X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/puzzles/blobdiff_plain/5d744557ee36c9408bacad0974c6b16b42de8d94..63ed24043747435fc5b67339248426ca236e0739:/solo.c diff --git a/solo.c b/solo.c index d564ad2..cbf00c5 100644 --- a/solo.c +++ b/solo.c @@ -91,7 +91,7 @@ #ifdef STANDALONE_SOLVER #include -int solver_show_working; +int solver_show_working, solver_recurse_depth; #endif #include "puzzles.h" @@ -110,16 +110,19 @@ typedef unsigned char digit; #define PREFERRED_TILE_SIZE 32 #define TILE_SIZE (ds->tilesize) #define BORDER (TILE_SIZE / 2) +#define GRIDEXTRA (TILE_SIZE / 32) #define FLASH_TIME 0.4F -enum { SYMM_NONE, SYMM_ROT2, SYMM_ROT4, SYMM_REF4 }; +enum { SYMM_NONE, SYMM_ROT2, SYMM_ROT4, SYMM_REF2, SYMM_REF2D, SYMM_REF4, + SYMM_REF4D, SYMM_REF8 }; -enum { DIFF_BLOCK, DIFF_SIMPLE, DIFF_INTERSECT, - DIFF_SET, DIFF_RECURSIVE, DIFF_AMBIGUOUS, DIFF_IMPOSSIBLE }; +enum { DIFF_BLOCK, DIFF_SIMPLE, DIFF_INTERSECT, DIFF_SET, DIFF_EXTREME, + DIFF_RECURSIVE, DIFF_AMBIGUOUS, DIFF_IMPOSSIBLE }; enum { COL_BACKGROUND, + COL_XDIAGONALS, COL_GRID, COL_CLUE, COL_USER, @@ -130,11 +133,65 @@ enum { }; struct game_params { + /* + * For a square puzzle, `c' and `r' indicate the puzzle + * parameters as described above. + * + * A jigsaw-style puzzle is indicated by r==1, in which case c + * can be whatever it likes (there is no constraint on + * compositeness - a 7x7 jigsaw sudoku makes perfect sense). + */ int c, r, symm, diff; + int xtype; /* require all digits in X-diagonals */ }; -struct game_state { +struct block_structure { + int refcount; + + /* + * For text formatting, we do need c and r here. + */ int c, r; + + /* + * For any square index, whichblock[i] gives its block index. + * + * For 0 <= b,i < cr, blocks[b][i] gives the index of the ith + * square in block b. + * + * whichblock and blocks are each dynamically allocated in + * their own right, but the subarrays in blocks are appended + * to the whichblock array, so shouldn't be freed + * individually. + */ + int *whichblock, **blocks; + +#ifdef STANDALONE_SOLVER + /* + * Textual descriptions of each block. For normal Sudoku these + * are of the form "(1,3)"; for jigsaw they are "starting at + * (5,7)". So the sensible usage in both cases is to say + * "elimination within block %s" with one of these strings. + * + * Only blocknames itself needs individually freeing; it's all + * one block. + */ + char **blocknames; +#endif +}; + +struct game_state { + /* + * For historical reasons, I use `cr' to denote the overall + * width/height of the puzzle. It was a natural notation when + * all puzzles were divided into blocks in a grid, but doesn't + * really make much sense given jigsaw puzzles. However, the + * obvious `n' is heavily used in the solver to describe the + * index of a number being placed, so `cr' will have to stay. + */ + int cr; + struct block_structure *blocks; + int xtype; digit *grid; unsigned char *pencil; /* c*r*c*r elements */ unsigned char *immutable; /* marks which digits are clues */ @@ -146,6 +203,7 @@ static game_params *default_params(void) game_params *ret = snew(game_params); ret->c = ret->r = 3; + ret->xtype = FALSE; ret->symm = SYMM_ROT2; /* a plausible default */ ret->diff = DIFF_BLOCK; /* so is this */ @@ -170,16 +228,22 @@ static int game_fetch_preset(int i, char **name, game_params **params) char *title; game_params params; } presets[] = { - { "2x2 Trivial", { 2, 2, SYMM_ROT2, DIFF_BLOCK } }, - { "2x3 Basic", { 2, 3, SYMM_ROT2, DIFF_SIMPLE } }, - { "3x3 Trivial", { 3, 3, SYMM_ROT2, DIFF_BLOCK } }, - { "3x3 Basic", { 3, 3, SYMM_ROT2, DIFF_SIMPLE } }, - { "3x3 Intermediate", { 3, 3, SYMM_ROT2, DIFF_INTERSECT } }, - { "3x3 Advanced", { 3, 3, SYMM_ROT2, DIFF_SET } }, - { "3x3 Unreasonable", { 3, 3, SYMM_ROT2, DIFF_RECURSIVE } }, + { "2x2 Trivial", { 2, 2, SYMM_ROT2, DIFF_BLOCK, FALSE } }, + { "2x3 Basic", { 2, 3, SYMM_ROT2, DIFF_SIMPLE, FALSE } }, + { "3x3 Trivial", { 3, 3, SYMM_ROT2, DIFF_BLOCK, FALSE } }, + { "3x3 Basic", { 3, 3, SYMM_ROT2, DIFF_SIMPLE, FALSE } }, + { "3x3 Basic X", { 3, 3, SYMM_ROT2, DIFF_SIMPLE, TRUE } }, + { "3x3 Intermediate", { 3, 3, SYMM_ROT2, DIFF_INTERSECT, FALSE } }, + { "3x3 Advanced", { 3, 3, SYMM_ROT2, DIFF_SET, FALSE } }, + { "3x3 Advanced X", { 3, 3, SYMM_ROT2, DIFF_SET, TRUE } }, + { "3x3 Extreme", { 3, 3, SYMM_ROT2, DIFF_EXTREME, FALSE } }, + { "3x3 Unreasonable", { 3, 3, SYMM_ROT2, DIFF_RECURSIVE, FALSE } }, + { "9 Jigsaw Basic", { 9, 1, SYMM_ROT2, DIFF_SIMPLE, FALSE } }, + { "9 Jigsaw Basic X", { 9, 1, SYMM_ROT2, DIFF_SIMPLE, TRUE } }, + { "9 Jigsaw Advanced", { 9, 1, SYMM_ROT2, DIFF_SET, FALSE } }, #ifndef SLOW_SYSTEM - { "3x4 Basic", { 3, 4, SYMM_ROT2, DIFF_SIMPLE } }, - { "4x4 Basic", { 4, 4, SYMM_ROT2, DIFF_SIMPLE } }, + { "3x4 Basic", { 3, 4, SYMM_ROT2, DIFF_SIMPLE, FALSE } }, + { "4x4 Basic", { 4, 4, SYMM_ROT2, DIFF_SIMPLE, FALSE } }, #endif }; @@ -194,21 +258,43 @@ static int game_fetch_preset(int i, char **name, game_params **params) static void decode_params(game_params *ret, char const *string) { + int seen_r = FALSE; + ret->c = ret->r = atoi(string); + ret->xtype = FALSE; while (*string && isdigit((unsigned char)*string)) string++; if (*string == 'x') { string++; ret->r = atoi(string); + seen_r = TRUE; while (*string && isdigit((unsigned char)*string)) string++; } while (*string) { - if (*string == 'r' || *string == 'm' || *string == 'a') { - int sn, sc; + if (*string == 'j') { + string++; + if (seen_r) + ret->c *= ret->r; + ret->r = 1; + } else if (*string == 'x') { + string++; + ret->xtype = TRUE; + } else if (*string == 'r' || *string == 'm' || *string == 'a') { + int sn, sc, sd; sc = *string++; + if (sc == 'm' && *string == 'd') { + sd = TRUE; + string++; + } else { + sd = FALSE; + } sn = atoi(string); while (*string && isdigit((unsigned char)*string)) string++; + if (sc == 'm' && sn == 8) + ret->symm = SYMM_REF8; if (sc == 'm' && sn == 4) - ret->symm = SYMM_REF4; + ret->symm = sd ? SYMM_REF4D : SYMM_REF4; + if (sc == 'm' && sn == 2) + ret->symm = sd ? SYMM_REF2D : SYMM_REF2; if (sc == 'r' && sn == 4) ret->symm = SYMM_ROT4; if (sc == 'r' && sn == 2) @@ -225,6 +311,8 @@ static void decode_params(game_params *ret, char const *string) string++, ret->diff = DIFF_INTERSECT; else if (*string == 'a') /* advanced */ string++, ret->diff = DIFF_SET; + else if (*string == 'e') /* extreme */ + string++, ret->diff = DIFF_EXTREME; else if (*string == 'u') /* unreasonable */ string++, ret->diff = DIFF_RECURSIVE; } else @@ -236,10 +324,20 @@ static char *encode_params(game_params *params, int full) { char str[80]; - sprintf(str, "%dx%d", params->c, params->r); + if (params->r > 1) + sprintf(str, "%dx%d", params->c, params->r); + else + sprintf(str, "%dj", params->c); + if (params->xtype) + strcat(str, "x"); + if (full) { switch (params->symm) { + case SYMM_REF8: strcat(str, "m8"); break; case SYMM_REF4: strcat(str, "m4"); break; + case SYMM_REF4D: strcat(str, "md4"); break; + case SYMM_REF2: strcat(str, "m2"); break; + case SYMM_REF2D: strcat(str, "md2"); break; case SYMM_ROT4: strcat(str, "r4"); break; /* case SYMM_ROT2: strcat(str, "r2"); break; [default] */ case SYMM_NONE: strcat(str, "a"); break; @@ -249,6 +347,7 @@ static char *encode_params(game_params *params, int full) case DIFF_SIMPLE: strcat(str, "db"); break; case DIFF_INTERSECT: strcat(str, "di"); break; case DIFF_SET: strcat(str, "da"); break; + case DIFF_EXTREME: strcat(str, "de"); break; case DIFF_RECURSIVE: strcat(str, "du"); break; } } @@ -260,7 +359,7 @@ static config_item *game_configure(game_params *params) config_item *ret; char buf[80]; - ret = snewn(5, config_item); + ret = snewn(7, config_item); ret[0].name = "Columns of sub-blocks"; ret[0].type = C_STRING; @@ -274,20 +373,32 @@ static config_item *game_configure(game_params *params) ret[1].sval = dupstr(buf); ret[1].ival = 0; - ret[2].name = "Symmetry"; - ret[2].type = C_CHOICES; - ret[2].sval = ":None:2-way rotation:4-way rotation:4-way mirror"; - ret[2].ival = params->symm; - - ret[3].name = "Difficulty"; - ret[3].type = C_CHOICES; - ret[3].sval = ":Trivial:Basic:Intermediate:Advanced:Unreasonable"; - ret[3].ival = params->diff; - - ret[4].name = NULL; - ret[4].type = C_END; - ret[4].sval = NULL; - ret[4].ival = 0; + ret[2].name = "\"X\" (require every number in each main diagonal)"; + ret[2].type = C_BOOLEAN; + ret[2].sval = NULL; + ret[2].ival = params->xtype; + + ret[3].name = "Jigsaw (irregularly shaped sub-blocks)"; + ret[3].type = C_BOOLEAN; + ret[3].sval = NULL; + ret[3].ival = (params->r == 1); + + ret[4].name = "Symmetry"; + ret[4].type = C_CHOICES; + ret[4].sval = ":None:2-way rotation:4-way rotation:2-way mirror:" + "2-way diagonal mirror:4-way mirror:4-way diagonal mirror:" + "8-way mirror"; + ret[4].ival = params->symm; + + ret[5].name = "Difficulty"; + ret[5].type = C_CHOICES; + ret[5].sval = ":Trivial:Basic:Intermediate:Advanced:Extreme:Unreasonable"; + ret[5].ival = params->diff; + + ret[6].name = NULL; + ret[6].type = C_END; + ret[6].sval = NULL; + ret[6].ival = 0; return ret; } @@ -298,292 +409,37 @@ static game_params *custom_params(config_item *cfg) ret->c = atoi(cfg[0].sval); ret->r = atoi(cfg[1].sval); - ret->symm = cfg[2].ival; - ret->diff = cfg[3].ival; + ret->xtype = cfg[2].ival; + if (cfg[3].ival) { + ret->c *= ret->r; + ret->r = 1; + } + ret->symm = cfg[4].ival; + ret->diff = cfg[5].ival; return ret; } -static char *validate_params(game_params *params) +static char *validate_params(game_params *params, int full) { - if (params->c < 2 || params->r < 2) + if (params->c < 2) return "Both dimensions must be at least 2"; if (params->c > ORDER_MAX || params->r > ORDER_MAX) return "Dimensions greater than "STR(ORDER_MAX)" are not supported"; + if ((params->c * params->r) > 35) + return "Unable to support more than 35 distinct symbols in a puzzle"; return NULL; } /* ---------------------------------------------------------------------- - * Full recursive Solo solver. - * - * The algorithm for this solver is shamelessly copied from a - * Python solver written by Andrew Wilkinson (which is GPLed, but - * I've reused only ideas and no code). It mostly just does the - * obvious recursive thing: pick an empty square, put one of the - * possible digits in it, recurse until all squares are filled, - * backtrack and change some choices if necessary. - * - * The clever bit is that every time it chooses which square to - * fill in next, it does so by counting the number of _possible_ - * numbers that can go in each square, and it prioritises so that - * it picks a square with the _lowest_ number of possibilities. The - * idea is that filling in lots of the obvious bits (particularly - * any squares with only one possibility) will cut down on the list - * of possibilities for other squares and hence reduce the enormous - * search space as much as possible as early as possible. - * - * In practice the algorithm appeared to work very well; run on - * sample problems from the Times it completed in well under a - * second on my G5 even when written in Python, and given an empty - * grid (so that in principle it would enumerate _all_ solved - * grids!) it found the first valid solution just as quickly. So - * with a bit more randomisation I see no reason not to use this as - * my grid generator. - */ - -/* - * Internal data structure used in solver to keep track of - * progress. - */ -struct rsolve_coord { int x, y, r; }; -struct rsolve_usage { - int c, r, cr; /* cr == c*r */ - /* grid is a copy of the input grid, modified as we go along */ - digit *grid; - /* row[y*cr+n-1] TRUE if digit n has been placed in row y */ - unsigned char *row; - /* col[x*cr+n-1] TRUE if digit n has been placed in row x */ - unsigned char *col; - /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */ - unsigned char *blk; - /* This lists all the empty spaces remaining in the grid. */ - struct rsolve_coord *spaces; - int nspaces; - /* If we need randomisation in the solve, this is our random state. */ - random_state *rs; - /* Number of solutions so far found, and maximum number we care about. */ - int solns, maxsolns; -}; - -/* - * The real recursive step in the solving function. - */ -static void rsolve_real(struct rsolve_usage *usage, digit *grid) -{ - int c = usage->c, r = usage->r, cr = usage->cr; - int i, j, n, sx, sy, bestm, bestr; - int *digits; - - /* - * Firstly, check for completion! If there are no spaces left - * in the grid, we have a solution. - */ - if (usage->nspaces == 0) { - if (!usage->solns) { - /* - * This is our first solution, so fill in the output grid. - */ - memcpy(grid, usage->grid, cr * cr); - } - usage->solns++; - return; - } - - /* - * Otherwise, there must be at least one space. Find the most - * constrained space, using the `r' field as a tie-breaker. - */ - bestm = cr+1; /* so that any space will beat it */ - bestr = 0; - i = sx = sy = -1; - for (j = 0; j < usage->nspaces; j++) { - int x = usage->spaces[j].x, y = usage->spaces[j].y; - int m; - - /* - * Find the number of digits that could go in this space. - */ - m = 0; - for (n = 0; n < cr; n++) - if (!usage->row[y*cr+n] && !usage->col[x*cr+n] && - !usage->blk[((y/c)*c+(x/r))*cr+n]) - m++; - - if (m < bestm || (m == bestm && usage->spaces[j].r < bestr)) { - bestm = m; - bestr = usage->spaces[j].r; - sx = x; - sy = y; - i = j; - } - } - - /* - * Swap that square into the final place in the spaces array, - * so that decrementing nspaces will remove it from the list. - */ - if (i != usage->nspaces-1) { - struct rsolve_coord t; - t = usage->spaces[usage->nspaces-1]; - usage->spaces[usage->nspaces-1] = usage->spaces[i]; - usage->spaces[i] = t; - } - - /* - * Now we've decided which square to start our recursion at, - * simply go through all possible values, shuffling them - * randomly first if necessary. - */ - digits = snewn(bestm, int); - j = 0; - for (n = 0; n < cr; n++) - if (!usage->row[sy*cr+n] && !usage->col[sx*cr+n] && - !usage->blk[((sy/c)*c+(sx/r))*cr+n]) { - digits[j++] = n+1; - } - - if (usage->rs) { - /* shuffle */ - for (i = j; i > 1; i--) { - int p = random_upto(usage->rs, i); - if (p != i-1) { - int t = digits[p]; - digits[p] = digits[i-1]; - digits[i-1] = t; - } - } - } - - /* And finally, go through the digit list and actually recurse. */ - for (i = 0; i < j; i++) { - n = digits[i]; - - /* Update the usage structure to reflect the placing of this digit. */ - usage->row[sy*cr+n-1] = usage->col[sx*cr+n-1] = - usage->blk[((sy/c)*c+(sx/r))*cr+n-1] = TRUE; - usage->grid[sy*cr+sx] = n; - usage->nspaces--; - - /* Call the solver recursively. */ - rsolve_real(usage, grid); - - /* - * If we have seen as many solutions as we need, terminate - * all processing immediately. - */ - if (usage->solns >= usage->maxsolns) - break; - - /* Revert the usage structure. */ - usage->row[sy*cr+n-1] = usage->col[sx*cr+n-1] = - usage->blk[((sy/c)*c+(sx/r))*cr+n-1] = FALSE; - usage->grid[sy*cr+sx] = 0; - usage->nspaces++; - } - - sfree(digits); -} - -/* - * Entry point to solver. You give it dimensions and a starting - * grid, which is simply an array of N^4 digits. In that array, 0 - * means an empty square, and 1..N mean a clue square. - * - * Return value is the number of solutions found; searching will - * stop after the provided `max'. (Thus, you can pass max==1 to - * indicate that you only care about finding _one_ solution, or - * max==2 to indicate that you want to know the difference between - * a unique and non-unique solution.) The input parameter `grid' is - * also filled in with the _first_ (or only) solution found by the - * solver. - */ -static int rsolve(int c, int r, digit *grid, random_state *rs, int max) -{ - struct rsolve_usage *usage; - int x, y, cr = c*r; - int ret; - - /* - * Create an rsolve_usage structure. - */ - usage = snew(struct rsolve_usage); - - usage->c = c; - usage->r = r; - usage->cr = cr; - - usage->grid = snewn(cr * cr, digit); - memcpy(usage->grid, grid, cr * cr); - - usage->row = snewn(cr * cr, unsigned char); - usage->col = snewn(cr * cr, unsigned char); - usage->blk = snewn(cr * cr, unsigned char); - memset(usage->row, FALSE, cr * cr); - memset(usage->col, FALSE, cr * cr); - memset(usage->blk, FALSE, cr * cr); - - usage->spaces = snewn(cr * cr, struct rsolve_coord); - usage->nspaces = 0; - - usage->solns = 0; - usage->maxsolns = max; - - usage->rs = rs; - - /* - * Now fill it in with data from the input grid. - */ - for (y = 0; y < cr; y++) { - for (x = 0; x < cr; x++) { - int v = grid[y*cr+x]; - if (v == 0) { - usage->spaces[usage->nspaces].x = x; - usage->spaces[usage->nspaces].y = y; - if (rs) - usage->spaces[usage->nspaces].r = random_bits(rs, 31); - else - usage->spaces[usage->nspaces].r = usage->nspaces; - usage->nspaces++; - } else { - usage->row[y*cr+v-1] = TRUE; - usage->col[x*cr+v-1] = TRUE; - usage->blk[((y/c)*c+(x/r))*cr+v-1] = TRUE; - } - } - } - - /* - * Run the real recursive solving function. - */ - rsolve_real(usage, grid); - ret = usage->solns; - - /* - * Clean up the usage structure now we have our answer. - */ - sfree(usage->spaces); - sfree(usage->blk); - sfree(usage->col); - sfree(usage->row); - sfree(usage->grid); - sfree(usage); - - /* - * And return. - */ - return ret; -} - -/* ---------------------------------------------------------------------- - * End of recursive solver code. - */ - -/* ---------------------------------------------------------------------- - * Less capable non-recursive solver. This one is used to check - * solubility of a grid as we gradually remove numbers from it: by - * verifying a grid using this solver we can ensure it isn't _too_ - * hard (e.g. does not actually require guessing and backtracking). - * + * Solver. + * + * This solver is used for two purposes: + * + to check solubility of a grid as we gradually remove numbers + * from it + * + to solve an externally generated puzzle when the user selects + * `Solve'. + * * It supports a variety of specific modes of reasoning. By * enabling or disabling subsets of these modes we can arrange a * range of difficulty levels. @@ -629,33 +485,25 @@ static int rsolve(int c, int r, digit *grid, random_state *rs, int max) * places, found by taking the _complement_ of the union of * the numbers' possible positions (or the spaces' possible * contents). - */ - -/* - * Within this solver, I'm going to transform all y-coordinates by - * inverting the significance of the block number and the position - * within the block. That is, we will start with the top row of - * each block in order, then the second row of each block in order, - * etc. * - * This transformation has the enormous advantage that it means - * every row, column _and_ block is described by an arithmetic - * progression of coordinates within the cubic array, so that I can - * use the same very simple function to do blockwise, row-wise and - * column-wise elimination. + * - Forcing chains (see comment for solver_forcing().) + * + * - Recursion. If all else fails, we pick one of the currently + * most constrained empty squares and take a random guess at its + * contents, then continue solving on that basis and see if we + * get any further. */ -#define YTRANS(y) (((y)%c)*r+(y)/c) -#define YUNTRANS(y) (((y)%r)*c+(y)/r) -struct nsolve_usage { - int c, r, cr; +struct solver_usage { + int cr; + struct block_structure *blocks; /* * We set up a cubic array, indexed by x, y and digit; each * element of this array is TRUE or FALSE according to whether * or not that digit _could_ in principle go in that position. * - * The way to index this array is cube[(x*cr+y)*cr+n-1]. - * y-coordinates in here are transformed. + * The way to index this array is cube[(y*cr+x)*cr+n-1]; there + * are macros below to help with this. */ unsigned char *cube; /* @@ -672,21 +520,31 @@ struct nsolve_usage { unsigned char *row; /* col[x*cr+n-1] TRUE if digit n has been placed in row x */ unsigned char *col; - /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */ + /* blk[i*cr+n-1] TRUE if digit n has been placed in block i */ unsigned char *blk; + /* diag[i*cr+n-1] TRUE if digit n has been placed in diagonal i */ + unsigned char *diag; /* diag 0 is \, 1 is / */ }; -#define cubepos(x,y,n) (((x)*usage->cr+(y))*usage->cr+(n)-1) +#define cubepos2(xy,n) ((xy)*usage->cr+(n)-1) +#define cubepos(x,y,n) cubepos2((y)*usage->cr+(x),n) #define cube(x,y,n) (usage->cube[cubepos(x,y,n)]) +#define cube2(xy,n) (usage->cube[cubepos2(xy,n)]) + +#define ondiag0(xy) ((xy) % (cr+1) == 0) +#define ondiag1(xy) ((xy) % (cr-1) == 0 && (xy) > 0 && (xy) < cr*cr-1) +#define diag0(i) ((i) * (cr+1)) +#define diag1(i) ((i+1) * (cr-1)) /* * Function called when we are certain that a particular square has * a particular number in it. The y-coordinate passed in here is * transformed. */ -static void nsolve_place(struct nsolve_usage *usage, int x, int y, int n) +static void solver_place(struct solver_usage *usage, int x, int y, int n) { - int c = usage->c, r = usage->r, cr = usage->cr; - int i, j, bx, by; + int cr = usage->cr; + int sqindex = y*cr+x; + int i, bi; assert(cube(x,y,n)); @@ -714,33 +572,48 @@ static void nsolve_place(struct nsolve_usage *usage, int x, int y, int n) /* * Rule out this number in all other positions in the block. */ - bx = (x/r)*r; - by = y % r; - for (i = 0; i < r; i++) - for (j = 0; j < c; j++) - if (bx+i != x || by+j*r != y) - cube(bx+i,by+j*r,n) = FALSE; + bi = usage->blocks->whichblock[sqindex]; + for (i = 0; i < cr; i++) { + int bp = usage->blocks->blocks[bi][i]; + if (bp != sqindex) + cube2(bp,n) = FALSE; + } /* * Enter the number in the result grid. */ - usage->grid[YUNTRANS(y)*cr+x] = n; + usage->grid[sqindex] = n; /* * Cross out this number from the list of numbers left to place * in its row, its column and its block. */ usage->row[y*cr+n-1] = usage->col[x*cr+n-1] = - usage->blk[((y%r)*c+(x/r))*cr+n-1] = TRUE; + usage->blk[bi*cr+n-1] = TRUE; + + if (usage->diag) { + if (ondiag0(sqindex)) { + for (i = 0; i < cr; i++) + if (diag0(i) != sqindex) + cube2(diag0(i),n) = FALSE; + usage->diag[n-1] = TRUE; + } + if (ondiag1(sqindex)) { + for (i = 0; i < cr; i++) + if (diag1(i) != sqindex) + cube2(diag1(i),n) = FALSE; + usage->diag[cr+n-1] = TRUE; + } + } } -static int nsolve_elim(struct nsolve_usage *usage, int start, int step +static int solver_elim(struct solver_usage *usage, int *indices #ifdef STANDALONE_SOLVER , char *fmt, ... #endif ) { - int c = usage->c, r = usage->r, cr = c*r; + int cr = usage->cr; int fpos, m, i; /* @@ -750,8 +623,8 @@ static int nsolve_elim(struct nsolve_usage *usage, int start, int step m = 0; fpos = -1; for (i = 0; i < cr; i++) - if (usage->cube[start+i*step]) { - fpos = start+i*step; + if (usage->cube[indices[i]]) { + fpos = indices[i]; m++; } @@ -760,69 +633,88 @@ static int nsolve_elim(struct nsolve_usage *usage, int start, int step assert(fpos >= 0); n = 1 + fpos % cr; - y = fpos / cr; - x = y / cr; - y %= cr; + x = fpos / cr; + y = x / cr; + x %= cr; - if (!usage->grid[YUNTRANS(y)*cr+x]) { + if (!usage->grid[y*cr+x]) { #ifdef STANDALONE_SOLVER if (solver_show_working) { va_list ap; + printf("%*s", solver_recurse_depth*4, ""); va_start(ap, fmt); vprintf(fmt, ap); va_end(ap); - printf(":\n placing %d at (%d,%d)\n", - n, 1+x, 1+YUNTRANS(y)); + printf(":\n%*s placing %d at (%d,%d)\n", + solver_recurse_depth*4, "", n, 1+x, 1+y); } #endif - nsolve_place(usage, x, y, n); - return TRUE; + solver_place(usage, x, y, n); + return +1; } + } else if (m == 0) { +#ifdef STANDALONE_SOLVER + if (solver_show_working) { + va_list ap; + printf("%*s", solver_recurse_depth*4, ""); + va_start(ap, fmt); + vprintf(fmt, ap); + va_end(ap); + printf(":\n%*s no possibilities available\n", + solver_recurse_depth*4, ""); + } +#endif + return -1; } - return FALSE; + return 0; } -static int nsolve_intersect(struct nsolve_usage *usage, - int start1, int step1, int start2, int step2 +static int solver_intersect(struct solver_usage *usage, + int *indices1, int *indices2 #ifdef STANDALONE_SOLVER , char *fmt, ... #endif ) { - int c = usage->c, r = usage->r, cr = c*r; - int ret, i; + int cr = usage->cr; + int ret, i, j; /* * Loop over the first domain and see if there's any set bit * not also in the second. */ - for (i = 0; i < cr; i++) { - int p = start1+i*step1; - if (usage->cube[p] && - !(p >= start2 && p < start2+cr*step2 && - (p - start2) % step2 == 0)) - return FALSE; /* there is, so we can't deduce */ + for (i = j = 0; i < cr; i++) { + int p = indices1[i]; + while (j < cr && indices2[j] < p) + j++; + if (usage->cube[p]) { + if (j < cr && indices2[j] == p) + continue; /* both domains contain this index */ + else + return 0; /* there is, so we can't deduce */ + } } /* * We have determined that all set bits in the first domain are * within its overlap with the second. So loop over the second * domain and remove all set bits that aren't also in that - * overlap; return TRUE iff we actually _did_ anything. + * overlap; return +1 iff we actually _did_ anything. */ - ret = FALSE; - for (i = 0; i < cr; i++) { - int p = start2+i*step2; - if (usage->cube[p] && - !(p >= start1 && p < start1+cr*step1 && (p - start1) % step1 == 0)) - { + ret = 0; + for (i = j = 0; i < cr; i++) { + int p = indices2[i]; + while (j < cr && indices1[j] < p) + j++; + if (usage->cube[p] && (j >= cr || indices1[j] != p)) { #ifdef STANDALONE_SOLVER if (solver_show_working) { int px, py, pn; if (!ret) { va_list ap; + printf("%*s", solver_recurse_depth*4, ""); va_start(ap, fmt); vprintf(fmt, ap); va_end(ap); @@ -830,15 +722,15 @@ static int nsolve_intersect(struct nsolve_usage *usage, } pn = 1 + p % cr; - py = p / cr; - px = py / cr; - py %= cr; + px = p / cr; + py = px / cr; + px %= cr; - printf(" ruling out %d at (%d,%d)\n", - pn, 1+px, 1+YUNTRANS(py)); + printf("%*s ruling out %d at (%d,%d)\n", + solver_recurse_depth*4, "", pn, 1+px, 1+py); } #endif - ret = TRUE; /* we did something */ + ret = +1; /* we did something */ usage->cube[p] = 0; } } @@ -846,19 +738,24 @@ static int nsolve_intersect(struct nsolve_usage *usage, return ret; } -struct nsolve_scratch { +struct solver_scratch { unsigned char *grid, *rowidx, *colidx, *set; + int *neighbours, *bfsqueue; + int *indexlist, *indexlist2; +#ifdef STANDALONE_SOLVER + int *bfsprev; +#endif }; -static int nsolve_set(struct nsolve_usage *usage, - struct nsolve_scratch *scratch, - int start, int step1, int step2 +static int solver_set(struct solver_usage *usage, + struct solver_scratch *scratch, + int *indices #ifdef STANDALONE_SOLVER , char *fmt, ... #endif ) { - int c = usage->c, r = usage->r, cr = c*r; + int cr = usage->cr; int i, j, n, count; unsigned char *grid = scratch->grid; unsigned char *rowidx = scratch->rowidx; @@ -876,16 +773,17 @@ static int nsolve_set(struct nsolve_usage *usage, for (i = 0; i < cr; i++) { int count = 0, first = -1; for (j = 0; j < cr; j++) - if (usage->cube[start+i*step1+j*step2]) + if (usage->cube[indices[i*cr+j]]) first = j, count++; - if (count == 0) { - /* - * This condition actually marks a completely insoluble - * (i.e. internally inconsistent) puzzle. We return and - * report no progress made. - */ - return FALSE; - } + + /* + * If count == 0, then there's a row with no 1s at all and + * the puzzle is internally inconsistent. However, we ought + * to have caught this already during the simpler reasoning + * methods, so we can safely fail an assertion if we reach + * this point here. + */ + assert(count > 0); if (count == 1) rowidx[i] = colidx[first] = FALSE; } @@ -908,7 +806,7 @@ static int nsolve_set(struct nsolve_usage *usage, */ for (i = 0; i < n; i++) for (j = 0; j < n; j++) - grid[i*cr+j] = usage->cube[start+rowidx[i]*step1+colidx[j]*step2]; + grid[i*cr+j] = usage->cube[indices[rowidx[i]*cr+colidx[j]]]; /* * Having done that, we now have a matrix in which every row @@ -951,7 +849,22 @@ static int nsolve_set(struct nsolve_usage *usage, * indicates a faulty deduction before this point or * even a bogus clue. */ - assert(rows <= n - count); + if (rows > n - count) { +#ifdef STANDALONE_SOLVER + if (solver_show_working) { + va_list ap; + printf("%*s", solver_recurse_depth*4, + ""); + va_start(ap, fmt); + vprintf(fmt, ap); + va_end(ap); + printf(":\n%*s contradiction reached\n", + solver_recurse_depth*4, ""); + } +#endif + return -1; + } + if (rows >= n - count) { int progress = FALSE; @@ -959,8 +872,8 @@ static int nsolve_set(struct nsolve_usage *usage, * We've got one! Now, for each row which _doesn't_ * satisfy the criterion, eliminate all its set * bits in the positions _not_ listed in `set'. - * Return TRUE (meaning progress has been made) if - * we successfully eliminated anything at all. + * Return +1 (meaning progress has been made) if we + * successfully eliminated anything at all. * * This involves referring back through * rowidx/colidx in order to work out