--- /dev/null
+/*
+ * Experimental grid generator for Nikoli's `Number Link' puzzle.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include "puzzles.h"
+
+/*
+ * 2005-07-08: This is currently a Path grid generator which will
+ * construct valid grids at a plausible speed. However, the grids
+ * are not of suitable quality to be used directly as puzzles.
+ *
+ * The basic strategy is to start with an empty grid, and
+ * repeatedly either (a) add a new path to it, or (b) extend one
+ * end of a path by one square in some direction and push other
+ * paths into new shapes in the process. The effect of this is that
+ * we are able to construct a set of paths which between them fill
+ * the entire grid.
+ *
+ * Quality issues: if we set the main loop to do (a) where possible
+ * and (b) only where necessary, we end up with a grid containing a
+ * few too many small paths, which therefore doesn't make for an
+ * interesting puzzle. If we reverse the priority so that we do (b)
+ * where possible and (a) only where necessary, we end up with some
+ * staggeringly interwoven grids with very very few separate paths,
+ * but the result of this is that there's invariably a solution
+ * other than the intended one which leaves many grid squares
+ * unfilled. There's also a separate problem which is that many
+ * grids have really boring and obvious paths in them, such as the
+ * entire bottom row of the grid being taken up by a single path.
+ *
+ * It's not impossible that a few tweaks might eliminate or reduce
+ * the incidence of boring paths, and might also find a happy
+ * medium between too many and too few. There remains the question
+ * of unique solutions, however. I fear there is no alternative but
+ * to write - somehow! - a solver.
+ *
+ * While I'm here, some notes on UI strategy for the parts of the
+ * puzzle implementation that _aren't_ the generator:
+ *
+ * - data model is to track connections between adjacent squares,
+ * so that you aren't limited to extending a path out from each
+ * number but can also mark sections of path which you know
+ * _will_ come in handy later.
+ *
+ * - user interface is to click in one square and drag to an
+ * adjacent one, thus creating a link between them. We can
+ * probably tolerate rapid mouse motion causing a drag directly
+ * to a square which is a rook move away, but any other rapid
+ * motion is ambiguous and probably the best option is to wait
+ * until the mouse returns to a square we know how to reach.
+ *
+ * - a drag causing the current path to backtrack has the effect
+ * of removing bits of it.
+ *
+ * - the UI should enforce at all times the constraint that at
+ * most two links can come into any square.
+ *
+ * - my Cunning Plan for actually implementing this: the game_ui
+ * contains a grid-sized array, which is copied from the current
+ * game_state on starting a drag. While a drag is active, the
+ * contents of the game_ui is adjusted with every mouse motion,
+ * and is displayed _in place_ of the game_state itself. On
+ * termination of a drag, the game_ui array is copied back into
+ * the new game_state (or rather, a string move is encoded which
+ * has precisely the set of link changes to cause that effect).
+ */
+
+/*
+ * Standard notation for directions.
+ */
+#define L 0
+#define U 1
+#define R 2
+#define D 3
+#define DX(dir) ( (dir)==L ? -1 : (dir)==R ? +1 : 0)
+#define DY(dir) ( (dir)==U ? -1 : (dir)==D ? +1 : 0)
+
+/*
+ * Perform a breadth-first search over a grid of squares with the
+ * colour of square (X,Y) given by grid[Y*w+X]. The search begins
+ * at (x,y), and finds all squares which are the same colour as
+ * (x,y) and reachable from it by orthogonal moves. On return:
+ * - dist[Y*w+X] gives the distance of (X,Y) from (x,y), or -1 if
+ * unreachable or a different colour
+ * - the returned value is the number of reachable squares,
+ * including (x,y) itself
+ * - list[0] up to list[returned value - 1] list those squares, in
+ * increasing order of distance from (x,y) (and in arbitrary
+ * order within that).
+ */
+static int bfs(int w, int h, int *grid, int x, int y, int *dist, int *list)
+{
+ int i, j, c, listsize, listdone;
+
+ /*
+ * Start by clearing the output arrays.
+ */
+ for (i = 0; i < w*h; i++)
+ dist[i] = list[i] = -1;
+
+ /*
+ * Set up the initial list.
+ */
+ listsize = 1;
+ listdone = 0;
+ list[0] = y*w+x;
+ dist[y*w+x] = 0;
+ c = grid[y*w+x];
+
+ /*
+ * Repeatedly process a square and add any extra squares to the
+ * end of list.
