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prime approximation function for a range

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This commit is contained in:
Matt Borland
2020-09-26 22:18:54 -05:00
parent 66c2642683
commit de1f331ebc
1 changed files with 7 additions and 1 deletions
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8
include/boost/math/special_functions/prime_sieve.hpp
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@@ -235,12 +235,18 @@ void sequential_segmented_sieve(Integer lower_bound, Integer upper_bound, Contai
} // End namespace detail
template<class Integer>
constexpr Integer prime_approximation(Integer upper_bound)
constexpr Integer prime_approximation(const Integer upper_bound)
{
constexpr auto c = 30 * std::log(113) / 113; // Magic numbers from wikipedia
return static_cast<Integer>(std::floor(c * upper_bound / std::log(static_cast<double>(upper_bound))));
}
template<class Integer>
constexpr Integer prime_approximation(const Integer lower_bound, const Integer upper_bound)
{
return prime_approximation(upper_bound) - prime_approximation(lower_bound);
}
template<class Integer>
constexpr void prime_reserve(Integer upper_bound, std::vector<Integer> &prime_container)
{