which actual @@ -976,14 +889,15 @@ static int nsolve_set(struct nsolve_usage *usage, if (!ok) { for (j = 0; j < n; j++) if (!set[j] && grid[i*cr+j]) { - int fpos = (start+rowidx[i]*step1+ - colidx[j]*step2); + int fpos = indices[rowidx[i]*cr+colidx[j]]; #ifdef STANDALONE_SOLVER if (solver_show_working) { int px, py, pn; - + if (!progress) { va_list ap; + printf("%*s", solver_recurse_depth*4, + ""); va_start(ap, fmt); vprintf(fmt, ap); va_end(ap); @@ -991,12 +905,13 @@ static int nsolve_set(struct nsolve_usage *usage, } pn = 1 + fpos % cr; - py = fpos / cr; - px = py / cr; - py %= cr; + px = fpos / cr; + py = px / cr; + px %= cr; - printf(" ruling out %d at (%d,%d)\n", - pn, 1+px, 1+YUNTRANS(py)); + printf("%*s ruling out %d at (%d,%d)\n", + solver_recurse_depth*4, "", + pn, 1+px, 1+py); } #endif progress = TRUE; @@ -1006,7 +921,7 @@ static int nsolve_set(struct nsolve_usage *usage, } if (progress) { - return TRUE; + return +1; } } } @@ -1024,45 +939,265 @@ static int nsolve_set(struct nsolve_usage *usage, break; /* done */ } - return FALSE; + return 0; } -static struct nsolve_scratch *nsolve_new_scratch(struct nsolve_usage *usage) +/* + * Look for forcing chains. A forcing chain is a path of + * pairwise-exclusive squares (i.e. each pair of adjacent squares + * in the path are in the same row, column or block) with the + * following properties: + * + * (a) Each square on the path has precisely two possible numbers. + * + * (b) Each pair of squares which are adjacent on the path share + * at least one possible number in common. + * + * (c) Each square in the middle of the path shares _both_ of its + * numbers with at least one of its neighbours (not the same + * one with both neighbours). + * + * These together imply that at least one of the possible number + * choices at one end of the path forces _all_ the rest of the + * numbers along the path. In order to make real use of this, we + * need further properties: + * + * (c) Ruling out some number N from the square at one end of the + * path forces the square at the other end to take the same + * number N. + * + * (d) The two end squares are both in line with some third + * square. + * + * (e) That third square currently has N as a possibility. + * + * If we can find all of that lot, we can deduce that at least one + * of the two ends of the forcing chain has number N, and that + * therefore the mutually adjacent third square does not. + * + * To find forcing chains, we're going to start a bfs at each + * suitable square, once for each of its two possible numbers. + */ +static int solver_forcing(struct solver_usage *usage, + struct solver_scratch *scratch) { - struct nsolve_scratch *scratch = snew(struct nsolve_scratch); int cr = usage->cr; - scratch->grid = snewn(cr*cr, unsigned char); - scratch->rowidx = snewn(cr, unsigned char); - scratch->colidx = snewn(cr, unsigned char); - scratch->set = snewn(cr, unsigned char); + int *bfsqueue = scratch->bfsqueue; +#ifdef STANDALONE_SOLVER + int *bfsprev = scratch->bfsprev; +#endif + unsigned char *number = scratch->grid; + int *neighbours = scratch->neighbours; + int x, y; + + for (y = 0; y < cr; y++) + for (x = 0; x < cr; x++) { + int count, t, n; + + /* + * If this square doesn't have exactly two candidate + * numbers, don't try it. + * + * In this loop we also sum the candidate numbers, + * which is a nasty hack to allow us to quickly find + * `the other one' (since we will shortly know there + * are exactly two). + */ + for (count = t = 0, n = 1; n <= cr; n++) + if (cube(x, y, n)) + count++, t += n; + if (count != 2) + continue; + + /* + * Now attempt a bfs for each candidate. + */ + for (n = 1; n <= cr; n++) + if (cube(x, y, n)) { + int orign, currn, head, tail; + + /* + * Begin a bfs. + */ + orign = n; + + memset(number, cr+1, cr*cr); + head = tail = 0; + bfsqueue[tail++] = y*cr+x; +#ifdef STANDALONE_SOLVER + bfsprev[y*cr+x] = -1; +#endif + number[y*cr+x] = t - n; + + while (head < tail) { + int xx, yy, nneighbours, xt, yt, i; + + xx = bfsqueue[head++]; + yy = xx / cr; + xx %= cr; + + currn = number[yy*cr+xx]; + + /* + * Find neighbours of yy,xx. + */ + nneighbours = 0; + for (yt = 0; yt < cr; yt++) + neighbours[nneighbours++] = yt*cr+xx; + for (xt = 0; xt < cr; xt++) + neighbours[nneighbours++] = yy*cr+xt; + xt = usage->blocks->whichblock[yy*cr+xx]; + for (yt = 0; yt < cr; yt++) + neighbours[nneighbours++] = usage->blocks->blocks[xt][yt]; + if (usage->diag) { + int sqindex = yy*cr+xx; + if (ondiag0(sqindex)) { + for (i = 0; i < cr; i++) + neighbours[nneighbours++] = diag0(i); + } + if (ondiag1(sqindex)) { + for (i = 0; i < cr; i++) + neighbours[nneighbours++] = diag1(i); + } + } + + /* + * Try visiting each of those neighbours. + */ + for (i = 0; i < nneighbours; i++) { + int cc, tt, nn; + + xt = neighbours[i] % cr; + yt = neighbours[i] / cr; + + /* + * We need this square to not be + * already visited, and to include + * currn as a possible number. + */ + if (number[yt*cr+xt] <= cr) + continue; + if (!cube(xt, yt, currn)) + continue; + + /* + * Don't visit _this_ square a second + * time! + */ + if (xt == xx && yt == yy) + continue; + + /* + * To continue with the bfs, we need + * this square to have exactly two + * possible numbers. + */ + for (cc = tt = 0, nn = 1; nn <= cr; nn++) + if (cube(xt, yt, nn)) + cc++, tt += nn; + if (cc == 2) { + bfsqueue[tail++] = yt*cr+xt; +#ifdef STANDALONE_SOLVER + bfsprev[yt*cr+xt] = yy*cr+xx; +#endif + number[yt*cr+xt] = tt - currn; + } + + /* + * One other possibility is that this + * might be the square in which we can + * make a real deduction: if it's + * adjacent to x,y, and currn is equal + * to the original number we ruled out. + */ + if (currn == orign && + (xt == x || yt == y || + (usage->blocks->whichblock[yt*cr+xt] == usage->blocks->whichblock[y*cr+x]) || + (usage->diag && ((ondiag0(yt*cr+xt) && ondiag0(y*cr+x)) || + (ondiag1(yt*cr+xt) && ondiag1(y*cr+x)))))) { +#ifdef STANDALONE_SOLVER + if (solver_show_working) { + char *sep = ""; + int xl, yl; + printf("%*sforcing chain, %d at ends of ", + solver_recurse_depth*4, "", orign); + xl = xx; + yl = yy; + while (1) { + printf("%s(%d,%d)", sep, 1+xl, + 1+yl); + xl = bfsprev[yl*cr+xl]; + if (xl < 0) + break; + yl = xl / cr; + xl %= cr; + sep = "-"; + } + printf("\n%*s ruling out %d at (%d,%d)\n", + solver_recurse_depth*4, "", + orign, 1+xt, 1+yt); + } +#endif + cube(xt, yt, orign) = FALSE; + return 1; + } + } + } + } + } + + return 0; +} + +static struct solver_scratch *solver_new_scratch(struct solver_usage *usage) +{ + struct solver_scratch *scratch = snew(struct solver_scratch); + int cr = usage->cr; + scratch->grid = snewn(cr*cr, unsigned char); + scratch->rowidx = snewn(cr, unsigned char); + scratch->colidx = snewn(cr, unsigned char); + scratch->set = snewn(cr, unsigned char); + scratch->neighbours = snewn(5*cr, int); + scratch->bfsqueue = snewn(cr*cr, int); +#ifdef STANDALONE_SOLVER + scratch->bfsprev = snewn(cr*cr, int); +#endif + scratch->indexlist = snewn(cr*cr, int); /* used for set elimination */ + scratch->indexlist2 = snewn(cr, int); /* only used for intersect() */ return scratch; } -static void nsolve_free_scratch(struct nsolve_scratch *scratch) +static void solver_free_scratch(struct solver_scratch *scratch) { +#ifdef STANDALONE_SOLVER + sfree(scratch->bfsprev); +#endif + sfree(scratch->bfsqueue); + sfree(scratch->neighbours); sfree(scratch->set); sfree(scratch->colidx); sfree(scratch->rowidx); sfree(scratch->grid); + sfree(scratch->indexlist); + sfree(scratch->indexlist2); sfree(scratch); } -static int nsolve(int c, int r, digit *grid) +static int solver(int cr, struct block_structure *blocks, int xtype, + digit *grid, int maxdiff) { - struct nsolve_usage *usage; - struct nsolve_scratch *scratch; - int cr = c*r; - int x, y, n; + struct solver_usage *usage; + struct solver_scratch *scratch; + int x, y, b, i, n, ret; int diff = DIFF_BLOCK; /* * Set up a usage structure as a clean slate (everything * possible). */ - usage = snew(struct nsolve_usage); - usage->c = c; - usage->r = r; + usage = snew(struct solver_usage); usage->cr = cr; + usage->blocks = blocks; usage->cube = snewn(cr*cr*cr, unsigned char); usage->grid = grid; /* write straight back to the input */ memset(usage->cube, TRUE, cr*cr*cr); @@ -1074,7 +1209,13 @@ static int nsolve(int c, int r, digit *grid) memset(usage->col, FALSE, cr * cr); memset(usage->blk, FALSE, cr * cr); - scratch = nsolve_new_scratch(usage); + if (xtype) { + usage->diag = snewn(cr * 2, unsigned char); + memset(usage->diag, FALSE, cr * 2); + } else + usage->diag = NULL; + + scratch = solver_new_scratch(usage); /* * Place all the clue numbers we are given. @@ -1082,7 +1223,7 @@ static int nsolve(int c, int r, digit *grid) for (x = 0; x < cr; x++) for (y = 0; y < cr; y++) if (grid[y*cr+x]) - nsolve_place(usage, x, YTRANS(y), grid[y*cr+x]); + solver_place(usage, x, y, grid[y*cr+x]); /* * Now loop over the grid repeatedly trying all permitted modes @@ -1104,196 +1245,874 @@ static int nsolve(int c, int r, digit *grid) /* * Blockwise positional elimination. */ - for (x = 0; x < cr; x += r) - for (y = 0; y < r; y++) - for (n = 1; n <= cr; n++) - if (!usage->blk[(y*c+(x/r))*cr+n-1] && - nsolve_elim(usage, cubepos(x,y,n), r*cr + for (b = 0; b < cr; b++) + for (n = 1; n <= cr; n++) + if (!usage->blk[b*cr+n-1]) { + for (i = 0; i < cr; i++) + scratch->indexlist[i] = cubepos2(usage->blocks->blocks[b][i],n); + ret = solver_elim(usage, scratch->indexlist #ifdef STANDALONE_SOLVER - , "positional elimination," - " block (%d,%d)", 1+x/r, 1+y + , "positional elimination," + " %d in block %s", n, + usage->blocks->blocknames[b] #endif - )) { - diff = max(diff, DIFF_BLOCK); - goto cont; - } + ); + if (ret < 0) { + diff = DIFF_IMPOSSIBLE; + goto got_result; + } else if (ret > 0) { + diff = max(diff, DIFF_BLOCK); + goto cont; + } + } + + if (maxdiff <= DIFF_BLOCK) + break; /* * Row-wise positional elimination. */ for (y = 0; y < cr; y++) for (n = 1; n <= cr; n++) - if (!usage->row[y*cr+n-1] && - nsolve_elim(usage, cubepos(0,y,n), cr*cr + if (!usage->row[y*cr+n-1]) { + for (x = 0; x < cr; x++) + scratch->indexlist[x] = cubepos(x, y, n); + ret = solver_elim(usage, scratch->indexlist #ifdef STANDALONE_SOLVER - , "positional elimination," - " row %d", 1+YUNTRANS(y) + , "positional elimination," + " %d in row %d", n, 1+y #endif - )) { - diff = max(diff, DIFF_SIMPLE); - goto cont; + ); + if (ret < 0) { + diff = DIFF_IMPOSSIBLE; + goto got_result; + } else if (ret > 0) { + diff = max(diff, DIFF_SIMPLE); + goto cont; + } } /* * Column-wise positional elimination. */ for (x = 0; x < cr; x++) for (n = 1; n <= cr; n++) - if (!usage->col[x*cr+n-1] && - nsolve_elim(usage, cubepos(x,0,n), cr + if (!usage->col[x*cr+n-1]) { + for (y = 0; y < cr; y++) + scratch->indexlist[y] = cubepos(x, y, n); + ret = solver_elim(usage, scratch->indexlist #ifdef STANDALONE_SOLVER - , "positional elimination," " column %d", 1+x + , "positional elimination," + " %d in column %d", n, 1+x #endif - )) { - diff = max(diff, DIFF_SIMPLE); - goto cont; + ); + if (ret < 0) { + diff = DIFF_IMPOSSIBLE; + goto got_result; + } else if (ret > 0) { + diff = max(diff, DIFF_SIMPLE); + goto cont; + } + } + + /* + * X-diagonal positional elimination. + */ + if (usage->diag) { + for (n = 1; n <= cr; n++) + if (!usage->diag[n-1]) { + for (i = 0; i < cr; i++) + scratch->indexlist[i] = cubepos2(diag0(i), n); + ret = solver_elim(usage, scratch->indexlist +#ifdef STANDALONE_SOLVER + , "positional elimination," + " %d in \\-diagonal", n +#endif + ); + if (ret < 0) { + diff = DIFF_IMPOSSIBLE; + goto got_result; + } else if (ret > 0) { + diff = max(diff, DIFF_SIMPLE); + goto cont; + } + } + for (n = 1; n <= cr; n++) + if (!usage->diag[cr+n-1]) { + for (i = 0; i < cr; i++) + scratch->indexlist[i] = cubepos2(diag1(i), n); + ret = solver_elim(usage, scratch->indexlist +#ifdef STANDALONE_SOLVER + , "positional elimination," + " %d in /-diagonal", n +#endif + ); + if (ret < 0) { + diff = DIFF_IMPOSSIBLE; + goto got_result; + } else if (ret > 0) { + diff = max(diff, DIFF_SIMPLE); + goto cont; + } } + } + + /* + * Numeric elimination. + */ + for (x = 0; x < cr; x++) + for (y = 0; y < cr; y++) + if (!usage->grid[y*cr+x]) { + for (n = 1; n <= cr; n++) + scratch->indexlist[n-1] = cubepos(x, y, n); + ret = solver_elim(usage, scratch->indexlist +#ifdef STANDALONE_SOLVER + , "numeric elimination at (%d,%d)", + 1+x, 1+y +#endif + ); + if (ret < 0) { + diff = DIFF_IMPOSSIBLE; + goto got_result; + } else if (ret > 0) { + diff = max(diff, DIFF_SIMPLE); + goto cont; + } + } + + if (maxdiff <= DIFF_SIMPLE) + break; + + /* + * Intersectional analysis, rows vs blocks. + */ + for (y = 0; y < cr; y++) + for (b = 0; b < cr; b++) + for (n = 1; n <= cr; n++) { + if (usage->row[y*cr+n-1] || + usage->blk[b*cr+n-1]) + continue; + for (i = 0; i < cr; i++) { + scratch->indexlist[i] = cubepos(i, y, n); + scratch->indexlist2[i] = cubepos2(usage->blocks->blocks[b][i], n); + } + /* + * solver_intersect() never returns -1. + */ + if (solver_intersect(usage, scratch->indexlist, + scratch->indexlist2 +#ifdef STANDALONE_SOLVER + , "intersectional analysis," + " %d in row %d vs block %s", + n, 1+y, usage->blocks->blocknames[b] +#endif + ) || + solver_intersect(usage, scratch->indexlist2, + scratch->indexlist +#ifdef STANDALONE_SOLVER + , "intersectional analysis," + " %d in block %s vs row %d", + n, usage->blocks->blocknames[b], 1+y +#endif + )) { + diff = max(diff, DIFF_INTERSECT); + goto cont; + } + } + + /* + * Intersectional analysis, columns vs blocks. + */ + for (x = 0; x < cr; x++) + for (b = 0; b < cr; b++) + for (n = 1; n <= cr; n++) { + if (usage->col[x*cr+n-1] || + usage->blk[b*cr+n-1]) + continue; + for (i = 0; i < cr; i++) { + scratch->indexlist[i] = cubepos(x, i, n); + scratch->indexlist2[i] = cubepos2(usage->blocks->blocks[b][i], n); + } + if (solver_intersect(usage, scratch->indexlist, + scratch->indexlist2 +#ifdef STANDALONE_SOLVER + , "intersectional analysis," + " %d in column %d vs block %s", + n, 1+x, usage->blocks->blocknames[b] +#endif + ) || + solver_intersect(usage, scratch->indexlist2, + scratch->indexlist +#ifdef STANDALONE_SOLVER + , "intersectional analysis," + " %d in block %s vs column %d", + n, usage->blocks->blocknames[b], 1+x +#endif + )) { + diff = max(diff, DIFF_INTERSECT); + goto cont; + } + } + + if (usage->diag) { + /* + * Intersectional