ref: 4ff90bd47f4bd3b11c4fb8b1ea25afb7b95f76da
dir: /loopy.c/
/*
* loopy.c: An implementation of the Nikoli game 'Loop the loop'.
* (c) Mike Pinna, 2005, 2006
*
* vim: set shiftwidth=4 :set textwidth=80:
*/
/*
* TODO:
*
* - Setting very high recursion depth seems to cause memory munching: are we
* recursing before checking completion, by any chance?
*
* - There's an interesting deductive technique which makes use of topology
* rather than just graph theory. Each _square_ in the grid is either inside
* or outside the loop; you can tell that two squares are on the same side
* of the loop if they're separated by an x (or, more generally, by a path
* crossing no LINE_UNKNOWNs and an even number of LINE_YESes), and on the
* opposite side of the loop if they're separated by a line (or an odd
* number of LINE_YESes and no LINE_UNKNOWNs). Oh, and any square separated
* from the outside of the grid by a LINE_YES or a LINE_NO is on the inside
* or outside respectively. So if you can track this for all squares, you
* figure out the state of the line between a pair once their relative
* insideness is known.
*
* - (Just a speed optimisation.) Consider some todo list queue where every
* time we modify something we mark it for consideration by other bits of
* the solver, to save iteration over things that have already been done.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <ctype.h>
#include <math.h>
#include "puzzles.h"
#include "tree234.h"
/* Debugging options */
/*#define DEBUG_CACHES*/
/*#define SHOW_WORKING*/
/* ----------------------------------------------------------------------
* Struct, enum and function declarations
*/
enum {
COL_BACKGROUND,
COL_FOREGROUND,
COL_HIGHLIGHT,
COL_MISTAKE,
NCOLOURS
};
struct game_state {
int w, h;
/* Put -1 in a square that doesn't get a clue */
signed char *clues;
/* Arrays of line states, stored left-to-right, top-to-bottom */
char *hl, *vl;
int solved;
int cheated;
int recursion_depth;
};
enum solver_status {
SOLVER_SOLVED, /* This is the only solution the solver could find */
SOLVER_MISTAKE, /* This is definitely not a solution */
SOLVER_AMBIGUOUS, /* This _might_ be an ambiguous solution */
SOLVER_INCOMPLETE /* This may be a partial solution */
};
typedef struct normal {
char *dot_atleastone;
char *dot_atmostone;
} normal_mode_state;
typedef struct hard {
int *linedsf;
} hard_mode_state;
typedef struct solver_state {
game_state *state;
int recursion_remaining;
enum solver_status solver_status;
/* NB looplen is the number of dots that are joined together at a point, ie a
* looplen of 1 means there are no lines to a particular dot */
int *looplen;
/* caches */
char *dot_yescount;
char *dot_nocount;
char *square_yescount;
char *square_nocount;
char *dot_solved, *square_solved;
int *dotdsf;
normal_mode_state *normal;
hard_mode_state *hard;
} solver_state;
/*
* 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,easy_mode_deductions) \
A(NORMAL,Normal,n,normal_mode_deductions) \
A(HARD,Hard,h,hard_mode_deductions)
#define ENUM(upper,title,lower,fn) DIFF_ ## upper,
#define TITLE(upper,title,lower,fn) #title,
#define ENCODE(upper,title,lower,fn) #lower
#define CONFIG(upper,title,lower,fn) ":" #title
#define SOLVER_FN_DECL(upper,title,lower,fn) static int fn(solver_state *);
#define SOLVER_FN(upper,title,lower,fn) &fn,
enum { DIFFLIST(ENUM) DIFF_MAX };
static char const *const diffnames[] = { DIFFLIST(TITLE) };
static char const diffchars[] = DIFFLIST(ENCODE);
#define DIFFCONFIG DIFFLIST(CONFIG)
DIFFLIST(SOLVER_FN_DECL);
static int (*(solver_fns[]))(solver_state *) = { DIFFLIST(SOLVER_FN) };
struct game_params {
int w, h;
int diff;
int rec;
};
enum line_state { LINE_YES, LINE_UNKNOWN, LINE_NO };
#define OPP(state) \
(2 - state)
enum direction { UP, LEFT, RIGHT, DOWN };
#define OPP_DIR(dir) \
(3 - dir)
struct game_drawstate {
int started;
int tilesize, linewidth;
int flashing;
char *hl, *vl;
char *clue_error;
};
static char *game_text_format(game_state *state);
static char *state_to_text(const game_state *state);
static char *validate_desc(game_params *params, char *desc);
static int get_line_status_from_point(const game_state *state,
int x, int y, enum direction d);
static int dot_order(const game_state* state, int i, int j, char line_type);
static int square_order(const game_state* state, int i, int j, char line_type);
static solver_state *solve_game_rec(const solver_state *sstate,
int diff);
#ifdef DEBUG_CACHES
static void check_caches(const solver_state* sstate);
#else
#define check_caches(s)
#endif
/* ----------------------------------------------------------------------
* Preprocessor magic
*/
/* General constants */
#define PREFERRED_TILE_SIZE 32
#define TILE_SIZE (ds->tilesize)
#define LINEWIDTH (ds->linewidth)
#define BORDER (TILE_SIZE / 2)
#define FLASH_TIME 0.5F
/* Counts of various things that we're interested in */
#define HL_COUNT(state) ((state)->w * ((state)->h + 1))
#define VL_COUNT(state) (((state)->w + 1) * (state)->h)
#define LINE_COUNT(state) (HL_COUNT(state) + VL_COUNT(state))
#define DOT_COUNT(state) (((state)->w + 1) * ((state)->h + 1))
#define SQUARE_COUNT(state) ((state)->w * (state)->h)
/* For indexing into arrays */
#define DOT_INDEX(state, x, y) ((x) + ((state)->w + 1) * (y))
#define SQUARE_INDEX(state, x, y) ((x) + ((state)->w) * (y))
#define HL_INDEX(state, x, y) SQUARE_INDEX(state, x, y)
#define VL_INDEX(state, x, y) DOT_INDEX(state, x, y)
/* Useful utility functions */
#define LEGAL_DOT(state, i, j) ((i) >= 0 && (j) >= 0 && \
(i) <= (state)->w && (j) <= (state)->h)
#define LEGAL_SQUARE(state, i, j) ((i) >= 0 && (j) >= 0 && \
(i) < (state)->w && (j) < (state)->h)
#define CLUE_AT(state, i, j) (LEGAL_SQUARE(state, i, j) ? \
LV_CLUE_AT(state, i, j) : -1)
#define LV_CLUE_AT(state, i, j) ((state)->clues[SQUARE_INDEX(state, i, j)])
#define BIT_SET(field, bit) ((field) & (1<<(bit)))
#define SET_BIT(field, bit) (BIT_SET(field, bit) ? FALSE : \
((field) |= (1<<(bit)), TRUE))
#define CLEAR_BIT(field, bit) (BIT_SET(field, bit) ? \
((field) &= ~(1<<(bit)), TRUE) : FALSE)
#define DIR2STR(d) \
((d == UP) ? "up" : \
(d == DOWN) ? "down" : \
(d == LEFT) ? "left" : \
(d == RIGHT) ? "right" : "oops")
#define CLUE2CHAR(c) \
((c < 0) ? ' ' : c + '0')
/* Lines that have particular relationships with given dots or squares */
#define ABOVE_SQUARE(state, i, j) ((state)->hl[(i) + (state)->w * (j)])
#define BELOW_SQUARE(state, i, j) ABOVE_SQUARE(state, i, (j)+1)
#define LEFTOF_SQUARE(state, i, j) ((state)->vl[(i) + ((state)->w + 1) * (j)])
#define RIGHTOF_SQUARE(state, i, j) LEFTOF_SQUARE(state, (i)+1, j)
/*
* These macros return rvalues only, but can cope with being passed
* out-of-range coordinates.
*/
/* XXX replace these with functions so we can create an array of function
* pointers for nicer iteration over them. This could probably be done with
* loads of other things for eliminating many nasty hacks. */
#define ABOVE_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || j <= 0) ? \
LINE_NO : LV_ABOVE_DOT(state, i, j))
#define BELOW_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || j >= (state)->h) ? \
LINE_NO : LV_BELOW_DOT(state, i, j))
#define LEFTOF_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || i <= 0) ? \
LINE_NO : LV_LEFTOF_DOT(state, i, j))
#define RIGHTOF_DOT(state, i, j) ((!LEGAL_DOT(state, i, j) || i >= (state)->w)? \
LINE_NO : LV_RIGHTOF_DOT(state, i, j))
/*
* These macros expect to be passed valid coordinates, and return
* lvalues.
*/
#define LV_BELOW_DOT(state, i, j) ((state)->vl[VL_INDEX(state, i, j)])
#define LV_ABOVE_DOT(state, i, j) LV_BELOW_DOT(state, i, (j)-1)
#define LV_RIGHTOF_DOT(state, i, j) ((state)->hl[HL_INDEX(state, i, j)])
#define LV_LEFTOF_DOT(state, i, j) LV_RIGHTOF_DOT(state, (i)-1, j)
/* Counts of interesting things */
#define DOT_YES_COUNT(sstate, i, j) \
((sstate)->dot_yescount[DOT_INDEX((sstate)->state, i, j)])
#define DOT_NO_COUNT(sstate, i, j) \
((sstate)->dot_nocount[DOT_INDEX((sstate)->state, i, j)])
#define SQUARE_YES_COUNT(sstate, i, j) \
((sstate)->square_yescount[SQUARE_INDEX((sstate)->state, i, j)])
#define SQUARE_NO_COUNT(sstate, i, j) \
((sstate)->square_nocount[SQUARE_INDEX((sstate)->state, i, j)])
/* Iterators. NB these iterate over height more slowly than over width so that
* the elements come out in 'reading' order */
/* XXX considering adding a 'current' element to each of these which gets the
* address of the current dot, say. But expecting we'd need more than that
* most of the time. */
#define FORALL(i, j, w, h) \
for ((j) = 0; (j) < (h); ++(j)) \
for ((i) = 0; (i) < (w); ++(i))
#define FORALL_DOTS(state, i, j) \
FORALL(i, j, (state)->w + 1, (state)->h + 1)
#define FORALL_SQUARES(state, i, j) \
FORALL(i, j, (state)->w, (state)->h)
#define FORALL_HL(state, i, j) \
FORALL(i, j, (state)->w, (state)->h+1)
#define FORALL_VL(state, i, j) \
FORALL(i, j, (state)->w+1, (state)->h)
/* ----------------------------------------------------------------------
* General struct manipulation and other straightforward code
*/
static game_state *dup_game(game_state *state)
{
game_state *ret = snew(game_state);
ret->h = state->h;
ret->w = state->w;
ret->solved = state->solved;
ret->cheated = state->cheated;
ret->clues = snewn(SQUARE_COUNT(state), signed char);
memcpy(ret->clues, state->clues, SQUARE_COUNT(state));
ret->hl = snewn(HL_COUNT(state), char);
memcpy(ret->hl, state->hl, HL_COUNT(state));
ret->vl = snewn(VL_COUNT(state), char);
memcpy(ret->vl, state->vl, VL_COUNT(state));
ret->recursion_depth = state->recursion_depth;
return ret;
}
static void free_game(game_state *state)
{
if (state) {
sfree(state->clues);
sfree(state->hl);
sfree(state->vl);
sfree(state);
}
}
static solver_state *new_solver_state(const game_state *state, int diff) {
int i, j;
solver_state *ret = snew(solver_state);
ret->state = dup_game((game_state *)state);
ret->recursion_remaining = state->recursion_depth;
ret->solver_status = SOLVER_INCOMPLETE;
ret->dotdsf = snew_dsf(DOT_COUNT(state));
ret->looplen = snewn(DOT_COUNT(state), int);
for (i = 0; i < DOT_COUNT(state); i++) {
ret->looplen[i] = 1;
}
ret->dot_solved = snewn(DOT_COUNT(state), char);
ret->square_solved = snewn(SQUARE_COUNT(state), char);
memset(ret->dot_solved, FALSE, DOT_COUNT(state));
memset(ret->square_solved, FALSE, SQUARE_COUNT(state));
ret->dot_yescount = snewn(DOT_COUNT(state), char);
memset(ret->dot_yescount, 0, DOT_COUNT(state));
ret->dot_nocount = snewn(DOT_COUNT(state), char);
memset(ret->dot_nocount, 0, DOT_COUNT(state));
ret->square_yescount = snewn(SQUARE_COUNT(state), char);
memset(ret->square_yescount, 0, SQUARE_COUNT(state));
ret->square_nocount = snewn(SQUARE_COUNT(state), char);
memset(ret->square_nocount, 0, SQUARE_COUNT(state));
/* dot_nocount needs special initialisation as we define lines coming off
* dots on edges as fixed at NO */
FORALL_DOTS(state, i, j) {
if (i == 0 || i == state->w)
++ret->dot_nocount[DOT_INDEX(state, i, j)];
if (j == 0 || j == state->h)
++ret->dot_nocount[DOT_INDEX(state, i, j)];
}
if (diff < DIFF_NORMAL) {
ret->normal = NULL;
} else {
ret->normal = snew(normal_mode_state);
ret->normal->dot_atmostone = snewn(DOT_COUNT(state), char);
memset(ret->normal->dot_atmostone, 0, DOT_COUNT(state));
ret->normal->dot_atleastone = snewn(DOT_COUNT(state), char);
memset(ret->normal->dot_atleastone, 0, DOT_COUNT(state));
}
if (diff < DIFF_HARD) {
ret->hard = NULL;
} else {
ret->hard = snew(hard_mode_state);
ret->hard->linedsf = snew_dsf(LINE_COUNT(state));
}
return ret;
}
static void free_solver_state(solver_state *sstate) {
if (sstate) {
free_game(sstate->state);
sfree(sstate->dotdsf);
sfree(sstate->looplen);
sfree(sstate->dot_solved);
sfree(sstate->square_solved);
sfree(sstate->dot_yescount);
sfree(sstate->dot_nocount);
sfree(sstate->square_yescount);
sfree(sstate->square_nocount);
if (sstate->normal) {
sfree(sstate->normal->dot_atleastone);
sfree(sstate->normal->dot_atmostone);
sfree(sstate->normal);
}
if (sstate->hard) {
sfree(sstate->hard->linedsf);
sfree(sstate->hard);
}
sfree(sstate);
}
}
static solver_state *dup_solver_state(const solver_state *sstate) {
game_state *state;
solver_state *ret = snew(solver_state);
ret->state = state = dup_game(sstate->state);
ret->recursion_remaining = sstate->recursion_remaining;
ret->solver_status = sstate->solver_status;
ret->dotdsf = snewn(DOT_COUNT(state), int);
ret->looplen = snewn(DOT_COUNT(state), int);
memcpy(ret->dotdsf, sstate->dotdsf,
DOT_COUNT(state) * sizeof(int));
memcpy(ret->looplen, sstate->looplen,
DOT_COUNT(state) * sizeof(int));
ret->dot_solved = snewn(DOT_COUNT(state), char);
ret->square_solved = snewn(SQUARE_COUNT(state), char);
memcpy(ret->dot_solved, sstate->dot_solved,
DOT_COUNT(state));
memcpy(ret->square_solved, sstate->square_solved,
SQUARE_COUNT(state));
ret->dot_yescount = snewn(DOT_COUNT(state), char);
memcpy(ret->dot_yescount, sstate->dot_yescount,
DOT_COUNT(state));
ret->dot_nocount = snewn(DOT_COUNT(state), char);
memcpy(ret->dot_nocount, sstate->dot_nocount,
DOT_COUNT(state));
ret->square_yescount = snewn(SQUARE_COUNT(state), char);
