Bits naive_gen_bits() {
Grid grid = naive_gen_grid();
Bits ret;
ret.init();
backtrack_to_bits(grid, &ret);
return ret;
}
Bits Permutation::permute_bits(Bits* bits) {
Bits ret;
ret.init();
for(int i=0; i < 81; i++) {
// p: spot in ret
Spot p = spot_of_idx(i);
// px: spot in bits
Spot px = permute_spot(p);
if(bits->has_value(px)) {
ret.set_value(p, permute_val(bits->get_value(px)));
} else {
for(int k=1; k <=9; k++) {
if(!bits->has_candidate(px, k)) {
ret.remove_candidate(p, permute_val(k));
}
}
}
}
return ret;
}