+ */
+ while (listdone < listsize) {
+ i = list[listdone++];
+ y = i / w;
+ x = i % w;
+ for (j = 0; j < 4; j++) {
+ int xx, yy, ii;
+
+ xx = x + DX(j);
+ yy = y + DY(j);
+ ii = yy*w+xx;
+
+ if (xx >= 0 && xx < w && yy >= 0 && yy < h &&
+ grid[ii] == c && dist[ii] == -1) {
+ dist[ii] = dist[i] + 1;
+ assert(listsize < w*h);
+ list[listsize++] = ii;
+ }
+ }
+ }
+
+ return listsize;
+}
+
+struct genctx {
+ int w, h;
+ int *grid, *sparegrid, *sparegrid2, *sparegrid3;
+ int *dist, *list;
+
+ int npaths, pathsize;
+ int *pathends, *sparepathends; /* 2*npaths entries */
+ int *pathspare; /* npaths entries */
+ int *extends; /* 8*npaths entries */
+};
+
+static struct genctx *new_genctx(int w, int h)
+{
+ struct genctx *ctx = snew(struct genctx);
+ ctx->w = w;
+ ctx->h = h;
+ ctx->grid = snewn(w * h, int);
+ ctx->sparegrid = snewn(w * h, int);
+ ctx->sparegrid2 = snewn(w * h, int);
+ ctx->sparegrid3 = snewn(w * h, int);
+ ctx->dist = snewn(w * h, int);
+ ctx->list = snewn(w * h, int);
+ ctx->npaths = ctx->pathsize = 0;
+ ctx->pathends = ctx->sparepathends = ctx->pathspare = ctx->extends = NULL;
+ return ctx;
+}
+
+static void free_genctx(struct genctx *ctx)
+{
+ sfree(ctx->grid);
+ sfree(ctx->sparegrid);
+ sfree(ctx->sparegrid2);
+ sfree(ctx->sparegrid3);
+ sfree(ctx->dist);
+ sfree(ctx->list);
+ sfree(ctx->pathends);
+ sfree(ctx->sparepathends);
+ sfree(ctx->pathspare);
+ sfree(ctx->extends);
+}
+
+static int newpath(struct genctx *ctx)
+{
+ int n;
+
+ n = ctx->npaths++;
+ if (ctx->npaths > ctx->pathsize) {
+ ctx->pathsize += 16;
+ ctx->pathends = sresize(ctx->pathends, ctx->pathsize*2, int);
+ ctx->sparepathends = sresize(ctx->sparepathends, ctx->pathsize*2, int);
+ ctx->pathspare = sresize(ctx->pathspare, ctx->pathsize, int);
+ ctx->extends = sresize(ctx->extends, ctx->pathsize*8, int);
+ }
+ return n;
+}
+
+static int is_endpoint(struct genctx *ctx, int x, int y)
+{
+ int w = ctx->w, h = ctx->h, c;
+
+ assert(x >= 0 && x < w && y >= 0 && y < h);
+
+ c = ctx->grid[y*w+x];
+ if (c < 0)
+ return FALSE; /* empty square is not an endpoint! */
+ assert(c >= 0 && c < ctx->npaths);
+ if (ctx->pathends[c*2] == y*w+x || ctx->pathends[c*2+1] == y*w+x)
+ return TRUE;
+ return FALSE;
+}
+
+/*
+ * Tries to extend a path by one square in the given direction,
+ * pushing other paths around if necessary. Returns TRUE on success
+ * or FALSE on failure.
+ */
+static int extend_path(struct genctx *ctx, int path, int end, int direction)
+{
+ int w = ctx->w, h = ctx->h;
+ int x, y, xe, ye, cut;
+ int i, j, jp, n, first, last;
+
+ assert(path >= 0 && path < ctx->npaths);
+ assert(end == 0 || end == 1);
+
+ /*
+ * Find the endpoint of the path and the point we plan to
+ * extend it into.
+ */
+ y = ctx->pathends[path * 2 + end] / w;
+ x = ctx->pathends[path * 2 + end] % w;
+ assert(x >= 0 && x < w && y >= 0 && y < h);
+
+ xe = x + DX(direction);
+ ye = y + DY(direction);
+ if (xe < 0 || xe >= w || ye < 0 || ye >= h)
+ return FALSE; /* could not extend in this direction */
+
+ /*
+ * We don't extend paths _directly_ into endpoints of other
+ * paths, although we don't mind too much if a knock-on effect
+ * of an extension is to push part of another path into a third
+ * path's endpoint.
