ref: c389f623f66fe5296f7ef5c66d88884607b82cff
parent: a8980f3736031dc971754bd7ecc55795680a62e5
author: Simon Tatham <anakin@pobox.com>
date: Mon Sep 12 13:13:26 EDT 2005
Patch from Mike: - remove the backtracking `Hard' level, on the grounds that it was incredibly slow and not really usable. - introduce an `Easy' difficulty level below the standard one; many people seem to find this puzzle unusually hard, so an easy level is particularly helpful. - highlight unfulfillable clue squares (but not yet any other types of obvious error). [originally from svn r6299]
--- a/loopy.c
+++ b/loopy.c
@@ -42,6 +42,16 @@
* (Of course the algorithm would have to fail an assertion
* if you tried to tell it two things it already knew to be
* opposite were equal, or vice versa!)
+ * This data structure would also be useful in the
+ * graph-theoretic part of the solver, where it could be used
+ * for storing information about which lines are known-identical
+ * or known-opposite. (For example if two lines bordering a 3
+ * are known-identical they must both be LINE_YES, and if they
+ * are known-opposite, the *other* two lines bordering that clue
+ * must be LINE_YES, etc). This may duplicate some
+ * functionality already present in the solver but it is more
+ * general and we could remove the old code, so that's no bad
+ * thing.
*/
#include <stdio.h>
@@ -59,7 +69,7 @@
#define LINEWIDTH TILE_SIZE / 16
#define BORDER (TILE_SIZE / 2)
-#define FLASH_TIME 0.4F
+#define FLASH_TIME 0.5F
#define HL_COUNT(state) ((state)->w * ((state)->h + 1))
#define VL_COUNT(state) (((state)->w + 1) * (state)->h)
@@ -114,15 +124,33 @@
COL_BACKGROUND,
COL_FOREGROUND,
COL_HIGHLIGHT,
+ COL_MISTAKE,
NCOLOURS
};
-enum line_state { LINE_UNKNOWN, LINE_YES, LINE_NO };+/*
+ * Difficulty levels. I do some macro ickery here to ensure that my
+ * enum and the various forms of my name list always match up.
+ */
+#define DIFFLIST(A) \
+ A(EASY,Easy,e) \
+ A(NORMAL,Normal,n)
+#define ENUM(upper,title,lower) DIFF_ ## upper,
+#define TITLE(upper,title,lower) #title,
+#define ENCODE(upper,title,lower) #lower
+#define CONFIG(upper,title,lower) ":" #title
+enum { DIFFLIST(ENUM) DIFFCOUNT };+static char const *const loopy_diffnames[] = { DIFFLIST(TITLE) };+static char const loopy_diffchars[] = DIFFLIST(ENCODE);
+#define DIFFCONFIG DIFFLIST(CONFIG)
+/* LINE_YES_ERROR is only used in the drawing routine */
+enum line_state { LINE_UNKNOWN, LINE_YES, LINE_NO /*, LINE_YES_ERROR*/ };+
enum direction { UP, DOWN, LEFT, RIGHT }; struct game_params {- int w, h, rec;
+ int w, h, diff, rec;
};
struct game_state {@@ -380,6 +408,7 @@
ret->h = 10;
ret->w = 10;
#endif
+ ret->diff = DIFF_EASY;
ret->rec = 0;
return ret;
@@ -396,15 +425,15 @@
char *desc;
game_params params;
} loopy_presets[] = {- { "4x4 Easy", { 4, 4, 0 } },- { "4x4 Hard", { 4, 4, 2 } },- { "7x7 Easy", { 7, 7, 0 } },- { "7x7 Hard", { 7, 7, 2 } },- { "10x10 Easy", { 10, 10, 0 } },+ { "4x4 Easy", { 4, 4, DIFF_EASY, 0 } },+ { "4x4 Normal", { 4, 4, DIFF_NORMAL, 0 } },+ { "7x7 Easy", { 7, 7, DIFF_EASY, 0 } },+ { "7x7 Normal", { 7, 7, DIFF_NORMAL, 0 } },+ { "10x10 Easy", { 10, 10, DIFF_EASY, 0 } },#ifndef SLOW_SYSTEM
- { "10x10 Hard", { 10, 10, 2 } },- { "15x15 Easy", { 15, 15, 0 } },- { "30x20 Easy", { 30, 20, 0 } }+ { "10x10 Normal", { 10, 10, DIFF_NORMAL, 0 } },+ { "15x15 Easy", { 15, 15, DIFF_EASY, 0 } },+ { "30x20 Easy", { 30, 20, DIFF_EASY, 0 } }#endif
