static puzzle_t *search(puzzle_t *puz) {
if (!propogate(puz)) {
return NULL;
}
if (solved(puz)) {
return puz;
}
// find best candidate
square_t *best = find_search_candidate(puz);
char *old_vals = strndup(best->vals, NUM_DIGITS);
assert(strlen(old_vals) == strlen(best->vals));
int val;
for (val = 0; val < strlen(old_vals); val++) {
puzzle_t *copy = copy_puzzle(puz);
assert(copy != puz);
copy->squares[best->row][best->col].vals[0] = old_vals[val];
copy->squares[best->row][best->col].vals[1] = '\0';
puzzle_t *return_puz;
if ((return_puz = search(copy)) != NULL) {
if (!solved(copy)) {
//free_puzzle(copy);
if ((puz != return_puz) && (puz != copy)) {
free_puzzle(puz);
}
else if ((copy != puz) && (copy != return_puz)) {
free_puzzle(copy);
}
}
//free_puzzle(copy);
return return_puz;
}
free_puzzle(copy);
}
return NULL;
}
int solver() {
int i, j, k, l, m, n, o, p, q;
potential = malloc(9 * 362880 * 10 * sizeof(char));
new_places = malloc(9 * 9 * sizeof(char));
//print_possible_lines();
load_possible_lines();
copy_puzzle();
for(i = 0; i < num_of_solutions[0]; i++) { // one for each line
print_time();
printf("i: %d\n", i);
copy_line(0, &potential[i * 10 + (offset(0)*10)]);
for(j = 0; j < num_of_solutions[1]; j++) {
copy_line(1, &potential[j * 10 + (offset(1)*10)]);
for(k = 0; k < num_of_solutions[2]; k++) {
copy_line(2, &potential[k * 10 + (offset(2)*10)]);
for(l = 0; l < num_of_solutions[3]; l++) {
copy_line(3, &potential[l * 10 + (offset(3)*10)]);
for(m = 0; m < num_of_solutions[4]; m++) {
copy_line(4, &potential[m * 10 + (offset(4)*10)]);
for(n = 0; n < num_of_solutions[5]; n++) {
copy_line(5, &potential[n * 10 + (offset(5)*10)]);
for(o = 0; o < num_of_solutions[6]; o++) {
copy_line(6, &potential[o * 10 + (offset(6)*10)]);
for(p = 0; p < num_of_solutions[7]; p++) {
copy_line(7, &potential[p * 10 + (offset(7)*10)]);
for(q = 0; q < num_of_solutions[8]; q++) {
copy_line(8, &potential[q * 10 + (offset(8)*10)]);
if(lines_valid() && columns_valid() && squares_valid()) {
return(1);
}
}
}
}
}
}
}
}
}
}
return(0);
}