+ */
+ if (is_endpoint(ctx, xe, ye))
+ return FALSE;
+
+ /*
+ * We can't extend a path back the way it came.
+ */
+ if (ctx->grid[ye*w+xe] == path)
+ return FALSE;
+
+ /*
+ * Paths may not double back on themselves. Check if the new
+ * point is adjacent to any point of this path other than (x,y).
+ */
+ for (j = 0; j < 4; j++) {
+ int xf, yf;
+
+ xf = xe + DX(j);
+ yf = ye + DY(j);
+
+ if (xf >= 0 && xf < w && yf >= 0 && yf < h &&
+ (xf != x || yf != y) && ctx->grid[yf*w+xf] == path)
+ return FALSE;
+ }
+
+ /*
+ * Now we're convinced it's valid to _attempt_ the extension.
+ * It may still fail if we run out of space to push other paths
+ * into.
+ *
+ * So now we can set up our temporary data structures. We will
+ * need:
+ *
+ * - a spare copy of the grid on which to gradually move paths
+ * around (sparegrid)
+ *
+ * - a second spare copy with which to remember how paths
+ * looked just before being cut (sparegrid2). FIXME: is
+ * sparegrid2 necessary? right now it's never different from
+ * grid itself
+ *
+ * - a third spare copy with which to do the internal
+ * calculations involved in reconstituting a cut path
+ * (sparegrid3)
+ *
+ * - something to track which paths currently need
+ * reconstituting after being cut, and which have already
+ * been cut (pathspare)
+ *
+ * - a spare copy of pathends to store the altered states in
+ * (sparepathends)
+ */
+ memcpy(ctx->sparegrid, ctx->grid, w*h*sizeof(int));
+ memcpy(ctx->sparegrid2, ctx->grid, w*h*sizeof(int));
+ memcpy(ctx->sparepathends, ctx->pathends, ctx->npaths*2*sizeof(int));
+ for (i = 0; i < ctx->npaths; i++)
+ ctx->pathspare[i] = 0; /* 0=untouched, 1=broken, 2=fixed */
+
+ /*
+ * Working in sparegrid, actually extend the path. If it cuts
+ * another, begin a loop in which we restore any cut path by
+ * moving it out of the way.
+ */
+ cut = ctx->sparegrid[ye*w+xe];
+ ctx->sparegrid[ye*w+xe] = path;
+ ctx->sparepathends[path*2+end] = ye*w+xe;
+ ctx->pathspare[path] = 2; /* this one is sacrosanct */
+ if (cut >= 0) {
+ assert(cut >= 0 && cut < ctx->npaths);
+ ctx->pathspare[cut] = 1; /* broken */
+
+ while (1) {
+ for (i = 0; i < ctx->npaths; i++)
+ if (ctx->pathspare[i] == 1)
+ break;
+ if (i == ctx->npaths)
+ break; /* we're done */
+
+ /*
+ * Path i needs restoring. So walk along its original
+ * track (as given in sparegrid2) and see where it's
+ * been cut. Where it has, surround the cut points in
+ * the same colour, without overwriting already-fixed
+ * paths.
+ */
+ memcpy(ctx->sparegrid3, ctx->sparegrid, w*h*sizeof(int));
+ n = bfs(w, h, ctx->sparegrid2,
+ ctx->pathends[i*2] % w, ctx->pathends[i*2] / w,
+ ctx->dist, ctx->list);
+ first = last = -1;
+if (ctx->sparegrid3[ctx->pathends[i*2]] != i ||
+ ctx->sparegrid3[ctx->pathends[i*2+1]] != i) return FALSE;/* FIXME */
+ for (j = 0; j < n; j++) {
+ jp = ctx->list[j];
+ assert(ctx->dist[jp] == j);
+ assert(ctx->sparegrid2[jp] == i);
+
+ /*
+ * Wipe out the original path in sparegrid.
+ */
+ if (ctx->sparegrid[jp] == i)
+ ctx->sparegrid[jp] = -1;
+
+ /*
+ * Be prepared to shorten the path at either end if
+ * the endpoints have been stomped on.