};
@@ -431,6 +460,7 @@
{params->h = params->w = atoi(string);
params->rec = 0;
+ params->diff = DIFF_EASY;
while (*string && isdigit((unsigned char)*string)) string++;
if (*string == 'x') {string++;
@@ -442,6 +472,15 @@
params->rec = atoi(string);
while (*string && isdigit((unsigned char)*string)) string++;
}
+ if (*string == 'd') {+ int i;
+
+ string++;
+ for (i = 0; i < DIFFCOUNT; i++)
+ if (*string == loopy_diffchars[i])
+ params->diff = i;
+ if (*string) string++;
+ }
}
static char *encode_params(game_params *params, int full)
@@ -449,7 +488,8 @@
char str[80];
sprintf(str, "%dx%d", params->w, params->h);
if (full)
- sprintf(str + strlen(str), "r%d", params->rec);
+ sprintf(str + strlen(str), "r%dd%c", params->rec,
+ loopy_diffchars[params->diff]);
return dupstr(str);
}
@@ -472,11 +512,10 @@
ret[1].sval = dupstr(buf);
ret[1].ival = 0;
- ret[2].name = "Recursion depth";
- ret[2].type = C_STRING;
- sprintf(buf, "%d", params->rec);
- ret[2].sval = dupstr(buf);
- ret[2].ival = 0;
+ ret[2].name = "Difficulty";
+ ret[2].type = C_CHOICES;
+ ret[2].sval = DIFFCONFIG;
+ ret[2].ival = params->diff;
ret[3].name = NULL;
ret[3].type = C_END;
@@ -492,7 +531,8 @@
ret->w = atoi(cfg[0].sval);
ret->h = atoi(cfg[1].sval);
- ret->rec = atoi(cfg[2].sval);
+ ret->rec = 0;
+ ret->diff = cfg[2].ival;
return ret;
}
@@ -503,6 +543,14 @@
return "Width and height must both be at least 4";
if (params->rec < 0)
return "Recursion depth can't be negative";
+
+ /*
+ * This shouldn't be able to happen at all, since decode_params
+ * and custom_params will never generate anything that isn't
+ * within range.
+ */
+ assert(params->diff >= 0 && params->diff < DIFFCOUNT);
+
return NULL;
}
@@ -855,15 +903,15 @@
return clues;
}
-static solver_state *solve_game_rec(const solver_state *sstate);
+static solver_state *solve_game_rec(const solver_state *sstate, int diff);
-static int game_has_unique_soln(const game_state *state)
+static int game_has_unique_soln(const game_state *state, int diff)
{int ret;
solver_state *sstate_new;
solver_state *sstate = new_solver_state((game_state *)state);
- sstate_new = solve_game_rec(sstate);
+ sstate_new = solve_game_rec(sstate, diff);
ret = (sstate_new->solver_status == SOLVER_SOLVED);
@@ -874,7 +922,7 @@
}
/* Remove clues one at a time at random. */
-static game_state *remove_clues(game_state *state, random_state *rs)
+static game_state *remove_clues(game_state *state, random_state *rs, int diff)
{int *square_list, squares;
game_state *ret = dup_game(state), *saved_ret;
@@ -896,7 +944,7 @@
saved_ret = dup_game(ret);
LV_CLUE_AT(ret, square_list[n] % state->w,
square_list[n] / state->w) = ' ';
- if (game_has_unique_soln(ret)) {+ if (game_has_unique_soln(ret, diff)) {free_game(saved_ret);
} else {free_game(ret);
@@ -926,6 +974,8 @@
state->hl = snewn(HL_COUNT(params), char);
state->vl = snewn(VL_COUNT(params), char);
+
+newboard_please:
memset(state->hl, LINE_UNKNOWN, HL_COUNT(params));
memset(state->vl, LINE_UNKNOWN, VL_COUNT(params));
@@ -935,14 +985,20 @@
/* Get a new random solvable board with all its clues filled in. Yes, this
* can loop for ever if the params are suitably unfavourable, but
* preventing games smaller than 4x4 seems to stop this happening */
+
do {state->clues = new_fullyclued_board(params, rs);
