book.cpp

// Format from HG Muller's documentation http://hgm.nubati.net/book_format.html

/*
book file source:

Human.bin, Titans.bin - Deep Saros engine https://digilander.libero.it/taioscacchi/programmi/saros-page.html
Book.bin - Ed Schröder's million base https://web.archive.org/web/20180104204744/http://top-5000.nl/pgn.htm, filtered with SCID, process from video https://www.youtube.com/watch?v=rskcUNoirPU

*/

#include <cassert>
#include <cmath>
#include <iostream>

#include "bitboard.h"
#include "book.h"
#include "movegen.h"
#include "move.h"

using ull = unsigned long long;

const ull RANDOM[781] = {
   0x9D39247E33776D41ULL, 0x2AF7398005AAA5C7ULL, 0x44DB015024623547ULL, 0x9C15F73E62A76AE2ULL,
   0x75834465489C0C89ULL, 0x3290AC3A203001BFULL, 0x0FBBAD1F61042279ULL, 0xE83A908FF2FB60CAULL,
   0x0D7E765D58755C10ULL, 0x1A083822CEAFE02DULL, 0x9605D5F0E25EC3B0ULL, 0xD021FF5CD13A2ED5ULL,
   0x40BDF15D4A672E32ULL, 0x011355146FD56395ULL, 0x5DB4832046F3D9E5ULL, 0x239F8B2D7FF719CCULL,
   0x05D1A1AE85B49AA1ULL, 0x679F848F6E8FC971ULL, 0x7449BBFF801FED0BULL, 0x7D11CDB1C3B7ADF0ULL,
   0x82C7709E781EB7CCULL, 0xF3218F1C9510786CULL, 0x331478F3AF51BBE6ULL, 0x4BB38DE5E7219443ULL,
   0xAA649C6EBCFD50FCULL, 0x8DBD98A352AFD40BULL, 0x87D2074B81D79217ULL, 0x19F3C751D3E92AE1ULL,
   0xB4AB30F062B19ABFULL, 0x7B0500AC42047AC4ULL, 0xC9452CA81A09D85DULL, 0x24AA6C514DA27500ULL,
   0x4C9F34427501B447ULL, 0x14A68FD73C910841ULL, 0xA71B9B83461CBD93ULL, 0x03488B95B0F1850FULL,
   0x637B2B34FF93C040ULL, 0x09D1BC9A3DD90A94ULL, 0x3575668334A1DD3BULL, 0x735E2B97A4C45A23ULL,
   0x18727070F1BD400BULL, 0x1FCBACD259BF02E7ULL, 0xD310A7C2CE9B6555ULL, 0xBF983FE0FE5D8244ULL,
   0x9F74D14F7454A824ULL, 0x51EBDC4AB9BA3035ULL, 0x5C82C505DB9AB0FAULL, 0xFCF7FE8A3430B241ULL,
   0x3253A729B9BA3DDEULL, 0x8C74C368081B3075ULL, 0xB9BC6C87167C33E7ULL, 0x7EF48F2B83024E20ULL,
   0x11D505D4C351BD7FULL, 0x6568FCA92C76A243ULL, 0x4DE0B0F40F32A7B8ULL, 0x96D693460CC37E5DULL,
   0x42E240CB63689F2FULL, 0x6D2BDCDAE2919661ULL, 0x42880B0236E4D951ULL, 0x5F0F4A5898171BB6ULL,
   0x39F890F579F92F88ULL, 0x93C5B5F47356388BULL, 0x63DC359D8D231B78ULL, 0xEC16CA8AEA98AD76ULL,
   0x5355F900C2A82DC7ULL, 0x07FB9F855A997142ULL, 0x5093417AA8A7ED5EULL, 0x7BCBC38DA25A7F3CULL,
   0x19FC8A768CF4B6D4ULL, 0x637A7780DECFC0D9ULL, 0x8249A47AEE0E41F7ULL, 0x79AD695501E7D1E8ULL,
   0x14ACBAF4777D5776ULL, 0xF145B6BECCDEA195ULL, 0xDABF2AC8201752FCULL, 0x24C3C94DF9C8D3F6ULL,
   0xBB6E2924F03912EAULL, 0x0CE26C0B95C980D9ULL, 0xA49CD132BFBF7CC4ULL, 0xE99D662AF4243939ULL,
   0x27E6AD7891165C3FULL, 0x8535F040B9744FF1ULL, 0x54B3F4FA5F40D873ULL, 0x72B12C32127FED2BULL,
   0xEE954D3C7B411F47ULL, 0x9A85AC909A24EAA1ULL, 0x70AC4CD9F04F21F5ULL, 0xF9B89D3E99A075C2ULL,
   0x87B3E2B2B5C907B1ULL, 0xA366E5B8C54F48B8ULL, 0xAE4A9346CC3F7CF2ULL, 0x1920C04D47267BBDULL,
   0x87BF02C6B49E2AE9ULL, 0x092237AC237F3859ULL, 0xFF07F64EF8ED14D0ULL, 0x8DE8DCA9F03CC54EULL,
   0x9C1633264DB49C89ULL, 0xB3F22C3D0B0B38EDULL, 0x390E5FB44D01144BULL, 0x5BFEA5B4712768E9ULL,
   0x1E1032911FA78984ULL, 0x9A74ACB964E78CB3ULL, 0x4F80F7A035DAFB04ULL, 0x6304D09A0B3738C4ULL,
   0x2171E64683023A08ULL, 0x5B9B63EB9CEFF80CULL, 0x506AACF489889342ULL, 0x1881AFC9A3A701D6ULL,