analysis, \-diagonal vs blocks. + */ + for (b = 0; b < cr; b++) + for (n = 1; n <= cr; n++) { + if (usage->diag[n-1] || + usage->blk[b*cr+n-1]) + continue; + for (i = 0; i < cr; i++) { + scratch->indexlist[i] = cubepos2(diag0(i), n); + scratch->indexlist2[i] = cubepos2(usage->blocks->blocks[b][i], n); + } + if (solver_intersect(usage, scratch->indexlist, + scratch->indexlist2 +#ifdef STANDALONE_SOLVER + , "intersectional analysis," + " %d in \\-diagonal vs block %s", + n, 1+x, usage->blocks->blocknames[b] +#endif + ) || + solver_intersect(usage, scratch->indexlist2, + scratch->indexlist +#ifdef STANDALONE_SOLVER + , "intersectional analysis," + " %d in block %s vs \\-diagonal", + n, usage->blocks->blocknames[b], 1+x +#endif + )) { + diff = max(diff, DIFF_INTERSECT); + goto cont; + } + } + + /* + * Intersectional analysis, /-diagonal vs blocks. + */ + for (b = 0; b < cr; b++) + for (n = 1; n <= cr; n++) { + if (usage->diag[cr+n-1] || + usage->blk[b*cr+n-1]) + continue; + for (i = 0; i < cr; i++) { + scratch->indexlist[i] = cubepos2(diag1(i), n); + scratch->indexlist2[i] = cubepos2(usage->blocks->blocks[b][i], n); + } + if (solver_intersect(usage, scratch->indexlist, + scratch->indexlist2 +#ifdef STANDALONE_SOLVER + , "intersectional analysis," + " %d in /-diagonal vs block %s", + n, 1+x, usage->blocks->blocknames[b] +#endif + ) || + solver_intersect(usage, scratch->indexlist2, + scratch->indexlist +#ifdef STANDALONE_SOLVER + , "intersectional analysis," + " %d in block %s vs /-diagonal", + n, usage->blocks->blocknames[b], 1+x +#endif + )) { + diff = max(diff, DIFF_INTERSECT); + goto cont; + } + } + } + + if (maxdiff <= DIFF_INTERSECT) + break; + + /* + * Blockwise set elimination. + */ + for (b = 0; b < cr; b++) { + for (i = 0; i < cr; i++) + for (n = 1; n <= cr; n++) + scratch->indexlist[i*cr+n-1] = cubepos2(usage->blocks->blocks[b][i], n); + ret = solver_set(usage, scratch, scratch->indexlist +#ifdef STANDALONE_SOLVER + , "set elimination, block %s", + usage->blocks->blocknames[b] +#endif + ); + if (ret < 0) { + diff = DIFF_IMPOSSIBLE; + goto got_result; + } else if (ret > 0) { + diff = max(diff, DIFF_SET); + goto cont; + } + } + + /* + * Row-wise set elimination. + */ + for (y = 0; y < cr; y++) { + for (x = 0; x < cr; x++) + for (n = 1; n <= cr; n++) + scratch->indexlist[x*cr+n-1] = cubepos(x, y, n); + ret = solver_set(usage, scratch, scratch->indexlist +#ifdef STANDALONE_SOLVER + , "set elimination, row %d", 1+y +#endif + ); + if (ret < 0) { + diff = DIFF_IMPOSSIBLE; + goto got_result; + } else if (ret > 0) { + diff = max(diff, DIFF_SET); + goto cont; + } + } + + /* + * Column-wise set elimination. + */ + for (x = 0; x < cr; x++) { + for (y = 0; y < cr; y++) + for (n = 1; n <= cr; n++) + scratch->indexlist[y*cr+n-1] = cubepos(x, y, n); + ret = solver_set(usage, scratch, scratch->indexlist +#ifdef STANDALONE_SOLVER + , "set elimination, column %d", 1+x +#endif + ); + if (ret < 0) { + diff = DIFF_IMPOSSIBLE; + goto got_result; + } else if (ret > 0) { + diff = max(diff, DIFF_SET); + goto cont; + } + } + + if (usage->diag) { + /* + * \-diagonal set elimination. + */ + for (i = 0; i < cr; i++) + for (n = 1; n <= cr; n++) + scratch->indexlist[i*cr+n-1] = cubepos2(diag0(i), n); + ret = solver_set(usage, scratch, scratch->indexlist +#ifdef STANDALONE_SOLVER + , "set elimination, \\-diagonal" +#endif + ); + if (ret < 0) { + diff = DIFF_IMPOSSIBLE; + goto got_result; + } else if (ret > 0) { + diff = max(diff, DIFF_SET); + goto cont; + } + + /* + * /-diagonal set elimination. + */ + for (i = 0; i < cr; i++) + for (n = 1; n <= cr; n++) + scratch->indexlist[i*cr+n-1] = cubepos2(diag1(i), n); + ret = solver_set(usage, scratch, scratch->indexlist +#ifdef STANDALONE_SOLVER + , "set elimination, \\-diagonal" +#endif + ); + if (ret < 0) { + diff = DIFF_IMPOSSIBLE; + goto got_result; + } else if (ret > 0) { + diff = max(diff, DIFF_SET); + goto cont; + } + } + + if (maxdiff <= DIFF_SET) + break; + + /* + * Row-vs-column set elimination on a single number. + */ + for (n = 1; n <= cr; n++) { + for (y = 0; y < cr; y++) + for (x = 0; x < cr; x++) + scratch->indexlist[y*cr+x] = cubepos(x, y, n); + ret = solver_set(usage, scratch, scratch->indexlist +#ifdef STANDALONE_SOLVER + , "positional set elimination, number %d", n +#endif + ); + if (ret < 0) { + diff = DIFF_IMPOSSIBLE; + goto got_result; + } else if (ret > 0) { + diff = max(diff, DIFF_EXTREME); + goto cont; + } + } + + /* + * Forcing chains. + */ + if (solver_forcing(usage, scratch)) { + diff = max(diff, DIFF_EXTREME); + goto cont; + } + + /* + * If we reach here, we have made no deductions in this + * iteration, so the algorithm terminates. + */ + break; + } + + /* + * Last chance: if we haven't fully solved the puzzle yet, try + * recursing based on guesses for a particular square. We pick + * one of the most constrained empty squares we can find, which + * has the effect of pruning the search tree as much as + * possible. + */ + if (maxdiff >= DIFF_RECURSIVE) { + int best, bestcount; + + best = -1; + bestcount = cr+1; + + for (y = 0; y < cr; y++) + for (x = 0; x < cr; x++) + if (!grid[y*cr+x]) { + int count; + + /* + * An unfilled square. Count the number of + * possible digits in it. + */ + count = 0; + for (n = 1; n <= cr; n++) + if (cube(x,y,n)) + count++; + + /* + * We should have found any impossibilities + * already, so this can safely be an assert. + */ + assert(count > 1); + + if (count < bestcount) { + bestcount = count; + best = y*cr+x; + } + } + + if (best != -1) { + int i, j; + digit *list, *ingrid, *outgrid; + + diff = DIFF_IMPOSSIBLE; /* no solution found yet */ + + /* + * Attempt recursion. + */ + y = best / cr; + x = best % cr; + + list = snewn(cr, digit); + ingrid = snewn(cr * cr, digit); + outgrid = snewn(cr * cr, digit); + memcpy(ingrid, grid, cr * cr); + + /* Make a list of the possible digits. */ + for (j = 0, n = 1; n <= cr; n++) + if (cube(x,y,n)) + list[j++] = n; + +#ifdef STANDALONE_SOLVER + if (solver_show_working) { + char *sep = ""; + printf("%*srecursing on (%d,%d) [", + solver_recurse_depth*4, "", x + 1, y + 1); + for (i = 0; i < j; i++) { + printf("%s%d", sep, list[i]); + sep = " or "; + } + printf("]\n"); + } +#endif + + /* + * And step along the list, recursing back into the + * main solver at every stage. + */ + for (i = 0; i < j; i++) { + int ret; + + memcpy(outgrid, ingrid, cr * cr); + outgrid[y*cr+x] = list[i]; + +#ifdef STANDALONE_SOLVER + if (solver_show_working) + printf("%*sguessing %d at (%d,%d)\n", + solver_recurse_depth*4, "", list[i], x + 1, y + 1); + solver_recurse_depth++; +#endif + + ret = solver(cr, blocks, xtype, outgrid, maxdiff); + +#ifdef STANDALONE_SOLVER + solver_recurse_depth--; + if (solver_show_working) { + printf("%*sretracting %d at (%d,%d)\n", + solver_recurse_depth*4, "", list[i], x + 1, y + 1); + } +#endif + + /* + * If we have our first solution, copy it into the + * grid we will return. + */ + if (diff == DIFF_IMPOSSIBLE && ret != DIFF_IMPOSSIBLE) + memcpy(grid, outgrid, cr*cr); + + if (ret == DIFF_AMBIGUOUS) + diff = DIFF_AMBIGUOUS; + else if (ret == DIFF_IMPOSSIBLE) + /* do not change our return value */; + else { + /* the recursion turned up exactly one solution */ + if (diff == DIFF_IMPOSSIBLE) + diff = DIFF_RECURSIVE; + else + diff = DIFF_AMBIGUOUS; + } + + /* + * As soon as we've found more than one solution, + * give up immediately. + */ + if (diff == DIFF_AMBIGUOUS) + break; + } + + sfree(outgrid); + sfree(ingrid); + sfree(list); + } + + } else { + /* + * We're forbidden to use recursion, so we just see whether + * our grid is fully solved, and return DIFF_IMPOSSIBLE + * otherwise. + */ + for (y = 0; y < cr; y++) + for (x = 0; x < cr; x++) + if (!grid[y*cr+x]) + diff = DIFF_IMPOSSIBLE; + } + + got_result:; + +#ifdef STANDALONE_SOLVER + if (solver_show_working) + printf("%*s%s found\n", + solver_recurse_depth*4, "", + diff == DIFF_IMPOSSIBLE ? "no solution" : + diff == DIFF_AMBIGUOUS ? "multiple solutions" : + "one solution"); +#endif + + sfree(usage->cube); + sfree(usage->row); + sfree(usage->col); + sfree(usage->blk); + sfree(usage); + + solver_free_scratch(scratch); + + return diff; +} + +/* ---------------------------------------------------------------------- + * End of solver code. + */ + +/* ---------------------------------------------------------------------- + * Solo filled-grid generator. + * + * This grid generator works by essentially trying to solve a grid + * starting from no clues, and not worrying that there's more than + * one possible solution. Unfortunately, it isn't computationally + * feasible to do this by calling the above solver with an empty + * grid, because that one needs to allocate a lot of scratch space + * at every recursion level. Instead, I have a much simpler + * algorithm which I shamelessly copied from a Python solver + * written by Andrew Wilkinson (which is GPLed, but I've reused + * only ideas and no code). It mostly just does the obvious + * recursive thing: pick an empty square, put one of the possible + * digits in it, recurse until all squares are filled, backtrack + * and change some choices if necessary. + * + * The clever bit is that every time it chooses which square to + * fill in next, it does so by counting the number of _possible_ + * numbers that can go in each square, and it prioritises so that + * it picks a square with the _lowest_ number of possibilities. The + * idea is that filling in lots of the obvious bits (particularly + * any squares with only one possibility) will cut down on the list + * of possibilities for other squares and hence reduce the enormous + * search space as much as possible as early as possible. + */ + +/* + * Internal data structure used in gridgen to keep track of + * progress. + */ +struct gridgen_coord { int x, y, r; }; +struct gridgen_usage { + int cr; + struct block_structure *blocks; + /* grid is a copy of the input grid, modified as we go along */ + digit *grid; + /* row[y*cr+n-1] TRUE if digit n has been placed in row y */ + unsigned char *row; + /* col[x*cr+n-1] TRUE if digit n has been placed in row x */ + unsigned char *col; + /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */ + unsigned char *blk; + /* diag[i*cr+n-1] TRUE if digit n has been placed in diagonal i */ + unsigned char *diag; + /* This lists all the empty spaces remaining in the grid. */ + struct gridgen_coord *spaces; + int nspaces; + /* If we need randomisation in the solve, this is our random state. */ + random_state *rs; +}; + +static void gridgen_place(struct gridgen_usage *usage, int x, int y, digit n, + int placing) +{ + int cr = usage->cr; + usage->row[y*cr+n-1] = usage->col[x*cr+n-1] = + usage->blk[usage->blocks->whichblock[y*cr+x]*cr+n-1] = placing; + if (usage->diag) { + if (ondiag0(y*cr+x)) + usage->diag[n-1] = placing; + if (ondiag1(y*cr+x)) + usage->diag[cr+n-1] = placing; + } + usage->grid[y*cr+x] = placing ? n : 0; +} + +/* + * The real recursive step in the generating function. + * + * Return values: 1 means solution found, 0 means no solution + * found on this branch. + */ +static int gridgen_real(struct gridgen_usage *usage, digit *grid, int *steps) +{ + int cr = usage->cr; + int i, j, n, sx, sy, bestm, bestr, ret; + int *digits; + + /* + * Firstly, check for completion! If there are no spaces left + * in the grid, we have a solution. + */ + if (usage->nspaces == 0) + return TRUE; + + /* + * Next, abandon generation if we went over our steps limit. + */ + if (*steps <= 0) + return FALSE; + (*steps)--; + + /* + * Otherwise, there must be at least one space. Find the most + * constrained space, using the `r' field as a tie-breaker. + */ + bestm = cr+1; /* so that any space will beat it */ + bestr = 0; + i = sx = sy = -1; + for (j = 0; j < usage->nspaces; j++) { + int x = usage->spaces[j].x, y = usage->spaces[j].y; + int m; + + /* + * Find the number of digits that could go in this space. + */ + m = 0; + for (n = 0; n < cr; n++) + if (!usage->row[y*cr+n] && !usage->col[x*cr+n] && + !usage->blk[usage->blocks->whichblock[y*cr+x]*cr+n] && + (!usage->diag || ((!ondiag0(y*cr+x) || !usage->diag[n]) && + (!ondiag1(y*cr+x) || !usage->diag[cr+n])))) + m++; + + if (m < bestm || (m == bestm && usage->spaces[j].r < bestr)) { + bestm = m; + bestr = usage->spaces[j].r; + sx = x; + sy = y; + i = j; + } + } + + /* + * Swap that square into the final place in the spaces array, + * so that decrementing nspaces will remove it from the list. + */ + if (i != usage->nspaces-1) { + struct gridgen_coord t; + t = usage->spaces[usage->nspaces-1]; + usage->spaces[usage->nspaces-1] = usage->spaces[i]; + usage->spaces[i] = t; + } + + /* + * Now we've decided which square to start our recursion at, + * simply go through all possible values, shuffling them + * randomly first if necessary. + */ + digits = snewn(bestm, int); + j = 0; + for (n = 0; n < cr; n++) + if (!usage->row[sy*cr+n] && !usage->col[sx*cr+n] && + !usage->blk[usage->blocks->whichblock[sy*cr+sx]*cr+n] && + (!usage->diag || ((!ondiag0(sy*cr+sx) || !usage->diag[n]) && + (!ondiag1(sy*cr+sx) || !usage->diag[cr+n])))) { + digits[j++] = n+1; + } + + if (usage->rs) + shuffle(digits, j, sizeof(*digits), usage->rs); + + /* And finally, go through the digit list and actually recurse. */ + ret = FALSE; + for (i = 0; i < j; i++) { + n = digits[i]; + + /* Update the usage structure to reflect the placing of this digit. */ + gridgen_place(usage, sx, sy, n, TRUE); + usage->nspaces--; + + /* Call the solver recursively. Stop when we find a solution. */ + if (gridgen_real(usage, grid, steps)) { + ret = TRUE; + break; + } + + /* Revert the usage structure. */ + gridgen_place(usage, sx, sy, n, FALSE); + usage->nspaces++; + } + + sfree(digits); + return ret; +} + +/* + * Entry point to generator. You give it parameters and a starting + * grid, which is simply an array of cr*cr digits. + */ +static int gridgen(int cr, struct block_structure *blocks, int xtype, + digit *grid, random_state *rs, int maxsteps) +{ + struct gridgen_usage *usage; + int x, y, ret; + + /* + * Clear the grid to start with. + */ + memset(grid, 0, cr*cr); - /* - * Numeric elimination. - */ - for (x = 0; x < cr; x++) - for (y = 0; y < cr; y++) - if (!usage->grid[YUNTRANS(y)*cr+x] && - nsolve_elim(usage, cubepos(x,y,1), 1 -#ifdef STANDALONE_SOLVER - , "numeric elimination at (%d,%d)", 1+x, - 1+YUNTRANS(y) -#endif - )) { - diff = max(diff, DIFF_SIMPLE); - goto cont; - } + /* + * Create a gridgen_usage structure. + */ + usage = snew(struct gridgen_usage); - /* - * Intersectional analysis, rows vs blocks. - */ - for (y = 0; y < cr; y++) - for (x = 0; x < cr; x += r) - for (n = 1; n <= cr; n++) - if (!usage->row[y*cr+n-1] && - !usage->blk[((y%r)*c+(x/r))*cr+n-1] && - (nsolve_intersect(usage, cubepos(0,y,n), cr*cr, - cubepos(x,y%r,n), r*cr -#ifdef STANDALONE_SOLVER - , "intersectional analysis," - " row %d vs block (%d,%d)", - 1+YUNTRANS(y), 1+x/r, 1+y%r -#endif - ) || - nsolve_intersect(usage, cubepos(x,y%r,n), r*cr, - cubepos(0,y,n), cr*cr -#ifdef STANDALONE_SOLVER - , "intersectional analysis," - " block (%d,%d) vs row %d", - 1+x/r, 1+y%r, 1+YUNTRANS(y) -#endif - ))) { - diff = max(diff, DIFF_INTERSECT); - goto cont; - } + usage->cr = cr; + usage->blocks = blocks; - /* - * Intersectional analysis, columns vs blocks. - */ - for (x = 0; x < cr; x++) - for (y = 0; y < r; y++) - for (n = 1; n <= cr; n++) - if (!usage->col[x*cr+n-1] && - !usage->blk[(y*c+(x/r))*cr+n-1] && - (nsolve_intersect(usage, cubepos(x,0,n), cr, - cubepos((x/r)*r,y,n), r*cr -#ifdef STANDALONE_SOLVER - , "intersectional analysis," - " column %d vs block (%d,%d)", - 1+x, 1+x/r, 1+y -#endif - ) || - nsolve_intersect(usage, cubepos((x/r)*r,y,n), r*cr, - cubepos(x,0,n), cr -#ifdef STANDALONE_SOLVER - , "intersectional analysis," - " block (%d,%d) vs column %d", - 1+x/r, 1+y, 1+x -#endif - ))) { - diff = max(diff, DIFF_INTERSECT); - goto cont; - } + usage->grid = grid; - /* - * Blockwise set elimination. - */ - for (x = 0; x < cr; x += r) - for (y = 0; y < r; y++) - if (nsolve_set(usage, scratch, cubepos(x,y,1), r*cr, 1 -#ifdef STANDALONE_SOLVER - , "set elimination, block (%d,%d)", 1+x/r, 1+y -#endif - )) { - diff = max(diff, DIFF_SET); - goto cont; - } + usage->row = snewn(cr * cr, unsigned char); + usage->col = snewn(cr * cr, unsigned char); + usage->blk = snewn(cr * cr, unsigned char); + memset(usage->row, FALSE, cr * cr); + memset(usage->col, FALSE, cr * cr); + memset(usage->blk, FALSE, cr * cr); - /* - * Row-wise set elimination. - */ - for (y = 0; y < cr; y++) - if (nsolve_set(usage, scratch, cubepos(0,y,1), cr*cr, 1 -#ifdef STANDALONE_SOLVER - , "set elimination, row %d", 1+YUNTRANS(y) -#endif - )) { - diff = max(diff, DIFF_SET); - goto cont; - } + if (xtype) { + usage->diag = snewn(2 * cr, unsigned char); + memset(usage->diag, FALSE, 2 * cr); + } else { + usage->diag = NULL; + } - /* - * Column-wise set elimination. - */ - for (x = 0; x < cr; x++) - if (nsolve_set(usage, scratch, cubepos(x,0,1), cr, 1 -#ifdef STANDALONE_SOLVER - , "set elimination, column %d", 1+x -#endif - )) { - diff = max(diff, DIFF_SET); - goto cont; - } + /* + * Begin by filling in the whole top row with randomly chosen + * numbers. This cannot introduce any bias or restriction on + * the available grids, since we already know those numbers + * are all distinct so all we're doing is choosing their + * labels. + */ + for (x = 0; x < cr; x++) + grid[x] = x+1; + shuffle(grid, cr, sizeof(*grid), rs); + for (x = 0; x < cr; x++) + gridgen_place(usage, x, 0, grid[x], TRUE); - /* - * If we reach here, we have made no deductions in this - * iteration, so the algorithm terminates. - */ - break; + usage->spaces = snewn(cr * cr, struct gridgen_coord); + usage->nspaces = 0; + + usage->rs = rs; + + /* + * Initialise the list of grid spaces, taking care to leave + * out the row I've already filled in above. + */ + for (y = 1; y < cr; y++) { + for (x = 0; x < cr; x++) { + usage->spaces[usage->nspaces].x = x; + usage->spaces[usage->nspaces].y = y; + usage->spaces[usage->nspaces].r = random_bits(rs, 31); + usage->nspaces++; + } } - nsolve_free_scratch(scratch); + /* + * Run the real generator function. + */ + ret = gridgen_real(usage, grid, &maxsteps); - sfree(usage->cube); - sfree(usage->row); - sfree(usage->col); + /* + * Clean up the usage structure now we have our answer. + */ + sfree(usage->spaces); sfree(usage->blk); + sfree(usage->col); + sfree(usage->row); sfree(usage); - for (x = 0; x < cr; x++) - for (y = 0; y < cr; y++) - if (!grid[y*cr+x]) - return DIFF_IMPOSSIBLE; - return diff; + return ret; } /* ---------------------------------------------------------------------- - * End of non-recursive solver code. + * End of grid generator code. */ /* * Check whether a grid contains a valid complete puzzle. */ -static int check_valid(int c, int r, digit *grid) +static int check_valid(int cr, struct block_structure *blocks, int xtype, + digit *grid) { - int cr = c*r; unsigned char *used; - int x, y, n; + int x, y, i, j, n; used = snewn(cr, unsigned char); @@ -1330,108 +2149,154 @@ static int check_valid(int c, int r, digit *grid) /* * Check that each block contains precisely one of everything. */ - for (x = 0; x < cr; x += r) { - for (y = 0; y < cr; y += c) { - int xx, yy; - memset(used, FALSE, cr); - for (xx = x; xx < x+r; xx++) - for (yy = 0; yy < y+c; yy++) - if (grid[yy*cr+xx] > 0 && grid[yy*cr+xx] <= cr) - used[grid[yy*cr+xx]-1] = TRUE; - for (n = 0; n < cr; n++) - if (!used[n]) { - sfree(used); - return FALSE; - } - } + for (i = 0; i < cr; i++) { + memset(used, FALSE, cr); + for (j = 0; j < cr; j++) + if (grid[blocks->blocks[i][j]] > 0 && + grid[blocks->blocks[i][j]] <= cr) + used[grid[blocks->blocks[i][j]]-1] = TRUE; + for (n = 0; n < cr; n++) + if (!used[n]) { + sfree(used); + return FALSE; + } + } + + /* + * Check that each diagonal contains precisely one of everything. + */ + if (xtype) { + memset(used, FALSE, cr); + for (i = 0; i < cr; i++) + if (grid[diag0(i)] > 0 && grid[diag0(i)] <= cr) + used[grid[diag0(i)]-1] = TRUE; + for (n = 0; n < cr; n++) + if (!used[n]) { + sfree(used); + return FALSE; + } + for (i = 0; i < cr; i++) + if (grid[diag1(i)] > 0 && grid[diag1(i)] <= cr) + used[grid[diag1(i)]-1] = TRUE; + for (n = 0; n < cr; n++) + if (!used[n]) { + sfree(used); + return FALSE; + } } sfree(used); return TRUE; } -static void symmetry_limit(game_params *params, int *xlim, int *ylim, int s) +static int symmetries(game_params *params, int x, int y, int *output, int s) { int c = params->c, r = params->r, cr = c*r; + int i = 0; + +#define ADD(x,y) (*output++ = (x), *output++ = (y), i++) + + ADD(x, y); switch (s) { case SYMM_NONE: - *xlim = *ylim = cr; - break; + break; /* just x,y is all we need */ case SYMM_ROT2: - *xlim = (cr+1) / 2; - *ylim = cr; - break; - case SYMM_REF4: + ADD(cr - 1 - x, cr - 1 - y); + break; case SYMM_ROT4: - *xlim = *ylim = (cr+1) / 2; - break; + ADD(cr - 1 - y, x); + ADD(y, cr - 1 - x); + ADD(cr - 1 - x, cr - 1 - y); + break; + case SYMM_REF2: + ADD(cr - 1 - x, y); + break; + case SYMM_REF2D: + ADD(y, x); + break; + case SYMM_REF4: + ADD(cr - 1 - x, y); + ADD(x, cr - 1 - y); + ADD(cr - 1 - x, cr - 1 - y); + break; + case SYMM_REF4D: + ADD(y, x); + ADD(cr - 1 - x, cr - 1 - y); + ADD(cr - 1 - y, cr - 1 - x); + break; + case SYMM_REF8: + ADD(cr - 1 - x, y); + ADD(x, cr - 1 - y); + ADD(cr - 1 - x, cr - 1 - y); + ADD(y, x); + ADD(y, cr - 1 - x); + ADD(cr - 1 - y, x); + ADD(cr - 1 - y, cr - 1 - x); + break; } + +#undef ADD + + return i; } -static int symmetries(game_params *params, int x, int y, int *output, int s) +static char *encode_solve_move(int cr, digit *grid) { - int c = params->c, r = params->r, cr = c*r; - int i = 0; + int i, len; + char *ret, *p, *sep; - *output++ = x; - *output++ = y; - i++; + /* + * It's surprisingly easy to work out _exactly_ how long this + * string needs to be. To decimal-encode all the numbers from 1 + * to n: + * + * - every number has a units digit; total is n. + * - all numbers above 9 have a tens digit; total is max(n-9,0). + * - all numbers above 99 have a hundreds digit; total is max(n-99,0). + * - and so on. + */ + len = 0; + for (i = 1; i <= cr; i *= 10) + len += max(cr - i + 1, 0); + len += cr; /* don't forget the commas */ + len *= cr; /* there are cr rows of these */ - switch (s) { - case SYMM_NONE: - break; /* just x,y is all we need */ - case SYMM_REF4: - case SYMM_ROT4: - switch (s) { - case SYMM_REF4: - *output++ = cr - 1 - x; - *output++ = y; - i++; - - *output++ = x; - *output++ = cr - 1 - y; - i++; - break; - case SYMM_ROT4: - *output++ = cr - 1 - y; - *output++ = x; - i++; - - *output++ = y; - *output++ = cr - 1 - x; - i++; - break; - } - /* fall through */ - case SYMM_ROT2: - *output++ = cr - 1 - x; - *output++ = cr - 1 - y; - i++; - break; + /* + * Now len is one bigger than the total size of the + * comma-separated numbers (because we counted an + * additional leading comma). We need to have a leading S + * and a trailing NUL, so we're off by one in total. + */ + len++; + + ret = snewn(len, char); + p = ret; + *p++ = 'S'; + sep = ""; + for (i = 0; i < cr*cr; i++) { + p += sprintf(p, "%s%d", sep, grid[i]); + sep = ","; } + *p++ = '\0'; + assert(p - ret == len); - return i; + return ret; } -struct game_aux_info { - int c, r; - digit *grid; -}; - static char *new_game_desc(game_params *params, random_state *rs, - game_aux_info **aux, int interactive) + char **aux, int interactive) { int c = params->c, r = params->r, cr = c*r; int area = cr*cr; + struct block_structure *blocks; digit *grid, *grid2; struct xy { int x, y; } *locs; int nlocs; - int ret; char *desc; int coords[16], ncoords; - int xlim, ylim; - int maxdiff, recursing; + int maxdiff; + int x, y, i, j; /* * Adjust the maximum difficulty level to be consistent with @@ -1447,125 +2312,136 @@ static char *new_game_desc(game_params *params, random_state *rs, locs = snewn(area, struct xy); grid2 = snewn(area, digit); + blocks = snew(struct block_structure); + blocks->c = params->c; blocks->r = params->r; + blocks->whichblock = snewn(area*2, int); + blocks->blocks = snewn(cr, int *); + for (i = 0; i < cr; i++) + blocks->blocks[i] = blocks->whichblock + area + i*cr; +#ifdef STANDALONE_SOLVER + assert(!"This should never happen, so we don't need to create blocknames"); +#endif + /* * Loop until we get a grid of the required difficulty. This is * nasty, but it seems to be unpleasantly hard to generate * difficult grids otherwise. */ - do { + while (1) { /* - * Start the recursive solver with an empty grid to generate a - * random solved state. + * Generate a random solved state, starting by + * constructing the block structure. */ - memset(grid, 0, area); - ret = rsolve(c, r, grid, rs, 1); - assert(ret == 1); - assert(check_valid(c, r, grid)); + if (r == 1) { /* jigsaw mode */ + int *dsf = divvy_rectangle(cr, cr, cr, rs); + int nb = 0; + + for (i = 0; i < area; i++) + blocks->whichblock[i] = -1; + for (i = 0; i < area; i++) { + int j = dsf_canonify(dsf, i); + if (blocks->whichblock[j] < 0) + blocks->whichblock[j] = nb++; + blocks->whichblock[i] = blocks->whichblock[j]; + } + assert(nb == cr); + + sfree(dsf); + } else { /* basic Sudoku mode */ + for (y = 0; y < cr; y++) + for (x = 0; x < cr; x++) + blocks->whichblock[y*cr+x] = (y/c) * c + (x/r); + } + for (i = 0; i < cr; i++) + blocks->blocks[i][cr-1] = 0; + for (i = 0; i < area; i++) { + int b = blocks->whichblock[i]; + j = blocks->blocks[b][cr-1]++; + assert(j < cr); + blocks->blocks[b][j] = i; + } + + if (!gridgen(cr, blocks, params->xtype, grid, rs, area*area)) + continue; + assert(check_valid(cr, blocks, params->xtype, grid)); /* - * Save the solved grid in the aux_info. + * Save the solved grid in aux. */ { - game_aux_info *ai = snew(game_aux_info); - ai->c = c; - ai->r = r; - ai->grid = snewn(cr * cr, digit); - memcpy(ai->grid, grid, cr * cr * sizeof(digit)); /* * We might already have written *aux the last time we * went round this loop, in which case we should free - * the old aux_info before overwriting it with the new - * one. + * the old aux before overwriting it with the new one. */ if (*aux) { - sfree((*aux)->grid); sfree(*aux); } - *aux = ai; + + *aux = encode_solve_move(cr, grid); } /* * Now we have a solved grid, start removing things from it * while preserving solubility. */ - symmetry_limit(params, &xlim, &ylim, params->symm); - recursing = FALSE; - while (1) { - int x, y, i, j; - /* - * Iterate over the grid and enumerate all the filled - * squares we could empty. - */ - nlocs = 0; - - for (x = 0; x < xlim; x++) - for (y = 0; y < ylim; y++) - if (grid[y*cr+x]) { - locs[nlocs].x = x; - locs[nlocs].y = y; - nlocs++; - } + /* + * Find the set of equivalence classes of squares permitted + * by the selected symmetry. We do this by enumerating all + * the grid squares which have no symmetric companion + * sorting lower than themselves. + */ + nlocs = 0; + for (y = 0; y < cr; y++) + for (x = 0; x < cr; x++) { + int i = y*cr+x; + int j; - /* - * Now shuffle that list. - */ - for (i = nlocs; i > 1; i--) { - int p = random_upto(rs, i); - if (p != i-1) { - struct xy t = locs[p]; - locs[p] = locs[i-1]; - locs[i-1] = t; + ncoords = symmetries(params, x, y, coords, params->symm); + for (j = 0; j < ncoords; j++) + if (coords[2*j+1]*cr+coords[2*j] < i) + break; + if (j == ncoords) { + locs[nlocs].x = x; + locs[nlocs].y = y; + nlocs++; } } - /* - * Now loop over the shuffled list and, for each element, - * see whether removing that element (and its reflections) - * from the grid will still leave the grid soluble by - * nsolve. - */ - for (i = 0; i < nlocs; i++) { - int ret; - - x = locs[i].x; - y = locs[i].y; + /* + * Now shuffle that list. + */ + shuffle(locs, nlocs, sizeof(*locs), rs); - memcpy(grid2, grid, area); - ncoords = symmetries(params, x, y, coords, params->symm); - for (j = 0; j < ncoords; j++) - grid2[coords[2*j+1]*cr+coords[2*j]] = 0; + /* + * Now loop over the shuffled list and, for each element, + * see whether removing that element (and its reflections) + * from the grid will still leave the grid soluble. + */ + for (i = 0; i < nlocs; i++) { + int ret; - if (recursing) - ret = (rsolve(c, r, grid2, NULL, 2) == 1); - else - ret = (nsolve(c, r, grid2) <= maxdiff); + x = locs[i].x; + y = locs[i].y; - if (ret) { - for (j = 0; j < ncoords; j++) - grid[coords[2*j+1]*cr+coords[2*j]] = 0; - break; - } - } + memcpy(grid2, grid, area); + ncoords = symmetries(params, x, y, coords, params->symm); + for (j = 0; j < ncoords; j++) + grid2[coords[2*j+1]*cr+coords[2*j]] = 0; - if (i == nlocs) { - /* - * There was nothing we could remove without - * destroying solvability. If we're trying to - * generate a recursion-only grid and haven't - * switched over to rsolve yet, we now