
2154
2155 /*
2156 * Draw the table legend.
2157 */
2158 for (x = 0; x < w; x++) {
2159 int sx = ds->sequence[x];
2160 long tile = (sx+1) | DF_LEGEND;
2161 if (ds->legend[x] != tile) {
2162 ds->legend[x] = tile;
2163 draw_tile(dr, ds, -1, x, tile, 0, 0);
2164 draw_tile(dr, ds, x, -1, tile, 0, 0);
2165 }
2166 }
2167
2168 for (y = 0; y < w; y++) {
2169 int sy = ds->sequence[y];
2170 for (x = 0; x < w; x++) {
2171 long tile = 0L, pencil = 0L, error;
2172 int sx = ds->sequence[x];
2173
2174 if (state->grid[sy*w+sx])
2175 tile = state->grid[sy*w+sx];
2176 else
2177 pencil = (long)state->pencil[sy*w+sx];
2178
2179 if (state->common->immutable[sy*w+sx])
2180 tile |= DF_IMMUTABLE;
2181
2182 if ((ui->drag == 5 && ui->dragnum == sy) ||
2183 (ui->drag == 6 && ui->dragnum == sx)) {
2184 tile |= DF_HIGHLIGHT;
2185 } else if (ui->hshow) {
2186 int i = abs(x - ui->ohx);
2187 bool highlight = false;
2188 if (ui->odn > 1) {
2189 /*
2190 * When a diagonal multifill selection is shown,
2191 * we show it in its original grid position
2192 * regardless of in-progress row/col drags. Moving
2193 * every square about would be horrible.
2194 */
2195 if (i >= 0 && i < ui->odn &&
2196 x == ui->ohx + i*ui->odx &&
2197 y == ui->ohy + i*ui->ody)
2198 highlight = true;
2199 } else {
2200 /*
2201 * For a single square, we move its highlight
2202 * around with the drag.
2203 */
2204 highlight = (ui->hx == sx && ui->hy == sy);
2205 }
2206 if (highlight)
2207 tile |= (ui->hpencil ? DF_HIGHLIGHT_PENCIL : DF_HIGHLIGHT);
2208 }
2209
2210 if (flashtime > 0 &&
2211 (flashtime <= FLASH_TIME/3 ||
2212 flashtime >= FLASH_TIME*2/3))
2213 tile |= DF_HIGHLIGHT; /* completion flash */
2214
2215 if (y <= 0 || state->dividers[ds->sequence[y-1]] == sy)
2216 tile |= DF_DIVIDER_TOP;
2217 if (y+1 >= w || state->dividers[sy] == ds->sequence[y+1])
2218 tile |= DF_DIVIDER_BOT;
2219 if (x <= 0 || state->dividers[ds->sequence[x-1]] == sx)
2220 tile |= DF_DIVIDER_LEFT;
2221 if (x+1 >= w || state->dividers[sx] == ds->sequence[x+1])
2222 tile |= DF_DIVIDER_RIGHT;
2223
2224 error = ds->errtmp[sy*w+sx];
2225
2226 if (ds->tiles[y*w+x] != tile ||
2227 ds->pencil[y*w+x] != pencil ||
2228 ds->errors[y*w+x] != error) {
2229 ds->tiles[y*w+x] = tile;
2230 ds->pencil[y*w+x] = pencil;
2231 ds->errors[y*w+x] = error;
2232 draw_tile(dr, ds, x, y, tile, pencil, error);
2233 }
2234 }
2235 }
2236}
2237
2238static float game_anim_length(const game_state *oldstate,
2239 const game_state *newstate, int dir, game_ui *ui)
2240{
2241 return 0.0F;
2242}
2243
2244static float game_flash_length(const game_state *oldstate,
2245 const game_state *newstate, int dir, game_ui *ui)
2246{
2247 if (!oldstate->completed && newstate->completed &&
2248 !oldstate->cheated && !newstate->cheated)
2249 return FLASH_TIME;
2250 return 0.0F;
2251}
2252
2253static void game_get_cursor_location(const game_ui *ui,
2254 const game_drawstate *ds,
2255 const game_state *state,
2256 const game_params *params,
2257 int *x, int *y, int *w, int *h)
2258{
2259}
2260
2261static int game_status(const game_state *state)
2262{
2263 return state->completed ? +1 : 0;
2264}
2265
2266static bool game_timing_state(const game_state *state, game_ui *ui)
2267{
2268 if (state->completed)
2269 return false;
2270 return true;
2271}
2272
2273static void game_print_size(const game_params *params, const game_ui *ui,
2274 float *x, float *y)
2275{
2276 int pw, ph;
2277
2278 /*
2279 * We use 9mm squares by default, like Solo.