memcpy(ret->square_yescount, sstate->square_yescount,
SQUARE_COUNT(state));
ret->square_nocount = snewn(SQUARE_COUNT(state), char);
memcpy(ret->square_nocount, sstate->square_nocount,
SQUARE_COUNT(state));
if (sstate->normal) {
ret->normal = snew(normal_mode_state);
ret->normal->dot_atmostone = snewn(DOT_COUNT(state), char);
memcpy(ret->normal->dot_atmostone, sstate->normal->dot_atmostone,
DOT_COUNT(state));
ret->normal->dot_atleastone = snewn(DOT_COUNT(state), char);
memcpy(ret->normal->dot_atleastone, sstate->normal->dot_atleastone,
DOT_COUNT(state));
} else {
ret->normal = NULL;
}
if (sstate->hard) {
ret->hard = snew(hard_mode_state);
ret->hard->linedsf = snewn(LINE_COUNT(state), int);
memcpy(ret->hard->linedsf, sstate->hard->linedsf,
LINE_COUNT(state) * sizeof(int));
} else {
ret->hard = NULL;
}
return ret;
}
static game_params *default_params(void)
{
game_params *ret = snew(game_params);
#ifdef SLOW_SYSTEM
ret->h = 4;
ret->w = 4;
#else
ret->h = 10;
ret->w = 10;
#endif
ret->diff = DIFF_EASY;
ret->rec = 0;
return ret;
}
static game_params *dup_params(game_params *params)
{
game_params *ret = snew(game_params);
*ret = *params; /* structure copy */
return ret;
}
static const game_params presets[] = {
{ 4, 4, DIFF_EASY, 0 },
{ 4, 4, DIFF_NORMAL, 0 },
{ 4, 4, DIFF_HARD, 0 },
{ 7, 7, DIFF_EASY, 0 },
{ 7, 7, DIFF_NORMAL, 0 },
{ 7, 7, DIFF_HARD, 0 },
{ 10, 10, DIFF_EASY, 0 },
{ 10, 10, DIFF_NORMAL, 0 },
{ 10, 10, DIFF_HARD, 0 },
#ifndef SLOW_SYSTEM
{ 15, 15, DIFF_EASY, 0 },
{ 15, 15, DIFF_NORMAL, 0 },
{ 15, 15, DIFF_HARD, 0 },
#ifndef SMALL_SCREEN
{ 30, 20, DIFF_EASY, 0 },
{ 30, 20, DIFF_NORMAL, 0 },
{ 30, 20, DIFF_HARD, 0 }
#endif
#endif
};
static int game_fetch_preset(int i, char **name, game_params **params)
{
game_params *tmppar;
char buf[80];
if (i < 0 || i >= lenof(presets))
return FALSE;
tmppar = snew(game_params);
*tmppar = presets[i];
*params = tmppar;
sprintf(buf, "%dx%d %s", tmppar->h, tmppar->w, diffnames[tmppar->diff]);
*name = dupstr(buf);
return TRUE;
}
static void free_params(game_params *params)
{
sfree(params);
}
static void decode_params(game_params *params, char const *string)
{
params->h = params->w = atoi(string);
params->rec = 0;
params->diff = DIFF_EASY;
while (*string && isdigit((unsigned char)*string)) string++;
if (*string == 'x') {
string++;
params->h = atoi(string);
while (*string && isdigit((unsigned char)*string)) string++;
}
if (*string == 'r') {
string++;
params->rec = atoi(string);
while (*string && isdigit((unsigned char)*string)) string++;
}
if (*string == 'd') {
int i;
string++;
for (i = 0; i < DIFF_MAX; i++)
if (*string == diffchars[i])
params->diff = i;
if (*string) string++;
}
}
static char *encode_params(game_params *params, int full)
{
char str[80];
sprintf(str, "%dx%d", params->w, params->h);
if (full)
sprintf(str + strlen(str), "r%dd%c", params->rec, diffchars[params->diff]);
return dupstr(str);
}
static config_item *game_configure(game_params *params)
{
config_item *ret;
char buf[80];
ret = snewn(4, config_item);
ret[0].name = "Width";
ret[0].type = C_STRING;
sprintf(buf, "%d", params->w);
ret[0].sval = dupstr(buf);
ret[0].ival = 0;
ret[1].name = "Height";
ret[1].type = C_STRING;
sprintf(buf, "%d", params->h);
ret[1].sval = dupstr(buf);
ret[1].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;
ret[3].sval = NULL;
ret[3].ival = 0;
return ret;
}
static game_params *custom_params(config_item *cfg)
{
game_params *ret = snew(game_params);
ret->w = atoi(cfg[0].sval);
ret->h = atoi(cfg[1].sval);
ret->rec = 0;
ret->diff = cfg[2].ival;
return ret;
}
static char *validate_params(game_params *params, int full)
{
if (params->w < 4 || params->h < 4)
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 < DIFF_MAX);
return NULL;
}
/* Returns a newly allocated string describing the current puzzle */
static char *state_to_text(const game_state *state)
{
char *retval;
char *description = snewn(SQUARE_COUNT(state) + 1, char);
char *dp = description;
int empty_count = 0;
int i, j;
FORALL_SQUARES(state, i, j) {
if (CLUE_AT(state, i, j) < 0) {
if (empty_count > 25) {
dp += sprintf(dp, "%c", (int)(empty_count + 'a' - 1));
empty_count = 0;
}
empty_count++;
} else {
if (empty_count) {
dp += sprintf(dp, "%c", (int)(empty_count + 'a' - 1));
empty_count = 0;
}
dp += sprintf(dp, "%c", (int)CLUE2CHAR(CLUE_AT(state, i, j)));
}
}
if (empty_count)
dp += sprintf(dp, "%c", (int)(empty_count + 'a' - 1));
retval = dupstr(description);
sfree(description);
return retval;
}
/* We require that the params pass the test in validate_params and that the
* description fills the entire game area */
static char *validate_desc(game_params *params, char *desc)
{
int count = 0;
for (; *desc; ++desc) {
if (*desc >= '0' && *desc <= '9') {
count++;
continue;
}
if (*desc >= 'a') {
count += *desc - 'a' + 1;
continue;
}
return "Unknown character in description";
}
if (count < SQUARE_COUNT(params))
return "Description too short for board size";
if (count > SQUARE_COUNT(params))
return "Description too long for board size";
return NULL;
}
/* Sums the lengths of the numbers in range [0,n) */
/* See equivalent function in solo.c for justification of this. */
static int len_0_to_n(int n)
{
int len = 1; /* Counting 0 as a bit of a special case */
int i;
for (i = 1; i < n; i *= 10) {
len += max(n - i, 0);
}
return len;
}
static char *encode_solve_move(const game_state *state)
{
int len, i, j;
char *ret, *p;
/* This is going to return a string representing the moves needed to set
* every line in a grid to be the same as the ones in 'state'. The exact
* length of this string is predictable. */
len = 1; /* Count the 'S' prefix */
/* Numbers in horizontal lines */
/* Horizontal lines, x position */
len += len_0_to_n(state->w) * (state->h + 1);
/* Horizontal lines, y position */
len += len_0_to_n(state->h + 1) * (state->w);
/* Vertical lines, y position */
len += len_0_to_n(state->h) * (state->w + 1);
/* Vertical lines, x position */
len += len_0_to_n(state->w + 1) * (state->h);
/* For each line we also have two letters and a comma */
len += 3 * (LINE_COUNT(state));
ret = snewn(len + 1, char);
p = ret;
p += sprintf(p, "S");
FORALL_HL(state, i, j) {
switch (RIGHTOF_DOT(state, i, j)) {
case LINE_YES:
p += sprintf(p, "%d,%dhy", i, j);
break;
case LINE_NO:
p += sprintf(p, "%d,%dhn", i, j);
break;
}
}
FORALL_VL(state, i, j) {
switch (BELOW_DOT(state, i, j)) {
case LINE_YES:
p += sprintf(p, "%d,%dvy", i, j);
break;
case LINE_NO:
p += sprintf(p, "%d,%dvn", i, j);
break;
}
}
/* No point in doing sums like that if they're going to be wrong */
assert(strlen(ret) <= (size_t)len);
return ret;
}
static game_ui *new_ui(game_state *state)
{
return NULL;
}
static void free_ui(game_ui *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)
{
}
#define SIZE(d) ((d) * TILE_SIZE + 2 * BORDER + 1)
static void game_compute_size(game_params *params, int tilesize,
int *x, int *y)
{
struct { int tilesize; } ads, *ds = &ads;
ads.tilesize = tilesize;
*x = SIZE(params->w);
*y = SIZE(params->h);
}
static void game_set_size(drawing *dr, game_drawstate *ds,
game_params *params, int tilesize)
{
ds->tilesize = tilesize;
ds->linewidth = max(1,tilesize/16);
}
static float *game_colours(frontend *fe, int *ncolours)
{
float *ret = snewn(4 * NCOLOURS, float);
frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
ret[COL_FOREGROUND * 3 + 0] = 0.0F;
ret[COL_FOREGROUND * 3 + 1] = 0.0F;
ret[COL_FOREGROUND * 3 + 2] = 0.0F;
ret[COL_HIGHLIGHT * 3 + 0] = 1.0F;
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;
}
static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
{
struct game_drawstate *ds = snew(struct game_drawstate);
ds->tilesize = ds->linewidth = 0;
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;
}
static void game_free_drawstate(drawing *dr, game_drawstate *ds)
{
sfree(ds->clue_error);
sfree(ds->hl);
sfree(ds->vl);
sfree(ds);
}
static int game_timing_state(game_state *state, game_ui *ui)
{
return TRUE;
}
static float game_anim_length(game_state *oldstate, game_state *newstate,
int dir, game_ui *ui)
{
return 0.0F;
}
static char *game_text_format(game_state *state)
{
int i, j;
int len;
char *ret, *rp;
len = (2 * state->w + 2) * (2 * state->h + 1);
rp = ret = snewn(len + 1, char);
#define DRAW_HL \
switch (ABOVE_SQUARE(state, i, j)) { \
case LINE_YES: \
rp += sprintf(rp, " -"); \
break; \
case LINE_NO: \
rp += sprintf(rp, " x"); \
break; \
case LINE_UNKNOWN: \
rp += sprintf(rp, " "); \
break; \
default: \
assert(!"Illegal line state for HL"); \
}
#define DRAW_VL \
switch (LEFTOF_SQUARE(state, i, j)) { \
case LINE_YES: \
rp += sprintf(rp, "|"); \
break; \
case LINE_NO: \
rp += sprintf(rp, "x"); \
break; \
case LINE_UNKNOWN: \
rp += sprintf(rp, " "); \
break; \
default: \
assert(!"Illegal line state for VL"); \
}
for (j = 0; j < state->h; ++j) {
for (i = 0; i < state->w; ++i) {
DRAW_HL;
}
rp += sprintf(rp, " \n");
for (i = 0; i < state->w; ++i) {
DRAW_VL;
rp += sprintf(rp, "%c", (int)CLUE2CHAR(CLUE_AT(state, i, j)));
}
DRAW_VL;
rp += sprintf(rp, "\n");
}
for (i = 0; i < state->w; ++i) {
DRAW_HL;
}
rp += sprintf(rp, " \n");
assert(strlen(ret) == len);
return ret;
}
/* ----------------------------------------------------------------------
* Debug code
*/
#ifdef DEBUG_CACHES
static void check_caches(const solver_state* sstate)
{
int i, j;
const game_state *state = sstate->state;
FORALL_DOTS(state, i, j) {
#if 0
fprintf(stderr, "dot [%d,%d] y: %d %d n: %d %d\n", i, j,
dot_order(state, i, j, LINE_YES),
sstate->dot_yescount[i + (state->w + 1) * j],
dot_order(state, i, j, LINE_NO),
sstate->dot_nocount[i + (state->w + 1) * j]);
#endif
assert(dot_order(state, i, j, LINE_YES) ==
DOT_YES_COUNT(sstate, i, j));
assert(dot_order(state, i, j, LINE_NO) ==
DOT_NO_COUNT(sstate, i, j));
}
FORALL_SQUARES(state, i, j) {
#if 0
fprintf(stderr, "square [%d,%d] y: %d %d n: %d %d\n", i, j,
square_order(state, i, j, LINE_YES),
sstate->square_yescount[i + state->w * j],
square_order(state, i, j, LINE_NO),
sstate->square_nocount[i + state->w * j]);
#endif
assert(square_order(state, i, j, LINE_YES) ==
SQUARE_YES_COUNT(sstate, i, j));
assert(square_order(state, i, j, LINE_NO) ==
SQUARE_NO_COUNT(sstate, i, j));
}
}
#if 0
#define check_caches(s) \
do { \
fprintf(stderr, "check_caches at line %d\n", __LINE__); \
check_caches(s); \
} while (0)
#endif
#endif /* DEBUG_CACHES */
/* ----------------------------------------------------------------------
* Solver utility functions
*/
static int set_line_bydot(solver_state *sstate, int x, int y, enum direction d,
enum line_state line_new
#ifdef SHOW_WORKING
, const char *reason
#endif
)
{
game_state *state = sstate->state;
/* This line borders at most two squares in our board. We figure out the
* x and y positions of those squares so we can record that their yes or no
* counts have been changed */
int sq1_x=-1, sq1_y=-1, sq2_x=-1, sq2_y=-1;
int otherdot_x=-1, otherdot_y=-1;
int progress = FALSE;
#if 0
fprintf(stderr, "set_line_bydot [%d,%d], %s, %d\n",
x, y, DIR2STR(d), line_new);
#endif
assert(line_new != LINE_UNKNOWN);
check_caches(sstate);
switch (d) {
case LEFT:
assert(x > 0);
if (LEFTOF_DOT(state, x, y) != line_new) {
LV_LEFTOF_DOT(state, x, y) = line_new;
otherdot_x = x-1;
otherdot_y = y;
sq1_x = x-1;
sq1_y = y-1;
sq2_x = x-1;
sq2_y = y;
progress = TRUE;
}
break;
case RIGHT:
assert(x < state->w);
if (RIGHTOF_DOT(state, x, y) != line_new) {
LV_RIGHTOF_DOT(state, x, y) = line_new;
otherdot_x = x+1;
otherdot_y = y;
sq1_x = x;
sq1_y = y-1;
sq2_x = x;
sq2_y = y;
progress = TRUE;
}
break;
case UP:
assert(y > 0);
if (ABOVE_DOT(state, x, y) != line_new) {
LV_ABOVE_DOT(state, x, y) = line_new;
otherdot_x = x;
otherdot_y = y-1;
sq1_x = x-1;
sq1_y = y-1;
sq2_x = x;
sq2_y = y-1;
progress = TRUE;
}
break;
case DOWN:
assert(y < state->h);
if (BELOW_DOT(state, x, y) != line_new) {
LV_BELOW_DOT(state, x, y) = line_new;
otherdot_x = x;
otherdot_y = y+1;
sq1_x = x-1;
sq1_y = y;
sq2_x = x;
sq2_y = y;
progress = TRUE;
}
break;
}
if (!progress)
return progress;
#ifdef SHOW_WORKING
fprintf(stderr, "set line [%d,%d] -> [%d,%d] to %s (%s)\n",
x, y, otherdot_x, otherdot_y, line_new == LINE_YES ? "YES" : "NO",
reason);
#endif
/* Above we updated the cache for the dot that the line in question reaches
* from the dot we've been told about. Here we update that for the dot
* named in our arguments. */
if (line_new == LINE_YES) {
if (sq1_x >= 0 && sq1_y >= 0)
++SQUARE_YES_COUNT(sstate, sq1_x, sq1_y);
if (sq2_x < state->w && sq2_y < state->h)
++SQUARE_YES_COUNT(sstate, sq2_x, sq2_y);
++DOT_YES_COUNT(sstate, x, y);
++DOT_YES_COUNT(sstate, otherdot_x, otherdot_y);
} else {
if (sq1_x >= 0 && sq1_y >= 0)
++SQUARE_NO_COUNT(sstate, sq1_x, sq1_y);
if (sq2_x < state->w && sq2_y < state->h)
++SQUARE_NO_COUNT(sstate, sq2_x, sq2_y);
++DOT_NO_COUNT(sstate, x, y);
++DOT_NO_COUNT(sstate, otherdot_x, otherdot_y);
}
check_caches(sstate);
return progress;
}
#ifdef SHOW_WORKING
#define set_line_bydot(a, b, c, d, e) \
set_line_bydot(a, b, c, d, e, __FUNCTION__)
#endif
/*
* Merge two dots due to the existence of an edge between them.
