1
0
Fork 0
mirror of https://github.com/bolero-MURAKAMI/Sprout synced 2024-11-12 21:09:01 +00:00
Sprout/sprout/random/shuffle_order.hpp
2013-08-07 00:15:09 +09:00

202 lines
7.2 KiB
C++

#ifndef SPROUT_RANDOM_SHUFFLE_ORDER_HPP
#define SPROUT_RANDOM_SHUFFLE_ORDER_HPP
#include <cstddef>
#include <cstdint>
#include <ios>
#include <istream>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/limits.hpp>
#include <sprout/array/array.hpp>
#include <sprout/operation/fixed/set.hpp>
#include <sprout/math/compare.hpp>
#include <sprout/random/random_result.hpp>
#include <sprout/random/linear_congruential.hpp>
#include <sprout/random/detail/signed_unsigned_tools.hpp>
#include <sprout/assert.hpp>
namespace sprout {
namespace random {
namespace detail {
template<typename UniformRandomNumberGenerator, std::size_t k>
class shuffle_order_engine_member {
protected:
typedef UniformRandomNumberGenerator base_type;
typedef typename base_type::result_type result_type;
public:
base_type rng_;
sprout::array<result_type, k> v_;
result_type y_;
};
} // namespace detail
//
// shuffle_order_engine
//
template<typename UniformRandomNumberGenerator, std::size_t k>
class shuffle_order_engine
: private sprout::random::detail::shuffle_order_engine_member<UniformRandomNumberGenerator, k>
{
static_assert(
sprout::numeric_limits<typename UniformRandomNumberGenerator::result_type>::is_integer,
"sprout::numeric_limits<typename UniformRandomNumberGenerator::result_type>::is_integer"
);
static_assert(k > 0, "k > 0");
private:
typedef sprout::random::detail::shuffle_order_engine_member<UniformRandomNumberGenerator, k> member_type;
public:
typedef UniformRandomNumberGenerator base_type;
typedef typename base_type::result_type result_type;
private:
struct private_constructor_tag {};
public:
SPROUT_STATIC_CONSTEXPR std::size_t buffer_size = k;
SPROUT_STATIC_CONSTEXPR std::size_t table_size = k;
public:
static SPROUT_CONSTEXPR result_type static_min() SPROUT_NOEXCEPT {
return base_type::static_min();
}
static SPROUT_CONSTEXPR result_type static_max() SPROUT_NOEXCEPT {
return base_type::static_max();
}
private:
template<typename Random, typename... Args>
static SPROUT_CONSTEXPR typename std::enable_if<
sizeof...(Args) == k,
member_type
>::type init_member_1(Random const& rnd, Args const&... args) {
return member_type{
rnd.engine(),
sprout::array<result_type, k>{{args...}},
rnd.result()
};
}
template<typename Random, typename... Args>
static SPROUT_CONSTEXPR typename std::enable_if<
sizeof...(Args) < k,
member_type
>::type init_member_1(Random const& rnd, Args const&... args) {
return init_member_1(rnd(), args..., rnd.result());
}
static SPROUT_CONSTEXPR member_type init_member(base_type const& rng) {
return init_member_1(rng());
}
private:
using member_type::rng_;
using member_type::v_;
using member_type::y_;
private:
SPROUT_CONSTEXPR shuffle_order_engine(
base_type const& rng,
sprout::array<result_type, k> const& v,
result_type const& y,
private_constructor_tag
)
: member_type{rng, v, y}
{}
template<typename Random, typename BaseUnsigned>
SPROUT_CONSTEXPR sprout::random::random_result<shuffle_order_engine>
generate_1(Random const& rnd, BaseUnsigned j) const {
return sprout::random::random_result<shuffle_order_engine>(
v_[j],
shuffle_order_engine(
rnd.engine(),
sprout::fixed::set(v_, j, rnd.result()),
v_[j],
private_constructor_tag()
)
);
}
template<typename BaseUnsigned>
SPROUT_CONSTEXPR sprout::random::random_result<shuffle_order_engine>
generate(BaseUnsigned brange, BaseUnsigned off) const {
return generate_1(
rng_(),
k == 1 ? BaseUnsigned(0)
: sprout::math::less(brange, sprout::numeric_limits<BaseUnsigned>::max() / k) ? BaseUnsigned(k * off / (brange + 1))
: sprout::math::less(brange, sprout::numeric_limits<std::uintmax_t>::max() / k)
? static_cast<BaseUnsigned>(static_cast<std::uintmax_t>(off) * k / (static_cast<std::uintmax_t>(brange) + 1))
//: static_cast<BaseUnsigned>(sprout::random::detail::muldiv(off, k, static_cast<std::uintmax_t>(brange) + 1)) // ???
