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abacus: bignum: remove magic number regarding base

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This commit is contained in:
Bruno BELANYI 2021-08-20 23:46:56 +02:00
parent 2489ce19b2
commit 44bb20e390
1 changed files with 11 additions and 9 deletions
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20
src/bignum/bignum.cc
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@ -13,6 +13,8 @@ using digits_type = std::vector<std::uint8_t>;
namespace { namespace {
auto static constexpr BASE = 10;
bool do_less_than(digits_type const& lhs, digits_type const& rhs) { bool do_less_than(digits_type const& lhs, digits_type const& rhs) {
return std::lexicographical_compare(lhs.rbegin(), lhs.rend(), rhs.rbegin(), return std::lexicographical_compare(lhs.rbegin(), lhs.rend(), rhs.rbegin(),
rhs.rend()); rhs.rend());
@ -30,8 +32,8 @@ digits_type do_addition(digits_type const& lhs, digits_type const& rhs) {
while (it1 != end1 && it2 != end2) { while (it1 != end1 && it2 != end2) {
int addition = *it1 + *it2 + carry; int addition = *it1 + *it2 + carry;
carry = addition / 10; carry = addition / BASE;
res.push_back(addition % 10); res.push_back(addition % BASE);
++it1; ++it1;
++it2; ++it2;
} }
@ -45,8 +47,8 @@ digits_type do_addition(digits_type const& lhs, digits_type const& rhs) {
while (it != end) { while (it != end) {
int addition = *it + carry; int addition = *it + carry;
carry = addition / 10; carry = addition / BASE;
res.push_back(addition % 10); res.push_back(addition % BASE);
++it; ++it;
} }
@ -77,8 +79,8 @@ digits_type do_multiplication(digits_type const& lhs, digits_type const& rhs) {
for (std::size_t j = 0; j < rhs.size(); ++j) { for (std::size_t j = 0; j < rhs.size(); ++j) {
int multiplication = lhs[i] * rhs[j]; int multiplication = lhs[i] * rhs[j];
res[i + j] += multiplication + carry; res[i + j] += multiplication + carry;
carry = res[i + j] / 10; carry = res[i + j] / BASE;
res[i + j] %= 10; res[i + j] %= BASE;
} }
res[i + rhs.size()] += carry; res[i + rhs.size()] += carry;
} }
@ -101,8 +103,8 @@ BigNum::BigNum(std::int64_t number) {
auto abs = static_cast<std::uint64_t>(std::abs(number)); auto abs = static_cast<std::uint64_t>(std::abs(number));
do { do {
digits_.push_back(abs % 10); digits_.push_back(abs % BASE);
abs /= 10; abs /= BASE;
} while (abs); } while (abs);
assert(is_canonicalized()); assert(is_canonicalized());
@ -266,7 +268,7 @@ bool BigNum::is_canonicalized() const {
} }
auto const overflow = std::find_if(digits_.begin(), digits_.end(), auto const overflow = std::find_if(digits_.begin(), digits_.end(),
[](auto v) { return v >= 10; }); [](auto v) { return v >= BASE; });
if (overflow != digits_.end()) { if (overflow != digits_.end()) {
return false; return false;
} }