* Updates the dsf tracking equivalence classes, and keeps track of
* the length of path each dot is currently a part of.
* Returns TRUE if the dots were already linked, ie if they are part of a
* closed loop, and false otherwise.
*/
static int merge_dots(solver_state *sstate, int x1, int y1, int x2, int y2)
{
int i, j, len;
i = y1 * (sstate->state->w + 1) + x1;
j = y2 * (sstate->state->w + 1) + x2;
i = dsf_canonify(sstate->dotdsf, i);
j = dsf_canonify(sstate->dotdsf, j);
if (i == j) {
return TRUE;
} else {
len = sstate->looplen[i] + sstate->looplen[j];
dsf_merge(sstate->dotdsf, i, j);
i = dsf_canonify(sstate->dotdsf, i);
sstate->looplen[i] = len;
return FALSE;
}
}
/* Seriously, these should be functions */
#define LINEDSF_INDEX(state, x, y, d) \
((d == UP) ? ((y-1) * (state->w + 1) + x) : \
(d == DOWN) ? ((y) * (state->w + 1) + x) : \
(d == LEFT) ? ((y) * (state->w) + x-1 + VL_COUNT(state)) : \
(d == RIGHT) ? ((y) * (state->w) + x + VL_COUNT(state)) : \
(assert(!"bad direction value"), 0))
static void linedsf_deindex(const game_state *state, int i,
int *px, int *py, enum direction *pd)
{
int i_mod;
if (i < VL_COUNT(state)) {
*(pd) = DOWN;
*(px) = (i) % (state->w+1);
*(py) = (i) / (state->w+1);
} else {
i_mod = i - VL_COUNT(state);
*(pd) = RIGHT;
*(px) = (i_mod) % (state->w);
*(py) = (i_mod) / (state->w);
}
}
/* Merge two lines because the solver has deduced that they must be either
* identical or opposite. Returns TRUE if this is new information, otherwise
* FALSE. */
static int merge_lines(solver_state *sstate,
int x1, int y1, enum direction d1,
int x2, int y2, enum direction d2,
int inverse
#ifdef SHOW_WORKING
, const char *reason
#endif
)
{
int i, j, inv_tmp;
i = LINEDSF_INDEX(sstate->state, x1, y1, d1);
j = LINEDSF_INDEX(sstate->state, x2, y2, d2);
assert(i < LINE_COUNT(sstate->state));
assert(j < LINE_COUNT(sstate->state));
i = edsf_canonify(sstate->hard->linedsf, i, &inv_tmp);
inverse ^= inv_tmp;
j = edsf_canonify(sstate->hard->linedsf, j, &inv_tmp);
inverse ^= inv_tmp;
edsf_merge(sstate->hard->linedsf, i, j, inverse);
#ifdef SHOW_WORKING
if (i != j) {
fprintf(stderr, "%s [%d,%d,%s] [%d,%d,%s] %s(%s)\n",
__FUNCTION__,
x1, y1, DIR2STR(d1),
x2, y2, DIR2STR(d2),
inverse ? "inverse " : "", reason);
}
#endif
return (i != j);
}
#ifdef SHOW_WORKING
#define merge_lines(a, b, c, d, e, f, g, h) \
merge_lines(a, b, c, d, e, f, g, h, __FUNCTION__)
#endif
/* Return 0 if the given lines are not in the same equivalence class, 1 if they
* are known identical, or 2 if they are known opposite */
#if 0
static int lines_related(solver_state *sstate,
int x1, int y1, enum direction d1,
int x2, int y2, enum direction d2)
{
int i, j, inv1, inv2;
i = LINEDSF_INDEX(sstate->state, x1, y1, d1);
j = LINEDSF_INDEX(sstate->state, x2, y2, d2);
i = edsf_canonify(sstate->hard->linedsf, i, &inv1);
j = edsf_canonify(sstate->hard->linedsf, j, &inv2);
if (i == j)
return (inv1 == inv2) ? 1 : 2;
else
return 0;
}
#endif
/* Count the number of lines of a particular type currently going into the
* given dot. Lines going off the edge of the board are assumed fixed no. */
static int dot_order(const game_state* state, int i, int j, char line_type)
{
int n = 0;
if (i > 0) {
if (line_type == LV_LEFTOF_DOT(state, i, j))
++n;
} else {
if (line_type == LINE_NO)
++n;
}
if (i < state->w) {
if (line_type == LV_RIGHTOF_DOT(state, i, j))
++n;
} else {
if (line_type == LINE_NO)
++n;
}
if (j > 0) {
if (line_type == LV_ABOVE_DOT(state, i, j))
++n;
} else {
if (line_type == LINE_NO)
++n;
}
if (j < state->h) {
if (line_type == LV_BELOW_DOT(state, i, j))
++n;
} else {
if (line_type == LINE_NO)
++n;
}
return n;
}
/* Count the number of lines of a particular type currently surrounding the
* given square */
static int square_order(const game_state* state, int i, int j, char line_type)
{
int n = 0;
if (ABOVE_SQUARE(state, i, j) == line_type)
++n;
if (BELOW_SQUARE(state, i, j) == line_type)
++n;
if (LEFTOF_SQUARE(state, i, j) == line_type)
++n;
if (RIGHTOF_SQUARE(state, i, j) == line_type)
++n;
return n;
}
/* Set all lines bordering a dot of type old_type to type new_type
* Return value tells caller whether this function actually did anything */
static int dot_setall(solver_state *sstate, int i, int j,
char old_type, char new_type)
{
int retval = FALSE, r;
game_state *state = sstate->state;
if (old_type == new_type)
return FALSE;
if (i > 0 && LEFTOF_DOT(state, i, j) == old_type) {
r = set_line_bydot(sstate, i, j, LEFT, new_type);
assert(r == TRUE);
retval = TRUE;
}
if (i < state->w && RIGHTOF_DOT(state, i, j) == old_type) {
r = set_line_bydot(sstate, i, j, RIGHT, new_type);
assert(r == TRUE);
retval = TRUE;
}
if (j > 0 && ABOVE_DOT(state, i, j) == old_type) {
r = set_line_bydot(sstate, i, j, UP, new_type);
assert(r == TRUE);
retval = TRUE;
}
if (j < state->h && BELOW_DOT(state, i, j) == old_type) {
r = set_line_bydot(sstate, i, j, DOWN, new_type);
assert(r == TRUE);
retval = TRUE;
}
return retval;
}
/* Set all lines bordering a square of type old_type to type new_type */
static int square_setall(solver_state *sstate, int i, int j,
char old_type, char new_type)
{
int r = FALSE;
game_state *state = sstate->state;
#if 0
fprintf(stderr, "square_setall [%d,%d] from %d to %d\n", i, j,
old_type, new_type);
#endif
if (ABOVE_SQUARE(state, i, j) == old_type) {
r = set_line_bydot(sstate, i, j, RIGHT, new_type);
assert(r == TRUE);
}
if (BELOW_SQUARE(state, i, j) == old_type) {
r = set_line_bydot(sstate, i, j+1, RIGHT, new_type);
assert(r == TRUE);
}
if (LEFTOF_SQUARE(state, i, j) == old_type) {
r = set_line_bydot(sstate, i, j, DOWN, new_type);
assert(r == TRUE);
}
if (RIGHTOF_SQUARE(state, i, j) == old_type) {
r = set_line_bydot(sstate, i+1, j, DOWN, new_type);
assert(r == TRUE);
}
return r;
}
/* ----------------------------------------------------------------------
* Loop generation and clue removal
*/
/* We're going to store a list of current candidate squares for lighting.
* Each square gets a 'score', which tells us how adding that square right
* now would affect the length of the solution loop. We're trying to
* maximise that quantity so will bias our random selection of squares to
* light towards those with high scores */
struct square {
int score;
unsigned long random;
int x, y;
};
static int get_square_cmpfn(void *v1, void *v2)
{
struct square *s1 = v1;
struct square *s2 = v2;
int r;
r = s1->x - s2->x;
if (r)
return r;
r = s1->y - s2->y;
if (r)
return r;
return 0;
}
static int square_sort_cmpfn(void *v1, void *v2)
{
struct square *s1 = v1;
struct square *s2 = v2;
int r;
r = s2->score - s1->score;
if (r) {
return r;
}
if (s1->random < s2->random)
return -1;
else if (s1->random > s2->random)
return 1;
/*
* It's _just_ possible that two squares might have been given
* the same random value. In that situation, fall back to
* comparing based on the coordinates. This introduces a tiny
* directional bias, but not a significant one.
*/
return get_square_cmpfn(v1, v2);
}
enum { SQUARE_LIT, SQUARE_UNLIT };
#define SQUARE_STATE(i, j) \
( LEGAL_SQUARE(state, i, j) ? \
LV_SQUARE_STATE(i,j) : \
SQUARE_UNLIT )
#define LV_SQUARE_STATE(i, j) board[SQUARE_INDEX(state, i, j)]
/* Generate a new complete set of clues for the given game_state (respecting
* the dimensions provided by said game_state) */
static void add_full_clues(game_state *state, random_state *rs)
{
signed char *clues;
char *board;
int i, j, a, b, c;
int board_area = SQUARE_COUNT(state);
int t;
struct square *square, *tmpsquare, *sq;
struct square square_pos;
/* These will contain exactly the same information, sorted into different
* orders */
tree234 *lightable_squares_sorted, *lightable_squares_gettable;
#define SQUARE_REACHABLE(i,j) \
(t = (SQUARE_STATE(i-1, j) == SQUARE_LIT || \
SQUARE_STATE(i+1, j) == SQUARE_LIT || \
SQUARE_STATE(i, j-1) == SQUARE_LIT || \
SQUARE_STATE(i, j+1) == SQUARE_LIT), \
t)
/* One situation in which we may not light a square is if that'll leave one
* square above/below and one left/right of us unlit, separated by a lit
* square diagnonal from us */
#define SQUARE_DIAGONAL_VIOLATION(i, j, h, v) \
(t = (SQUARE_STATE((i)+(h), (j)) == SQUARE_UNLIT && \
SQUARE_STATE((i), (j)+(v)) == SQUARE_UNLIT && \
SQUARE_STATE((i)+(h), (j)+(v)) == SQUARE_LIT), \
t)
/* We also may not light a square if it will form a loop of lit squares
* around some unlit squares, as then the game soln won't have a single
* loop */
#define SQUARE_LOOP_VIOLATION(i, j, lit1, lit2) \
(SQUARE_STATE((i)+1, (j)) == lit1 && \
SQUARE_STATE((i)-1, (j)) == lit1 && \
SQUARE_STATE((i), (j)+1) == lit2 && \
SQUARE_STATE((i), (j)-1) == lit2)
#define CAN_LIGHT_SQUARE(i, j) \
(SQUARE_REACHABLE(i, j) && \
!SQUARE_DIAGONAL_VIOLATION(i, j, -1, -1) && \
!SQUARE_DIAGONAL_VIOLATION(i, j, +1, -1) && \
!SQUARE_DIAGONAL_VIOLATION(i, j, -1, +1) && \
!SQUARE_DIAGONAL_VIOLATION(i, j, +1, +1) && \
!SQUARE_LOOP_VIOLATION(i, j, SQUARE_LIT, SQUARE_UNLIT) && \
!SQUARE_LOOP_VIOLATION(i, j, SQUARE_UNLIT, SQUARE_LIT))
#define IS_LIGHTING_CANDIDATE(i, j) \
(SQUARE_STATE(i, j) == SQUARE_UNLIT && \
CAN_LIGHT_SQUARE(i,j))
/* The 'score' of a square reflects its current desirability for selection
* as the next square to light. We want to encourage moving into uncharted
* areas so we give scores according to how many of the square's neighbours
* are currently unlit. */
/* UNLIT SCORE
* 3 2
* 2 0
* 1 -2
*/
#define SQUARE_SCORE(i,j) \
(2*((SQUARE_STATE(i-1, j) == SQUARE_UNLIT) + \
(SQUARE_STATE(i+1, j) == SQUARE_UNLIT) + \
(SQUARE_STATE(i, j-1) == SQUARE_UNLIT) + \
(SQUARE_STATE(i, j+1) == SQUARE_UNLIT)) - 4)
/* When a square gets lit, this defines how far away from that square we
* need to go recomputing scores */
#define SCORE_DISTANCE 1
board = snewn(board_area, char);
clues = state->clues;
/* Make a board */
memset(board, SQUARE_UNLIT, board_area);
/* Seed the board with a single lit square near the middle */
i = state->w / 2;
j = state->h / 2;
if (state->w & 1 && random_bits(rs, 1))
++i;
if (state->h & 1 && random_bits(rs, 1))
++j;
LV_SQUARE_STATE(i, j) = SQUARE_LIT;
/* We need a way of favouring squares that will increase our loopiness.