   0x6503080440750644ULL, 0xDFD395339CDBF4A7ULL, 0xEF927DBCF00C20F2ULL, 0x7B32F7D1E03680ECULL,
   0xB9FD7620E7316243ULL, 0x05A7E8A57DB91B77ULL, 0xB5889C6E15630A75ULL, 0x4A750A09CE9573F7ULL,
   0xCF464CEC899A2F8AULL, 0xF538639CE705B824ULL, 0x3C79A0FF5580EF7FULL, 0xEDE6C87F8477609DULL,
   0x799E81F05BC93F31ULL, 0x86536B8CF3428A8CULL, 0x97D7374C60087B73ULL, 0xA246637CFF328532ULL,
   0x043FCAE60CC0EBA0ULL, 0x920E449535DD359EULL, 0x70EB093B15B290CCULL, 0x73A1921916591CBDULL,
   0x56436C9FE1A1AA8DULL, 0xEFAC4B70633B8F81ULL, 0xBB215798D45DF7AFULL, 0x45F20042F24F1768ULL,
   0x930F80F4E8EB7462ULL, 0xFF6712FFCFD75EA1ULL, 0xAE623FD67468AA70ULL, 0xDD2C5BC84BC8D8FCULL,
   0x7EED120D54CF2DD9ULL, 0x22FE545401165F1CULL, 0xC91800E98FB99929ULL, 0x808BD68E6AC10365ULL,
   0xDEC468145B7605F6ULL, 0x1BEDE3A3AEF53302ULL, 0x43539603D6C55602ULL, 0xAA969B5C691CCB7AULL,
   0xA87832D392EFEE56ULL, 0x65942C7B3C7E11AEULL, 0xDED2D633CAD004F6ULL, 0x21F08570F420E565ULL,
   0xB415938D7DA94E3CULL, 0x91B859E59ECB6350ULL, 0x10CFF333E0ED804AULL, 0x28AED140BE0BB7DDULL,
   0xC5CC1D89724FA456ULL, 0x5648F680F11A2741ULL, 0x2D255069F0B7DAB3ULL, 0x9BC5A38EF729ABD4ULL,
   0xEF2F054308F6A2BCULL, 0xAF2042F5CC5C2858ULL, 0x480412BAB7F5BE2AULL, 0xAEF3AF4A563DFE43ULL,
   0x19AFE59AE451497FULL, 0x52593803DFF1E840ULL, 0xF4F076E65F2CE6F0ULL, 0x11379625747D5AF3ULL,
   0xBCE5D2248682C115ULL, 0x9DA4243DE836994FULL, 0x066F70B33FE09017ULL, 0x4DC4DE189B671A1CULL,
   0x51039AB7712457C3ULL, 0xC07A3F80C31FB4B4ULL, 0xB46EE9C5E64A6E7CULL, 0xB3819A42ABE61C87ULL,
   0x21A007933A522A20ULL, 0x2DF16F761598AA4FULL, 0x763C4A1371B368FDULL, 0xF793C46702E086A0ULL,
   0xD7288E012AEB8D31ULL, 0xDE336A2A4BC1C44BULL, 0x0BF692B38D079F23ULL, 0x2C604A7A177326B3ULL,
   0x4850E73E03EB6064ULL, 0xCFC447F1E53C8E1BULL, 0xB05CA3F564268D99ULL, 0x9AE182C8BC9474E8ULL,
   0xA4FC4BD4FC5558CAULL, 0xE755178D58FC4E76ULL, 0x69B97DB1A4C03DFEULL, 0xF9B5B7C4ACC67C96ULL,
   0xFC6A82D64B8655FBULL, 0x9C684CB6C4D24417ULL, 0x8EC97D2917456ED0ULL, 0x6703DF9D2924E97EULL,
   0xC547F57E42A7444EULL, 0x78E37644E7CAD29EULL, 0xFE9A44E9362F05FAULL, 0x08BD35CC38336615ULL,
   0x9315E5EB3A129ACEULL, 0x94061B871E04DF75ULL, 0xDF1D9F9D784BA010ULL, 0x3BBA57B68871B59DULL,
   0xD2B7ADEEDED1F73FULL, 0xF7A255D83BC373F8ULL, 0xD7F4F2448C0CEB81ULL, 0xD95BE88CD210FFA7ULL,
   0x336F52F8FF4728E7ULL, 0xA74049DAC312AC71ULL, 0xA2F61BB6E437FDB5ULL, 0x4F2A5CB07F6A35B3ULL,
   0x87D380BDA5BF7859ULL, 0x16B9F7E06C453A21ULL, 0x7BA2484C8A0FD54EULL, 0xF3A678CAD9A2E38CULL,
   0x39B0BF7DDE437BA2ULL, 0xFCAF55C1BF8A4424ULL, 0x18FCF680573FA594ULL, 0x4C0563B89F495AC3ULL,
   0x40E087931A00930DULL, 0x8CFFA9412EB642C1ULL, 0x68CA39053261169FULL, 0x7A1EE967D27579E2ULL,
   0x9D1D60E5076F5B6FULL, 0x3810E399B6F65BA2ULL, 0x32095B6D4AB5F9B1ULL, 0x35CAB62109DD038AULL,
   0xA90B24499FCFAFB1ULL, 0x77A225A07CC2C6BDULL, 0x513E5E634C70E331ULL, 0x4361C0CA3F692F12ULL,
   0xD941ACA44B20A45BULL, 0x528F7C8602C5807BULL, 0x52AB92BEB9613989ULL, 0x9D1DFA2EFC557F73ULL,
   0x722FF175F572C348ULL, 0x1D1260A51107FE97ULL, 0x7A249A57EC0C9BA2ULL, 0x04208FE9E8F7F2D6ULL,
   0x5A110C6058B920A0ULL, 0x0CD9A497658A5698ULL, 0x56FD23C8F9715A4CULL, 0x284C847B9D887AAEULL,
   0x04FEABFBBDB619CBULL, 0x742E1E651C60BA83ULL, 0x9A9632E65904AD3CULL, 0x881B82A13B51B9E2ULL,