2280 */
2281 game_compute_size(params, 900, ui, &pw, &ph);
2282 *x = pw / 100.0F;
2283 *y = ph / 100.0F;
2284}
2285
2286static void game_print(drawing *dr, const game_state *state, const game_ui *ui,
2287 int tilesize)
2288{
2289 int w = state->par.w;
2290 int ink = print_mono_colour(dr, 0);
2291 int x, y;
2292
2293 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2294 game_drawstate ads, *ds = &ads;
2295 game_set_size(dr, ds, NULL, tilesize);
2296
2297 /*
2298 * Border.
2299 */
2300 print_line_width(dr, 3 * TILESIZE / 40);
2301 draw_rect_outline(dr, BORDER + LEGEND, BORDER + LEGEND,
2302 w*TILESIZE, w*TILESIZE, ink);
2303
2304 /*
2305 * Legend on table.
2306 */
2307 for (x = 0; x < w; x++) {
2308 char str[2];
2309 str[1] = '\0';
2310 str[0] = TOCHAR(x+1, state->par.id);
2311 draw_text(dr, BORDER+LEGEND + x*TILESIZE + TILESIZE/2,
2312 BORDER + TILESIZE/2,
2313 FONT_VARIABLE, TILESIZE/2,
2314 ALIGN_VCENTRE | ALIGN_HCENTRE, ink, str);
2315 draw_text(dr, BORDER + TILESIZE/2,
2316 BORDER+LEGEND + x*TILESIZE + TILESIZE/2,
2317 FONT_VARIABLE, TILESIZE/2,
2318 ALIGN_VCENTRE | ALIGN_HCENTRE, ink, str);
2319 }
2320
2321 /*
2322 * Main grid.
2323 */
2324 for (x = 1; x < w; x++) {
2325 print_line_width(dr, TILESIZE / 40);
2326 draw_line(dr, BORDER+LEGEND+x*TILESIZE, BORDER+LEGEND,
2327 BORDER+LEGEND+x*TILESIZE, BORDER+LEGEND+w*TILESIZE, ink);
2328 }
2329 for (y = 1; y < w; y++) {
2330 print_line_width(dr, TILESIZE / 40);
2331 draw_line(dr, BORDER+LEGEND, BORDER+LEGEND+y*TILESIZE,
2332 BORDER+LEGEND+w*TILESIZE, BORDER+LEGEND+y*TILESIZE, ink);
2333 }
2334
2335 /*
2336 * Numbers.