- } while (!game_has_unique_soln(state));
+ } while (!game_has_unique_soln(state, params->diff));
- state_new = remove_clues(state, rs);
+ state_new = remove_clues(state, rs, params->diff);
free_game(state);
state = state_new;
+ if (params->diff > 0 && game_has_unique_soln(state, params->diff-1)) {+ /* Board is too easy */
+ goto newboard_please;
+ }
+
empty_count = 0;
for (j = 0; j < params->h; ++j) { for (i = 0; i < params->w; ++i) {@@ -1007,7 +1063,7 @@
int n;
const char *dp = desc;
- state->recursion_depth = params->rec;
+ state->recursion_depth = 0; /* XXX pending removal, probably */
state->h = params->h;
state->w = params->w;
@@ -1256,7 +1312,7 @@
}
/* No point in doing sums like that if they're going to be wrong */
- assert(strlen(ret) <= (size_t)len);
+ assert(strlen(ret) == (size_t)len);
return ret;
}
@@ -1425,10 +1481,29 @@
}
}
+#if 0
+/* This will fail an assertion if {dx,dy} are anything other than {-1,0}, {1,0}+ * {0,-1} or {0,1} */+static int line_status_from_point(const game_state *state,
+ int x, int y, int dx, int dy)
+{+ if (dx == -1 && dy == 0)
+ return LEFTOF_DOT(state, x, y);
+ if (dx == 1 && dy == 0)
+ return RIGHTOF_DOT(state, x, y);
+ if (dx == 0 && dy == -1)
+ return ABOVE_DOT(state, x, y);
+ if (dx == 0 && dy == 1)
+ return BELOW_DOT(state, x, y);
+ assert(!"Illegal dx or dy in line_status_from_point");
+ return 0;
+}
+#endif
+
/* This will return a dynamically allocated solver_state containing the (more)
* solved grid */
-static solver_state *solve_game_rec(const solver_state *sstate_start)
+static solver_state *solve_game_rec(const solver_state *sstate_start, int diff)
{int i, j;
int current_yes, current_no, desired;
@@ -1460,6 +1535,14 @@
} \
} while (0)
+#define FOUND_MISTAKE \
+ do { \+ sstate->solver_status = SOLVER_MISTAKE; \
+ free_solver_state(sstate_saved); \
+ return sstate; \
+ } while (0)
+
+
sstate_saved = NULL;
RETURN_IF_SOLVED;
@@ -1481,12 +1564,16 @@
current_yes = square_order(sstate->state, i, j, LINE_YES);
current_no = square_order(sstate->state, i, j, LINE_NO);
- if (desired <= current_yes) {+ if (desired < current_yes)
+ FOUND_MISTAKE;
+ if (desired == current_yes) {square_setall(sstate->state, i, j, LINE_UNKNOWN, LINE_NO);
continue;
}
- if (4 - desired <= current_no) {+ if (4 - desired < current_no)
+ FOUND_MISTAKE;
+ if (4 - desired == current_no) {square_setall(sstate->state, i, j, LINE_UNKNOWN, LINE_YES);
}
}
@@ -1513,19 +1600,24 @@
} \
}
case 1:
+ if (diff > DIFF_EASY) {#define HANDLE_DLINE(dline, dir1_dot, dir2_dot) \
H1(dline, dir1_dot, dir2_dot, dot_atleastone)
- /* 1 yes, 1 no, so exactly one of unknowns is yes */
- DOT_DLINES;
+ /* 1 yes, 1 no, so exactly one of unknowns is
+ * yes */
+ DOT_DLINES;
#undef HANDLE_DLINE
+ }
/* fall through */
case 0:
+ if (diff > DIFF_EASY) {#define HANDLE_DLINE(dline, dir1_dot, dir2_dot) \
H1(dline, dir1_dot, dir2_dot, dot_atmostone)
- /* 1 yes, fewer than 2 no, so at most one of
- * unknowns is yes */
- DOT_DLINES;
+ /* 1 yes, fewer than 2 no, so at most one of
+ * unknowns is yes */
+ DOT_DLINES;
#undef HANDLE_DLINE
+ }
#undef H1
break;
case 2: /* 1 yes, 2 no */
@@ -1535,9 +1627,13 @@
}
break;
case 2:
- case 3:
dot_setall(sstate->state, i, j, LINE_UNKNOWN, LINE_NO);
+ break;
+ case 3:
+ FOUND_MISTAKE;
+ break;
}