: (SPROUT_ASSERT_MSG(0, "Sorry, not implemented."), sprout::random::random_result<shuffle_order_engine>())
);
}
public:
SPROUT_CONSTEXPR shuffle_order_engine()
: member_type(init_member(base_type()))
{}
explicit SPROUT_CONSTEXPR shuffle_order_engine(result_type const& s)
: member_type(init_member(base_type(s)))
{}
explicit SPROUT_CONSTEXPR shuffle_order_engine(base_type const& rng)
: member_type(init_member(rng))
{}
SPROUT_CONSTEXPR result_type min() const SPROUT_NOEXCEPT {
return rng_.min();
}
SPROUT_CONSTEXPR result_type max() const SPROUT_NOEXCEPT {
return rng_.max();
}
SPROUT_CONSTEXPR sprout::random::random_result<shuffle_order_engine> operator()() const {
typedef typename std::make_unsigned<result_type>::type base_unsigned;
return generate(
base_unsigned(sprout::random::detail::subtract<result_type>()(max(), min())),
base_unsigned(sprout::random::detail::subtract<result_type>()(y_, min()))
);
}
SPROUT_CONSTEXPR base_type const& base() const SPROUT_NOEXCEPT {
return rng_;
}
friend SPROUT_CONSTEXPR bool operator==(shuffle_order_engine const& lhs, shuffle_order_engine const& rhs) SPROUT_NOEXCEPT {
return lhs.rng_ == rhs.rng_ && lhs.y_ == rhs.y_ && lhs.v_ == rhs.v_;
}
friend SPROUT_CONSTEXPR bool operator!=(shuffle_order_engine const& lhs, shuffle_order_engine const& rhs) SPROUT_NOEXCEPT {
return !(lhs == rhs);
}
template<typename Elem, typename Traits>
friend std::basic_istream<Elem, Traits>& operator>>(
std::basic_istream<Elem, Traits>& lhs,
shuffle_order_engine& rhs
)
{
lhs >> rhs.rng_;
for (std::size_t i = 0; i < k; ++i) {
lhs >> std::ws >> rhs.v_[i];
}
lhs >> std::ws >> rhs.y_;
return lhs;
}
template<typename Elem, typename Traits>
friend std::basic_ostream<Elem, Traits>& operator<<(
std::basic_ostream<Elem, Traits>& lhs,
shuffle_order_engine const& rhs
)
{
lhs << rhs.rng_;
for (std::size_t i = 0; i < k; ++i) {
lhs << ' ' << rhs.v_[i];
}
lhs << ' ' << rhs.y_;
return lhs;
}
};
template<typename UniformRandomNumberGenerator, std::size_t k>
SPROUT_CONSTEXPR_OR_CONST std::size_t sprout::random::shuffle_order_engine<UniformRandomNumberGenerator, k>::buffer_size;
template<typename UniformRandomNumberGenerator, std::size_t k>
SPROUT_CONSTEXPR_OR_CONST std::size_t sprout::random::shuffle_order_engine<UniformRandomNumberGenerator, k>::table_size;
//
// knuth_b
//
typedef sprout::random::shuffle_order_engine<sprout::random::minstd_rand0, 256> knuth_b;
//
// kreutzer1986
//
typedef sprout::random::shuffle_order_engine<sprout::random::linear_congruential_engine<std::uint32_t, 1366, 150889, 714025>, 97> kreutzer1986;
} // namespace random
using sprout::random::shuffle_order_engine;
using sprout::random::knuth_b;
using sprout::random::kreutzer1986;
} // namespace sprout
#endif // #ifndef SPROUT_RANDOM_SHUFFLE_ORDER_HPP