* We do this by maintaining a list of all candidate squares sorted by
* their score and choose randomly from that with appropriate skew.
* In order to avoid consistently biasing towards particular squares, we
* need the sort order _within_ each group of scores to be completely
* random. But it would be abusing the hospitality of the tree234 data
* structure if our comparison function were nondeterministic :-). So with
* each square we associate a random number that does not change during a
* particular run of the generator, and use that as a secondary sort key.
* Yes, this means we will be biased towards particular random squares in
* any one run but that doesn't actually matter. */
lightable_squares_sorted = newtree234(square_sort_cmpfn);
lightable_squares_gettable = newtree234(get_square_cmpfn);
#define ADD_SQUARE(s) \
do { \
sq = add234(lightable_squares_sorted, s); \
assert(sq == s); \
sq = add234(lightable_squares_gettable, s); \
assert(sq == s); \
} while (0)
#define REMOVE_SQUARE(s) \
do { \
sq = del234(lightable_squares_sorted, s); \
assert(sq); \
sq = del234(lightable_squares_gettable, s); \
assert(sq); \
} while (0)
#define HANDLE_DIR(a, b) \
square = snew(struct square); \
square->x = (i)+(a); \
square->y = (j)+(b); \
square->score = 2; \
square->random = random_bits(rs, 31); \
ADD_SQUARE(square);
HANDLE_DIR(-1, 0);
HANDLE_DIR( 1, 0);
HANDLE_DIR( 0,-1);
HANDLE_DIR( 0, 1);
#undef HANDLE_DIR
/* Light squares one at a time until the board is interesting enough */
while (TRUE)
{
/* We have count234(lightable_squares) possibilities, and in
* lightable_squares_sorted they are sorted with the most desirable
* first. */
c = count234(lightable_squares_sorted);
if (c == 0)
break;
assert(c == count234(lightable_squares_gettable));
/* Check that the best square available is any good */
square = (struct square *)index234(lightable_squares_sorted, 0);
assert(square);
/*
* We never want to _decrease_ the loop's perimeter. Making
* moves that leave the perimeter the same is occasionally
* useful: if it were _never_ done then the user would be
* able to deduce illicitly that any degree-zero vertex was
* on the outside of the loop. So we do it sometimes but
* not always.
*/
if (square->score < 0 || (square->score == 0 &&
random_upto(rs, 2) == 0)) {
break;
}
assert(square->score == SQUARE_SCORE(square->x, square->y));
assert(SQUARE_STATE(square->x, square->y) == SQUARE_UNLIT);
assert(square->x >= 0 && square->x < state->w);
assert(square->y >= 0 && square->y < state->h);
/* Update data structures */
LV_SQUARE_STATE(square->x, square->y) = SQUARE_LIT;
REMOVE_SQUARE(square);
/* We might have changed the score of any squares up to 2 units away in
* any direction */
for (b = -SCORE_DISTANCE; b <= SCORE_DISTANCE; b++) {
for (a = -SCORE_DISTANCE; a <= SCORE_DISTANCE; a++) {
if (!a && !b)
continue;
square_pos.x = square->x + a;
square_pos.y = square->y + b;
if (square_pos.x < 0 || square_pos.x >= state->w ||
square_pos.y < 0 || square_pos.y >= state->h) {
continue;
}
tmpsquare = find234(lightable_squares_gettable, &square_pos,
NULL);
if (tmpsquare) {
assert(tmpsquare->x == square_pos.x);
assert(tmpsquare->y == square_pos.y);
assert(SQUARE_STATE(tmpsquare->x, tmpsquare->y) ==
SQUARE_UNLIT);
REMOVE_SQUARE(tmpsquare);
} else {
tmpsquare = snew(struct square);
tmpsquare->x = square_pos.x;
tmpsquare->y = square_pos.y;
tmpsquare->random = random_bits(rs, 31);
}
tmpsquare->score = SQUARE_SCORE(tmpsquare->x, tmpsquare->y);
if (IS_LIGHTING_CANDIDATE(tmpsquare->x, tmpsquare->y)) {
ADD_SQUARE(tmpsquare);
} else {
sfree(tmpsquare);
}
}
}
sfree(square);
}
/* Clean up */
while ((square = delpos234(lightable_squares_gettable, 0)) != NULL)
sfree(square);
freetree234(lightable_squares_gettable);
freetree234(lightable_squares_sorted);
/* Copy out all the clues */
FORALL_SQUARES(state, i, j) {
c = SQUARE_STATE(i, j);
LV_CLUE_AT(state, i, j) = 0;
if (SQUARE_STATE(i-1, j) != c) ++LV_CLUE_AT(state, i, j);
if (SQUARE_STATE(i+1, j) != c) ++LV_CLUE_AT(state, i, j);
if (SQUARE_STATE(i, j-1) != c) ++LV_CLUE_AT(state, i, j);
if (SQUARE_STATE(i, j+1) != c) ++LV_CLUE_AT(state, i, j);
}
sfree(board);
}
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, diff);
sstate_new = solve_game_rec(sstate, diff);
assert(sstate_new->solver_status != SOLVER_MISTAKE);
ret = (sstate_new->solver_status == SOLVER_SOLVED);
free_solver_state(sstate_new);
free_solver_state(sstate);
return ret;
}
/* Remove clues one at a time at random. */
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;
int n;
#ifdef SHOW_WORKING
char *desc;
#endif
/* We need to remove some clues. We'll do this by forming a list of all
* available clues, shuffling it, then going along one at a
* time clearing each clue in turn for which doing so doesn't render the
* board unsolvable. */
squares = state->w * state->h;
square_list = snewn(squares, int);
for (n = 0; n < squares; ++n) {
square_list[n] = n;
}
shuffle(square_list, squares, sizeof(int), rs);
for (n = 0; n < squares; ++n) {
saved_ret = dup_game(ret);
LV_CLUE_AT(ret, square_list[n] % state->w,
square_list[n] / state->w) = -1;
#ifdef SHOW_WORKING
desc = state_to_text(ret);
fprintf(stderr, "%dx%d:%s\n", state->w, state->h, desc);
sfree(desc);
#endif
if (game_has_unique_soln(ret, diff)) {
free_game(saved_ret);
} else {
free_game(ret);
ret = saved_ret;
}
}
sfree(square_list);
return ret;
}
static char *new_game_desc(game_params *params, random_state *rs,
char **aux, int interactive)
{
/* solution and description both use run-length encoding in obvious ways */
char *retval;
game_state *state = snew(game_state), *state_new;
state->h = params->h;
state->w = params->w;
state->clues = snewn(SQUARE_COUNT(params), signed char);
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));
state->solved = state->cheated = FALSE;
state->recursion_depth = params->rec;
/* 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 {
add_full_clues(state, rs);
} while (!game_has_unique_soln(state, params->diff));
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)) {
#ifdef SHOW_WORKING
fprintf(stderr, "Rejecting board, it is too easy\n");
#endif
goto newboard_please;
}
retval = state_to_text(state);
free_game(state);
assert(!validate_desc(params, retval));
return retval;
}
static game_state *new_game(midend *me, game_params *params, char *desc)
{
int i,j;
game_state *state = snew(game_state);
int empties_to_make = 0;
int n;
const char *dp = desc;
state->recursion_depth = 0; /* XXX pending removal, probably */
state->h = params->h;
state->w = params->w;
state->clues = snewn(SQUARE_COUNT(params), signed char);
state->hl = snewn(HL_COUNT(params), char);
state->vl = snewn(VL_COUNT(params), char);
state->solved = state->cheated = FALSE;
FORALL_SQUARES(params, i, j) {
if (empties_to_make) {
empties_to_make--;
LV_CLUE_AT(state, i, j) = -1;
continue;
}
assert(*dp);
n = *dp - '0';
if (n >= 0 && n < 10) {
LV_CLUE_AT(state, i, j) = n;
} else {
n = *dp - 'a' + 1;
assert(n > 0);
LV_CLUE_AT(state, i, j) = -1;
empties_to_make = n - 1;
}
++dp;
}
memset(state->hl, LINE_UNKNOWN, HL_COUNT(params));
memset(state->vl, LINE_UNKNOWN, VL_COUNT(params));
return state;
}
enum { LOOP_NONE=0, LOOP_SOLN, LOOP_NOT_SOLN };
/* ----------------------------------------------------------------------
* Solver logic
*
* Our solver modes operate as follows. Each mode also uses the modes above it.
*
* Easy Mode
* Just implement the rules of the game.
*
* Normal Mode
* For each pair of lines through each dot we store a bit for whether
* at least one of them is on and whether at most one is on. (If we know
* both or neither is on that's already stored more directly.) That's six
* bits per dot. Bit number n represents the lines shown in dline_desc.
*
* Advanced Mode
* Use edsf data structure to make equivalence classes of lines that are
* known identical to or opposite to one another.
*/
/* The order the following are defined in is very important, see below.
* The last two fields may seem non-obvious: they specify that when talking
* about a square the dx and dy offsets should be added to the square coords to
* get to the right dot. Where dx and dy are -1 this means that the dline
* doesn't make sense for a square. */
/* XXX can this be done with a struct instead? */
#define DLINES \
DLINE(DLINE_UD, UP, DOWN, -1, -1) \
DLINE(DLINE_LR, LEFT, RIGHT, -1, -1) \
DLINE(DLINE_UR, UP, RIGHT, 0, 1) \
DLINE(DLINE_DL, DOWN, LEFT, 1, 0) \
DLINE(DLINE_UL, UP, LEFT, 1, 1) \
DLINE(DLINE_DR, DOWN, RIGHT, 0, 0)
#define OPP_DLINE(dline_desc) ((dline_desc) ^ 1)
enum dline_desc {
#define DLINE(desc, dir1, dir2, dx, dy) \
desc,
DLINES
#undef DLINE
};
struct dline {
enum dline_desc desc;
enum direction dir1, dir2;
int dx, dy;
};
const static struct dline dlines[] = {
#define DLINE(desc, dir1, dir2, dx, dy) \
{ desc, dir1, dir2, dx, dy },
DLINES
#undef DLINE
};
#define FORALL_DOT_DLINES(dl_iter) \
for (dl_iter = 0; dl_iter < lenof(dlines); ++dl_iter)
#define FORALL_SQUARE_DLINES(dl_iter) \
for (dl_iter = 2; dl_iter < lenof(dlines); ++dl_iter)
#define DL2STR(d) \
((d==DLINE_UD) ? "DLINE_UD": \
(d==DLINE_LR) ? "DLINE_LR": \
(d==DLINE_UR) ? "DLINE_UR": \
(d==DLINE_DL) ? "DLINE_DL": \
(d==DLINE_UL) ? "DLINE_UL": \
(d==DLINE_DR) ? "DLINE_DR": \
"oops")
#define CHECK_DLINE_SENSIBLE(d) assert(dlines[(d)].dx != -1 && dlines[(d)].dy != -1)
/* This will fail an assertion if the directions handed to it are the same, as
* no dline corresponds to that */
static enum dline_desc dline_desc_from_dirs(enum direction dir1,
enum direction dir2)
{
int i;
assert (dir1 != dir2);
for (i = 0; i < lenof(dlines); ++i) {
if ((dir1 == dlines[i].dir1 && dir2 == dlines[i].dir2) ||
(dir1 == dlines[i].dir2 && dir2 == dlines[i].dir1)) {
return dlines[i].desc;
}
}
assert(!"dline not found");
return DLINE_UD; /* placate compiler */
}
/* The following functions allow you to get or set info about the selected
* dline corresponding to the dot or square at [i,j]. You'll get an assertion
* failure if you talk about a dline that doesn't exist, ie if you ask about
* non-touching lines around a square. */
static int get_dot_dline(const game_state *state, const char *dline_array,
int i, int j, enum dline_desc desc)
{
/* fprintf(stderr, "get_dot_dline %p [%d,%d] %s\n", dline_array, i, j, DL2STR(desc)); */
return BIT_SET(dline_array[i + (state->w + 1) * j], desc);
}
static int set_dot_dline(game_state *state, char *dline_array,
int i, int j, enum dline_desc desc
#ifdef SHOW_WORKING
, const char *reason
#endif
)
{
int ret;
ret = SET_BIT(dline_array[i + (state->w + 1) * j], desc);
#ifdef SHOW_WORKING
if (ret)
fprintf(stderr, "set_dot_dline %p [%d,%d] %s (%s)\n", dline_array, i, j, DL2STR(desc), reason);
#endif
return ret;
}
static int get_square_dline(game_state *state, char *dline_array,
int i, int j, enum dline_desc desc)
{
CHECK_DLINE_SENSIBLE(desc);
/* fprintf(stderr, "get_square_dline %p [%d,%d] %s\n", dline_array, i, j, DL2STR(desc)); */
return BIT_SET(dline_array[(i+dlines[desc].dx) + (state->w + 1) * (j+dlines[desc].dy)],
desc);
}
static int set_square_dline(game_state *state, char *dline_array,
int i, int j, enum dline_desc desc
#ifdef SHOW_WORKING
, const char *reason
#endif
)
{
int ret;
CHECK_DLINE_SENSIBLE(desc);
ret = SET_BIT(dline_array[(i+dlines[desc].dx) + (state->w + 1) * (j+dlines[desc].dy)], desc);
#ifdef SHOW_WORKING
if (ret)
fprintf(stderr, "set_square_dline %p [%d,%d] %s (%s)\n", dline_array, i, j, DL2STR(desc), reason);
#endif
return ret;
}
#ifdef SHOW_WORKING
#define set_dot_dline(a, b, c, d, e) \
set_dot_dline(a, b, c, d, e, __FUNCTION__)
#define set_square_dline(a, b, c, d, e) \
set_square_dline(a, b, c, d, e, __FUNCTION__)
#endif
static int set_dot_opp_dline(game_state *state, char *dline_array,
int i, int j, enum dline_desc desc)
{
return set_dot_dline(state, dline_array, i, j, OPP_DLINE(desc));
}
static int set_square_opp_dline(game_state *state, char *dline_array,
int i, int j, enum dline_desc desc)
{
return set_square_dline(state, dline_array, i, j, OPP_DLINE(desc));
}
/* Find out if both the lines in the given dline are UNKNOWN */
static int dline_both_unknown(const game_state *state, int i, int j,
enum dline_desc desc)
{
return
(get_line_status_from_point(state, i, j, dlines[desc].dir1) == LINE_UNKNOWN) &&
(get_line_status_from_point(state, i, j, dlines[desc].dir2) == LINE_UNKNOWN);
}
#define SQUARE_DLINES \
HANDLE_DLINE(DLINE_UL, RIGHTOF_SQUARE, BELOW_SQUARE, 1, 1); \
HANDLE_DLINE(DLINE_UR, LEFTOF_SQUARE, BELOW_SQUARE, 0, 1); \
HANDLE_DLINE(DLINE_DL, RIGHTOF_SQUARE, ABOVE_SQUARE, 1, 0); \
HANDLE_DLINE(DLINE_DR, LEFTOF_SQUARE, ABOVE_SQUARE, 0, 0);
#define DOT_DLINES \
HANDLE_DLINE(DLINE_UD, ABOVE_DOT, BELOW_DOT); \
HANDLE_DLINE(DLINE_LR, LEFTOF_DOT, RIGHTOF_DOT); \
HANDLE_DLINE(DLINE_UL, ABOVE_DOT, LEFTOF_DOT); \
HANDLE_DLINE(DLINE_UR, ABOVE_DOT, RIGHTOF_DOT); \
HANDLE_DLINE(DLINE_DL, BELOW_DOT, LEFTOF_DOT); \
HANDLE_DLINE(DLINE_DR, BELOW_DOT, RIGHTOF_DOT);
static void array_setall(char *array, char from, char to, int len)
{
char *p = array, *p_old = p;
int len_remaining = len;
while ((p = memchr(p, from, len_remaining))) {
*p = to;
len_remaining -= p - p_old;
p_old = p;
}
}
static int get_line_status_from_point(const game_state *state,
int x, int y, enum direction d)
{
switch (d) {
case LEFT:
return LEFTOF_DOT(state, x, y);
case RIGHT:
return RIGHTOF_DOT(state, x, y);
case UP:
return ABOVE_DOT(state, x, y);
case DOWN:
return BELOW_DOT(state, x, y);
}
return 0;
}
/* First and second args are coord offset from top left of square to one end
* of line in question, third and fourth args are the direction from the first
* end of the line to the second. Fifth arg is the direction of the line from
* the coord offset position.