   0x506E6744CD974924ULL, 0xB0183DB56FFC6A79ULL, 0x0ED9B915C66ED37EULL, 0x5E11E86D5873D484ULL,
   0xF678647E3519AC6EULL, 0x1B85D488D0F20CC5ULL, 0xDAB9FE6525D89021ULL, 0x0D151D86ADB73615ULL,
   0xA865A54EDCC0F019ULL, 0x93C42566AEF98FFBULL, 0x99E7AFEABE000731ULL, 0x48CBFF086DDF285AULL,
   0x7F9B6AF1EBF78BAFULL, 0x58627E1A149BBA21ULL, 0x2CD16E2ABD791E33ULL, 0xD363EFF5F0977996ULL,
   0x0CE2A38C344A6EEDULL, 0x1A804AADB9CFA741ULL, 0x907F30421D78C5DEULL, 0x501F65EDB3034D07ULL,
   0x37624AE5A48FA6E9ULL, 0x957BAF61700CFF4EULL, 0x3A6C27934E31188AULL, 0xD49503536ABCA345ULL,
   0x088E049589C432E0ULL, 0xF943AEE7FEBF21B8ULL, 0x6C3B8E3E336139D3ULL, 0x364F6FFA464EE52EULL,
   0xD60F6DCEDC314222ULL, 0x56963B0DCA418FC0ULL, 0x16F50EDF91E513AFULL, 0xEF1955914B609F93ULL,
   0x565601C0364E3228ULL, 0xECB53939887E8175ULL, 0xBAC7A9A18531294BULL, 0xB344C470397BBA52ULL,
   0x65D34954DAF3CEBDULL, 0xB4B81B3FA97511E2ULL, 0xB422061193D6F6A7ULL, 0x071582401C38434DULL,
   0x7A13F18BBEDC4FF5ULL, 0xBC4097B116C524D2ULL, 0x59B97885E2F2EA28ULL, 0x99170A5DC3115544ULL,
   0x6F423357E7C6A9F9ULL, 0x325928EE6E6F8794ULL, 0xD0E4366228B03343ULL, 0x565C31F7DE89EA27ULL,
   0x30F5611484119414ULL, 0xD873DB391292ED4FULL, 0x7BD94E1D8E17DEBCULL, 0xC7D9F16864A76E94ULL,
   0x947AE053EE56E63CULL, 0xC8C93882F9475F5FULL, 0x3A9BF55BA91F81CAULL, 0xD9A11FBB3D9808E4ULL,
   0x0FD22063EDC29FCAULL, 0xB3F256D8ACA0B0B9ULL, 0xB03031A8B4516E84ULL, 0x35DD37D5871448AFULL,
   0xE9F6082B05542E4EULL, 0xEBFAFA33D7254B59ULL, 0x9255ABB50D532280ULL, 0xB9AB4CE57F2D34F3ULL,
   0x693501D628297551ULL, 0xC62C58F97DD949BFULL, 0xCD454F8F19C5126AULL, 0xBBE83F4ECC2BDECBULL,
   0xDC842B7E2819E230ULL, 0xBA89142E007503B8ULL, 0xA3BC941D0A5061CBULL, 0xE9F6760E32CD8021ULL,
   0x09C7E552BC76492FULL, 0x852F54934DA55CC9ULL, 0x8107FCCF064FCF56ULL, 0x098954D51FFF6580ULL,
   0x23B70EDB1955C4BFULL, 0xC330DE426430F69DULL, 0x4715ED43E8A45C0AULL, 0xA8D7E4DAB780A08DULL,
   0x0572B974F03CE0BBULL, 0xB57D2E985E1419C7ULL, 0xE8D9ECBE2CF3D73FULL, 0x2FE4B17170E59750ULL,
   0x11317BA87905E790ULL, 0x7FBF21EC8A1F45ECULL, 0x1725CABFCB045B00ULL, 0x964E915CD5E2B207ULL,
   0x3E2B8BCBF016D66DULL, 0xBE7444E39328A0ACULL, 0xF85B2B4FBCDE44B7ULL, 0x49353FEA39BA63B1ULL,
   0x1DD01AAFCD53486AULL, 0x1FCA8A92FD719F85ULL, 0xFC7C95D827357AFAULL, 0x18A6A990C8B35EBDULL,
   0xCCCB7005C6B9C28DULL, 0x3BDBB92C43B17F26ULL, 0xAA70B5B4F89695A2ULL, 0xE94C39A54A98307FULL,
   0xB7A0B174CFF6F36EULL, 0xD4DBA84729AF48ADULL, 0x2E18BC1AD9704A68ULL, 0x2DE0966DAF2F8B1CULL,
   0xB9C11D5B1E43A07EULL, 0x64972D68DEE33360ULL, 0x94628D38D0C20584ULL, 0xDBC0D2B6AB90A559ULL,
   0xD2733C4335C6A72FULL, 0x7E75D99D94A70F4DULL, 0x6CED1983376FA72BULL, 0x97FCAACBF030BC24ULL,
   0x7B77497B32503B12ULL, 0x8547EDDFB81CCB94ULL, 0x79999CDFF70902CBULL, 0xCFFE1939438E9B24ULL,
   0x829626E3892D95D7ULL, 0x92FAE24291F2B3F1ULL, 0x63E22C147B9C3403ULL, 0xC678B6D860284A1CULL,
   0x5873888850659AE7ULL, 0x0981DCD296A8736DULL, 0x9F65789A6509A440ULL, 0x9FF38FED72E9052FULL,
   0xE479EE5B9930578CULL, 0xE7F28ECD2D49EECDULL, 0x56C074A581EA17FEULL, 0x5544F7D774B14AEFULL,
   0x7B3F0195FC6F290FULL, 0x12153635B2C0CF57ULL, 0x7F5126DBBA5E0CA7ULL, 0x7A76956C3EAFB413ULL,
