ParityBitEntries
Declared in astar/PatternDatabase.h; the same class on the site of Doxygen.
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class ParityBitEntries
the entries of a pattern table, the second bit of the distance, eight in a byte
With the blank ignored, every move of the abstraction costs 1 and changes the Manhattan distance m of the pattern by one unit, so that the distance h has the parity of m and two neighbours differ by exactly one; hence the bit \( \lfloor h / 2 \rfloor \bmod 2 \) and the parity of m give h modulo 4, which tells \( +1 \) from \( -1 \). This is the 1-bit encoding of Clausecker and Reinefeld (SoCS 2019); like Mod3Entries, its values are relative [see Mod3Entries].
Public Functions
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inline int residue(std::uint64_t r, int m) const noexcept
the residue modulo 4 of the distance of the rank r, whose placement has Manhattan distance m
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inline std::uint64_t entries(void) const noexcept
the number of the entries
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inline std::size_t bytes(void) const noexcept
the bytes of the entries
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inline std::vector<std::uint8_t> payload(void) const
the bytes written in a file
Public Static Functions
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template<class M>
static inline ParityBitEntries encode( - const std::vector<std::uint8_t> &h,
- M &&m,
- unsigned = 1
the encoding of the distances h
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static inline ParityBitEntries decode(std::vector<std::uint8_t> data, std::uint64_t n, unsigned = 1)
the encoding of n entries read from a file
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inline int residue(std::uint64_t r, int m) const noexcept