+static int compare_int(const void *av, const void *bv)
+{
+ const int *a = (const int *)av;
+ const int *b = (const int *)bv;
+ if (*a < *b)
+ return -1;
+ else if (*a > *b)
+ return +1;
+ else
+ return 0;
+}
+
+static game_state *solve_game(game_state *state, game_aux_info *aux,
+ char **error)
+{
+ game_state *ret = dup_game(state);
+ int i;
+
+ /*
+ * Simply replace the grid with a solved one. For this game,
+ * this isn't a useful operation for actually telling the user
+ * what they should have done, but it is useful for
+ * conveniently being able to get hold of a clean state from
+ * which to practise manoeuvres.
+ */
+ qsort(ret->grid, ret->w*ret->h, sizeof(int), compare_int);
+ for (i = 0; i < ret->w*ret->h; i++)
+ ret->grid[i] &= ~3;
+ ret->used_solve = ret->just_used_solve = TRUE;
+ ret->completed = ret->movecount;
+
+ return ret;
+}
+