+ */
+ if (ctx->sparegrid3[jp] == i) {
+ if (first < 0)
+ first = jp;
+ last = jp;
+ }
+
+ if (ctx->sparegrid3[jp] != i) {
+ int jx = jp % w, jy = jp / w;
+ int dx, dy;
+ for (dy = -1; dy <= +1; dy++)
+ for (dx = -1; dx <= +1; dx++) {
+ int newp, newv;
+ if (!dy && !dx)
+ continue; /* central square */
+ if (jx+dx < 0 || jx+dx >= w ||
+ jy+dy < 0 || jy+dy >= h)
+ continue; /* out of range */
+ newp = (jy+dy)*w+(jx+dx);
+ newv = ctx->sparegrid3[newp];
+ if (newv >= 0 && (newv == i ||
+ ctx->pathspare[newv] == 2))
+ continue; /* can't use this square */
+ ctx->sparegrid3[newp] = i;
+ }
+ }
+ }
+
+ if (first < 0 || last < 0)
+ return FALSE; /* path is completely wiped out! */
+
+ /*
+ * Now we've covered sparegrid3 in possible squares for
+ * the new layout of path i. Find the actual layout
+ * we're going to use by bfs: we want the shortest path
+ * from one endpoint to the other.
+ */
+ n = bfs(w, h, ctx->sparegrid3, first % w, first / w,
+ ctx->dist, ctx->list);
+ if (ctx->dist[last] < 2) {
+ /*
+ * Either there is no way to get between the path's
+ * endpoints, or the remaining endpoints simply
+ * aren't far enough apart to make the path viable
+ * any more. This means the entire push operation
+ * has failed.
+ */
+ return FALSE;
+ }
+
+ /*
+ * Write the new path into sparegrid. Also save the new
+ * endpoint locations, in case they've changed.
+ */
+ jp = last;
+ j = ctx->dist[jp];
+ while (1) {
+ int d;
+
+ if (ctx->sparegrid[jp] >= 0) {
+ if (ctx->pathspare[ctx->sparegrid[jp]] == 2)
+ return FALSE; /* somehow we've hit a fixed path */
+ ctx->pathspare[ctx->sparegrid[jp]] = 1; /* broken */
+ }
+ ctx->sparegrid[jp] = i;
+
+ if (j == 0)
+ break;
+
+ /*
+ * Now look at the neighbours of jp to find one
+ * which has dist[] one less.
+ */
+ for (d = 0; d < 4; d++) {
+ int jx = (jp % w) + DX(d), jy = (jp / w) + DY(d);
+ if (jx >= 0 && jx < w && jy >= 0 && jy < w &&
+ ctx->dist[jy*w+jx] == j-1) {
+ jp = jy*w+jx;
+ j--;
+ break;
+ }
+ }
+ assert(d < 4);
+ }
+
+ ctx->sparepathends[i*2] = first;
+ ctx->sparepathends[i*2+1] = last;
+//printf("new ends of path %d: %d,%d\n", i, first, last);
+ ctx->pathspare[i] = 2; /* fixed */
+ }
+ }
+
+ /*
+ * If we got here, the extension was successful!
+ */
+ memcpy(ctx->grid, ctx->sparegrid, w*h*sizeof(int));
+ memcpy(ctx->pathends, ctx->sparepathends, ctx->npaths*2*sizeof(int));
+ return TRUE;
+}
+
+/*
+ * Tries to add a new path to the grid.
+ */
+static int add_path(struct genctx *ctx, random_state *rs)
+{
+ int w = ctx->w, h = ctx->h;
+ int i, ii, n;
+
+ /*
+ * Our strategy is:
+ * - randomly choose an empty square in the grid
+ * - do a BFS from that point to find a long path starting
+ * from it
+ * - if we run out of viable empty squares, return failure.
+ */
+
+ /*
+ * Use `sparegrid' to collect a list of empty squares.
+ */
+ n = 0;
+ for (i = 0; i < w*h; i++)
+ if (ctx->grid[i] == -1)
+ ctx->sparegrid[n++] = i;
+
+ /*
+ * Shuffle the grid.