do; - * otherwise we give up. - */ - if (maxdiff == DIFF_RECURSIVE && !recursing) { - recursing = TRUE; - } else { - break; - } + ret = solver(cr, blocks, params->xtype, grid2, maxdiff); + if (ret <= maxdiff) { + for (j = 0; j < ncoords; j++) + grid[coords[2*j+1]*cr+coords[2*j]] = 0; } } memcpy(grid2, grid, area); - } while (nsolve(c, r, grid2) < maxdiff); + + if (solver(cr, blocks, params->xtype, grid2, maxdiff) == maxdiff) + break; /* found one! */ + } sfree(grid2); sfree(locs); @@ -1578,7 +2454,7 @@ static char *new_game_desc(game_params *params, random_state *rs, char *p; int run, i; - desc = snewn(5 * area, char); + desc = snewn(7 * area, char); p = desc; run = 0; for (i = 0; i <= area; i++) { @@ -1609,7 +2485,60 @@ static char *new_game_desc(game_params *params, random_state *rs, run = 0; } } - assert(p - desc < 5 * area); + + if (r == 1) { + int currrun = 0; + + *p++ = ','; + + /* + * Encode the block structure. We do this by encoding + * the pattern of dividing lines: first we iterate + * over the cr*(cr-1) internal vertical grid lines in + * ordinary reading order, then over the cr*(cr-1) + * internal horizontal ones in transposed reading + * order. + * + * We encode the number of non-lines between the + * lines; _ means zero (two adjacent divisions), a + * means 1, ..., y means 25, and z means 25 non-lines + * _and no following line_ (so that za means 26, zb 27 + * etc). + */ + for (i = 0; i <= 2*cr*(cr-1); i++) { + int p0, p1, edge; + + if (i == 2*cr*(cr-1)) { + edge = TRUE; /* terminating virtual edge */ + } else { + if (i < cr*(cr-1)) { + y = i/(cr-1); + x = i%(cr-1); + p0 = y*cr+x; + p1 = y*cr+x+1; + } else { + x = i/(cr-1) - cr; + y = i%(cr-1); + p0 = y*cr+x; + p1 = (y+1)*cr+x; + } + edge = (blocks->whichblock[p0] != blocks->whichblock[p1]); + } + + if (edge) { + while (currrun > 25) + *p++ = 'z', currrun -= 25; + if (currrun) + *p++ = 'a'-1 + currrun; + else + *p++ = '_'; + currrun = 0; + } else + currrun++; + } + } + + assert(p - desc < 7 * area); *p++ = '\0'; desc = sresize(desc, p - desc, char); } @@ -1619,24 +2548,22 @@ static char *new_game_desc(game_params *params, random_state *rs, return desc; } -static void game_free_aux_info(game_aux_info *aux) -{ - sfree(aux->grid); - sfree(aux); -} - static char *validate_desc(game_params *params, char *desc) { - int area = params->r * params->r * params->c * params->c; + int cr = params->c * params->r, area = cr*cr; int squares = 0; + int *dsf; - while (*desc) { + while (*desc && *desc != ',') { int n = *desc++; if (n >= 'a' && n <= 'z') { squares += n - 'a' + 1; } else if (n == '_') { /* do nothing */; } else if (n > '0' && n <= '9') { + int val = atoi(desc-1); + if (val < 1 || val > params->c * params->r) + return "Out-of-range number in game description"; squares++; while (*desc >= '0' && *desc <= '9') desc++; @@ -1650,17 +2577,151 @@ static char *validate_desc(game_params *params, char *desc) if (squares > area) return "Too much data to fit in grid"; + if (params->r == 1) { + int pos; + + /* + * Now we expect a suffix giving the jigsaw block + * structure. Parse it and validate that it divides the + * grid into the right number of regions which are the + * right size. + */ + if (*desc != ',') + return "Expected jigsaw block structure in game description"; + pos = 0; + + dsf = snew_dsf(area); + desc++; + + while (*desc) { + int c, adv; + + if (*desc == '_') + c = 0; + else if (*desc >= 'a' && *desc <= 'z') + c = *desc - 'a' + 1; + else { + sfree(dsf); + return "Invalid character in game description"; + } + desc++; + + adv = (c != 25); /* 'z' is a special case */ + + while (c-- > 0) { + int p0, p1; + + /* + * Non-edge; merge the two dsf classes on either + * side of it. + */ + if (pos >= 2*cr*(cr-1)) { + sfree(dsf); + return "Too much data in block structure specification"; + } else if (pos < cr*(cr-1)) { + int y = pos/(cr-1); + int x = pos%(cr-1); + p0 = y*cr+x; + p1 = y*cr+x+1; + } else { + int x = pos/(cr-1) - cr; + int y = pos%(cr-1); + p0 = y*cr+x; + p1 = (y+1)*cr+x; + } + dsf_merge(dsf, p0, p1); + + pos++; + } + if (adv) + pos++; + } + + /* + * When desc is exhausted, we expect to have gone exactly + * one space _past_ the end of the grid, due to the dummy + * edge at the end. + */ + if (pos != 2*cr*(cr-1)+1) { + sfree(dsf); + return "Not enough data in block structure specification"; + } + + /* + * Now we've got our dsf. Verify that it matches + * expectations. + */ + { + int *canons, *counts; + int i, j, c, ncanons = 0; + + canons = snewn(cr, int); + counts = snewn(cr, int); + + for (i = 0; i < area; i++) { + j = dsf_canonify(dsf, i); + + for (c = 0; c < ncanons; c++) + if (canons[c] == j) { + counts[c]++; + if (counts[c] > cr) { + sfree(dsf); + sfree(canons); + sfree(counts); + return "A jigsaw block is too big"; + } + break; + } + + if (c == ncanons) { + if (ncanons >= cr) { + sfree(dsf); + sfree(canons); + sfree(counts); + return "Too many distinct jigsaw blocks"; + } + canons[ncanons] = j; + counts[ncanons] = 1; + ncanons++; + } + } + + /* + * If we've managed to get through that loop without + * tripping either of the error conditions, then we + * must have partitioned the entire grid into at most + * cr blocks of at most cr squares each; therefore we + * must have _exactly_ cr blocks of _exactly_ cr + * squares each. I'll verify that by assertion just in + * case something has gone horribly wrong, but it + * shouldn't have been able to happen by duff input, + * only by a bug in the above code. + */ + assert(ncanons == cr); + for (c = 0; c < ncanons; c++) + assert(counts[c] == cr); + + sfree(canons); + sfree(counts); + } + + sfree(dsf); + } else { + if (*desc) + return "Unexpected jigsaw block structure in game description"; + } + return NULL; } -static game_state *new_game(midend_data *me, game_params *params, char *desc) +static game_state *new_game(midend *me, game_params *params, char *desc) { game_state *state = snew(game_state); int c = params->c, r = params->r, cr = c*r, area = cr * cr; int i; - state->c = params->c; - state->r = params->r; + state->cr = cr; + state->xtype = params->xtype; state->grid = snewn(area, digit); state->pencil = snewn(area * cr, unsigned char); @@ -1668,10 +2729,21 @@ static game_state *new_game(midend_data *me, game_params *params, char *desc) state->immutable = snewn(area, unsigned char); memset(state->immutable, FALSE, area); + state->blocks = snew(struct block_structure); + state->blocks->c = c; state->blocks->r = r; + state->blocks->refcount = 1; + state->blocks->whichblock = snewn(area*2, int); + state->blocks->blocks = snewn(cr, int *); + for (i = 0; i < cr; i++) + state->blocks->blocks[i] = state->blocks->whichblock + area + i*cr; +#ifdef STANDALONE_SOLVER + state->blocks->blocknames = (char **)smalloc(cr*(sizeof(char *)+80)); +#endif + state->completed = state->cheated = FALSE; i = 0; - while (*desc) { + while (*desc && *desc != ',') { int n = *desc++; if (n >= 'a' && n <= 'z') { int run = n - 'a' + 1; @@ -1692,16 +2764,147 @@ static game_state *new_game(midend_data *me, game_params *params, char *desc) } assert(i == area); + if (r == 1) { + int pos = 0; + int *dsf; + int nb; + + assert(*desc == ','); + + dsf = snew_dsf(area); + desc++; + + while (*desc) { + int c, adv; + + if (*desc == '_') + c = 0; + else { + assert(*desc >= 'a' && *desc <= 'z'); + c = *desc - 'a' + 1; + } + desc++; + + adv = (c != 25); /* 'z' is a special case */ + + while (c-- > 0) { + int p0, p1; + + /* + * Non-edge; merge the two dsf classes on either + * side of it. + */ + assert(pos < 2*cr*(cr-1)); + if (pos < cr*(cr-1)) { + int y = pos/(cr-1); + int x = pos%(cr-1); + p0 = y*cr+x; + p1 = y*cr+x+1; + } else { + int x = pos/(cr-1) - cr; + int y = pos%(cr-1); + p0 = y*cr+x; + p1 = (y+1)*cr+x; + } + dsf_merge(dsf, p0, p1); + + pos++; + } + if (adv) + pos++; + } + + /* + * When desc is exhausted, we expect to have gone exactly + * one space _past_ the end of the grid, due to the dummy + * edge at the end. + */ + assert(pos == 2*cr*(cr-1)+1); + + /* + * Now we've got our dsf. Translate it into a block + * structure. + */ + nb = 0; + for (i = 0; i < area; i++) + state->blocks->whichblock[i] = -1; + for (i = 0; i < area; i++) { + int j = dsf_canonify(dsf, i); + if (state->blocks->whichblock[j] < 0) + state->blocks->whichblock[j] = nb++; + state->blocks->whichblock[i] = state->blocks->whichblock[j]; + } + assert(nb == cr); + + sfree(dsf); + } else { + int x, y; + + assert(!*desc); + + for (y = 0; y < cr; y++) + for (x = 0; x < cr; x++) + state->blocks->whichblock[y*cr+x] = (y/c) * c + (x/r); + } + + /* + * Having sorted out whichblock[], set up the block index arrays. + */ + for (i = 0; i < cr; i++) + state->blocks->blocks[i][cr-1] = 0; + for (i = 0; i < area; i++) { + int b = state->blocks->whichblock[i]; + int j = state->blocks->blocks[b][cr-1]++; + assert(j < cr); + state->blocks->blocks[b][j] = i; + } + +#ifdef STANDALONE_SOLVER + /* + * Set up the block names for solver diagnostic output. + */ + { + char *p = (char *)(state->blocks->blocknames + cr); + + if (r == 1) { + for (i = 0; i < cr; i++) + state->blocks->blocknames[i] = NULL; + + for (i = 0; i < area; i++) { + int j = state->blocks->whichblock[i]; + if (!state->blocks->blocknames[j]) { + state->blocks->blocknames[j] = p; + p += 1 + sprintf(p, "starting at (%d,%d)", + 1 + i%cr, 1 + i/cr); + } + } + } else { + int bx, by; + for (by = 0; by < r; by++) + for (bx = 0; bx < c; bx++) { + state->blocks->blocknames[by*c+bx] = p; + p += 1 + sprintf(p, "(%d,%d)", bx+1, by+1); + } + } + assert(p - (char *)state->blocks->blocknames < cr*(sizeof(char *)+80)); + for (i = 0; i < cr; i++) + assert(state->blocks->blocknames[i]); + } +#endif + return state; } static game_state *dup_game(game_state *state) { game_state *ret = snew(game_state); - int c = state->c, r = state->r, cr = c*r, area = cr * cr; + int cr = state->cr, area = cr * cr; - ret->c = state->c; - ret->r = state->r; + ret->cr = state->cr; + ret->xtype = state->xtype; + + ret->blocks = state->blocks; + ret->blocks->refcount++; ret->grid = snewn(area, digit); memcpy(ret->grid, state->grid, area); @@ -1720,108 +2923,254 @@ static game_state *dup_game(game_state *state) static void free_game(game_state *state) { + if (--state->blocks->refcount == 0) { + sfree(state->blocks->whichblock); + sfree(state->blocks->blocks); +#ifdef STANDALONE_SOLVER + sfree(state->blocks->blocknames); +#endif + sfree(state->blocks); + } sfree(state->immutable); sfree(state->pencil); sfree(state->grid); sfree(state); } -static game_state *solve_game(game_state *state, game_aux_info *ai, - char **error) +static char *solve_game(game_state *state, game_state *currstate, + char *ai, char **error) { - game_state *ret; - int c = state->c, r = state->r, cr = c*r; - int rsolve_ret; - - ret = dup_game(state); - ret->completed = ret->cheated = TRUE; + int cr = state->cr; + char *ret; + digit *grid; + int solve_ret; /* - * If we already have the solution in the aux_info, save - * ourselves some time. + * If we already have the solution in ai, save ourselves some + * time. */ - if (ai) { + if (ai) + return dupstr(ai); - assert(c == ai->c); - assert(r == ai->r); - memcpy(ret->grid, ai->grid, cr * cr * sizeof(digit)); + grid = snewn(cr*cr, digit); + memcpy(grid, state->grid, cr*cr); + solve_ret = solver(cr, state->blocks, state->xtype, grid, DIFF_RECURSIVE); - } else { - rsolve_ret = rsolve(c, r, ret->grid, NULL, 2); + *error = NULL; - if (rsolve_ret != 1) { - free_game(ret); - if (rsolve_ret == 0) - *error = "No solution exists for this puzzle"; - else - *error = "Multiple solutions exist for this puzzle"; - return NULL; - } + if (solve_ret == DIFF_IMPOSSIBLE) + *error = "No solution exists for this puzzle"; + else if (solve_ret == DIFF_AMBIGUOUS) + *error = "Multiple solutions exist for this puzzle"; + + if (*error) { + sfree(grid); + return NULL; } + ret = encode_solve_move(cr, grid); + + sfree(grid); + return ret; } -static char *grid_text_format(int c, int r, digit *grid) +static char *grid_text_format(int cr, struct block_structure *blocks, + int xtype, digit *grid) { - int cr = c*r; + int vmod, hmod; int x, y; - int maxlen; - char *ret, *p; + int totallen, linelen, nlines; + char *ret, *p, ch; + + /* + * For non-jigsaw Sudoku, we format in the way we always have, + * by having the digits unevenly spaced so that the dividing + * lines can fit in: + * + * . . | . . + * . . | . . + * ----+---- + * . . | . . + * . . | . . + * + * For jigsaw puzzles, however, we must leave space between + * _all_ pairs of digits for an optional dividing line, so we + * have to move to the rather ugly + * + * . . . . + * ------+------ + * . . | . . + * +---+ + * . . | . | . + * ------+ | + * . . . | . + * + * We deal with both cases using the same formatting code; we + * simply invent a vmod value such that there's a vertical + * dividing line before column i iff i is divisible by vmod + * (so it's r in the first case and 1 in the second), and hmod + * likewise for horizontal dividing lines. + */ + + if (blocks->r != 1) { + vmod = blocks->r; + hmod = blocks->c; + } else { + vmod = hmod = 1; + } /* - * There are cr lines of digits, plus r-1 lines of block - * separators. Each line contains cr digits, cr-1 separating - * spaces, and c-1 two-character block separators. Thus, the - * total length of a line is 2*cr+2*c-3 (not counting the - * newline), and there are cr+r-1 of them. + * Line length: we have cr digits, each with a space after it, + * and (cr-1)/vmod dividing lines, each with a space after it. + * The final space is replaced by a newline, but that doesn't + * affect the length. */ - maxlen = (cr+r-1) * (2*cr+2*c-2); - ret = snewn(maxlen+1, char); - p = ret; + linelen = 2*(cr + (cr-1)/vmod); + /* + * Number of lines: we have cr rows of digits, and (cr-1)/hmod + * dividing rows. + */ + nlines = cr + (cr-1)/hmod; + + /* + * Allocate the space. + */ + totallen = linelen * nlines; + ret = snewn(totallen+1, char); /* leave room for terminating NUL */ + + /* + * Write the text. + */ + p = ret; for (y = 0; y < cr; y++) { - for (x = 0; x < cr; x++) { - int ch = grid[y * cr + x]; - if (ch == 0) - ch = ' '; - else if (ch <= 9) - ch = '0' + ch; - else - ch = 'a' + ch-10; - *p++ = ch; - if (x+1 < cr) { - *p++ = ' '; - if ((x+1) % r == 0) { - *p++ = '|'; - *p++ = ' '; - } - } - } - *p++ = '\n'; - if (y+1 < cr && (y+1) % c == 0) { - for (x = 0; x < cr; x++) { - *p++ = '-'; - if (x+1 < cr) { - *p++ = '-'; - if ((x+1) % r == 0) { - *p++ = '+'; - *p++ = '-'; - } - } - } - *p++ = '\n'; - } + /* + * Row of digits. + */ + for (x = 0; x < cr; x++) { + /* + * Digit. + */ + digit d = grid[y*cr+x]; + + if (d == 0) { + /* + * Empty space: we usually write a dot, but we'll + * highlight spaces on the X-diagonals (in X mode) + * by using underscores instead. + */ + if (xtype && (ondiag0(y*cr+x) || ondiag1(y*cr+x))) + ch = '_'; + else + ch = '.'; + } else if (d <= 9) { + ch = '0' + d; + } else { + ch = 'a' + d-10; + } + + *p++ = ch; + if (x == cr-1) { + *p++ = '\n'; + continue; + } + *p++ = ' '; + + if ((x+1) % vmod) + continue; + + /* + * Optional dividing line. + */ + if (blocks->whichblock[y*cr+x] != blocks->whichblock[y*cr+x+1]) + ch = '|'; + else + ch = ' '; + *p++ = ch; + *p++ = ' '; + } + if (y == cr-1 || (y+1) % hmod) + continue; + + /* + * Dividing row. + */ + for (x = 0; x < cr; x++) { + int dwid; + int tl, tr, bl, br; + + /* + * Division between two squares. This varies + * complicatedly in length. + */ + dwid = 2; /* digit and its following space */ + if (x == cr-1) + dwid--; /* no following space at end of line */ + if (x > 0 && x % vmod == 0) + dwid++; /* preceding space after a divider */ + + if (blocks->whichblock[y*cr+x] != blocks->whichblock[(y+1)*cr+x]) + ch = '-'; + else + ch = ' '; + + while (dwid-- > 0) + *p++ = ch; + + if (x == cr-1) { + *p++ = '\n'; + break; + } + + if ((x+1) % vmod) + continue; + + /* + * Corner square. This is: + * - a space if all four surrounding squares are in + * the same block + * - a vertical line if the two left ones are in one + * block and the two right in another + * - a horizontal line if the two top ones are in one + * block and the two bottom in another + * - a plus sign in all other cases. (If we had a + * richer character set available we could break + * this case up further by doing fun things with + * line-drawing T-pieces.) + */ + tl = blocks->whichblock[y*cr+x]; + tr = blocks->whichblock[y*cr+x+1]; + bl = blocks->whichblock[(y+1)*cr+x]; + br = blocks->whichblock[(y+1)*cr+x+1]; + + if (tl == tr && tr == bl && bl == br) + ch = ' '; + else if (tl == bl && tr == br) + ch = '|'; + else if (tl == tr && bl == br) + ch = '-'; + else + ch = '+'; + + *p++ = ch; + } } - assert(p - ret == maxlen); + assert(p - ret == totallen); *p = '\0'; return ret; } +static int game_can_format_as_text_now(game_params *params) +{ + return TRUE; +} + static char *game_text_format(game_state *state) { - return grid_text_format(state->c, state->r, state->grid); + return grid_text_format(state->cr, state->blocks, state->xtype, + state->grid); } struct game_ui { @@ -1854,10 +3203,19 @@ static void free_ui(game_ui *ui) sfree(ui); } +static char *encode_ui(game_ui *ui) +{ + return NULL; +} + +static void decode_ui(game_ui *ui, char *encoding) +{ +} + static void game_changed_state(game_ui *ui, game_state *oldstate, game_state *newstate) { - int c = newstate->c, r = newstate->r, cr = c*r; + int cr = newstate->cr; /* * We prevent pencil-mode highlighting of a filled square. So * if the user has just filled in a square which we had a @@ -1872,7 +3230,7 @@ static void game_changed_state(game_ui *ui, game_state *oldstate, struct game_drawstate { int started; - int c, r, cr; + int cr, xtype; int tilesize; digit *grid; unsigned char *pencil; @@ -1881,12 +3239,12 @@ struct game_drawstate { int *entered_items; }; -static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, - int x, int y, int button) +static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, + int x, int y, int button) { - int c = from->c, r = from->r, cr = c*r; + int cr = state->cr; int tx, ty; - game_state *ret; + char buf[80]; button &= ~MOD_MASK; @@ -1895,7 +3253,7 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, if (tx >= 0 && tx < cr && ty >= 0 && ty < cr) { if (button == LEFT_BUTTON) { - if (from->immutable[ty*cr+tx]) { + if (state->immutable[ty*cr+tx]) { ui->hx = ui->hy = -1; } else if (tx == ui->hx && ty == ui->hy && ui->hpencil == 0) { ui->hx = ui->hy = -1; @@ -1904,13 +3262,13 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, ui->hy = ty; ui->hpencil = 0; } - return from; /* UI activity occurred */ + return ""; /* UI activity occurred */ } if (button == RIGHT_BUTTON) { /* * Pencil-mode highlighting for non filled squares. */ - if (from->grid[ty*cr+tx] == 0) { + if (state->grid[ty*cr+tx] == 0) { if (tx == ui->hx && ty == ui->hy && ui->hpencil) { ui->hx = ui->hy = -1; } else { @@ -1921,7 +3279,7 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, } else { ui->hx = ui->hy = -1; } - return from; /* UI activity occurred */ + return ""; /* UI activity occurred */ } } @@ -1929,13 +3287,13 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, ((button >= '1' && button <= '9' && button - '0' <= cr) || (button >= 'a' && button <= 'z' && button - 'a' + 10 <= cr) || (button >= 'A' && button <= 'Z' && button - 'A' + 10 <= cr) || - button == ' ')) { + button == ' ' || button == '\010' || button == '\177')) { int n = button - '0'; if (button >= 'A' && button <= 'Z') n = button - 'A' + 10; if (button >= 'a' && button <= 'z') n = button - 'a' + 10; - if (button == ' ') + if (button == ' ' || button == '\010' || button == '\177') n = 0; /* @@ -1944,7 +3302,7 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, * able to highlight the square, but it never hurts to be * careful. */ - if (from->immutable[ui->hy*cr+ui->hx]) + if (state->immutable[ui->hy*cr+ui->hx]) return NULL; /* @@ -1953,31 +3311,70 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, * have even been able to pencil-highlight the square, but * it never hurts to be careful. */ - if (ui->hpencil && from->grid[ui->hy*cr+ui->hx]) + if (ui->hpencil && state->grid[ui->hy*cr+ui->hx]) return NULL; + sprintf(buf, "%c%d,%d,%d", + (char)(ui->hpencil && n > 0 ? 'P' : 'R'), ui->hx, ui->hy, n); + + ui->hx = ui->hy = -1; + + return dupstr(buf); + } + + return NULL; +} + +static game_state *execute_move(game_state *from, char *move) +{ + int cr = from->cr; + game_state *ret; + int x, y, n; + + if (move[0] == 'S') { + char *p; + + ret = dup_game(from); + ret->completed = ret->cheated = TRUE; + + p = move+1; + for (n = 0; n < cr*cr; n++) { + ret->grid[n] = atoi(p); + + if (!*p || ret->grid[n] < 1 || ret->grid[n] > cr) { + free_game(ret); + return NULL; + } + + while (*p && isdigit((unsigned char)*p)) p++; + if (*p == ',') p++; + } + + return ret; + } else if ((move[0] == 'P' || move[0] == 'R') && + sscanf(move+1, "%d,%d,%d", &x, &y, &n) == 3 && + x >= 0 && x < cr && y >= 0 && y < cr && n >= 0 && n <= cr) { + ret = dup_game(from); - if (ui->hpencil && n > 0) { - int index = (ui->hy*cr+ui->hx) * cr + (n-1); + if (move[0] == 'P' && n > 0) { + int index = (y*cr+x) * cr + (n-1); ret->pencil[index] = !ret->pencil[index]; } else { - ret->grid[ui->hy*cr+ui->hx] = n; - memset(ret->pencil + (ui->hy*cr+ui->hx)*cr, 0, cr); + ret->grid[y*cr+x] = n; + memset(ret->pencil + (y*cr+x)*cr, 0, cr); /* * We've made a real change to the grid. Check to see * if the game has been completed. */ - if (!ret->completed && check_valid(c, r, ret->grid)) { + if (!ret->completed && check_valid(cr, ret->blocks, ret->xtype, + ret->grid)) { ret->completed = TRUE; } } - ui->hx = ui->hy = -1; - - return ret; /* made a valid move */ - } - - return NULL; + return ret; + } else + return NULL; /* couldn't parse move string */ } /* ---------------------------------------------------------------------- @@ -1985,30 +3382,35 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, */ #define SIZE(cr) ((cr) * TILE_SIZE + 2*BORDER + 1) -#define GETTILESIZE(cr, w) ( (w-1) / (cr+1) ) +#define GETTILESIZE(cr, w) ( (double)(w-1) / (double)(cr+1) ) -static void game_size(game_params *params, game_drawstate *ds, - int *x, int *y, int expand) +static void game_compute_size(game_params *params, int tilesize, + int *x, int *y) { - int c = params->c, r = params->r, cr = c*r; - int ts; + /* Ick: fake up `ds->tilesize' for macro expansion purposes */ + struct { int tilesize; } ads, *ds = &ads; + ads.tilesize = tilesize; - ts = min(GETTILESIZE(cr, *x), GETTILESIZE(cr, *y)); - if (expand) - ds->tilesize = ts; - else - ds->tilesize = min(ts, PREFERRED_TILE_SIZE); + *x = SIZE(params->c * params->r); + *y = SIZE(params->c * params->r); +} - *x = SIZE(cr); - *y = SIZE(cr); +static void game_set_size(drawing *dr, game_drawstate *ds, + game_params *params, int tilesize) +{ + ds->tilesize = tilesize; } -static float *game_colours(frontend *fe, game_state *state, int *ncolours) +static float *game_colours(frontend *fe, int *ncolours) { float *ret = snewn(3 * NCOLOURS, float); frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); + ret[COL_XDIAGONALS * 3 + 0] = 0.9F * ret[COL_BACKGROUND * 3 + 0]; + ret[COL_XDIAGONALS * 3 + 1] = 0.9F * ret[COL_BACKGROUND * 3 + 1]; + ret[COL_XDIAGONALS * 3 + 2] = 0.9F * ret[COL_BACKGROUND * 3 + 2]; + ret[COL_GRID * 3 + 0] = 0.0F; ret[COL_GRID * 3 + 1] = 0.0F; ret[COL_GRID * 3 + 2] = 0.0F; @@ -2021,9 +3423,9 @@ static float *game_colours(frontend *fe, game_state *state, int *ncolours) ret[COL_USER * 3 + 1] = 0.6F * ret[COL_BACKGROUND * 3 + 1]; ret[COL_USER * 3 + 2] = 0.0F; - ret[COL_HIGHLIGHT * 3 + 0] = 0.85F * ret[COL_BACKGROUND * 3 + 0]; - ret[COL_HIGHLIGHT * 3 + 1] = 0.85F * ret[COL_BACKGROUND * 3 + 1]; - ret[COL_HIGHLIGHT * 3 + 2] = 0.85F * ret[COL_BACKGROUND * 3 + 2]; + ret[COL_HIGHLIGHT * 3 + 0] = 0.78F * ret[COL_BACKGROUND * 3 + 0]; + ret[COL_HIGHLIGHT * 3 + 1] = 0.78F * ret[COL_BACKGROUND * 3 + 1]; + ret[COL_HIGHLIGHT * 3 + 2] = 0.78F * ret[COL_BACKGROUND * 3 + 2]; ret[COL_ERROR * 3 + 0] = 1.0F; ret[COL_ERROR * 3 + 1] = 0.0F; @@ -2037,17 +3439,16 @@ static float *game_colours(frontend *fe, game_state *state, int *ncolours) return ret; } -static game_drawstate *game_new_drawstate(game_state *state) +static game_drawstate *game_new_drawstate(drawing *dr, game_state *state) { struct game_drawstate *ds = snew(struct game_drawstate); - int c = state->c, r = state->r, cr = c*r; + int cr = state->cr; ds->started = FALSE; - ds->c = c; - ds->r = r; ds->cr = cr; + ds->xtype = state->xtype; ds->grid = snewn(cr*cr, digit); - memset(ds->grid, 0, cr*cr); + memset(ds->grid, cr+2, cr*cr); ds->pencil = snewn(cr*cr*cr, digit); memset(ds->pencil, 0, cr*cr*cr); ds->hl = snewn(cr*cr, unsigned char); @@ -2057,7 +3458,7 @@ static game_drawstate *game_new_drawstate(game_state *state) return ds; } -static void game_free_drawstate(game_drawstate *ds) +static void game_free_drawstate(drawing *dr, game_drawstate *ds) { sfree(ds->hl); sfree(ds->pencil); @@ -2066,10 +3467,10 @@ static void game_free_drawstate(game_drawstate *ds) sfree(ds); } -static void draw_number(frontend *fe, game_drawstate *ds, game_state *state, +static void draw_number(drawing *dr, game_drawstate *ds, game_state *state, int x, int y, int hl) { - int c = state->c, r = state->r, cr = c*r; + int cr = state->cr; int tx, ty; int cx, cy, cw, ch; char str[2]; @@ -2079,27 +3480,43 @@ static void draw_number(frontend *fe, game_drawstate *ds, game_state *state, !memcmp(ds->pencil+(y*cr+x)*cr, state->pencil+(y*cr+x)*cr, cr)) return; /* no change required */ - tx = BORDER + x * TILE_SIZE + 2; - ty = BORDER + y * TILE_SIZE + 2; + tx = BORDER + x * TILE_SIZE + 1 + GRIDEXTRA; + ty = BORDER + y * TILE_SIZE + 1 + GRIDEXTRA; cx = tx; cy = ty; - cw = TILE_SIZE-3; - ch = TILE_SIZE-3; + cw = TILE_SIZE-1-2*GRIDEXTRA; + ch = TILE_SIZE-1-2*GRIDEXTRA; - if (x % r) - cx--, cw++; - if ((x+1) % r) - cw++; - if (y % c) - cy--, ch++; - if ((y+1) % c) - ch++; + if (x > 0 && state->blocks->whichblock[y*cr+x] == state->blocks->whichblock[y*cr+x-1]) + cx -= GRIDEXTRA, cw += GRIDEXTRA; + if (x+1 < cr && state->blocks->whichblock[y*cr+x] == state->blocks->whichblock[y*cr+x+1]) + cw += GRIDEXTRA; + if (y > 0 && state->blocks->whichblock[y*cr+x] == state->blocks->whichblock[(y-1)*cr+x]) + cy -= GRIDEXTRA, ch += GRIDEXTRA; + if (y+1 < cr && state->blocks->whichblock[y*cr+x] == state->blocks->whichblock[(y+1)*cr+x]) + ch += GRIDEXTRA; - clip(fe, cx, cy, cw, ch); + clip(dr, cx, cy, cw, ch); /* background needs erasing */ - draw_rect(fe, cx, cy, cw, ch, (hl & 15) == 1 ? COL_HIGHLIGHT : COL_BACKGROUND); + draw_rect(dr, cx, cy, cw, ch, + ((hl & 15) == 1 ? COL_HIGHLIGHT : + (ds->xtype && (ondiag0(y*cr+x) || ondiag1(y*cr+x))) ? COL_XDIAGONALS : + COL_BACKGROUND)); + + /* + * Draw the corners of thick lines in corner-adjacent squares, + * which jut into this square by one pixel. + */ + if (x > 0 && y > 0 && state->blocks->whichblock[y*cr+x] != state->blocks->whichblock[(y-1)*cr+x-1]) + draw_rect(dr, tx-GRIDEXTRA, ty-GRIDEXTRA, GRIDEXTRA, GRIDEXTRA, COL_GRID); + if (x+1 < cr && y > 0 && state->blocks->whichblock[y*cr+x] != state->blocks->whichblock[(y-1)*cr+x+1]) + draw_rect(dr, tx+TILE_SIZE-1-2*GRIDEXTRA, ty-GRIDEXTRA, GRIDEXTRA, GRIDEXTRA, COL_GRID); + if (x > 0 && y+1 < cr && state->blocks->whichblock[y*cr+x] != state->blocks->whichblock[(y+1)*cr+x-1]) + draw_rect(dr, tx-GRIDEXTRA, ty+TILE_SIZE-1-2*GRIDEXTRA, GRIDEXTRA, GRIDEXTRA, COL_GRID); + if (x+1 < cr && y+1 < cr && state->blocks->whichblock[y*cr+x] != state->blocks->whichblock[(y+1)*cr+x+1]) + draw_rect(dr, tx+TILE_SIZE-1-2*GRIDEXTRA, ty+TILE_SIZE-1-2*GRIDEXTRA, GRIDEXTRA, GRIDEXTRA, COL_GRID); /* pencil-mode highlight */ if ((hl & 15) == 2) { @@ -2110,7 +3527,7 @@ static void draw_number(frontend *fe, game_drawstate *ds, game_state *state, coords[3] = cy; coords[4] = cx; coords[5] = cy+ch/2; - draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT); + draw_polygon(dr, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT); } /* new number needs drawing? */ @@ -2119,7 +3536,7 @@ static void draw_number(frontend *fe, game_drawstate *ds, game_state *state, str[0] = state->grid[y*cr+x] + '0'; if (str[0] > '9') str[0] += 'a' - ('9'+1); - draw_text(fe, tx + TILE_SIZE/2, ty + TILE_SIZE/2, + draw_text(dr, tx + TILE_SIZE/2, ty + TILE_SIZE/2, FONT_VARIABLE, TILE_SIZE/2, ALIGN_VCENTRE | ALIGN_HCENTRE, state->immutable[y*cr+x] ? COL_CLUE : (hl & 16) ? COL_ERROR : COL_USER, str); } else { @@ -2154,7 +3571,7 @@ static void draw_number(frontend *fe, game_drawstate *ds, game_state *state, str[0] = i + '1'; if (str[0] > '9') str[0] += 'a' - ('9'+1); - draw_text(fe, tx + (4*dx+3) * TILE_SIZE / (4*pw+2), + draw_text(dr, tx + (4*dx+3) * TILE_SIZE / (4*pw+2), ty + (4*dy+3) * TILE_SIZE / (4*ph+2), FONT_VARIABLE, fontsize, ALIGN_VCENTRE | ALIGN_HCENTRE, COL_PENCIL, str); @@ -2162,20 +3579,20 @@ static void draw_number(frontend *fe, game_drawstate *ds, game_state *state, } } - unclip(fe); + unclip(dr); - draw_update(fe, cx, cy, cw, ch); + draw_update(dr, cx, cy, cw, ch); ds->grid[y*cr+x] = state->grid[y*cr+x]; memcpy(ds->pencil+(y*cr+x)*cr, state->pencil+(y*cr+x)*cr, cr); ds->hl[y*cr+x] = hl; } -static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, +static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate, game_state *state, int dir, game_ui *ui, float animtime, float flashtime) { - int c = state->c, r = state->r, cr = c*r; + int cr = state->cr; int x, y; if (!ds->started) { @@ -2185,21 +3602,16 @@ static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, * all games should start by drawing a big * background-colour rectangle covering the whole window. */ - draw_rect(fe, 0, 0, SIZE(cr), SIZE(cr), COL_BACKGROUND); + draw_rect(dr, 0, 0, SIZE(cr), SIZE(cr), COL_BACKGROUND); /* - * Draw the grid. + * Draw the grid. We draw it as a big thick rectangle of + * COL_GRID initially; individual calls to draw_number() + * will poke the right-shaped holes in it. */ - for (x = 0; x <= cr; x++) { - int thick = (x % r ? 