   0x3D5774A11D31AB39ULL, 0x8A1B083821F40CB4ULL, 0x7B4A38E32537DF62ULL, 0x950113646D1D6E03ULL,
   0x4DA8979A0041E8A9ULL, 0x3BC36E078F7515D7ULL, 0x5D0A12F27AD310D1ULL, 0x7F9D1A2E1EBE1327ULL,
   0xDA3A361B1C5157B1ULL, 0xDCDD7D20903D0C25ULL, 0x36833336D068F707ULL, 0xCE68341F79893389ULL,
   0xAB9090168DD05F34ULL, 0x43954B3252DC25E5ULL, 0xB438C2B67F98E5E9ULL, 0x10DCD78E3851A492ULL,
   0xDBC27AB5447822BFULL, 0x9B3CDB65F82CA382ULL, 0xB67B7896167B4C84ULL, 0xBFCED1B0048EAC50ULL,
   0xA9119B60369FFEBDULL, 0x1FFF7AC80904BF45ULL, 0xAC12FB171817EEE7ULL, 0xAF08DA9177DDA93DULL,
   0x1B0CAB936E65C744ULL, 0xB559EB1D04E5E932ULL, 0xC37B45B3F8D6F2BAULL, 0xC3A9DC228CAAC9E9ULL,
   0xF3B8B6675A6507FFULL, 0x9FC477DE4ED681DAULL, 0x67378D8ECCEF96CBULL, 0x6DD856D94D259236ULL,
   0xA319CE15B0B4DB31ULL, 0x073973751F12DD5EULL, 0x8A8E849EB32781A5ULL, 0xE1925C71285279F5ULL,
   0x74C04BF1790C0EFEULL, 0x4DDA48153C94938AULL, 0x9D266D6A1CC0542CULL, 0x7440FB816508C4FEULL,
   0x13328503DF48229FULL, 0xD6BF7BAEE43CAC40ULL, 0x4838D65F6EF6748FULL, 0x1E152328F3318DEAULL,
   0x8F8419A348F296BFULL, 0x72C8834A5957B511ULL, 0xD7A023A73260B45CULL, 0x94EBC8ABCFB56DAEULL,
   0x9FC10D0F989993E0ULL, 0xDE68A2355B93CAE6ULL, 0xA44CFE79AE538BBEULL, 0x9D1D84FCCE371425ULL,
   0x51D2B1AB2DDFB636ULL, 0x2FD7E4B9E72CD38CULL, 0x65CA5B96B7552210ULL, 0xDD69A0D8AB3B546DULL,
   0x604D51B25FBF70E2ULL, 0x73AA8A564FB7AC9EULL, 0x1A8C1E992B941148ULL, 0xAAC40A2703D9BEA0ULL,
   0x764DBEAE7FA4F3A6ULL, 0x1E99B96E70A9BE8BULL, 0x2C5E9DEB57EF4743ULL, 0x3A938FEE32D29981ULL,
   0x26E6DB8FFDF5ADFEULL, 0x469356C504EC9F9DULL, 0xC8763C5B08D1908CULL, 0x3F6C6AF859D80055ULL,
   0x7F7CC39420A3A545ULL, 0x9BFB227EBDF4C5CEULL, 0x89039D79D6FC5C5CULL, 0x8FE88B57305E2AB6ULL,
   0xA09E8C8C35AB96DEULL, 0xFA7E393983325753ULL, 0xD6B6D0ECC617C699ULL, 0xDFEA21EA9E7557E3ULL,
   0xB67C1FA481680AF8ULL, 0xCA1E3785A9E724E5ULL, 0x1CFC8BED0D681639ULL, 0xD18D8549D140CAEAULL,
   0x4ED0FE7E9DC91335ULL, 0xE4DBF0634473F5D2ULL, 0x1761F93A44D5AEFEULL, 0x53898E4C3910DA55ULL,
   0x734DE8181F6EC39AULL, 0x2680B122BAA28D97ULL, 0x298AF231C85BAFABULL, 0x7983EED3740847D5ULL,
   0x66C1A2A1A60CD889ULL, 0x9E17E49642A3E4C1ULL, 0xEDB454E7BADC0805ULL, 0x50B704CAB602C329ULL,
   0x4CC317FB9CDDD023ULL, 0x66B4835D9EAFEA22ULL, 0x219B97E26FFC81BDULL, 0x261E4E4C0A333A9DULL,
   0x1FE2CCA76517DB90ULL, 0xD7504DFA8816EDBBULL, 0xB9571FA04DC089C8ULL, 0x1DDC0325259B27DEULL,
   0xCF3F4688801EB9AAULL, 0xF4F5D05C10CAB243ULL, 0x38B6525C21A42B0EULL, 0x36F60E2BA4FA6800ULL,
   0xEB3593803173E0CEULL, 0x9C4CD6257C5A3603ULL, 0xAF0C317D32ADAA8AULL, 0x258E5A80C7204C4BULL,
   0x8B889D624D44885DULL, 0xF4D14597E660F855ULL, 0xD4347F66EC8941C3ULL, 0xE699ED85B0DFB40DULL,
   0x2472F6207C2D0484ULL, 0xC2A1E7B5B459AEB5ULL, 0xAB4F6451CC1D45ECULL, 0x63767572AE3D6174ULL,
   0xA59E0BD101731A28ULL, 0x116D0016CB948F09ULL, 0x2CF9C8CA052F6E9FULL, 0x0B090A7560A968E3ULL,
   0xABEEDDB2DDE06FF1ULL, 0x58EFC10B06A2068DULL, 0xC6E57A78FBD986E0ULL, 0x2EAB8CA63CE802D7ULL,
   0x14A195640116F336ULL, 0x7C0828DD624EC390ULL, 0xD74BBE77E6116AC7ULL, 0x804456AF10F5FB53ULL,
   0xEBE9EA2ADF4321C7ULL, 0x03219A39EE587A30ULL, 0x49787FEF17AF9924ULL, 0xA1E9300CD8520548ULL,
   0x5B45E522E4B1B4EFULL, 0xB49C3B3995091A36ULL, 0xD4490AD526F14431ULL, 0x12A8F216AF9418C2ULL,
