Mod3Entries Class Reference

the entries of a pattern table, the distance modulo 3, five in a byte More...

#include <PBeFS/astar/PatternDatabase.h>

Public Member Functions
int	residue (std::uint64_t r, int) const noexcept
	the residue modulo 3 of the distance of the rank r, whose placement has Manhattan distance m
std::uint64_t	entries (void) const noexcept
	the number of the entries
std::size_t	bytes (void) const noexcept
	the bytes of the entries
std::vector< std::uint8_t >	payload (void) const
	the bytes written in a file

Static Public Member Functions
template<class M>
static Mod3Entries	encode (const std::vector< std::uint8_t > &h, M &&, unsigned=1)
	the encoding of the distances h
static Mod3Entries	decode (std::vector< std::uint8_t > data, std::uint64_t n, unsigned=1)
	the encoding of n entries read from a file

Static Public Attributes
static constexpr std::uint32_t	code = 3
	the code in a file
static constexpr const char *	name = "mod3"
	the name
static constexpr bool	relative = true
	relative values
static constexpr int	modulus = 3
	values modulo 3

Detailed Description

the entries of a pattern table, the distance modulo 3, five in a byte

The byte holds \( \sum_{j < 5} x_j 3^j \) for the residues \( x_j \) of five consecutive ranks, i.e., \( 8 / 5 = 1.6 \) bits per entry (Breyer and Korf, AAAI 2010). The value of a placement is not stored: it is that of a neighbour plus the difference of the residues [see AdditivePDB::delta()], or it is found from the residues alone by a descent to the goal [see PatternTable::exact()]; both need a table whose neighbours differ by at most one, i.e., with the blank ignored.

Member Function Documentation

bytes()

std::size_t bytes ( void ) const

inlinenodiscardnoexcept

the bytes of the entries

decode()

Mod3Entries decode ( std::vector< std::uint8_t > data, std::uint64_t n, unsigned = 1 )

inlinestaticnodiscard

the encoding of n entries read from a file

encode()

template<class M>

Mod3Entries encode ( const std::vector< std::uint8_t > & h, M && , unsigned = 1 )

inlinestaticnodiscard

the encoding of the distances h

entries()

std::uint64_t entries ( void ) const

inlinenodiscardnoexcept

the number of the entries

payload()

std::vector< std::uint8_t > payload ( void ) const

inlinenodiscard

the bytes written in a file

residue()

int residue ( std::uint64_t r, int  ) const

inlinenodiscardnoexcept

the residue modulo 3 of the distance of the rank r, whose placement has Manhattan distance m

Member Data Documentation

code

std::uint32_t code = 3

staticconstexpr

the code in a file

modulus

int modulus = 3

staticconstexpr

values modulo 3

name

const char* name = "mod3"

staticconstexpr

the name

relative

bool relative = true

staticconstexpr

relative values

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The documentation for this class was generated from the following file:

• PBeFS/astar/PatternDatabase.h