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Pretty fast KPK endgame table generator
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Pretty fast KPK endgame table generator

Solve the endgame with King and Pawn vs. King and make the result available through a probing function call interface. For use in chess programs and provided under a 2-clause BSD-style license. See the file `LICENSE' for details.

This implementation is quite fast because it handles the superposition of possible black king locations per step.

kpkGenerate CPU time [seconds]: 0.001582
kpkTable size [bytes]: 32768
kpkSelfCheck: OK
kpkProbe 26/26: OK

The implementation is agnostic to board geometry. See the file `kpk.h' for instructions on how to adapt to an alternative square indexing.

Distance to conversion (DTC) is not provided, but is trivial to add. Please contact the author if you need advice.

Tested using several combinations of System : Linux/Ubuntu 14.04, FreeBSD 9.0, Raspberry Pi, OSX 10.10.5 Hardware : i7-3720QM, i7-5960X, FX-8350, ARMv6, ARMv7 Compiler : gcc, clang


 *  Probe a KPK position from the in memory endgame table.
 *  Returns 0 for draw, 1 for win and -1 for loss.
 *  The position must be legal for meaningful results.
 *  `side' is 0 for white to move and 1 for black to move.
 *  If the table has not been generated yet, this will be
 *  done automatically at the first invocation.
int kpkProbe(int side, int wKing, int wPawn, int bKing);

 *  Explicitly generate the KPK table.
 *  Returns the memory size for info.
 *  This can take up to 2 milliseconds on a 2.6GHz Intel i7.
int kpkGenerate(void);

 *  Perform a self check on the bitbase.
 *  Returns 0 on failure, 1 for success.
int kpkSelfCheck(void);
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