   0x001F837CC7350524ULL, 0x1877B51E57A764D5ULL, 0xA2853B80F17F58EEULL, 0x993E1DE72D36D310ULL,
   0xB3598080CE64A656ULL, 0x252F59CF0D9F04BBULL, 0xD23C8E176D113600ULL, 0x1BDA0492E7E4586EULL,
   0x21E0BD5026C619BFULL, 0x3B097ADAF088F94EULL, 0x8D14DEDB30BE846EULL, 0xF95CFFA23AF5F6F4ULL,
   0x3871700761B3F743ULL, 0xCA672B91E9E4FA16ULL, 0x64C8E531BFF53B55ULL, 0x241260ED4AD1E87DULL,
   0x106C09B972D2E822ULL, 0x7FBA195410E5CA30ULL, 0x7884D9BC6CB569D8ULL, 0x0647DFEDCD894A29ULL,
   0x63573FF03E224774ULL, 0x4FC8E9560F91B123ULL, 0x1DB956E450275779ULL, 0xB8D91274B9E9D4FBULL,
   0xA2EBEE47E2FBFCE1ULL, 0xD9F1F30CCD97FB09ULL, 0xEFED53D75FD64E6BULL, 0x2E6D02C36017F67FULL,
   0xA9AA4D20DB084E9BULL, 0xB64BE8D8B25396C1ULL, 0x70CB6AF7C2D5BCF0ULL, 0x98F076A4F7A2322EULL,
   0xBF84470805E69B5FULL, 0x94C3251F06F90CF3ULL, 0x3E003E616A6591E9ULL, 0xB925A6CD0421AFF3ULL,
   0x61BDD1307C66E300ULL, 0xBF8D5108E27E0D48ULL, 0x240AB57A8B888B20ULL, 0xFC87614BAF287E07ULL,
   0xEF02CDD06FFDB432ULL, 0xA1082C0466DF6C0AULL, 0x8215E577001332C8ULL, 0xD39BB9C3A48DB6CFULL,
   0x2738259634305C14ULL, 0x61CF4F94C97DF93DULL, 0x1B6BACA2AE4E125BULL, 0x758F450C88572E0BULL,
   0x959F587D507A8359ULL, 0xB063E962E045F54DULL, 0x60E8ED72C0DFF5D1ULL, 0x7B64978555326F9FULL,
   0xFD080D236DA814BAULL, 0x8C90FD9B083F4558ULL, 0x106F72FE81E2C590ULL, 0x7976033A39F7D952ULL,
   0xA4EC0132764CA04BULL, 0x733EA705FAE4FA77ULL, 0xB4D8F77BC3E56167ULL, 0x9E21F4F903B33FD9ULL,
   0x9D765E419FB69F6DULL, 0xD30C088BA61EA5EFULL, 0x5D94337FBFAF7F5BULL, 0x1A4E4822EB4D7A59ULL,
   0x6FFE73E81B637FB3ULL, 0xDDF957BC36D8B9CAULL, 0x64D0E29EEA8838B3ULL, 0x08DD9BDFD96B9F63ULL,
   0x087E79E5A57D1D13ULL, 0xE328E230E3E2B3FBULL, 0x1C2559E30F0946BEULL, 0x720BF5F26F4D2EAAULL,
   0xB0774D261CC609DBULL, 0x443F64EC5A371195ULL, 0x4112CF68649A260EULL, 0xD813F2FAB7F5C5CAULL,
   0x660D3257380841EEULL, 0x59AC2C7873F910A3ULL, 0xE846963877671A17ULL, 0x93B633ABFA3469F8ULL,
   0xC0C0F5A60EF4CDCFULL, 0xCAF21ECD4377B28CULL, 0x57277707199B8175ULL, 0x506C11B9D90E8B1DULL,
   0xD83CC2687A19255FULL, 0x4A29C6465A314CD1ULL, 0xED2DF21216235097ULL, 0xB5635C95FF7296E2ULL,
   0x22AF003AB672E811ULL, 0x52E762596BF68235ULL, 0x9AEBA33AC6ECC6B0ULL, 0x944F6DE09134DFB6ULL,
   0x6C47BEC883A7DE39ULL, 0x6AD047C430A12104ULL, 0xA5B1CFDBA0AB4067ULL, 0x7C45D833AFF07862ULL,
   0x5092EF950A16DA0BULL, 0x9338E69C052B8E7BULL, 0x455A4B4CFE30E3F5ULL, 0x6B02E63195AD0CF8ULL,
   0x6B17B224BAD6BF27ULL, 0xD1E0CCD25BB9C169ULL, 0xDE0C89A556B9AE70ULL, 0x50065E535A213CF6ULL,
   0x9C1169FA2777B874ULL, 0x78EDEFD694AF1EEDULL, 0x6DC93D9526A50E68ULL, 0xEE97F453F06791EDULL,
   0x32AB0EDB696703D3ULL, 0x3A6853C7E70757A7ULL, 0x31865CED6120F37DULL, 0x67FEF95D92607890ULL,
   0x1F2B1D1F15F6DC9CULL, 0xB69E38A8965C6B65ULL, 0xAA9119FF184CCCF4ULL, 0xF43C732873F24C13ULL,
   0xFB4A3D794A9A80D2ULL, 0x3550C2321FD6109CULL, 0x371F77E76BB8417EULL, 0x6BFA9AAE5EC05779ULL,
   0xCD04F3FF001A4778ULL, 0xE3273522064480CAULL, 0x9F91508BFFCFC14AULL, 0x049A7F41061A9E60ULL,
   0xFCB6BE43A9F2FE9BULL, 0x08DE8A1C7797DA9BULL, 0x8F9887E6078735A1ULL, 0xB5B4071DBFC73A66ULL,
   0x230E343DFBA08D33ULL, 0x43ED7F5A0FAE657DULL, 0x3A88A0FBBCB05C63ULL, 0x21874B8B4D2DBC4FULL,
   0x1BDEA12E35F6A8C9ULL, 0x53C065C6C8E63528ULL, 0xE34A1D250E7A8D6BULL, 0xD6B04D3B7651DD7EULL,