+ if (diff > DIFF_EASY) {#define HANDLE_DLINE(dline, dir1_dot, dir2_dot) \
if (sstate->dot_atleastone \
[i + (sstate->state->w + 1) * j] & 1<<dline) { \@@ -1544,9 +1640,10 @@
sstate->dot_atmostone \
[i + (sstate->state->w + 1) * j] |= 1<<OPP_DLINE(dline); \
}
- /* If at least one of a dline in a dot is YES, at most one of
- * the opposite dline to that dot must be YES. */
- DOT_DLINES;
+ /* If at least one of a dline in a dot is YES, at most one
+ * of the opposite dline to that dot must be YES. */
+ DOT_DLINES;
+ }
#undef HANDLE_DLINE
}
}
@@ -1566,26 +1663,31 @@
dir1_sq(sstate->state, i, j) = line_set; \
} \
}
+ if (diff > DIFF_EASY) {#define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
H1(dline, dir1_sq, dir2_sq, a, b, dot_atmostone, \
LINE_YES, LINE_NO)
- /* If at most one of the DLINE is on, and one is definitely on,
- * set the other to definitely off */
- SQUARE_DLINES;
+ /* If at most one of the DLINE is on, and one is definitely
+ * on, set the other to definitely off */
+ SQUARE_DLINES;
#undef HANDLE_DLINE
+ }
+ if (diff > DIFF_EASY) {#define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
H1(dline, dir1_sq, dir2_sq, a, b, dot_atleastone, \
LINE_NO, LINE_YES)
- /* If at least one of the DLINE is on, and one is definitely
- * off, set the other to definitely on */
- SQUARE_DLINES;
+ /* If at least one of the DLINE is on, and one is definitely
+ * off, set the other to definitely on */
+ SQUARE_DLINES;
#undef HANDLE_DLINE
+ }
#undef H1
switch (CLUE_AT(sstate->state, i, j)) {case '0':
case '1':
+ if (diff > DIFF_EASY) {#define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
/* At most one of any DLINE can be set */ \
sstate->dot_atmostone \
@@ -1598,10 +1700,12 @@
i+(1-a), j+(1-b), \
LINE_UNKNOWN, LINE_NO); \
}
- SQUARE_DLINES;
+ SQUARE_DLINES;
#undef HANDLE_DLINE
+ }
break;
case '2':
+ if (diff > DIFF_EASY) {#define H1(dline, dot_at1one, dot_at2one, a, b) \
if (sstate->dot_at1one \
[i+a + (sstate->state->w + 1) * (j+b)] & \
@@ -1613,14 +1717,16 @@
#define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
H1(dline, dot_atleastone, dot_atmostone, a, b); \
H1(dline, dot_atmostone, dot_atleastone, a, b);
- /* If at least one of one DLINE is set, at most one of
- * the opposing one is and vice versa */
- SQUARE_DLINES;
+ /* If at least one of one DLINE is set, at most one
+ * of the opposing one is and vice versa */
+ SQUARE_DLINES;
+ }
#undef HANDLE_DLINE
#undef H1
break;
case '3':
case '4':
+ if (diff > DIFF_EASY) {#define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
/* At least one of any DLINE can be set */ \
sstate->dot_atleastone \
@@ -1633,8 +1739,9 @@
i+(1-a), j+(1-b), \
LINE_UNKNOWN, LINE_YES); \
}
- SQUARE_DLINES;
+ SQUARE_DLINES;
#undef HANDLE_DLINE
+ }
break;
}
}
@@ -1809,10 +1916,10 @@
/* Perform recursive calls */
if (sstate->recursion_remaining) {- sstate->recursion_remaining--;
-
sstate_saved = dup_solver_state(sstate);
+ sstate->recursion_remaining--;
+
recursive_soln_count = 0;
sstate_rec_solved = NULL;
@@ -1837,7 +1944,7 @@
if (dir_dot(sstate->state, i, j) == LINE_UNKNOWN) { \ debug(("Trying " #dir_dot " at [%d,%d]\n", i, j)); \LV_##dir_dot(sstate->state, i, j) = LINE_YES; \
- sstate_tmp = solve_game_rec(sstate); \
+ sstate_tmp = solve_game_rec(sstate, diff); \
switch (sstate_tmp->solver_status) { \case SOLVER_AMBIGUOUS: \
