void process_deriviate_solutions(
struct Board *board,
struct Num_Coordinates *solution,
int *points,
int *iterations)
{
int i, j, best_i, best_j;
int best_change, current_change;
do
{
(*iterations)++;
best_i = NONE;
best_j = NONE;
i = best_change = 0;
while (i < solution->count)
{
i = find_number_to_swap(board, solution, i);
j = i + 1;
while (j < solution->count)
{
j = find_number_to_swap(board, solution, j);
if (j < solution->count)
{
current_change = assess_deriviate(solution, points, i, j);
if (current_change > best_change)
{
best_i = i;
best_j = j;
best_change = current_change;
}
}
j++;
}
i++;
}
if (best_change > 0)
{
swap_numbers(solution, best_i, best_j);
update_points(solution, points, best_i - 1, best_i + 1);
update_points(solution, points, best_j - 1, best_j + 1);
}
} while (best_change > 0);
}
/* randomly swap out values, by num_itr,
* number of iterations, of known solved puzzle;
* should result in a new (completed) random puzzle
*/
static int build_puzzle(int* puzzle, int* matrix)
{
int num_itr = 0, x = 0, y = 0;
puts("generating sudoku puzzle ...");
/* There is a stdlib call "rand"; this function is tuned primarily for speed
* and distribution, not for unpredictability. Almost all built-in random
* functions for various languages and frameworks use this function by
* default. There are also "cryptographic" random number generators that are
* much less predictable, but run much slower. These should be used in any sort
* of security-related application. - tylerl
* http://stackoverflow.com/questions/822323/how-to-generate-a-random-number-in-c
*/
#ifdef JSW_RANDOM
puts("using jsw_srand()");
jsw_seed(time(NULL));
num_itr = (jsw_rand() % 1000000);
#else
puts("using srand()");
srand(time(NULL));
num_itr = (rand() % 1000000);
#endif
printf("number iterations: %d\n", num_itr);
for (int i = 0; i<num_itr; i++)
{
#ifdef JSW_RANDOM
x = (jsw_rand() % 9);
y = (jsw_rand() % 9);
#else
x = (rand() % 9);
y = (rand() % 9);
#endif
x++;
y++;
/* printf("x = %d, y = %d\n", x, y); */
swap_numbers(puzzle, x, y);
}
print_grid(puzzle_solution);
remove_values(matrix);
return 0;
}
