void poly_mul(const umap_vec_mpz &A, const umap_vec_mpz &B, umap_vec_mpz &C)
{
vec_int exp;
int n = (A.begin()->first).size();
exp.assign(n, 0); // Initialize to [0]*n
/*
std::cout << "A: " << A.load_factor() << " " << A.bucket_count() << " " << A.size() << " "
<< A.max_bucket_count() << std::endl;
std::cout << "B: " << B.load_factor() << " " << B.bucket_count() << " " << B.size() << " "
<< B.max_bucket_count() << std::endl;
std::cout << "C: " << C.load_factor() << " " << C.bucket_count() << " " << C.size() << " "
<< C.max_bucket_count() << std::endl;
*/
for (const auto &a: A) {
for (const auto &b: B) {
monomial_mul(a.first, b.first, exp);
mp_addmul(C[exp], a.second, b.second);
}
}
/*
std::cout << "C: " << C.load_factor() << " " << C.bucket_count() << " " << C.size() << " "
<< C.max_bucket_count() << std::endl;
for (const std::size_t n=0; n < C.bucket_count(); n++) {
std::cout << n << ": " << C.bucket_size(n) << "|";
for (auto it = C.begin(n); it != C.end(n); ++it)
std::cout << " " << it->first << myhash2(it->first) % C.bucket_count();
std::cout << std::endl;
}
*/
}
void GaloisFieldDict::gf_div(const GaloisFieldDict &o,
const Ptr<GaloisFieldDict> &quo,
const Ptr<GaloisFieldDict> &rem) const
{
if (modulo_ != o.modulo_)
throw std::runtime_error("Error: field must be same.");
if (o.dict_.empty())
throw std::runtime_error("ZeroDivisionError");
std::vector<integer_class> dict_out;
if (dict_.empty()) {
*quo = GaloisFieldDict::from_vec(dict_out, modulo_);
*rem = GaloisFieldDict::from_vec(dict_, modulo_);
return;
}
auto dict_divisor = o.dict_;
unsigned int deg_dividend = this->degree();
unsigned int deg_divisor = o.degree();
if (deg_dividend < deg_divisor) {
*quo = GaloisFieldDict::from_vec(dict_out, modulo_);
*rem = GaloisFieldDict::from_vec(dict_, modulo_);
} else {
dict_out = dict_;
integer_class inv;
mp_invert(inv, *(dict_divisor.rbegin()), modulo_);
integer_class coeff;
for (auto it = deg_dividend + 1; it-- != 0;) {
coeff = dict_out[it];
auto lb = deg_divisor + it > deg_dividend
? deg_divisor + it - deg_dividend
: 0;
auto ub = std::min(it + 1, deg_divisor);
for (size_t j = lb; j < ub; ++j) {
mp_addmul(coeff, dict_out[it - j + deg_divisor],
-dict_divisor[j]);
}
if (it >= deg_divisor)
coeff *= inv;
mp_fdiv_r(coeff, coeff, modulo_);
dict_out[it] = coeff;
}
std::vector<integer_class> dict_rem, dict_quo;
dict_rem.resize(deg_divisor);
dict_quo.resize(deg_dividend - deg_divisor + 1);
for (unsigned it = 0; it < dict_out.size(); it++) {
if (it < deg_divisor)
dict_rem[it] = dict_out[it];
else
dict_quo[it - deg_divisor] = dict_out[it];
}
*quo = GaloisFieldDict::from_vec(dict_quo, modulo_);
*rem = GaloisFieldDict::from_vec(dict_rem, modulo_);
}
}