2337 */
2338 for (y = 0; y < w; y++)
2339 for (x = 0; x < w; x++)
2340 if (state->grid[y*w+x]) {
2341 char str[2];
2342 str[1] = '\0';
2343 str[0] = TOCHAR(state->grid[y*w+x], state->par.id);
2344 draw_text(dr, BORDER+LEGEND + x*TILESIZE + TILESIZE/2,
2345 BORDER+LEGEND + y*TILESIZE + TILESIZE/2,
2346 FONT_VARIABLE, TILESIZE/2,
2347 ALIGN_VCENTRE | ALIGN_HCENTRE, ink, str);
2348 }
2349}
2350
2351#ifdef COMBINED
2352#define thegame group
2353#endif
2354
2355const struct game thegame = {
2356 "Group", NULL, NULL,
2357 default_params,
2358 game_fetch_preset, NULL,
2359 decode_params,
2360 encode_params,
2361 free_params,
2362 dup_params,
2363 true, game_configure, custom_params,
2364 validate_params,
2365 new_game_desc,
2366 validate_desc,
2367 new_game,
2368 dup_game,
2369 free_game,
2370 true, solve_game,
2371 true, game_can_format_as_text_now, game_text_format,
2372 get_prefs, set_prefs,
2373 new_ui,
2374 free_ui,
2375 NULL, /* encode_ui */
2376 NULL, /* decode_ui */
2377 NULL, /* game_request_keys */
2378 game_changed_state,
2379 current_key_label,
2380 interpret_move,
2381 execute_move,
2382 PREFERRED_TILESIZE, game_compute_size, game_set_size,
2383 game_colours,
2384 game_new_drawstate,
2385 game_free_drawstate,
2386 game_redraw,
2387 game_anim_length,
2388 game_flash_length,
2389 game_get_cursor_location,
2390 game_status,
2391 true, false, game_print_size, game_print,
2392 false, /* wants_statusbar */
2393 false, game_timing_state,
2394 REQUIRE_RBUTTON | REQUIRE_NUMPAD, /* flags */
2395};
2396
2397#ifdef STANDALONE_SOLVER
2398
2399#include <stdarg.h>
2400
2401int main(int argc, char **argv)
2402{
2403 game_params *p;
2404 game_state *s;
2405 char *id = NULL, *desc;
2406 const char *err;
2407 digit *grid;
2408 bool grade = false;
2409 int ret, diff;
2410 bool really_show_working = false;
2411
2412 while (--argc > 0) {
2413 char *p = *++argv;
2414 if (!strcmp(p, "-v")) {
2415 really_show_working = true;
2416 } else if (!strcmp(p, "-g")) {
2417 grade = true;
2418 } else if (*p == '-') {
2419 fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p);
2420 return 1;
2421 } else {
2422 id = p;
2423 }
2424 }
2425
2426 if (!id) {
2427 fprintf(stderr, "usage: %s [-g | -v] <game_id>\n", argv[0]);
2428 return 1;
2429 }
2430
2431 desc = strchr(id, ':');
2432 if (!desc) {
2433 fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]);
2434 return 1;
2435 }
2436 *desc++ = '\0';
2437
2438 p = default_params();
2439 decode_params(p, id);
2440 err = validate_desc(p, desc);
2441 if (err) {
2442 fprintf(stderr, "%s: %s\n", argv[0], err);
2443 return 1;
2444 }
2445 s = new_game(NULL, p, desc);
2446
2447 grid = snewn(p->w * p->w, digit);
2448
2449 /*
2450 * When solving a Normal puzzle, we don't want to bother the
2451 * user with Hard-level deductions. For this reason, we grade
2452 * the puzzle internally before doing anything else.
2453 */
2454 ret = -1; /* placate optimiser */
2455 solver_show_working = 0;
2456 for (diff = 0; diff < DIFFCOUNT; diff++) {
2457 memcpy(grid, s->grid, p->w * p->w);
2458 ret = solver(&s->par, grid, diff);
2459 if (ret <= diff)
2460 break;
2461 }
2462
2463 if (diff == DIFFCOUNT) {
2464 if (really_show_working) {
2465 solver_show_working = true;
2466 memcpy(grid, s->grid, p->w * p->w);
2467 ret = solver(&s->par, grid, DIFFCOUNT - 1);
2468 }
2469 if (grade)
2470 printf("Difficulty rating: ambiguous\n");
2471 else
2472 printf("Unable to find a unique solution\n");
2473 } else {
2474 if (grade) {
2475 if (ret == diff_impossible)
2476 printf("Difficulty rating: impossible (no solution exists)\n");
2477 else
2478 printf("Difficulty rating: %s\n", group_diffnames[ret]);
2479 } else {
2480 solver_show_working = really_show_working;
2481 memcpy(grid, s->grid, p->w * p->w);
2482 ret = solver(&s->par, grid, diff);
2483 if (ret != diff)
2484 printf("Puzzle is inconsistent\n");
2485 else {
2486 memcpy(s->grid, grid, p->w * p->w);
2487 fputs(game_text_format(s), stdout);
2488 }
2489 }
2490 }
2491
2492 return 0;
2493}
2494
2495#endif
2496
2497/* vim: set shiftwidth=4 tabstop=8: */
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-19 08:20:12 +0000