/*
* Modulo Operator
*/
word BigInt::operator%=(word mod)
{
if(mod == 0)
throw BigInt::DivideByZero();
if(is_power_of_2(mod))
{
word result = (word_at(0) & (mod - 1));
clear();
grow_to(2);
m_reg[0] = result;
return result;
}
word remainder = 0;
for(size_t j = sig_words(); j > 0; --j)
remainder = bigint_modop(remainder, word_at(j-1), mod);
clear();
grow_to(2);
if(remainder && sign() == BigInt::Negative)
m_reg[0] = mod - remainder;
else
m_reg[0] = remainder;
set_sign(BigInt::Positive);
return word_at(0);
}
/*
* Modulo Operator
*/
word operator%(const BigInt& n, word mod)
{
if(mod == 0)
throw BigInt::DivideByZero();
if(power_of_2(mod))
return (n.word_at(0) & (mod - 1));
word remainder = 0;
for(size_t j = n.sig_words(); j > 0; --j)
remainder = bigint_modop(remainder, n.word_at(j-1), mod);
if(remainder && n.sign() == BigInt::Negative)
return mod - remainder;
return remainder;
}