* How confusing.
*/
#define SQUARE_LINES \
SQUARE_LINE( 0, 0, RIGHT, RIGHTOF_DOT, UP); \
SQUARE_LINE( 0, +1, RIGHT, RIGHTOF_DOT, DOWN); \
SQUARE_LINE( 0, 0, DOWN, BELOW_DOT, LEFT); \
SQUARE_LINE(+1, 0, DOWN, BELOW_DOT, RIGHT);
/* Set pairs of lines around this square which are known to be identical to
* the given line_state */
static int square_setall_identical(solver_state *sstate, int x, int y,
enum line_state line_new)
{
/* can[dir] contains the canonical line associated with the line in
* direction dir from the square in question. Similarly inv[dir] is
* whether or not the line in question is inverse to its canonical
* element. */
int can[4], inv[4], i, j;
int retval = FALSE;
i = 0;
#if 0
fprintf(stderr, "Setting all identical unknown lines around square "
"[%d,%d] to %d:\n", x, y, line_new);
#endif
#define SQUARE_LINE(dx, dy, linedir, dir_dot, sqdir) \
can[sqdir] = \
edsf_canonify(sstate->hard->linedsf, \
LINEDSF_INDEX(sstate->state, x+(dx), y+(dy), linedir), \
&inv[sqdir]);
SQUARE_LINES;
#undef SQUARE_LINE
for (j = 0; j < 4; ++j) {
for (i = 0; i < 4; ++i) {
if (i == j)
continue;
if (can[i] == can[j] && inv[i] == inv[j]) {
/* Lines in directions i and j are identical.
* Only do j now, we'll do i when the loop causes us to
* consider {i,j} in the opposite order. */
#define SQUARE_LINE(dx, dy, dir, c, sqdir) \
if (j == sqdir) { \
retval = set_line_bydot(sstate, x+(dx), y+(dy), dir, line_new); \
if (retval) { \
break; \
} \
}
SQUARE_LINES;
#undef SQUARE_LINE
}
}
}
return retval;
}
#if 0
/* Set all identical lines passing through the current dot to the chosen line
* state. (implicitly this only looks at UNKNOWN lines) */
static int dot_setall_identical(solver_state *sstate, int x, int y,
enum line_state line_new)
{
/* The implementation of this is a little naughty but I can't see how to do
* it elegantly any other way */
int can[4], inv[4], i, j;
enum direction d;
int retval = FALSE;
for (d = 0; d < 4; ++d) {
can[d] = edsf_canonify(sstate->hard->linedsf,
LINEDSF_INDEX(sstate->state, x, y, d),
inv+d);
}
for (j = 0; j < 4; ++j) {
next_j:
for (i = 0; i < j; ++i) {
if (can[i] == can[j] && inv[i] == inv[j]) {
/* Lines in directions i and j are identical */
if (get_line_status_from_point(sstate->state, x, y, j) ==
LINE_UNKNOWN) {
set_line_bydot(sstate->state, x, y, j,
line_new);
retval = TRUE;
goto next_j;
}
}
}
}
return retval;
}
#endif
static int square_setboth_in_dline(solver_state *sstate, enum dline_desc dd,
int i, int j, enum line_state line_new)
{
int retval = FALSE;
const struct dline dll = dlines[dd], *dl = &dll;
#if 0
fprintf(stderr, "square_setboth_in_dline %s [%d,%d] to %d\n",
DL2STR(dd), i, j, line_new);
#endif
CHECK_DLINE_SENSIBLE(dd);
retval |=
set_line_bydot(sstate, i+dl->dx, j+dl->dy, dl->dir1, line_new);
retval |=
set_line_bydot(sstate, i+dl->dx, j+dl->dy, dl->dir2, line_new);
return retval;
}
/* Call this function to register that the two unknown lines going into the dot
* [x,y] are identical or opposite (depending on the value of 'inverse'). This
* function will cause an assertion failure if anything other than exactly two
* lines into the dot are unknown.
* As usual returns TRUE if any progress was made, otherwise FALSE. */
static int dot_relate_2_unknowns(solver_state *sstate, int x, int y, int inverse)
{
enum direction d1=DOWN, d2=DOWN; /* Just to keep compiler quiet */
int dirs_set = 0;
#define TRY_DIR(d) \
if (get_line_status_from_point(sstate->state, x, y, d) == \
LINE_UNKNOWN) { \
if (dirs_set == 0) \
d1 = d; \
else { \
assert(dirs_set == 1); \
d2 = d; \
} \
dirs_set++; \
} while (0)
TRY_DIR(UP);
TRY_DIR(DOWN);
TRY_DIR(LEFT);
TRY_DIR(RIGHT);
#undef TRY_DIR
assert(dirs_set == 2);
assert(d1 != d2);
#if 0
fprintf(stderr, "Lines in direction %s and %s from dot [%d,%d] are %s\n",
DIR2STR(d1), DIR2STR(d2), x, y, inverse?"opposite":"the same");
#endif
return merge_lines(sstate, x, y, d1, x, y, d2, inverse);
}
/* Very similar to dot_relate_2_unknowns. */
static int square_relate_2_unknowns(solver_state *sstate, int x, int y, int inverse)
{
enum direction d1=DOWN, d2=DOWN;
int x1=-1, y1=-1, x2=-1, y2=-1;
int dirs_set = 0;
#if 0
fprintf(stderr, "2 unknowns around square [%d,%d] are %s\n",
x, y, inverse?"opposite":"the same");
#endif
#define TRY_DIR(i, j, d, dir_sq) \
do { \
if (dir_sq(sstate->state, x, y) == LINE_UNKNOWN) { \
if (dirs_set == 0) { \
d1 = d; x1 = i; y1 = j; \
} else { \
assert(dirs_set == 1); \
d2 = d; x2 = i; y2 = j; \
} \
dirs_set++; \
} \
} while (0)
TRY_DIR(x, y, RIGHT, ABOVE_SQUARE);
TRY_DIR(x, y, DOWN, LEFTOF_SQUARE);
TRY_DIR(x+1, y, DOWN, RIGHTOF_SQUARE);
TRY_DIR(x, y+1, RIGHT, BELOW_SQUARE);
#undef TRY_DIR
assert(dirs_set == 2);
#if 0
fprintf(stderr, "Line in direction %s from dot [%d,%d] and line in direction %s from dot [%2d,%2d] are %s\n",
DIR2STR(d1), x1, y1, DIR2STR(d2), x2, y2, inverse?"opposite":"the same");
#endif
return merge_lines(sstate, x1, y1, d1, x2, y2, d2, inverse);
}
/* Figure out if any dlines can be 'collapsed' (and do so if they can). This
* can happen if one of the lines is known and due to the dline status this
* tells us state of the other, or if there's an interaction with the linedsf
* (ie if atmostone is set for a dline and the lines are known identical they
* must both be LINE_NO, etc). XXX at the moment only the former is
* implemented, and indeed the latter should be implemented in the hard mode
* solver only.
*/
static int dot_collapse_dlines(solver_state *sstate, int i, int j)
{
int progress = FALSE;
enum direction dir1, dir2;
int dir1st;
int dlset;
game_state *state = sstate->state;
enum dline_desc dd;
for (dir1 = 0; dir1 < 4; dir1++) {
dir1st = get_line_status_from_point(state, i, j, dir1);
if (dir1st == LINE_UNKNOWN)
continue;
/* dir2 iterates over the whole range rather than starting at dir1+1
* because test below is asymmetric */
for (dir2 = 0; dir2 < 4; dir2++) {
if (dir1 == dir2)
continue;
if ((i == 0 && (dir1 == LEFT || dir2 == LEFT)) ||
(j == 0 && (dir1 == UP || dir2 == UP)) ||
(i == state->w && (dir1 == RIGHT || dir2 == RIGHT)) ||
(j == state->h && (dir1 == DOWN || dir2 == DOWN))) {
continue;
}
#if 0
fprintf(stderr, "dot_collapse_dlines [%d,%d], %s %s\n", i, j,
DIR2STR(dir1), DIR2STR(dir2));
#endif
if (get_line_status_from_point(state, i, j, dir2) ==
LINE_UNKNOWN) {
dd = dline_desc_from_dirs(dir1, dir2);
dlset = get_dot_dline(state, sstate->normal->dot_atmostone, i, j, dd);
if (dlset && dir1st == LINE_YES) {
/* fprintf(stderr, "setting %s to NO\n", DIR2STR(dir2)); */
progress |=
set_line_bydot(sstate, i, j, dir2, LINE_NO);
}
dlset = get_dot_dline(state, sstate->normal->dot_atleastone, i, j, dd);
if (dlset && dir1st == LINE_NO) {
/* fprintf(stderr, "setting %s to YES\n", DIR2STR(dir2)); */
progress |=
set_line_bydot(sstate, i, j, dir2, LINE_YES);
}
}
}
}
return progress;
}
/*
* These are the main solver functions.
*
* Their return values are diff values corresponding to the lowest mode solver
* that would notice the work that they have done. For example if the normal
* mode solver adds actual lines or crosses, it will return DIFF_EASY as the
* easy mode solver might be able to make progress using that. It doesn't make
* sense for one of them to return a diff value higher than that of the
* function itself.
*
* Each function returns the lowest value it can, as early as possible, in
* order to try and pass as much work as possible back to the lower level
* solvers which progress more quickly.
*/
/* PROPOSED NEW DESIGN:
* We have a work queue consisting of 'events' notifying us that something has
* happened that a particular solver mode might be interested in. For example
* the hard mode solver might do something that helps the normal mode solver at
* dot [x,y] in which case it will enqueue an event recording this fact. Then
* we pull events off the work queue, and hand each in turn to the solver that
* is interested in them. If a solver reports that it failed we pass the same
* event on to progressively more advanced solvers and the loop detector. Once
* we've exhausted an event, or it has helped us progress, we drop it and
* continue to the next one. The events are sorted first in order of solver
* complexity (easy first) then order of insertion (oldest first).
* Once we run out of events we loop over each permitted solver in turn
* (easiest first) until either a deduction is made (and an event therefore
* emerges) or no further deductions can be made (in which case we've failed).
*
* QUESTIONS:
* * How do we 'loop over' a solver when both dots and squares are concerned.
* Answer: first all squares then all dots.