+ */
+ for (i = n; i-- > 1 ;) {
+ int k = random_upto(rs, i+1);
+ if (k != i) {
+ int t = ctx->sparegrid[i];
+ ctx->sparegrid[i] = ctx->sparegrid[k];
+ ctx->sparegrid[k] = t;
+ }
+ }
+
+ /*
+ * Loop over it trying to add paths. This looks like a
+ * horrifying N^4 algorithm (that is, (w*h)^2), but I predict
+ * that in fact the worst case will very rarely arise because
+ * when there's lots of grid space an attempt will succeed very
+ * quickly.
+ */
+ for (ii = 0; ii < n; ii++) {
+ int i = ctx->sparegrid[ii];
+ int y = i / w, x = i % w, nsq;
+ int r, c, j;
+
+ /*
+ * BFS from here to find long paths.
+ */
+ nsq = bfs(w, h, ctx->grid, x, y, ctx->dist, ctx->list);
+
+ /*
+ * If there aren't any long enough, give up immediately.
+ */
+ assert(nsq > 0); /* must be the start square at least! */
+ if (ctx->dist[ctx->list[nsq-1]] < 3)
+ continue;
+
+ /*
+ * Find the first viable endpoint in ctx->list (i.e. the
+ * first point with distance at least three). I could
+ * binary-search for this, but that would be O(log N)
+ * whereas in fact I can get a constant time bound by just
+ * searching up from the start - after all, there can be at
+ * most 13 points at _less_ than distance 3 from the
+ * starting one!
+ */
+ for (j = 0; j < nsq; j++)
+ if (ctx->dist[ctx->list[j]] >= 3)
+ break;
+ assert(j < nsq); /* we tested above that there was one */
+
+ /*
+ * Now we know that any element of `list' between j and nsq
+ * would be valid in principle. However, we want a few long
+ * paths rather than many small ones, so select only those
+ * elements which are either the maximum length or one
+ * below it.
+ */
+ while (ctx->dist[ctx->list[j]] + 1 < ctx->dist[ctx->list[nsq-1]])
+ j++;
+ r = j + random_upto(rs, nsq - j);
+ j = ctx->list[r];
+
+ /*
+ * And that's our endpoint. Mark the new path on the grid.
+ */
+ c = newpath(ctx);
+ ctx->pathends[c*2] = i;
+ ctx->pathends[c*2+1] = j;
+ ctx->grid[j] = c;
+ while (j != i) {
+ int d, np, index, pts[4];
+ np = 0;
+ for (d = 0; d < 4; d++) {
+ int xn = (j % w) + DX(d), yn = (j / w) + DY(d);
+ if (xn >= 0 && xn < w && yn >= 0 && yn < w &&
+ ctx->dist[yn*w+xn] == ctx->dist[j] - 1)
+ pts[np++] = yn*w+xn;
+ }
+ if (np > 1)
+ index = random_upto(rs, np);
+ else
+ index = 0;
+ j = pts[index];
+ ctx->grid[j] = c;
+ }
+
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+/*
+ * The main grid generation loop.
+ */
+static void gridgen_mainloop(struct genctx *ctx, random_state *rs)
+{
+ int w = ctx->w, h = ctx->h;
+ int i, n;
+
+ /*
+ * The generation algorithm doesn't always converge. Loop round
+ * until it does.
+ */
+ while (1) {
+ for (i = 0; i < w*h; i++)
+ ctx->grid[i] = -1;
+ ctx->npaths = 0;
+
+ while (1) {
+ /*
+ * See if the grid is full.
+ */
+ for (i = 0; i < w*h; i++)
+ if (ctx->grid[i] < 0)
+ break;
+ if (i == w*h)
+ return;
+
+#ifdef GENERATION_DIAGNOSTICS
+ {
+ int x, y;
+ for (y = 0; y < h; y++) {
+ printf("|");
+ for (x = 0; x < w; x++) {
+ if (ctx->grid[y*w+x] >= 0)
+ printf("%2d", ctx->grid[y*w+x]);
+ else
+ printf(" .");
+ }
+ printf(" |\n");
+ }
+ }
+#endif
+ /*
+ * Try adding a path.
+ */
+ if (add_path(ctx, rs)) {
+#ifdef GENERATION_DIAGNOSTICS
+ printf("added path\n");
+#endif
+ continue;
+ }
+
+ /*
+ * Try extending a path. First list all the possible
+ * extensions.
+ */
+ for (i = 0; i < ctx->npaths * 8; i++)
+ ctx->extends[i] = i;
+ n = i;
+
+ /*
+ * Then shuffle the list.
