nfrom = state->nums[from]; nto = state->nums[to];
- /* can't move _from_ the final number, or _to_ the 1. */
- if (nfrom == state->n || nto == 1)
+ /* can't move _from_ the preset final number, or _to_ the preset 1. */
+ if (((nfrom == state->n) && (state->flags[from] & FLAG_IMMUTABLE)) ||
+ ((nto == 1) && (state->flags[to] & FLAG_IMMUTABLE)))
return 0;
/* can't create a new connection between cells in the same region
/* --- Linked-list and numbers array --- */
/* Assuming numbers are always up-to-date, there are only four possibilities
- * for regions changing:
+ * for regions changing after a single valid move:
*
* 1) two differently-coloured regions being combined (the resulting colouring
* should be based on the larger of the two regions)
* There should never be any complications with regions containing 3 colours
* being combined, since two of those colours should have been merged on a
* previous move.
- */
-
-/* New algorithm for working out numbering:
*
- * At start, only remove numbers from cells with neither prev nor next.
- * Search for all cells with !prev && next (head of chain); for each one:
- * Search the group for a 'real' number: if we find one the num. for
- the head of the chain is trivial.
- * Otherwise, if we _don't_ have a number already:
- * If head->next has a number, that number is the one we should use
- * Otherwise pick the smallest unused colour set.
- * and if we _do_ have a number already:
- * Work out the size of this group (the dsf must already have been set up)
- * Start enumerating through the group counting squares that have the
- same colouring as us
- * If we reach a square with a different colour, work out which set is
- bigger (ncol1 vs ncol2 == sz-ncol1), and use that colour
- * If we reached a square with no colour (or the end of the group, which
- would be weird under the circumstances) just keep the existing colour.
+ * Most of the complications are in ensuring we don't accidentally set two
+ * regions with the same colour (e.g. if a region was split). If this happens
+ * we always try and give the largest original portion the original colour.
*/
#define COLOUR(a) ((a) / (state->n+1))
#define START(c) ((c) * (state->n+1))
-static int lowest_start(game_state *state, int *scratch)
-{
- int i, c;
-
- /* Fill in 'scratch' array with the currently-used colours... */
- memset(scratch, 0, state->n * sizeof(int));
- for (i = 0; i < state->n; i++) {
- if (state->nums[i] != 0)
- scratch[COLOUR(state->nums[i])] = 1;
- }
- /* ... and return the first one that was unused. */
- for (c = 1; c < state->n; c++) { /* NB start at 1 */
- if (scratch[c] == 0)
- return START(c);
- }
- assert(!"shouldn't get here");
- return -1; /* suyb */
-}
-
-static int used_colour(game_state *state, int i, int start)
-{
- int j;
- for (j = 0; j < i; j++) {
- if (state->nums[j] == start)
- return 1;
- }
- return 0;
-}
+struct head_meta {
+ int i; /* position */
+ int sz; /* size of region */
+ int start; /* region start number preferred, or 0 if !preference */
+ int preference; /* 0 if we have no preference (and should just pick one) */
+ const char *why;
+};
-static int head_number(game_state *state, int i, int *scratch)
+static void head_number(game_state *state, int i, struct head_meta *head)
{
- int off = 0, found = 0, start = 0, ss, j = i, c, n, sz;
- const char *why = NULL;
+ int off = 0, ss, j = i, c, n, sz;
+ /* Insist we really were passed the head of a chain. */
assert(state->prev[i] == -1 && state->next[i] != -1);
+ head->i = i;
+ head->sz = dsf_size(state->dsf, i);
+ head->why = NULL;
+
/* Search through this chain looking for real numbers, checking that
* they match up (if there are more than one). */
+ head->preference = 0;
while (j != -1) {
if (state->flags[j] & FLAG_IMMUTABLE) {
ss = state->nums[j] - off;
- if (!found) {
- start = ss;
- found = 1;
- why = "contains cell with immutable number";
- } else if (start != ss) {
+ if (!head->preference) {
+ head->start = ss;