*/
static int easy_mode_deductions(solver_state *sstate)
{
int i, j, h, w, current_yes, current_no;
game_state *state;
int diff = DIFF_MAX;
state = sstate->state;
h = state->h;
w = state->w;
/* Per-square deductions */
FORALL_SQUARES(state, i, j) {
if (sstate->square_solved[SQUARE_INDEX(state, i, j)])
continue;
current_yes = SQUARE_YES_COUNT(sstate, i, j);
current_no = SQUARE_NO_COUNT(sstate, i, j);
if (current_yes + current_no == 4) {
sstate->square_solved[SQUARE_INDEX(state, i, j)] = TRUE;
/* diff = min(diff, DIFF_EASY); */
continue;
}
if (CLUE_AT(state, i, j) < 0)
continue;
if (CLUE_AT(state, i, j) < current_yes) {
#if 0
fprintf(stderr, "detected error [%d,%d] in %s at line %d\n", i, j, __FUNCTION__, __LINE__);
#endif
sstate->solver_status = SOLVER_MISTAKE;
return DIFF_EASY;
}
if (CLUE_AT(state, i, j) == current_yes) {
if (square_setall(sstate, i, j, LINE_UNKNOWN, LINE_NO))
diff = min(diff, DIFF_EASY);
sstate->square_solved[SQUARE_INDEX(state, i, j)] = TRUE;
continue;
}
if (4 - CLUE_AT(state, i, j) < current_no) {
#if 0
fprintf(stderr, "detected error [%d,%d] in %s at line %d\n", i, j, __FUNCTION__, __LINE__);
#endif
sstate->solver_status = SOLVER_MISTAKE;
return DIFF_EASY;
}
if (4 - CLUE_AT(state, i, j) == current_no) {
if (square_setall(sstate, i, j, LINE_UNKNOWN, LINE_YES))
diff = min(diff, DIFF_EASY);
sstate->square_solved[SQUARE_INDEX(state, i, j)] = TRUE;
continue;
}
}
check_caches(sstate);
/* Per-dot deductions */
FORALL_DOTS(state, i, j) {
if (sstate->dot_solved[DOT_INDEX(state, i, j)])
continue;
switch (DOT_YES_COUNT(sstate, i, j)) {
case 0:
switch (DOT_NO_COUNT(sstate, i, j)) {
case 3:
#if 0
fprintf(stderr, "dot [%d,%d]: 0 yes, 3 no\n", i, j);
#endif
dot_setall(sstate, i, j, LINE_UNKNOWN, LINE_NO);
diff = min(diff, DIFF_EASY);
/* fall through */
case 4:
sstate->dot_solved[DOT_INDEX(state, i, j)] = TRUE;
break;
}
break;
case 1:
switch (DOT_NO_COUNT(sstate, i, j)) {
case 2: /* 1 yes, 2 no */
#if 0
fprintf(stderr, "dot [%d,%d]: 1 yes, 2 no\n", i, j);
#endif
dot_setall(sstate, i, j, LINE_UNKNOWN, LINE_YES);
diff = min(diff, DIFF_EASY);
sstate->dot_solved[DOT_INDEX(state, i, j)] = TRUE;
break;
case 3: /* 1 yes, 3 no */
#if 0
fprintf(stderr, "detected error [%d,%d] in %s at line %d\n", i, j, __FUNCTION__, __LINE__);
#endif
sstate->solver_status = SOLVER_MISTAKE;
return DIFF_EASY;
}
break;
case 2:
#if 0
fprintf(stderr, "dot [%d,%d]: 2 yes\n", i, j);
#endif
dot_setall(sstate, i, j, LINE_UNKNOWN, LINE_NO);
diff = min(diff, DIFF_EASY);
sstate->dot_solved[DOT_INDEX(state, i, j)] = TRUE;
break;
case 3:
case 4:
#if 0
fprintf(stderr, "detected error [%d,%d] in %s at line %d\n", i, j, __FUNCTION__, __LINE__);
#endif
sstate->solver_status = SOLVER_MISTAKE;
return DIFF_EASY;
}
}
check_caches(sstate);
return diff;
}
static int normal_mode_deductions(solver_state *sstate)
{
int i, j;
game_state *state = sstate->state;
enum dline_desc dd;
int diff = DIFF_MAX;
FORALL_SQUARES(state, i, j) {
if (sstate->square_solved[SQUARE_INDEX(state, i, j)])
continue;
if (CLUE_AT(state, i, j) < 0)
continue;
switch (CLUE_AT(state, i, j)) {
case 1:
#if 0
fprintf(stderr, "clue [%d,%d] is 1, doing dline ops\n",
i, j);
#endif
FORALL_SQUARE_DLINES(dd) {
/* At most one of any DLINE can be set */
if (set_square_dline(state,
sstate->normal->dot_atmostone,
i, j, dd)) {
diff = min(diff, DIFF_NORMAL);
}
if (get_square_dline(state,
sstate->normal->dot_atleastone,
i, j, dd)) {
/* This DLINE provides enough YESes to solve the clue */
if (square_setboth_in_dline(sstate, OPP_DLINE(dd),
i, j, LINE_NO)) {
diff = min(diff, DIFF_EASY);
}
}
}
break;
case 2:
/* If at least one of one DLINE is set, at most one
* of the opposing one is and vice versa */
#if 0
fprintf(stderr, "clue [%d,%d] is 2, doing dline ops\n",
i, j);
#endif
FORALL_SQUARE_DLINES(dd) {
if (get_square_dline(state,
sstate->normal->dot_atmostone,
i, j, dd)) {
if (set_square_opp_dline(state,
sstate->normal->dot_atleastone,
i, j, dd)) {
diff = min(diff, DIFF_NORMAL);
}
}
if (get_square_dline(state,
sstate->normal->dot_atleastone,
i, j, dd)) {
if (set_square_opp_dline(state,
sstate->normal->dot_atmostone,
i, j, dd)) {
diff = min(diff, DIFF_NORMAL);
}
}
}
break;
case 3:
#if 0
fprintf(stderr, "clue [%d,%d] is 3, doing dline ops\n",
i, j);
#endif
FORALL_SQUARE_DLINES(dd) {
/* At least one of any DLINE must be set */
if (set_square_dline(state,
sstate->normal->dot_atleastone,
i, j, dd)) {
diff = min(diff, DIFF_NORMAL);
}
if (get_square_dline(state,
sstate->normal->dot_atmostone,
i, j, dd)) {
/* This DLINE provides enough NOs to solve the clue */
if (square_setboth_in_dline(sstate, OPP_DLINE(dd),
i, j, LINE_YES)) {
diff = min(diff, DIFF_EASY);
}
}
}
break;
}
}
check_caches(sstate);
if (diff < DIFF_NORMAL)
return diff;
FORALL_DOTS(state, i, j) {
if (sstate->dot_solved[DOT_INDEX(state, i, j)])
continue;
#if 0
text = game_text_format(state);
fprintf(stderr, "-----------------\n%s", text);
sfree(text);
#endif
switch (DOT_YES_COUNT(sstate, i, j)) {
case 0:
switch (DOT_NO_COUNT(sstate, i, j)) {
case 1:
/* Make note that at most one of each unknown DLINE
* is YES */
break;
}
break;
case 1:
switch (DOT_NO_COUNT(sstate, i, j)) {
case 1:
/* 1 yes, 1 no, so exactly one of unknowns is
* yes */
#if 0
fprintf(stderr, "dot [%d,%d]: 1 yes, 1 no\n", i, j);
#endif
FORALL_DOT_DLINES(dd) {
if (dline_both_unknown(state,
i, j, dd)) {
if (set_dot_dline(state,
sstate->normal->dot_atleastone,
i, j, dd)) {
diff = min(diff, DIFF_NORMAL);
}
}
}
/* fall through */
case 0:
#if 0
fprintf(stderr, "dot [%d,%d]: 1 yes, 0 or 1 no\n", i, j);
#endif
/* 1 yes, fewer than 2 no, so at most one of
* unknowns is yes */
FORALL_DOT_DLINES(dd) {
if (dline_both_unknown(state,
i, j, dd)) {
if (set_dot_dline(state,
sstate->normal->dot_atmostone,
i, j, dd)) {
diff = min(diff, DIFF_NORMAL);
}
}
}
break;
}
break;
}
/* DLINE deductions that don't depend on the exact number of
* LINE_YESs or LINE_NOs */
/* 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. */
FORALL_DOT_DLINES(dd) {
if (get_dot_dline(state,
sstate->normal->dot_atleastone,
i, j, dd)) {
if (set_dot_opp_dline(state,
sstate->normal->dot_atmostone,
i, j, dd)) {
diff = min(diff, DIFF_NORMAL);
}
}
}
if (dot_collapse_dlines(sstate, i, j))
diff = min(diff, DIFF_EASY);
}
check_caches(sstate);
return diff;
}
static int hard_mode_deductions(solver_state *sstate)
{
int i, j, a, b, s;
game_state *state = sstate->state;
const int h=state->h, w=state->w;
enum direction dir1, dir2;
int can1, can2, inv1, inv2;
int diff = DIFF_MAX;
enum dline_desc dd;
FORALL_SQUARES(state, i, j) {
if (sstate->square_solved[SQUARE_INDEX(state, i, j)])
continue;
switch (CLUE_AT(state, i, j)) {
case -1:
continue;
case 1:
if (square_setall_identical(sstate, i, j, LINE_NO))
diff = min(diff, DIFF_EASY);
break;
case 3:
if (square_setall_identical(sstate, i, j, LINE_YES))
diff = min(diff, DIFF_EASY);
break;
}
if (SQUARE_YES_COUNT(sstate, i, j) +
SQUARE_NO_COUNT(sstate, i, j) == 2) {
/* There are exactly two unknown lines bordering this
* square. */
if (SQUARE_YES_COUNT(sstate, i, j) + 1 ==
CLUE_AT(state, i, j)) {
/* They must be different */
if (square_relate_2_unknowns(sstate, i, j, TRUE))
diff = min(diff, DIFF_HARD);
}
}
}
check_caches(sstate);
FORALL_DOTS(state, i, j) {
if (DOT_YES_COUNT(sstate, i, j) == 1 &&
DOT_NO_COUNT(sstate, i, j) == 1) {
if (dot_relate_2_unknowns(sstate, i, j, TRUE))
diff = min(diff, DIFF_HARD);
continue;
}
if (DOT_YES_COUNT(sstate, i, j) == 0 &&
DOT_NO_COUNT(sstate, i, j) == 2) {
if (dot_relate_2_unknowns(sstate, i, j, FALSE))
diff = min(diff, DIFF_HARD);
continue;
}
}
/* If two lines into a dot are related, the other two lines into that dot
* are related in the same way. */
/* iter over points that aren't on edges */
for (i = 1; i < w; ++i) {
for (j = 1; j < h; ++j) {
if (sstate->dot_solved[DOT_INDEX(state, i, j)])
continue;
/* iter over directions */
for (dir1 = 0; dir1 < 4; ++dir1) {
for (dir2 = dir1+1; dir2 < 4; ++dir2) {
/* canonify both lines */
can1 = edsf_canonify
(sstate->hard->linedsf,
LINEDSF_INDEX(state, i, j, dir1),
&inv1);
can2 = edsf_canonify
(sstate->hard->linedsf,
LINEDSF_INDEX(state, i, j, dir2),
&inv2);
/* merge opposite lines */
if (can1 == can2) {
if (merge_lines(sstate,
i, j, OPP_DIR(dir1),
i, j, OPP_DIR(dir2),
inv1 ^ inv2)) {
diff = min(diff, DIFF_HARD);
}
}
}
}
}
}
/* If the state of a line is known, deduce the state of its canonical line
* too. */
FORALL_DOTS(state, i, j) {
/* Do this even if the dot we're on is solved */
if (i < w) {
can1 = edsf_canonify(sstate->hard->linedsf,
LINEDSF_INDEX(state, i, j, RIGHT),
&inv1);
linedsf_deindex(state, can1, &a, &b, &dir1);
s = RIGHTOF_DOT(state, i, j);
if (s != LINE_UNKNOWN)
{
if (set_line_bydot(sstate, a, b, dir1, inv1 ? OPP(s) : s))
diff = min(diff, DIFF_EASY);
}
}
if (j < h) {
can1 = edsf_canonify(sstate->hard->linedsf,
LINEDSF_INDEX(state, i, j, DOWN),
&inv1);
linedsf_deindex(state, can1, &a, &b, &dir1);
s = BELOW_DOT(state, i, j);
if (s != LINE_UNKNOWN)
{
if (set_line_bydot(sstate, a, b, dir1, inv1 ? OPP(s) : s))
diff = min(diff, DIFF_EASY);
}
}
}
/* Interactions between dline and linedsf */
FORALL_DOTS(state, i, j) {
if (sstate->dot_solved[DOT_INDEX(state, i, j)])
continue;
FORALL_DOT_DLINES(dd) {
const struct dline dll = dlines[dd], *dl = &dll;
if (i == 0 && (dl->dir1 == LEFT || dl->dir2 == LEFT))
continue;
if (i == w && (dl->dir1 == RIGHT || dl->dir2 == RIGHT))
continue;
if (j == 0 && (dl->dir1 == UP || dl->dir2 == UP))
continue;
if (j == h && (dl->dir1 == DOWN || dl->dir2 == DOWN))
continue;
if (get_dot_dline(state, sstate->normal->dot_atleastone,
i, j, dd) &&
get_dot_dline(state, sstate->normal->dot_atmostone,
i, j, dd)) {
/* atleastone && atmostone => inverse */
if (merge_lines(sstate, i, j, dl->dir1, i, j, dl->dir2, 1)) {
diff = min(diff, DIFF_HARD);
}
} else {
/* don't have atleastone and atmostone for this dline */
can1 = edsf_canonify(sstate->hard->linedsf,
LINEDSF_INDEX(state, i, j, dl->dir1),
&inv1);
can2 = edsf_canonify(sstate->hard->linedsf,
LINEDSF_INDEX(state, i, j, dl->dir2),
&inv2);
if (can1 == can2) {
if (inv1 == inv2) {
/* identical => collapse dline */
if (get_dot_dline(state,
sstate->normal->dot_atleastone,
i, j, dd)) {
if (set_line_bydot(sstate, i, j,
dl->dir1, LINE_YES)) {
diff = min(diff, DIFF_EASY);
}
if (set_line_bydot(sstate, i, j,
dl->dir2, LINE_YES)) {
diff = min(diff, DIFF_EASY);
}
} else if (get_dot_dline(state,
sstate->normal->dot_atmostone,
i, j, dd)) {
if (set_line_bydot(sstate, i, j,
dl->dir1, LINE_NO)) {
diff = min(diff, DIFF_EASY);
}
if (set_line_bydot(sstate, i, j,
dl->dir2, LINE_NO)) {
diff = min(diff, DIFF_EASY);
}
}
} else {
/* inverse => atleastone && atmostone */
if (set_dot_dline(state,
sstate->normal->dot_atleastone,
i, j, dd)) {
diff = min(diff, DIFF_NORMAL);
}
if (set_dot_dline(state,
sstate->normal->dot_atmostone,
i, j, dd)) {
diff = min(diff, DIFF_NORMAL);
}
}
}
}
}
}
/* If the state of the canonical line for line 'l' is known, deduce the
* state of 'l' */
FORALL_DOTS(state, i, j) {
if (sstate->dot_solved[DOT_INDEX(state, i, j)])
continue;
if (i < w) {
can1 = edsf_canonify(sstate->hard->linedsf,
LINEDSF_INDEX(state, i, j, RIGHT),
&inv1);
linedsf_deindex(state, can1, &a, &b, &dir1);
s = get_line_status_from_point(state, a, b, dir1);
if (s != LINE_UNKNOWN)
{
if (set_line_bydot(sstate, i, j, RIGHT, inv1 ? OPP(s) : s))
diff = min(diff, DIFF_EASY);
}
}
if (j < h) {
can1 = edsf_canonify(sstate->hard->linedsf,
LINEDSF_INDEX(state, i, j, DOWN),
&inv1);
linedsf_deindex(state, can1, &a, &b, &dir1);
s = get_line_status_from_point(state, a, b, dir1);
if (s != LINE_UNKNOWN)
{
if (set_line_bydot(sstate, i, j, DOWN, inv1 ? OPP(s) : s))
diff = min(diff, DIFF_EASY);
}
}
}
return diff;
}
static int loop_deductions(solver_state *sstate)
{
int edgecount = 0, clues = 0, satclues = 0, sm1clues = 0;
game_state *state = sstate->state;
int shortest_chainlen = DOT_COUNT(state);
int loop_found = FALSE;
int d;
int dots_connected;
int progress = FALSE;
int i, j;
/*
* Go through the grid and update for all the new edges.