debug(("Solver ambiguous, returning\n")); \@@ -1878,14 +1985,10 @@
for (i = 0; i < sstate->state->w + 1; ++i) {/* Only perform recursive calls on 'loose ends' */
if (dot_order(sstate->state, i, j, LINE_YES) == 1) {- if (LEFTOF_DOT(sstate->state, i, j) == LINE_UNKNOWN)
- DO_RECURSIVE_CALL(LEFTOF_DOT);
- if (RIGHTOF_DOT(sstate->state, i, j) == LINE_UNKNOWN)
- DO_RECURSIVE_CALL(RIGHTOF_DOT);
- if (ABOVE_DOT(sstate->state, i, j) == LINE_UNKNOWN)
- DO_RECURSIVE_CALL(ABOVE_DOT);
- if (BELOW_DOT(sstate->state, i, j) == LINE_UNKNOWN)
- DO_RECURSIVE_CALL(BELOW_DOT);
+ DO_RECURSIVE_CALL(LEFTOF_DOT);
+ DO_RECURSIVE_CALL(RIGHTOF_DOT);
+ DO_RECURSIVE_CALL(ABOVE_DOT);
+ DO_RECURSIVE_CALL(BELOW_DOT);
}
}
}
@@ -1978,7 +2081,7 @@
solver_state *sstate, *new_sstate;
sstate = new_solver_state(state);
- new_sstate = solve_game_rec(sstate);
+ new_sstate = solve_game_rec(sstate, DIFFCOUNT);
if (new_sstate->solver_status == SOLVER_SOLVED) {soln = encode_solve_move(new_sstate->state);
@@ -2084,6 +2187,7 @@
int tilesize;
int flashing;
char *hl, *vl;
+ char *clue_error;
};
static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
@@ -2378,6 +2482,10 @@
ret[COL_HIGHLIGHT * 3 + 1] = 1.0F;
ret[COL_HIGHLIGHT * 3 + 2] = 1.0F;
+ ret[COL_MISTAKE * 3 + 0] = 1.0F;
+ ret[COL_MISTAKE * 3 + 1] = 0.0F;
+ ret[COL_MISTAKE * 3 + 2] = 0.0F;
+
*ncolours = NCOLOURS;
return ret;
}
@@ -2390,10 +2498,12 @@
ds->started = 0;
ds->hl = snewn(HL_COUNT(state), char);
ds->vl = snewn(VL_COUNT(state), char);
+ ds->clue_error = snewn(SQUARE_COUNT(state), char);
ds->flashing = 0;
memset(ds->hl, LINE_UNKNOWN, HL_COUNT(state));
memset(ds->vl, LINE_UNKNOWN, VL_COUNT(state));
+ memset(ds->clue_error, 0, SQUARE_COUNT(state));
return ds;
}
@@ -2400,6 +2510,7 @@
static void game_free_drawstate(drawing *dr, game_drawstate *ds)
{+ sfree(ds->clue_error);
sfree(ds->hl);
sfree(ds->vl);
sfree(ds);
@@ -2409,10 +2520,11 @@
game_state *state, int dir, game_ui *ui,
float animtime, float flashtime)
{- int i, j;
+ int i, j, n;
int w = state->w, h = state->h;
char c[2];
int line_colour, flash_changed;
+ int clue_mistake;
if (!ds->started) {/*
@@ -2465,6 +2577,44 @@
#define CROSS_SIZE (3 * LINEWIDTH / 2)
+ /* Redraw clue colours if necessary */
+ for (j = 0; j < h; ++j) {+ for (i = 0; i < w; ++i) {+ c[0] = CLUE_AT(state, i, j);
+ c[1] = '\0';
+ if (c[0] == ' ')
+ continue;
+
+ n = c[0] - '0';
+ assert(n >= 0 && n <= 4);
+
+ clue_mistake = (square_order(state, i, j, LINE_YES) > n ||
+ square_order(state, i, j, LINE_NO ) > (4-n));
+
+ if (clue_mistake != ds->clue_error[i * w + j]) {+ draw_rect(dr,
+ BORDER + i * TILE_SIZE + CROSS_SIZE,
+ BORDER + j * TILE_SIZE + CROSS_SIZE,
+ TILE_SIZE - CROSS_SIZE * 2, TILE_SIZE - CROSS_SIZE * 2,
+ COL_BACKGROUND);
+ draw_text(dr,
+ BORDER + i * TILE_SIZE + TILE_SIZE/2,
+ BORDER + j * TILE_SIZE + TILE_SIZE/2,
+ FONT_VARIABLE, TILE_SIZE/2,
+ ALIGN_VCENTRE | ALIGN_HCENTRE,
+ clue_mistake ? COL_MISTAKE : COL_FOREGROUND, c);
+ draw_update(dr, i * TILE_SIZE + BORDER, j * TILE_SIZE + BORDER,
+ TILE_SIZE, TILE_SIZE);
+
+ ds->clue_error[i * w + j] = clue_mistake;
+ }
+ }
+ }
+
+ /* I've also had a request to colour lines red if they make a non-solution
+ * loop, or if more than two lines go into any point. I think that would
+ * be good some time. */
+
#define CLEAR_VL(i, j) do { \draw_rect(dr, \
BORDER + i * TILE_SIZE - CROSS_SIZE, \
--
⑨