shithub: puzzles

--- a/unfinished/slide.c

+++ b/unfinished/slide.c

@@ -23,17 +23,8 @@

  * 	 up on compactness and just bite the bullet and have the

  * 	 target area right outside the main wall, but mostly I

  * 	 think it's OK.

- *     * but adjust the presets, because 8x6 is _slow_ to

- * 	 generate.

- *     * also, introduce a difficulty scheme, in the form of

- * 	 limiting the minimum move count. This is obviously

- * 	 sensible, because it also speeds up generation since the

- * 	 solver can bomb out once it hits that ceiling!

- * 	  + I was going to say I'd need to work out a minimum move

- * 	    count for each grid size, but actually I think not: if

- * 	    you ask for too few moves, it just has to remove still

- * 	    more singletons, until at move count 1 you end up with

- * 	    nothing in your way at all and it SERVES YOU RIGHT!

+ *     * the move limit tends to make the game _slower_ to

+ * 	 generate, which is odd. Perhaps investigate why.

  *  - Improve the graphics.

  *     * All the colours are a bit wishy-washy. _Some_ dark

@@ -140,6 +131,7 @@

 struct game_params {

     int w, h;

+    int maxmoves;

};

 struct game_immutable_state {

@@ -162,17 +154,17 @@

     game_params *ret = snew(game_params);

-    ret->w = 8;

+    ret->w = 7;

     ret->h = 6;

+    ret->maxmoves = 40;

     return ret;

 static const struct game_params slide_presets[] = {

-    {6, 5},

-    {7, 5},

-    {7, 6},

-    {8, 6},

+    {7, 6, 25},

+    {7, 6, -1},

+    {8, 6, -1},

};

 static int game_fetch_preset(int i, char **name, game_params **params)

@@ -187,6 +179,10 @@

     *ret = slide_presets[i];

     sprintf(str, "%dx%d", ret->w, ret->h);

+    if (ret->maxmoves >= 0)

+	sprintf(str + strlen(str), ", max %d moves", ret->maxmoves);

+    else

+	sprintf(str + strlen(str), ", no move limit");

     *name = dupstr(str);

     *params = ret;

@@ -212,7 +208,16 @@

     if (*string == 'x') {

         string++;

         params->h = atoi(string);

+	while (*string && isdigit((unsigned char)*string)) string++;

+    if (*string == 'm') {

+        string++;

+        params->maxmoves = atoi(string);

+	while (*string && isdigit((unsigned char)*string)) string++;

+    } else if (*string == 'u') {

+	string++;

+	params->maxmoves = -1;

+    }

 static char *encode_params(game_params *params, int full)

@@ -220,6 +225,10 @@

     char data[256];

     sprintf(data, "%dx%d", params->w, params->h);

+    if (params->maxmoves >= 0)

+	sprintf(data + strlen(data), "m%d", params->maxmoves);

+    else

+	sprintf(data + strlen(data), "u");

     return dupstr(data);

@@ -229,7 +238,7 @@

     config_item *ret;

     char buf[80];

-    ret = snewn(3, config_item);

+    ret = snewn(4, config_item);

     ret[0].name = "Width";

     ret[0].type = C_STRING;

@@ -243,11 +252,17 @@

     ret[1].sval = dupstr(buf);

     ret[1].ival = 0;

-    ret[2].name = NULL;

-    ret[2].type = C_END;

-    ret[2].sval = NULL;

+    ret[2].name = "Solution length limit";

+    ret[2].type = C_STRING;

+    sprintf(buf, "%d", params->maxmoves);

+    ret[2].sval = dupstr(buf);

     ret[2].ival = 0;

+    ret[3].name = NULL;

+    ret[3].type = C_END;

+    ret[3].sval = NULL;

+    ret[3].ival = 0;

     return ret;

@@ -257,6 +272,7 @@

     ret->w = atoi(cfg[0].sval);

     ret->h = atoi(cfg[1].sval);

+    ret->maxmoves = atoi(cfg[2].sval);

     return ret;

@@ -389,7 +405,8 @@

  * as-yet-unprovided parameter.

*/

 static int solve_board(int w, int h, unsigned char *board,

-		       unsigned char *forcefield, int tx, int ty)

+		       unsigned char *forcefield, int tx, int ty,

+		       int movelimit)

     int wh = w*h;

     struct board *b, *b2, *b3;

@@ -443,6 +460,14 @@

     while ((b = delpos234(queue, 0)) != NULL) {

 	qlen--;

+	if (movelimit >= 0 && b->dist >= movelimit) {

+	    /*

+	     * The problem is not soluble in under `movelimit'

+	     * moves, so we can quit right now.

+	     */

+	    b2 = NULL;

+	    goto done;

+	}

 	if (b->dist != lastdist) {

 #ifdef SOLVER_DIAGNOSTICS

 	    printf("dist %d (%d)\n", b->dist, count234(sorted));

@@ -572,7 +597,7 @@

 static void generate_board(int w, int h, int *rtx, int *rty, int *minmoves,

 			   random_state *rs, unsigned char **rboard,

-			   unsigned char **rforcefield)

+			   unsigned char **rforcefield, int movelimit)

     int wh = w*h;

     unsigned char *board, *board2, *forcefield;

@@ -628,7 +653,7 @@

 		 * See if the board is already soluble.

*/

 		if ((moves = solve_board(w, h, board, forcefield,

-					 tx, ty)) >= 0)

+					 tx, ty, movelimit)) >= 0)

 		    goto soluble;

/*

@@ -678,9 +703,7 @@

 	c1 = dsf_canonify(dsf, p1);

 	c2 = dsf_canonify(dsf, p2);

 	if (tried_merge[c1 * wh + c2])

-{printf("aha\n");

 	    continue;

-}

/*

 	 * In order to be mergeable, these two squares must each

@@ -730,7 +753,7 @@

 		} while (p2 < wh && board[p2] != DIST(p2-i));

-	j = solve_board(w, h, board, forcefield, tx, ty);

+	j = solve_board(w, h, board, forcefield, tx, ty, movelimit);

 	if (j < 0) {

/*

 	     * Didn't work. Revert the merge.

@@ -776,7 +799,7 @@

     int i;

     generate_board(params->w, params->h, &tx, &ty, &minmoves, rs,

-		   &board, &forcefield);

+		   &board, &forcefield, params->maxmoves);

 #ifdef GENERATOR_DIAGNOSTICS

 	char *t = board_text_format(params->w, params->h, board);