* Since merge_dots() is idempotent, the simplest way to
* do this is just to update for _all_ the edges.
*
* Also, while we're here, we count the edges, count the
* clues, count the satisfied clues, and count the
* satisfied-minus-one clues.
*/
FORALL_DOTS(state, i, j) {
if (RIGHTOF_DOT(state, i, j) == LINE_YES) {
loop_found |= merge_dots(sstate, i, j, i+1, j);
edgecount++;
}
if (BELOW_DOT(state, i, j) == LINE_YES) {
loop_found |= merge_dots(sstate, i, j, i, j+1);
edgecount++;
}
if (CLUE_AT(state, i, j) >= 0) {
int c = CLUE_AT(state, i, j);
int o = SQUARE_YES_COUNT(sstate, i, j);
if (o == c)
satclues++;
else if (o == c-1)
sm1clues++;
clues++;
}
}
for (i = 0; i < DOT_COUNT(state); ++i) {
dots_connected =
sstate->looplen[dsf_canonify(sstate->dotdsf, i)];
if (dots_connected > 1)
shortest_chainlen = min(shortest_chainlen, dots_connected);
}
assert(sstate->solver_status == SOLVER_INCOMPLETE);
if (satclues == clues && shortest_chainlen == edgecount) {
sstate->solver_status = SOLVER_SOLVED;
/* This discovery clearly counts as progress, even if we haven't
* just added any lines or anything */
progress = TRUE;
goto finished_loop_deductionsing;
}
/*
* Now go through looking for LINE_UNKNOWN edges which
* connect two dots that are already in the same
* equivalence class. If we find one, test to see if the
* loop it would create is a solution.
*/
FORALL_DOTS(state, i, j) {
for (d = 0; d < 2; d++) {
int i2, j2, eqclass, val;
if (d == 0) {
if (RIGHTOF_DOT(state, i, j) !=
LINE_UNKNOWN)
continue;
i2 = i+1;
j2 = j;
} else {
if (BELOW_DOT(state, i, j) !=
LINE_UNKNOWN) {
continue;
}
i2 = i;
j2 = j+1;
}
eqclass = dsf_canonify(sstate->dotdsf, j * (state->w+1) + i);
if (eqclass != dsf_canonify(sstate->dotdsf,
j2 * (state->w+1) + i2)) {
continue;
}
val = LINE_NO; /* loop is bad until proven otherwise */
/*
* This edge would form a loop. Next
* question: how long would the loop be?
* Would it equal the total number of edges
* (plus the one we'd be adding if we added
* it)?
*/
if (sstate->looplen[eqclass] == edgecount + 1) {
int sm1_nearby;
int cx, cy;
/*
* This edge would form a loop which
* took in all the edges in the entire
* grid. So now we need to work out
* whether it would be a valid solution
* to the puzzle, which means we have to
* check if it satisfies all the clues.
* This means that every clue must be
* either satisfied or satisfied-minus-
* 1, and also that the number of
* satisfied-minus-1 clues must be at
* most two and they must lie on either
* side of this edge.
*/
sm1_nearby = 0;
cx = i - (j2-j);
cy = j - (i2-i);
if (CLUE_AT(state, cx,cy) >= 0 &&
square_order(state, cx,cy, LINE_YES) ==
CLUE_AT(state, cx,cy) - 1) {
sm1_nearby++;
}
if (CLUE_AT(state, i, j) >= 0 &&
SQUARE_YES_COUNT(sstate, i, j) ==
CLUE_AT(state, i, j) - 1) {
sm1_nearby++;
}
if (sm1clues == sm1_nearby &&
sm1clues + satclues == clues) {
val = LINE_YES; /* loop is good! */
}
}
/*
* Right. Now we know that adding this edge
* would form a loop, and we know whether
* that loop would be a viable solution or
* not.
*
* If adding this edge produces a solution,
* then we know we've found _a_ solution but
* we don't know that it's _the_ solution -
* if it were provably the solution then
* we'd have deduced this edge some time ago
* without the need to do loop detection. So
* in this state we return SOLVER_AMBIGUOUS,
* which has the effect that hitting Solve
* on a user-provided puzzle will fill in a
* solution but using the solver to
* construct new puzzles won't consider this
* a reasonable deduction for the user to
* make.
*/
if (d == 0) {
progress = set_line_bydot(sstate, i, j, RIGHT, val);
assert(progress == TRUE);
} else {
progress = set_line_bydot(sstate, i, j, DOWN, val);
assert(progress == TRUE);
}
if (val == LINE_YES) {
sstate->solver_status = SOLVER_AMBIGUOUS;
goto finished_loop_deductionsing;
}
}
}
finished_loop_deductionsing:
return progress ? DIFF_EASY : DIFF_MAX;
}
/* This will return a dynamically allocated solver_state containing the (more)
* solved grid */
static solver_state *solve_game_rec(const solver_state *sstate_start,
int diff)
{
int i, j;
int w, h;
solver_state *sstate, *sstate_saved, *sstate_tmp;
solver_state *sstate_rec_solved;
int recursive_soln_count;
int solver_progress;
game_state *state;
/* Indicates which solver we should call next. This is a sensible starting
* point */
int current_solver = DIFF_EASY, next_solver;
#ifdef SHOW_WORKING
char *text;
#endif
#if 0
printf("solve_game_rec: recursion_remaining = %d\n",
sstate_start->recursion_remaining);
#endif
sstate = dup_solver_state(sstate_start);
/* Cache the values of some variables for readability */
state = sstate->state;
h = state->h;
w = state->w;
sstate_saved = NULL;
nonrecursive_solver:
solver_progress = FALSE;
check_caches(sstate);
do {
#ifdef SHOW_WORKING
text = game_text_format(state);
fprintf(stderr, "-----------------\n%s", text);
sfree(text);
#endif
if (sstate->solver_status == SOLVER_MISTAKE)
return sstate;
/* fprintf(stderr, "Invoking solver %d\n", current_solver); */
next_solver = solver_fns[current_solver](sstate);
if (next_solver == DIFF_MAX) {
/* fprintf(stderr, "Current solver failed\n"); */
if (current_solver < diff && current_solver + 1 < DIFF_MAX) {
/* Try next beefier solver */
next_solver = current_solver + 1;
} else {
/* fprintf(stderr, "Doing loop deductions\n"); */
next_solver = loop_deductions(sstate);
}
}
if (sstate->solver_status == SOLVER_SOLVED ||
sstate->solver_status == SOLVER_AMBIGUOUS) {
/* fprintf(stderr, "Solver completed\n"); */
break;
}
/* Once we've looped over all permitted solvers then the loop
* deductions without making any progress, we'll exit this while loop */
current_solver = next_solver;
} while (current_solver < DIFF_MAX);
if (sstate->solver_status == SOLVER_SOLVED ||
sstate->solver_status == SOLVER_AMBIGUOUS) {
/* s/LINE_UNKNOWN/LINE_NO/g */
array_setall(sstate->state->hl, LINE_UNKNOWN, LINE_NO,
HL_COUNT(sstate->state));
array_setall(sstate->state->vl, LINE_UNKNOWN, LINE_NO,
VL_COUNT(sstate->state));
return sstate;
}
/* Perform recursive calls */
if (sstate->recursion_remaining) {
sstate_saved = dup_solver_state(sstate);
sstate->recursion_remaining--;
recursive_soln_count = 0;
sstate_rec_solved = NULL;
/* Memory management:
* sstate_saved won't be modified but needs to be freed when we have
* finished with it.
* sstate is expected to contain our 'best' solution by the time we
* finish this section of code. It's the thing we'll try adding lines
* to, seeing if they make it more solvable.
* If sstate_rec_solved is non-NULL, it will supersede sstate
* eventually. sstate_tmp should not hold a value persistently.
*/
/* NB SOLVER_AMBIGUOUS is like SOLVER_SOLVED except the solver is aware
* of the possibility of additional solutions. So as soon as we have a
* SOLVER_AMBIGUOUS we can safely propagate it back to our caller, but
* if we get a SOLVER_SOLVED we want to keep trying in case we find
* further solutions and have to mark it ambiguous.
*/
#define DO_RECURSIVE_CALL(dir_dot) \
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, diff); \
switch (sstate_tmp->solver_status) { \
case SOLVER_AMBIGUOUS: \
debug(("Solver ambiguous, returning\n")); \
sstate_rec_solved = sstate_tmp; \
goto finished_recursion; \
case SOLVER_SOLVED: \
switch (++recursive_soln_count) { \
case 1: \
debug(("One solution found\n")); \
sstate_rec_solved = sstate_tmp; \
break; \
case 2: \
debug(("Ambiguous solutions found\n")); \
free_solver_state(sstate_tmp); \
sstate_rec_solved->solver_status = SOLVER_AMBIGUOUS; \
goto finished_recursion; \
default: \
assert(!"recursive_soln_count out of range"); \
break; \
} \
break; \
case SOLVER_MISTAKE: \
debug(("Non-solution found\n")); \
free_solver_state(sstate_tmp); \
free_solver_state(sstate_saved); \
LV_##dir_dot(sstate->state, i, j) = LINE_NO; \
goto nonrecursive_solver; \
case SOLVER_INCOMPLETE: \
debug(("Recursive step inconclusive\n")); \
free_solver_state(sstate_tmp); \
break; \
} \
free_solver_state(sstate); \
sstate = dup_solver_state(sstate_saved); \
}
FORALL_DOTS(state, i, j) {
/* Only perform recursive calls on 'loose ends' */
if (DOT_YES_COUNT(sstate, i, j) == 1) {
DO_RECURSIVE_CALL(LEFTOF_DOT);
DO_RECURSIVE_CALL(RIGHTOF_DOT);
DO_RECURSIVE_CALL(ABOVE_DOT);
DO_RECURSIVE_CALL(BELOW_DOT);
}
}
finished_recursion:
if (sstate_rec_solved) {
free_solver_state(sstate);
sstate = sstate_rec_solved;
}
}
return sstate;
}
#if 0
#define HANDLE_DLINE(dline, dir1_sq, dir2_sq, a, b) \
if (sstate->normal->dot_atmostone[i+a + (sstate->state->w + 1) * (j+b)] & \
1<<dline) { \
if (square_order(sstate->state, i, j, LINE_UNKNOWN) - 1 == \
CLUE_AT(sstate->state, i, j) - '0') { \
square_setall(sstate->state, i, j, LINE_UNKNOWN, LINE_YES); \
/* XXX the following may overwrite known data! */ \
dir1_sq(sstate->state, i, j) = LINE_UNKNOWN; \
dir2_sq(sstate->state, i, j) = LINE_UNKNOWN; \
} \
}
SQUARE_DLINES;
#undef HANDLE_DLINE
#endif
static char *solve_game(game_state *state, game_state *currstate,
char *aux, char **error)
{
char *soln = NULL;
solver_state *sstate, *new_sstate;
sstate = new_solver_state(state, DIFF_MAX);
new_sstate = solve_game_rec(sstate, DIFF_MAX);
if (new_sstate->solver_status == SOLVER_SOLVED) {
soln = encode_solve_move(new_sstate->state);
} else if (new_sstate->solver_status == SOLVER_AMBIGUOUS) {
soln = encode_solve_move(new_sstate->state);
/**error = "Solver found ambiguous solutions"; */
} else {
soln = encode_solve_move(new_sstate->state);
/**error = "Solver failed"; */
}
free_solver_state(new_sstate);
free_solver_state(sstate);
return soln;
}
/* ----------------------------------------------------------------------
* Drawing and mouse-handling
*/
static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
int x, int y, int button)
{
int hl_selected;
int i, j, p, q;
char *ret, buf[80];
char button_char = ' ';
enum line_state old_state;
button &= ~MOD_MASK;
/* Around each line is a diamond-shaped region where points within that
* region are closer to this line than any other. We assume any click
* within a line's diamond was meant for that line. It would all be a lot
* simpler if the / and % operators respected modulo arithmetic properly
* for negative numbers. */
x -= BORDER;
y -= BORDER;
/* Get the coordinates of the square the click was in */
i = (x + TILE_SIZE) / TILE_SIZE - 1;
j = (y + TILE_SIZE) / TILE_SIZE - 1;
/* Get the precise position inside square [i,j] */
p = (x + TILE_SIZE) % TILE_SIZE;
q = (y + TILE_SIZE) % TILE_SIZE;
/* After this bit of magic [i,j] will correspond to the point either above
* or to the left of the line selected */
if (p > q) {
if (TILE_SIZE - p > q) {
hl_selected = TRUE;
} else {
hl_selected = FALSE;
++i;
}
} else {
if (TILE_SIZE - q > p) {
hl_selected = FALSE;
} else {
hl_selected = TRUE;
++j;
}
}
if (i < 0 || j < 0)
return NULL;
if (hl_selected) {
if (i >= state->w || j >= state->h + 1)
return NULL;
} else {
if (i >= state->w + 1 || j >= state->h)
return NULL;
}
/* I think it's only possible to play this game with mouse clicks, sorry */
/* Maybe will add mouse drag support some time */
if (hl_selected)
old_state = RIGHTOF_DOT(state, i, j);
else
old_state = BELOW_DOT(state, i, j);
switch (button) {
case LEFT_BUTTON:
switch (old_state) {
case LINE_UNKNOWN:
button_char = 'y';
break;
case LINE_YES:
case LINE_NO:
button_char = 'u';
break;
}
break;
case MIDDLE_BUTTON:
button_char = 'u';
break;
case RIGHT_BUTTON:
switch (old_state) {
case LINE_UNKNOWN:
button_char = 'n';
break;
case LINE_NO:
case LINE_YES:
button_char = 'u';
break;
}
break;
default:
return NULL;
}
sprintf(buf, "%d,%d%c%c", i, j, (int)(hl_selected ? 'h' : 'v'), (int)button_char);
ret = dupstr(buf);
return ret;
}
static game_state *execute_move(game_state *state, char *move)
{
int i, j;
game_state *newstate = dup_game(state);
if (move[0] == 'S') {
move++;
newstate->cheated = TRUE;
}
while (*move) {
i = atoi(move);
move = strchr(move, ',');
if (!move)
goto fail;
j = atoi(++move);
move += strspn(move, "1234567890");
switch (*(move++)) {
case 'h':
if (i >= newstate->w || j > newstate->h)
goto fail;
switch (*(move++)) {
case 'y':
LV_RIGHTOF_DOT(newstate, i, j) = LINE_YES;
break;
case 'n':
LV_RIGHTOF_DOT(newstate, i, j) = LINE_NO;
break;
case 'u':
LV_RIGHTOF_DOT(newstate, i, j) = LINE_UNKNOWN;
break;
default:
goto fail;
}
break;
case 'v':
if (i > newstate->w || j >= newstate->h)
goto fail;
switch (*(move++)) {
case 'y':
LV_BELOW_DOT(newstate, i, j) = LINE_YES;
break;
case 'n':
LV_BELOW_DOT(newstate, i, j) = LINE_NO;
break;
case 'u':
LV_BELOW_DOT(newstate, i, j) = LINE_UNKNOWN;
break;
default:
goto fail;
}
break;
default:
goto fail;
}
}
/*
* Check for completion.