   0x5E90277E7CB39E2DULL, 0x2C046F22062DC67DULL, 0xB10BB459132D0A26ULL, 0x3FA9DDFB67E2F199ULL,
   0x0E09B88E1914F7AFULL, 0x10E8B35AF3EEAB37ULL, 0x9EEDECA8E272B933ULL, 0xD4C718BC4AE8AE5FULL,
   0x81536D601170FC20ULL, 0x91B534F885818A06ULL, 0xEC8177F83F900978ULL, 0x190E714FADA5156EULL,
   0xB592BF39B0364963ULL, 0x89C350C893AE7DC1ULL, 0xAC042E70F8B383F2ULL, 0xB49B52E587A1EE60ULL,
   0xFB152FE3FF26DA89ULL, 0x3E666E6F69AE2C15ULL, 0x3B544EBE544C19F9ULL, 0xE805A1E290CF2456ULL,
   0x24B33C9D7ED25117ULL, 0xE74733427B72F0C1ULL, 0x0A804D18B7097475ULL, 0x57E3306D881EDB4FULL,
   0x4AE7D6A36EB5DBCBULL, 0x2D8D5432157064C8ULL, 0xD1E649DE1E7F268BULL, 0x8A328A1CEDFE552CULL,
   0x07A3AEC79624C7DAULL, 0x84547DDC3E203C94ULL, 0x990A98FD5071D263ULL, 0x1A4FF12616EEFC89ULL,
   0xF6F7FD1431714200ULL, 0x30C05B1BA332F41CULL, 0x8D2636B81555A786ULL, 0x46C9FEB55D120902ULL,
   0xCCEC0A73B49C9921ULL, 0x4E9D2827355FC492ULL, 0x19EBB029435DCB0FULL, 0x4659D2B743848A2CULL,
   0x963EF2C96B33BE31ULL, 0x74F85198B05A2E7DULL, 0x5A0F544DD2B1FB18ULL, 0x03727073C2E134B1ULL,
   0xC7F6AA2DE59AEA61ULL, 0x352787BAA0D7C22FULL, 0x9853EAB63B5E0B35ULL, 0xABBDCDD7ED5C0860ULL,
   0xCF05DAF5AC8D77B0ULL, 0x49CAD48CEBF4A71EULL, 0x7A4C10EC2158C4A6ULL, 0xD9E92AA246BF719EULL,
   0x13AE978D09FE5557ULL, 0x730499AF921549FFULL, 0x4E4B705B92903BA4ULL, 0xFF577222C14F0A3AULL,
   0x55B6344CF97AAFAEULL, 0xB862225B055B6960ULL, 0xCAC09AFBDDD2CDB4ULL, 0xDAF8E9829FE96B5FULL,
   0xB5FDFC5D3132C498ULL, 0x310CB380DB6F7503ULL, 0xE87FBB46217A360EULL, 0x2102AE466EBB1148ULL,
   0xF8549E1A3AA5E00DULL, 0x07A69AFDCC42261AULL, 0xC4C118BFE78FEAAEULL, 0xF9F4892ED96BD438ULL,
   0x1AF3DBE25D8F45DAULL, 0xF5B4B0B0D2DEEEB4ULL, 0x962ACEEFA82E1C84ULL, 0x046E3ECAAF453CE9ULL,
   0xF05D129681949A4CULL, 0x964781CE734B3C84ULL, 0x9C2ED44081CE5FBDULL, 0x522E23F3925E319EULL,
   0x177E00F9FC32F791ULL, 0x2BC60A63A6F3B3F2ULL, 0x222BBFAE61725606ULL, 0x486289DDCC3D6780ULL,
   0x7DC7785B8EFDFC80ULL, 0x8AF38731C02BA980ULL, 0x1FAB64EA29A2DDF7ULL, 0xE4D9429322CD065AULL,
   0x9DA058C67844F20CULL, 0x24C0E332B70019B0ULL, 0x233003B5A6CFE6ADULL, 0xD586BD01C5C217F6ULL,
   0x5E5637885F29BC2BULL, 0x7EBA726D8C94094BULL, 0x0A56A5F0BFE39272ULL, 0xD79476A84EE20D06ULL,
   0x9E4C1269BAA4BF37ULL, 0x17EFEE45B0DEE640ULL, 0x1D95B0A5FCF90BC6ULL, 0x93CBE0B699C2585DULL,
   0x65FA4F227A2B6D79ULL, 0xD5F9E858292504D5ULL, 0xC2B5A03F71471A6FULL, 0x59300222B4561E00ULL,
   0xCE2F8642CA0712DCULL, 0x7CA9723FBB2E8988ULL, 0x2785338347F2BA08ULL, 0xC61BB3A141E50E8CULL,
   0x150F361DAB9DEC26ULL, 0x9F6A419D382595F4ULL, 0x64A53DC924FE7AC9ULL, 0x142DE49FFF7A7C3DULL,
   0x0C335248857FA9E7ULL, 0x0A9C32D5EAE45305ULL, 0xE6C42178C4BBB92EULL, 0x71F1CE2490D20B07ULL,
   0xF1BCC3D275AFE51AULL, 0xE728E8C83C334074ULL, 0x96FBF83A12884624ULL, 0x81A1549FD6573DA5ULL,
   0x5FA7867CAF35E149ULL, 0x56986E2EF3ED091BULL, 0x917F1DD5F8886C61ULL, 0xD20D8C88C8FFE65FULL,
   0x31D71DCE64B2C310ULL, 0xF165B587DF898190ULL, 0xA57E6339DD2CF3A0ULL, 0x1EF6E6DBB1961EC9ULL,
   0x70CC73D90BC26E24ULL, 0xE21A6B35DF0C3AD7ULL, 0x003A93D8B2806962ULL, 0x1C99DED33CB890A1ULL,
   0xCF3145DE0ADD4289ULL, 0xD0E4427A5514FB72ULL, 0x77C621CC9FB3A483ULL, 0x67A34DAC4356550BULL,
   0xF8D626AAAF278509ULL,
};