+ head->preference = 1;
+ head->why = "contains cell with immutable number";
+ } else if (head->start != ss) {
debug(("head_number: chain with non-sequential numbers!"));
state->impossible = 1;
}
j = state->next[j];
assert(j != i); /* we have created a loop, obviously wrong */
}
- if (found) goto done;
-
- if (state->nums[i] == 0) {
- if (state->nums[state->next[i]] != 0) {
- /* make sure we start at a 0 offset. */
- start = START(COLOUR(state->nums[state->next[i]]));
- why = "adding blank cell to head of numbered region";
- } else {
- start = lowest_start(state, scratch);
- why = "lowest available colour group";
- }
- found = 1;
+ if (head->preference) goto done;
+
+ if (state->nums[i] == 0 && state->nums[state->next[i]] > state->n) {
+ /* (probably) empty cell onto the head of a coloured region:
+ * make sure we start at a 0 offset. */
+ head->start = START(COLOUR(state->nums[state->next[i]]));
+ head->preference = 1;
+ head->why = "adding blank cell to head of numbered region";
+ } else if (state->nums[i] <= state->n) {
+ /* if we're 0 we're probably just blank -- but even if we're a
+ * (real) numbered region, we don't have an immutable number
+ * in it (any more) otherwise it'd have been caught above, so
+ * reassign the colour. */
+ head->start = 0;
+ head->preference = 0;
+ head->why = "lowest available colour group";
} else {
c = COLOUR(state->nums[i]);
n = 1;
j = i;
while (state->next[j] != -1) {
j = state->next[j];
- if (state->nums[j] == 0) {
- start = START(c);
- found = 1;
- why = "adding blank cell to end of numbered region";
- break;
+ if (state->nums[j] == 0 && state->next[j] == -1) {
+ head->start = START(c);
+ head->preference = 1;
+ head->why = "adding blank cell to end of numbered region";
+ goto done;
}
if (COLOUR(state->nums[j]) == c)
n++;
else {
int start_alternate = START(COLOUR(state->nums[j]));
- if (n < (sz - n) && !used_colour(state, i, start_alternate)) {
- start = start_alternate;
- why = "joining two coloured regions, swapping to larger colour";
+ if (n < (sz - n)) {
+ head->start = start_alternate;
+ head->preference = 1;
+ head->why = "joining two coloured regions, swapping to larger colour";
} else {
- start = START(c);
- why = "joining two coloured regions, taking largest";
+ head->start = START(c);
+ head->preference = 1;
+ head->why = "joining two coloured regions, taking largest";
}
- found = 1;
- break;
+ goto done;
}
}
/* If we got here then we may have split a region into
* two; make sure we don't assign a colour we've already used. */
- if (!found) {
- start = (c == 0) ? lowest_start(state, scratch) : START(c);
- why = "got to end of coloured region";
- found = 1;
- }
- if (used_colour(state, i, start)) {
- start = lowest_start(state, scratch);
- why = "split region in two, lowest available colour group";
+ if (c == 0) {
+ /* not convinced this shouldn't be an assertion failure here. */
+ head->start = 0;
+ head->preference = 0;
+ } else {
+ head->start = START(c);
+ head->preference = 1;
}
+ head->why = "got to end of coloured region";
}
done:
- assert(found && why != NULL);
- debug(("Chain at (%d,%d) numbered at %d: %s.",
- i%state->w, i/state->w, start, why));
- return start;
+ assert(head->why != NULL);
+ if (head->preference)
+ debug(("Chain at (%d,%d) numbered for preference at %d (colour %d): %s.",
+ head->i%state->w, head->i/state->w,
+ head->start, COLOUR(head->start), head->why));
+ else
+ debug(("Chain at (%d,%d) using next available colour: %s.",
+ head->i%state->w, head->i/state->w,
+ head->why));
}
#if 0
}
}
+static int compare_heads(const void *a, const void *b)
+{
+ struct head_meta *ha = (struct head_meta *)a;
+ struct head_meta *hb = (struct head_meta *)b;
+
+ /* Heads with preferred colours first... */
+ if (ha->preference && !hb->preference) return -1;
+ if (hb->preference && !ha->preference) return 1;
+
+ /* ...then heads with low colours first... */
+ if (ha->start < hb->start) return -1;
+ if (ha->start > hb->start) return 1;
+