*/
i = 0; /* placate optimiser */
for (j = 0; j <= newstate->h; j++) {
for (i = 0; i < newstate->w; i++)
if (LV_RIGHTOF_DOT(newstate, i, j) == LINE_YES)
break;
if (i < newstate->w)
break;
}
if (j <= newstate->h) {
int prevdir = 'R';
int x = i, y = j;
int looplen, count;
/*
* We've found a horizontal edge at (i,j). Follow it round
* to see if it's part of a loop.
*/
looplen = 0;
while (1) {
int order = dot_order(newstate, x, y, LINE_YES);
if (order != 2)
goto completion_check_done;
if (LEFTOF_DOT(newstate, x, y) == LINE_YES && prevdir != 'L') {
x--;
prevdir = 'R';
} else if (RIGHTOF_DOT(newstate, x, y) == LINE_YES &&
prevdir != 'R') {
x++;
prevdir = 'L';
} else if (ABOVE_DOT(newstate, x, y) == LINE_YES &&
prevdir != 'U') {
y--;
prevdir = 'D';
} else if (BELOW_DOT(newstate, x, y) == LINE_YES &&
prevdir != 'D') {
y++;
prevdir = 'U';
} else {
assert(!"Can't happen"); /* dot_order guarantees success */
}
looplen++;
if (x == i && y == j)
break;
}
if (x != i || y != j || looplen == 0)
goto completion_check_done;
/*
* We've traced our way round a loop, and we know how many
* line segments were involved. Count _all_ the line
* segments in the grid, to see if the loop includes them
* all.
*/
count = 0;
FORALL_DOTS(newstate, i, j) {
count += ((RIGHTOF_DOT(newstate, i, j) == LINE_YES) +
(BELOW_DOT(newstate, i, j) == LINE_YES));
}
assert(count >= looplen);
if (count != looplen)
goto completion_check_done;
/*
* The grid contains one closed loop and nothing else.
* Check that all the clues are satisfied.
*/
FORALL_SQUARES(newstate, i, j) {
if (CLUE_AT(newstate, i, j) >= 0) {
if (square_order(newstate, i, j, LINE_YES) !=
CLUE_AT(newstate, i, j)) {
goto completion_check_done;
}
}
}
/*
* Completed!
*/
newstate->solved = TRUE;
}
completion_check_done:
return newstate;
fail:
free_game(newstate);
return NULL;
}
/* ----------------------------------------------------------------------
* Drawing routines.
*/
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 i, j, n;
char c[2];
int line_colour, flash_changed;
int clue_mistake;
if (!ds->started) {
/*
* The initial contents of the window are not guaranteed and
* can vary with front ends. To be on the safe side, all games
* should start by drawing a big background-colour rectangle
* covering the whole window.
*/
draw_rect(dr, 0, 0, SIZE(state->w), SIZE(state->h), COL_BACKGROUND);
/* Draw dots */
FORALL_DOTS(state, i, j) {
draw_rect(dr,
BORDER + i * TILE_SIZE - LINEWIDTH/2,
BORDER + j * TILE_SIZE - LINEWIDTH/2,
LINEWIDTH, LINEWIDTH, COL_FOREGROUND);
}
/* Draw clues */
FORALL_SQUARES(state, i, j) {
c[0] = CLUE2CHAR(CLUE_AT(state, i, j));
c[1] = '\0';
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, COL_FOREGROUND, c);
}
draw_update(dr, 0, 0,
state->w * TILE_SIZE + 2*BORDER + 1,
state->h * TILE_SIZE + 2*BORDER + 1);
ds->started = TRUE;
}
if (flashtime > 0 &&
(flashtime <= FLASH_TIME/3 ||
flashtime >= FLASH_TIME*2/3)) {
flash_changed = !ds->flashing;
ds->flashing = TRUE;
line_colour = COL_HIGHLIGHT;
} else {
flash_changed = ds->flashing;
ds->flashing = FALSE;
line_colour = COL_FOREGROUND;
}
#define CROSS_SIZE (3 * LINEWIDTH / 2)
/* Redraw clue colours if necessary */
FORALL_SQUARES(state, i, j) {
n = CLUE_AT(state, i, j);
if (n < 0)
continue;
assert(n >= 0 && n <= 4);
c[0] = CLUE2CHAR(CLUE_AT(state, i, j));
c[1] = '\0';
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[SQUARE_INDEX(state, i, 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[SQUARE_INDEX(state, i, 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, \
BORDER + j * TILE_SIZE + LINEWIDTH - LINEWIDTH/2, \
CROSS_SIZE * 2, \
TILE_SIZE - LINEWIDTH, \
COL_BACKGROUND); \
draw_update(dr, \
BORDER + i * TILE_SIZE - CROSS_SIZE, \
BORDER + j * TILE_SIZE - CROSS_SIZE, \
CROSS_SIZE*2, \
TILE_SIZE + CROSS_SIZE*2); \
} while (0)
#define CLEAR_HL(i, j) \
do { \
draw_rect(dr, \
BORDER + i * TILE_SIZE + LINEWIDTH - LINEWIDTH/2, \
BORDER + j * TILE_SIZE - CROSS_SIZE, \
TILE_SIZE - LINEWIDTH, \
CROSS_SIZE * 2, \
COL_BACKGROUND); \
draw_update(dr, \
BORDER + i * TILE_SIZE - CROSS_SIZE, \
BORDER + j * TILE_SIZE - CROSS_SIZE, \
TILE_SIZE + CROSS_SIZE*2, \
CROSS_SIZE*2); \
} while (0)
/* Vertical lines */
FORALL_VL(state, i, j) {
switch (BELOW_DOT(state, i, j)) {
case LINE_UNKNOWN:
if (ds->vl[VL_INDEX(state, i, j)] != BELOW_DOT(state, i, j)) {
CLEAR_VL(i, j);
}
break;
case LINE_YES:
if (ds->vl[VL_INDEX(state, i, j)] != BELOW_DOT(state, i, j) ||
flash_changed) {
CLEAR_VL(i, j);
draw_rect(dr,
BORDER + i * TILE_SIZE - LINEWIDTH/2,
BORDER + j * TILE_SIZE + LINEWIDTH - LINEWIDTH/2,
LINEWIDTH, TILE_SIZE - LINEWIDTH,
line_colour);
}
break;
case LINE_NO:
if (ds->vl[VL_INDEX(state, i, j)] != BELOW_DOT(state, i, j)) {
CLEAR_VL(i, j);
draw_line(dr,
BORDER + i * TILE_SIZE - CROSS_SIZE,
BORDER + j * TILE_SIZE + TILE_SIZE/2 - CROSS_SIZE,
BORDER + i * TILE_SIZE + CROSS_SIZE - 1,
BORDER + j * TILE_SIZE + TILE_SIZE/2 + CROSS_SIZE - 1,
COL_FOREGROUND);
draw_line(dr,
BORDER + i * TILE_SIZE + CROSS_SIZE - 1,
BORDER + j * TILE_SIZE + TILE_SIZE/2 - CROSS_SIZE,
BORDER + i * TILE_SIZE - CROSS_SIZE,
BORDER + j * TILE_SIZE + TILE_SIZE/2 + CROSS_SIZE - 1,
COL_FOREGROUND);
}
break;
}
ds->vl[VL_INDEX(state, i, j)] = BELOW_DOT(state, i, j);
}
/* Horizontal lines */
FORALL_HL(state, i, j) {
switch (RIGHTOF_DOT(state, i, j)) {
case LINE_UNKNOWN:
if (ds->hl[HL_INDEX(state, i, j)] != RIGHTOF_DOT(state, i, j)) {
CLEAR_HL(i, j);
}
break;
case LINE_YES:
if (ds->hl[HL_INDEX(state, i, j)] != RIGHTOF_DOT(state, i, j) ||
flash_changed) {
CLEAR_HL(i, j);
draw_rect(dr,
BORDER + i * TILE_SIZE + LINEWIDTH - LINEWIDTH/2,
BORDER + j * TILE_SIZE - LINEWIDTH/2,
TILE_SIZE - LINEWIDTH, LINEWIDTH,
line_colour);
}
break;
case LINE_NO:
if (ds->hl[HL_INDEX(state, i, j)] != RIGHTOF_DOT(state, i, j)) {
CLEAR_HL(i, j);
draw_line(dr,
BORDER + i * TILE_SIZE + TILE_SIZE/2 - CROSS_SIZE,
BORDER + j * TILE_SIZE + CROSS_SIZE - 1,
BORDER + i * TILE_SIZE + TILE_SIZE/2 + CROSS_SIZE - 1,
BORDER + j * TILE_SIZE - CROSS_SIZE,
COL_FOREGROUND);
draw_line(dr,
BORDER + i * TILE_SIZE + TILE_SIZE/2 - CROSS_SIZE,
BORDER + j * TILE_SIZE - CROSS_SIZE,
BORDER + i * TILE_SIZE + TILE_SIZE/2 + CROSS_SIZE - 1,
BORDER + j * TILE_SIZE + CROSS_SIZE - 1,
COL_FOREGROUND);
break;
}
}
ds->hl[HL_INDEX(state, i, j)] = RIGHTOF_DOT(state, i, j);
}
}
static float game_flash_length(game_state *oldstate, game_state *newstate,
int dir, game_ui *ui)
{
if (!oldstate->solved && newstate->solved &&
!oldstate->cheated && !newstate->cheated) {
return FLASH_TIME;
}
return 0.0F;
}
static void game_print_size(game_params *params, float *x, float *y)
{
int pw, ph;
/*
* I'll use 7mm squares by default.
*/
game_compute_size(params, 700, &pw, &ph);
*x = pw / 100.0F;
*y = ph / 100.0F;
}
static void game_print(drawing *dr, game_state *state, int tilesize)
{
int ink = print_mono_colour(dr, 0);
int x, y;
game_drawstate ads, *ds = &ads;
game_set_size(dr, ds, NULL, tilesize);
/*
* Dots. I'll deliberately make the dots a bit wider than the
* lines, so you can still see them. (And also because it's
* annoyingly tricky to make them _exactly_ the same size...)
*/
FORALL_DOTS(state, x, y) {
draw_circle(dr, BORDER + x * TILE_SIZE, BORDER + y * TILE_SIZE,
LINEWIDTH, ink, ink);
}
/*
* Clues.
*/
FORALL_SQUARES(state, x, y) {
if (CLUE_AT(state, x, y) >= 0) {
char c[2];
c[0] = CLUE2CHAR(CLUE_AT(state, x, y));
c[1] = '\0';
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, c);
}
}
/*
* Lines. (At the moment, I'm not bothering with crosses.)
*/
FORALL_HL(state, x, y) {
if (RIGHTOF_DOT(state, x, y) == LINE_YES)
draw_rect(dr, BORDER + x * TILE_SIZE,
BORDER + y * TILE_SIZE - LINEWIDTH/2,
TILE_SIZE, (LINEWIDTH/2) * 2 + 1, ink);
}
FORALL_VL(state, x, y) {
if (BELOW_DOT(state, x, y) == LINE_YES)
draw_rect(dr, BORDER + x * TILE_SIZE - LINEWIDTH/2,
BORDER + y * TILE_SIZE,
(LINEWIDTH/2) * 2 + 1, TILE_SIZE, ink);
}
}
#ifdef COMBINED
#define thegame loopy
#endif
const struct game thegame = {
"Loopy", "games.loopy", "loopy",
default_params,
game_fetch_preset,
decode_params,
encode_params,
free_params,
dup_params,
TRUE, game_configure, custom_params,
validate_params,
new_game_desc,
validate_desc,
new_game,
dup_game,
free_game,
1, solve_game,
TRUE, game_text_format,
new_ui,
free_ui,
encode_ui,
decode_ui,
game_changed_state,
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,
TRUE, FALSE, game_print_size, game_print,
FALSE /* wants_statusbar */,
FALSE, game_timing_state,
0, /* mouse_priorities */
};