/* from HG Muller:
The array Random64 is in fact a concatenation of four subarrays

RandomPiece     (offset:   0, length: 768)
RandomCastle    (offset: 768, length:   4) 
RandomEnPassant (offset: 772, length:   8)
RandomTurn      (offset: 780, length:   1)

white pawn    1 -> PAWN = 0
white knight  3 -> KNIGHT = 1
white bishop  5 -> BISHOP = 2
white rook    7 -> ROOK = 3
white queen   9 -> QUEEN = 4
white king   11 -> KING = 5
black pawn    0 -> PAWN + 6 = 6
black knight  2 -> KNIGHT + 6 = 7
black bishop  4 -> BISHOP + 6 = 8
black rook    6 -> ROOK + 6 = 9
black queen   8 -> QUEEN + 6 = 10
black king   10 -> KING + 6 = 11
*/

enum RANDOM_OFFSETS { PIECE = 0, CASTLE = 768, EP = 772, TURN = 780 };

const int POLYGLOT_PIECE_TYPE[12] = { 1, 3, 5, 7, 9, 11, 0, 2, 4, 6, 8, 10 };
const int POLYGLOT_SQUARES[64][2] = {
	{7, 0}, {6, 0}, {5, 0}, {4, 0}, {3, 0}, {2, 0}, {1, 0}, {0, 0},
	{7, 1}, {6, 1}, {5, 1}, {4, 1}, {3, 1}, {2, 1}, {1, 1}, {0, 1},
	{7, 2}, {6, 2}, {5, 2}, {4, 2}, {3, 2}, {2, 2}, {1, 2}, {0, 2},
	{7, 3}, {6, 3}, {5, 3}, {4, 3}, {3, 3}, {2, 3}, {1, 3}, {0, 3},
	{7, 4}, {6, 4}, {5, 4}, {4, 4}, {3, 4}, {2, 4}, {1, 4}, {0, 4},
	{7, 5}, {6, 5}, {5, 5}, {4, 5}, {3, 5}, {2, 5}, {1, 5}, {0, 5},
	{7, 6}, {6, 6}, {5, 6}, {4, 6}, {3, 6}, {2, 6}, {1, 6}, {0, 6},
	{7, 7}, {6, 7}, {5, 7}, {4, 7}, {3, 7}, {2, 7}, {1, 7}, {0, 7},
};

ull book::gen_polyglot_key(const bitboard::Position &board) {
	ull pieces = 0;
	for (int i = 0; i < 64; i++) {
		if (board.mailbox[i] == -1)
			continue;
		ull currentPiece = 64 * POLYGLOT_PIECE_TYPE[board.mailbox[i]] + 8 * POLYGLOT_SQUARES[i][1] + POLYGLOT_SQUARES[i][0];
		pieces ^= RANDOM[PIECE + currentPiece];
	}