0 : 1); - draw_rect(fe, BORDER + x*TILE_SIZE - thick, BORDER-1, - 1+2*thick, cr*TILE_SIZE+3, COL_GRID); - } - for (y = 0; y <= cr; y++) { - int thick = (y % c ? 0 : 1); - draw_rect(fe, BORDER-1, BORDER + y*TILE_SIZE - thick, - cr*TILE_SIZE+3, 1+2*thick, COL_GRID); - } + draw_rect(dr, BORDER-GRIDEXTRA, BORDER-GRIDEXTRA, + cr*TILE_SIZE+1+2*GRIDEXTRA, cr*TILE_SIZE+1+2*GRIDEXTRA, + COL_GRID); } /* @@ -2212,10 +3624,16 @@ static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, for (y = 0; y < cr; y++) { digit d = state->grid[y*cr+x]; if (d) { - int box = (x/r)+(y/c)*c; - ds->entered_items[x*cr+d-1] |= ((ds->entered_items[x*cr+d-1] & 1) << 1) | 1; + int box = state->blocks->whichblock[y*cr+x]; + ds->entered_items[x*cr+d-1] |= ((ds->entered_items[x*cr+d-1] & 1) << 1) | 1; ds->entered_items[y*cr+d-1] |= ((ds->entered_items[y*cr+d-1] & 4) << 1) | 4; ds->entered_items[box*cr+d-1] |= ((ds->entered_items[box*cr+d-1] & 16) << 1) | 16; + if (ds->xtype) { + if (ondiag0(y*cr+x)) + ds->entered_items[d-1] |= ((ds->entered_items[d-1] & 64) << 1) | 64; + if (ondiag1(y*cr+x)) + ds->entered_items[cr+d-1] |= ((ds->entered_items[cr+d-1] & 64) << 1) | 64; + } } } @@ -2240,10 +3658,12 @@ static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, * in a single row, column, or box). */ if (d && ((ds->entered_items[x*cr+d-1] & 2) || (ds->entered_items[y*cr+d-1] & 8) || - (ds->entered_items[((x/r)+(y/c)*c)*cr+d-1] & 32))) + (ds->entered_items[state->blocks->whichblock[y*cr+x]*cr+d-1] & 32) || + (ds->xtype && ((ondiag0(y*cr+x) && (ds->entered_items[d-1] & 128)) || + (ondiag1(y*cr+x) && (ds->entered_items[cr+d-1] & 128)))))) highlight |= 16; - draw_number(fe, ds, state, x, y, highlight); + draw_number(dr, ds, state, x, y, highlight); } } @@ -2251,7 +3671,7 @@ static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, * Update the _entire_ grid if necessary. */ if (!ds->started) { - draw_update(fe, 0, 0, SIZE(cr), SIZE(cr)); + draw_update(dr, 0, 0, SIZE(cr), SIZE(cr)); ds->started = TRUE; } } @@ -2271,14 +3691,233 @@ static float game_flash_length(game_state *oldstate, game_state *newstate, return 0.0F; } -static int game_wants_statusbar(void) +static int game_timing_state(game_state *state, game_ui *ui) +{ + return TRUE; +} + +static void game_print_size(game_params *params, float *x, float *y) { - return FALSE; + int pw, ph; + + /* + * I'll use 9mm squares by default. They should be quite big + * for this game, because players will want to jot down no end + * of pencil marks in the squares. + */ + game_compute_size(params, 900, &pw, &ph); + *x = pw / 100.0; + *y = ph / 100.0; } -static int game_timing_state(game_state *state) +static void game_print(drawing *dr, game_state *state, int tilesize) { - return TRUE; + int cr = state->cr; + int ink = print_mono_colour(dr, 0); + int x, y; + + /* Ick: fake up `ds->tilesize' for macro expansion purposes */ + game_drawstate ads, *ds = &ads; + game_set_size(dr, ds, NULL, tilesize); + + /* + * Border. + */ + print_line_width(dr, 3 * TILE_SIZE / 40); + draw_rect_outline(dr, BORDER, BORDER, cr*TILE_SIZE, cr*TILE_SIZE, ink); + + /* + * Highlight X-diagonal squares. + */ + if (state->xtype) { + int i; + int xhighlight = print_grey_colour(dr, 0.90F); + + for (i = 0; i < cr; i++) + draw_rect(dr, BORDER + i*TILE_SIZE, BORDER + i*TILE_SIZE, + TILE_SIZE, TILE_SIZE, xhighlight); + for (i = 0; i < cr; i++) + if (i*2 != cr-1) /* avoid redoing centre square, just for fun */ + draw_rect(dr, BORDER + i*TILE_SIZE, + BORDER + (cr-1-i)*TILE_SIZE, + TILE_SIZE, TILE_SIZE, xhighlight); + } + + /* + * Main grid. + */ + for (x = 1; x < cr; x++) { + print_line_width(dr, TILE_SIZE / 40); + draw_line(dr, BORDER+x*TILE_SIZE, BORDER, + BORDER+x*TILE_SIZE, BORDER+cr*TILE_SIZE, ink); + } + for (y = 1; y < cr; y++) { + print_line_width(dr, TILE_SIZE / 40); + draw_line(dr, BORDER, BORDER+y*TILE_SIZE, + BORDER+cr*TILE_SIZE, BORDER+y*TILE_SIZE, ink); + } + + /* + * Thick lines between cells. In order to do this using the + * line-drawing rather than rectangle-drawing API (so as to + * get line thicknesses to scale correctly) and yet have + * correctly mitred joins between lines, we must do this by + * tracing the boundary of each sub-block and drawing it in + * one go as a single polygon. + */ + { + int *coords; + int bi, i, n; + int x, y, dx, dy, sx, sy, sdx, sdy; + + print_line_width(dr, 3 * TILE_SIZE / 40); + + /* + * Maximum perimeter of a k-omino is 2k+2. (Proof: start + * with k unconnected squares, with total perimeter 4k. + * Now repeatedly join two disconnected components + * together into a larger one; every time you do so you + * remove at least two unit edges, and you require k-1 of + * these operations to create a single connected piece, so + * you must have at most 4k-2(k-1) = 2k+2 unit edges left + * afterwards.) + */ + coords = snewn(4*cr+4, int); /* 2k+2 points, 2 coords per point */ + + /* + * Iterate over all the blocks. + */ + for (bi = 0; bi < cr; bi++) { + + /* + * For each block, find a starting square within it + * which has a boundary at the left. + */ + for (i = 0; i < cr; i++) { + int j = state->blocks->blocks[bi][i]; + if (j % cr == 0 || state->blocks->whichblock[j-1] != bi) + break; + } + assert(i < cr); /* every block must have _some_ leftmost square */ + x = state->blocks->blocks[bi][i] % cr; + y = state->blocks->blocks[bi][i] / cr; + dx = -1; + dy = 0; + + /* + * Now begin tracing round the perimeter. At all + * times, (x,y) describes some square within the + * block, and (x+dx,y+dy) is some adjacent square + * outside it; so the edge between those two squares + * is always an edge of the block. + */ + sx = x, sy = y, sdx = dx, sdy = dy; /* save starting position */ + n = 0; + do { + int cx, cy, tx, ty, nin; + + /* + * To begin with, record the point at one end of + * the edge. To do this, we translate (x,y) down + * and right by half a unit (so they're describing + * a point in the _centre_ of the square) and then + * translate back again in a manner rotated by dy + * and dx. + */ + assert(n < 2*cr+2); + cx = ((2*x+1) + dy + dx) / 2; + cy = ((2*y+1) - dx + dy) / 2; + coords[2*n+0] = BORDER + cx * TILE_SIZE; + coords[2*n+1] = BORDER + cy * TILE_SIZE; + n++; + + /* + * Now advance to the next edge, by looking at the + * two squares beyond it. If they're both outside + * the block, we turn right (by leaving x,y the + * same and rotating dx,dy clockwise); if they're + * both inside, we turn left (by rotating dx,dy + * anticlockwise and contriving to leave x+dx,y+dy + * unchanged); if one of each, we go straight on + * (and may enforce by assertion that they're one + * of each the _right_ way round). + */ + nin = 0; + tx = x - dy + dx; + ty = y + dx + dy; + nin += (tx >= 0 && tx < cr && ty >= 0 && ty < cr && + state->blocks->whichblock[ty*cr+tx] == bi); + tx = x - dy; + ty = y + dx; + nin += (tx >= 0 && tx < cr && ty >= 0 && ty < cr && + state->blocks->whichblock[ty*cr+tx] == bi); + if (nin == 0) { + /* + * Turn right. + */ + int tmp; + tmp = dx; + dx = -dy; + dy = tmp; + } else if (nin == 2) { + /* + * Turn left. + */ + int tmp; + + x += dx; + y += dy; + + tmp = dx; + dx = dy; + dy = -tmp; + + x -= dx; + y -= dy; + } else { + /* + * Go straight on. + */ + x -= dy; + y += dx; + } + + /* + * Now enforce by assertion that we ended up + * somewhere sensible. + */ + assert(x >= 0 && x < cr && y >= 0 && y < cr && + state->blocks->whichblock[y*cr+x] == bi); + assert(x+dx < 0 || x+dx >= cr || y+dy < 0 || y+dy >= cr || + state->blocks->whichblock[(y+dy)*cr+(x+dx)] != bi); + + } while (x != sx || y != sy || dx != sdx || dy != sdy); + + /* + * That's our polygon; now draw it. + */ + draw_polygon(dr, coords, n, -1, ink); + } + + sfree(coords); + } + + /* + * Numbers. + */ + for (y = 0; y < cr; y++) + for (x = 0; x < cr; x++) + if (state->grid[y*cr+x]) { + char str[2]; + str[1] = '\0'; + str[0] = state->grid[y*cr+x] + '0'; + if (str[0] > '9') + str[0] += 'a' - ('9'+1); + draw_text(dr, BORDER + x*TILE_SIZE + TILE_SIZE/2, + BORDER + y*TILE_SIZE + TILE_SIZE/2, + FONT_VARIABLE, TILE_SIZE/2, + ALIGN_VCENTRE | ALIGN_HCENTRE, ink, str); + } } #ifdef COMBINED @@ -2286,7 +3925,7 @@ static int game_timing_state(game_state *state) #endif const struct game thegame = { - "Solo", "games.solo", + "Solo", "games.solo", "solo", default_params, game_fetch_preset, decode_params, @@ -2296,89 +3935,50 @@ const struct game thegame = { TRUE, game_configure, custom_params, validate_params, new_game_desc, - game_free_aux_info, validate_desc, new_game, dup_game, free_game, TRUE, solve_game, - TRUE, game_text_format, + TRUE, game_can_format_as_text_now, game_text_format, new_ui, free_ui, + encode_ui, + decode_ui, game_changed_state, - make_move, - game_size, + interpret_move, + execute_move, + PREFERRED_TILE_SIZE, game_compute_size, game_set_size, game_colours, game_new_drawstate, game_free_drawstate, game_redraw, game_anim_length, game_flash_length, - game_wants_statusbar, + TRUE, FALSE, game_print_size, game_print, + FALSE, /* wants_statusbar */ FALSE, game_timing_state, - 0, /* mouse_priorities */ + REQUIRE_RBUTTON | REQUIRE_NUMPAD, /* flags */ }; #ifdef STANDALONE_SOLVER -/* - * gcc -DSTANDALONE_SOLVER -o solosolver solo.c malloc.c - */ - -void frontend_default_colour(frontend *fe, float *output) {} -void draw_text(frontend *fe, int x, int y, int fonttype, int fontsize, - int align, int colour, char *text) {} -void draw_rect(frontend *fe, int x, int y, int w, int h, int colour) {} -void draw_line(frontend *fe, int x1, int y1, int x2, int y2, int colour) {} -void draw_polygon(frontend *fe, int *coords, int npoints, - int fill, int colour) {} -void clip(frontend *fe, int x, int y, int w, int h) {} -void unclip(frontend *fe) {} -void start_draw(frontend *fe) {} -void draw_update(frontend *fe, int x, int y, int w, int h) {} -void end_draw(frontend *fe) {} -unsigned long random_bits(random_state *state, int bits) -{ assert(!"Shouldn't get randomness"); return 0; } -unsigned long random_upto(random_state *state, unsigned long limit) -{ assert(!"Shouldn't get randomness"); return 0; } - -void fatal(char *fmt, ...) -{ - va_list ap; - - fprintf(stderr, "fatal error: "); - - va_start(ap, fmt); - vfprintf(stderr, fmt, ap); - va_end(ap); - - fprintf(stderr, "\n"); - exit(1); -} - int main(int argc, char **argv) { game_params *p; game_state *s; - int recurse = TRUE; char *id = NULL, *desc, *err; - int y, x; int grade = FALSE; + int ret; while (--argc > 0) { char *p = *++argv; - if (!strcmp(p, "-r")) { - recurse = TRUE; - } else if (!strcmp(p, "-n")) { - recurse = FALSE; - } else if (!strcmp(p, "-v")) { + if (!strcmp(p, "-v")) { solver_show_working = TRUE; - recurse = FALSE; } else if (!strcmp(p, "-g")) { grade = TRUE; - recurse = FALSE; } else if (*p == '-') { - fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0]); + fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p); return 1; } else { id = p; @@ -2386,7 +3986,7 @@ int main(int argc, char **argv) } if (!id) { - fprintf(stderr, "usage: %s [-n | -r | -g | -v] \n", argv[0]); + fprintf(stderr, "usage: %s [-g | -v] \n", argv[0]); return 1; } @@ -2406,42 +4006,22 @@ int main(int argc, char **argv) } s = new_game(NULL, p, desc); - if (recurse) { - int ret = rsolve(p->c, p->r, s->grid, NULL, 2); - if (ret > 1) { - fprintf(stderr, "%s: rsolve: multiple solutions detected\n", - argv[0]); - } + ret = solver(s->cr, s->blocks, s->xtype, s->grid, DIFF_RECURSIVE); + if (grade) { + printf("Difficulty rating: %s\n", + ret==DIFF_BLOCK ? "Trivial (blockwise positional elimination only)": + ret==DIFF_SIMPLE ? "Basic (row/column/number elimination required)": + ret==DIFF_INTERSECT ? "Intermediate (intersectional analysis required)": + ret==DIFF_SET ? "Advanced (set elimination required)": + ret==DIFF_EXTREME ? "Extreme (complex non-recursive techniques required)": + ret==DIFF_RECURSIVE ? "Unreasonable (guesswork and backtracking required)": + ret==DIFF_AMBIGUOUS ? "Ambiguous (multiple solutions exist)": + ret==DIFF_IMPOSSIBLE ? "Impossible (no solution exists)": + "INTERNAL ERROR: unrecognised difficulty code"); } else { - int ret = nsolve(p->c, p->r, s->grid); - if (grade) { - if (ret == DIFF_IMPOSSIBLE) { - /* - * Now resort to rsolve to determine whether it's - * really soluble. - */ - ret = rsolve(p->c, p->r, s->grid, NULL, 2); - if (ret == 0) - ret = DIFF_IMPOSSIBLE; - else if (ret == 1) - ret = DIFF_RECURSIVE; - else - ret = DIFF_AMBIGUOUS; - } - printf("Difficulty rating: %s\n", - ret==DIFF_BLOCK ? "Trivial (blockwise positional elimination only)": - ret==DIFF_SIMPLE ? "Basic (row/column/number elimination required)": - ret==DIFF_INTERSECT ? "Intermediate (intersectional analysis required)": - ret==DIFF_SET ? "Advanced (set elimination required)": - ret==DIFF_RECURSIVE ? "Unreasonable (guesswork and backtracking required)": - ret==DIFF_AMBIGUOUS ? "Ambiguous (multiple solutions exist)": - ret==DIFF_IMPOSSIBLE ? "Impossible (no solution exists)": - "INTERNAL ERROR: unrecognised difficulty code"); - } + printf("%s\n", grid_text_format(s->cr, s->blocks, s->xtype, s->grid)); } - printf("%s\n", grid_text_format(p->c, p->r, s->grid)); - return 0; }