+ /* ... then large regions first... */
+ if (ha->sz > hb->sz) return -1;
+ if (ha->sz < hb->sz) return 1;
+
+ /* ... then position. */
+ if (ha->i > hb->i) return -1;
+ if (ha->i < hb->i) return 1;
+
+ return 0;
+}
+
+static int lowest_start(game_state *state, struct head_meta *heads, int nheads)
+{
+ int n, c;
+
+ /* NB start at 1: colour 0 is real numbers */
+ for (c = 1; c < state->n; c++) {
+ for (n = 0; n < nheads; n++) {
+ if (COLOUR(heads[n].start) == c)
+ goto used;
+ }
+ return c;
+used:
+ ;
+ }
+ assert(!"No available colours!");
+ return 0;
+}
+
static void update_numbers(game_state *state)
{
- int i, j, nnum;
- int *scratch = snewn(state->n, int);
+ int i, j, n, nnum, nheads;
+ struct head_meta *heads = snewn(state->n, struct head_meta);
- for (i = 0; i < state->n; i++)
- state->numsi[i] = -1;
+ for (n = 0; n < state->n; n++)
+ state->numsi[n] = -1;
for (i = 0; i < state->n; i++) {
if (state->flags[i] & FLAG_IMMUTABLE) {
- assert(state->nums[i] >= 0);
+ assert(state->nums[i] > 0);
assert(state->nums[i] <= state->n);
state->numsi[state->nums[i]] = i;
}
}
connect_numbers(state);
+ /* Construct an array of the heads of all current regions, together
+ * with their preferred colours. */
+ nheads = 0;
for (i = 0; i < state->n; i++) {
/* Look for a cell that is the start of a chain
* (has a next but no prev). */
if (state->prev[i] != -1 || state->next[i] == -1) continue;
- nnum = head_number(state, i, scratch);
- j = i;
+ head_number(state, i, &heads[nheads++]);
+ }
+
+ /* Sort that array:
+ * - heads with preferred colours first, then
+ * - heads with low colours first, then
+ * - large regions first
+ */
+ qsort(heads, nheads, sizeof(struct head_meta), compare_heads);
+
+ /* Remove duplicate-coloured regions. */
+ for (n = nheads-1; n >= 0; n--) { /* order is important! */
+ if ((n != 0) && (heads[n].start == heads[n-1].start)) {
+ /* We have a duplicate-coloured region: since we're
+ * sorted in size order and this is not the first
+ * of its colour it's not the largest: recolour it. */
+ heads[n].start = START(lowest_start(state, heads, nheads));
+ heads[n].preference = -1; /* '-1' means 'was duplicate' */
+ }
+ else if (!heads[n].preference) {
+ assert(heads[n].start == 0);
+ heads[n].start = START(lowest_start(state, heads, nheads));
+ }
+ }
+
+ debug(("Region colouring after duplicate removal:"));
+
+ for (n = 0; n < nheads; n++) {
+ debug((" Chain at (%d,%d) sz %d numbered at %d (colour %d): %s%s",
+ heads[n].i % state->w, heads[n].i / state->w, heads[n].sz,
+ heads[n].start, COLOUR(heads[n].start), heads[n].why,
+ heads[n].preference == 0 ? " (next available)" :
+ heads[n].preference < 0 ? " (duplicate, next available)" : ""));
+
+ nnum = heads[n].start;
+ j = heads[n].i;
while (j != -1) {
- if (nnum > 0 && nnum <= state->n)
- state->numsi[nnum] = j;
- state->nums[j] = nnum++;
+ if (!(state->flags[j] & FLAG_IMMUTABLE)) {
+ if (nnum > 0 && nnum <= state->n)
+ state->numsi[nnum] = j;
+ state->nums[j] = nnum;
+ }
+ nnum++;
j = state->next[j];
- assert(j != i); /* loop?! */
+ assert(j != heads[n].i); /* loop?! */
}
}
/*debug_numbers(state);*/
- sfree(scratch);
+ sfree(heads);
}
static int check_completion(game_state *state, int mark_errors)
if (button == LEFT_BUTTON) {
/* disallow dragging from the final number. */
- if (state->nums[y*w+x] == state->n) return NULL;
+ if ((state->nums[y*w+x] == state->n) &&
+ (state->flags[y*w+x] & FLAG_IMMUTABLE))
+ return NULL;
} else if (button == RIGHT_BUTTON) {
/* disallow dragging to the first number. */
- if (state->nums[y*w+x] == 1) return NULL;
+ if ((state->nums[y*w+x] == 1) &&
+ (state->flags[y*w+x] & FLAG_IMMUTABLE))
+ return NULL;
}
ui->dragging = TRUE;
else if (f & F_ARROW_POINT) arrowcol = mid(COL_ARROW, setcol);
else arrowcol = COL_ARROW;
- if (f & (F_ERROR)) textcol = COL_ERROR;
+ if ((f & F_ERROR) && !(f & F_IMMUTABLE)) textcol = COL_ERROR;
else {
if (f & F_IMMUTABLE) textcol = COL_NUMBER_SET;
else textcol = COL_NUMBER;
~ian / sgt-puzzles.git / commitdiff