	ull castle = 0;
	if (board.castle[WHITE_SHORT])
		castle ^= RANDOM[CASTLE + 0];
	if (board.castle[WHITE_LONG])
		castle ^= RANDOM[CASTLE + 1];
	if (board.castle[BLACK_SHORT])
		castle ^= RANDOM[CASTLE + 2];
	if (board.castle[BLACK_LONG])
		castle ^= RANDOM[CASTLE + 3];

	ull enpassant = 0;
	if (board.enPassant != -1)
		enpassant = RANDOM[EP + 7 - (board.enPassant % 8)];

	ull turn = 0;
	if (board.turn == WHITE)
		turn = RANDOM[TURN];

	return pieces ^ castle ^ enpassant ^ turn;
}

int convert_polyglot_move(const bitboard::Position &board, int move) {
	int destFile = (move & 0b111);
	int destRow = (move & 0b111000) >> 3;
	int fromFile = (move & 0b111000000) >> 6;
	int fromRow = (move & 0b111000000000) >> 9;
	int promote = (move & 0b111000000000000) >> 12;

	int dest = (destRow * 8 + (7 - destFile));
	int from = (fromRow * 8 + (7 - fromFile));

	// detect castling

	if (from == E1 && board.mailbox[dest] == KING) {
		if (dest == H1)
			return NEW_MOVE(E1, G1, WHITE_SHORT, 0, 0);
		if (dest == A1)
			return NEW_MOVE(E1, C1, WHITE_LONG, 0, 0);
	}
	if (from == E8 && board.mailbox[dest] == KING + 6) {
		if (dest == H8)
			return NEW_MOVE(E8, G8, BLACK_SHORT, 0, 0);
		if (dest == A8)
			return NEW_MOVE(E8, C8, BLACK_LONG, 0, 0);
	}

	return move::uci_to_move(board, from, dest, promote);
}

// CREDIT: Fabien Letouzey's Fruit Engine, version 2.1, src found at https://arctrix.com/nas/chess/fruit
// Code from here to end of file copied from Fruit with minor adjustments

// Fruit util.cpp

void my_random_init() {
  	srand(time(NULL));
}

int my_random(int n) {
	double r;

	assert(n > 0);

	r = double(rand()) / (double(RAND_MAX) + 1.0);

	return int(floor(r * double(n)));
}

// Fruit book.cpp

struct Entry {
   ull key;
   int move, count, n, sum;
};

static FILE *BookFile;
static int BookSize;

void book_init() {
	my_random_init();
	BookFile = NULL;
	BookSize = 0;
}

void book::book_open(const char file_name[]) {
	book_init();
	assert(file_name != NULL);

	BookFile = fopen(file_name, "rb");

	if (BookFile != NULL) {
		if (fseek(BookFile,0,SEEK_END) == -1) {
			//  my_fatal("book_open(): fseek(): %s\n",strerror(errno));
		}

		BookSize = ftell(BookFile) / 16;
		//   if (BookSize == -1) my_fatal("book_open(): ftell(): %s\n",strerror(errno));
	}
}

void book_close() {
	if (BookFile != NULL && fclose(BookFile) == EOF) {
		// my_fatal("book_close(): fclose(): %s\n",strerror(errno));
	}
}

static ull read_integer(FILE *file, int size) {
	ull n;
	int b;

	assert(file != NULL);
	assert(size > 0 && size <= 8);

	n = 0;

	for (int i = 0; i < size; i++) {

		b = fgetc(file);

		if (b == EOF) {
			if (feof(file)) {
				// my_fatal("read_integer(): fgetc(): EOF reached\n");
			} else { // error
				// my_fatal("read_integer(): fgetc(): %s\n",strerror(errno));
			}
		}

		assert(b >= 0 && b < 256);
		n = (n << 8) | b;
	}

	return n;
}

static void read_entry(Entry *entry, int n) {
	assert(entry != NULL);
	assert(n >= 0 && n < BookSize);

	assert(BookFile != NULL);

	if (fseek(BookFile, n * 16, SEEK_SET) == -1) {
		// my_fatal("read_entry(): fseek(): %s\n",strerror(errno));
	}

	entry->key = read_integer(BookFile,8);
	entry->move = read_integer(BookFile,2);
	entry->count = read_integer(BookFile,2);
	entry->n = read_integer(BookFile,2);
	entry->sum = read_integer(BookFile,2);
}

static int find_pos(ull key) {
	int left, right, mid;
	Entry entry[1];

	// binary search (finds the leftmost entry)

	left = 0;
	right = BookSize - 1;

	assert(left <= right);

	while (left < right) {
		mid = (left + right) / 2;
		assert(mid >= left && mid < right);

		read_entry(entry, mid);

		if (key <= entry->key)
			right = mid;
		else
			left = mid+1;
	}

	assert(left == right);

	read_entry(entry, left);

	return (entry->key == key) ? left : BookSize;
}

int book::book_move(const bitboard::Position &board) {
	ull key = book::gen_polyglot_key(board);

	int best_move, best_score, move, score;
	Entry entry[1];

	if (BookFile != NULL && BookSize != 0) {
		// draw a move according to a fixed probability distribution

		best_move = -1;
		best_score = 0;

		for (int pos = find_pos(key); pos < BookSize; pos++) {
			read_entry(entry, pos);
			if (entry->key != key)
				break;

			move = entry->move;
			score = entry->count;

			// pick this move?

			assert(score > 0);

			best_score += score;
			if (my_random(best_score) < score)
				best_move = move;
			// best_move = move;
		}

		if (best_move != -1)
			return convert_polyglot_move(board, best_move);
	}

	return -1;
}