+ */
+ for (i = n; i-- > 1 ;) {
+ int k = random_upto(rs, i+1);
+ if (k != i) {
+ int t = ctx->extends[i];
+ ctx->extends[i] = ctx->extends[k];
+ ctx->extends[k] = t;
+ }
+ }
+
+ /*
+ * Now try each one in turn until one works.
+ */
+ for (i = 0; i < n; i++) {
+ int p, d, e;
+ p = ctx->extends[i];
+ d = p % 4;
+ p /= 4;
+ e = p % 2;
+ p /= 2;
+
+#ifdef GENERATION_DIAGNOSTICS
+ printf("trying to extend path %d end %d (%d,%d) in dir %d\n", p, e,
+ ctx->pathends[p*2+e] % w,
+ ctx->pathends[p*2+e] / w, d);
+#endif
+ if (extend_path(ctx, p, e, d)) {
+#ifdef GENERATION_DIAGNOSTICS
+ printf("extended path %d end %d (%d,%d) in dir %d\n", p, e,
+ ctx->pathends[p*2+e] % w,
+ ctx->pathends[p*2+e] / w, d);
+#endif
+ break;
+ }
+ }
+
+ if (i < n)
+ continue;
+
+ break;
+ }
+ }
+}
+
+/*
+ * Wrapper function which deals with the boring bits such as
+ * removing the solution from the generated grid, shuffling the
+ * numeric labels and creating/disposing of the context structure.
+ */
+static int *gridgen(int w, int h, random_state *rs)
+{
+ struct genctx *ctx;
+ int *ret;
+ int i;
+
+ ctx = new_genctx(w, h);
+
+ gridgen_mainloop(ctx, rs);
+
+ /*
+ * There is likely to be an ordering bias in the numbers
+ * (longer paths on lower numbers due to there having been more
+ * grid space when laying them down). So we must shuffle the
+ * numbers. We use ctx->pathspare for this.
+ *
+ * This is also as good a time as any to shift to numbering
+ * from 1, for display to the user.
+ */
+ for (i = 0; i < ctx->npaths; i++)
+ ctx->pathspare[i] = i+1;
+ for (i = ctx->npaths; i-- > 1 ;) {
+ int k = random_upto(rs, i+1);
+ if (k != i) {
+ int t = ctx->pathspare[i];
+ ctx->pathspare[i] = ctx->pathspare[k];
+ ctx->pathspare[k] = t;
+ }
+ }
+
+ /* FIXME: remove this at some point! */
+ {
+ int y, x;
+ for (y = 0; y < h; y++) {
+ printf("|");
+ for (x = 0; x < w; x++) {
+ assert(ctx->grid[y*w+x] >= 0);
+ printf("%2d", ctx->pathspare[ctx->grid[y*w+x]]);
+ }
+ printf(" |\n");
+ }
+ printf("\n");
+ }
+
+ /*
+ * Clear the grid, and write in just the endpoints.
+ */
+ for (i = 0; i < w*h; i++)
+ ctx->grid[i] = 0;
+ for (i = 0; i < ctx->npaths; i++) {
+ ctx->grid[ctx->pathends[i*2]] =
+ ctx->grid[ctx->pathends[i*2+1]] = ctx->pathspare[i];
+ }
+
+ ret = ctx->grid;
+ ctx->grid = NULL;
+
+ free_genctx(ctx);
+
+ return ret;
+}
+
+#ifdef TEST_GEN
+
+#define TEST_GENERAL
+
+int main(void)
+{
+ int w = 10, h = 8;
+ random_state *rs = random_init("12345", 5);
+ int x, y, i, *grid;
+
+ for (i = 0; i < 10; i++) {
+ grid = gridgen(w, h, rs);
+
+ for (y = 0; y < h; y++) {
+ printf("|");
+ for (x = 0; x < w; x++) {
+ if (grid[y*w+x] > 0)
+ printf("%2d", grid[y*w+x]);
+ else
+ printf(" .");
+ }
+ printf(" |\n");
+ }
+ printf("\n");
+
+ sfree(grid);
+ }
+
+ return 0;
+}
+#endif
+
+#ifdef TEST_GENERAL
+#include <stdarg.h>
+
+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);
+}
+#endif
~mdw / sgt / puzzles / blobdiff