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#include "chess.h"
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#include "chess.h"
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#include "data.h"
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#include "data.h"
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/* last modified 04/29/15 */
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/* last modified 08/03/16 */
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/*
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/*
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 *******************************************************************************
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 *******************************************************************************
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 *                                                                             *
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 *                                                                             *
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 *   Repeat() is used to detect a draw by repetition.  The repetition list is  *
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 *   Repeat() is used to detect a draw by repetition.  The repetition list is  *
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 *   a simple 1d array that contains the Zobrist signatures for each position  *
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 *   a simple 1d array that contains the Zobrist signatures for each position  *
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 */
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 */
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  tree->rep_list[rep_index + ply] = HashKey;
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  tree->rep_list[rep_index + ply] = HashKey;
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  if (Reversible(ply) < 4)
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  if (Reversible(ply) < 4)
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    return 0;
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    return 0;
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  if (Reversible(ply) > 99)
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  if (Reversible(ply) > 99)
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    return 2;
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    return 3;
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/*
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/*
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 ************************************************************
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 ************************************************************
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 *                                                          *
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 *                                                          *
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 *  Now we scan the right part of the repetition list,      *
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 *  Now we scan the right part of the repetition list,      *
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 *  which is to search backward from the entry for 2 plies  *
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 *  which is to search backward from the entry for 2 plies  *
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 ************************************************************
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 ************************************************************
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 */
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 */
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  count = Reversible(ply) / 2 - 1;
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  count = Reversible(ply) / 2 - 1;
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  for (where = rep_index + ply - 4; count; where -= 2, count--) {
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  for (where = rep_index + ply - 4; count; where -= 2, count--) {
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    if (HashKey == tree->rep_list[where])
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    if (HashKey == tree->rep_list[where])
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      return 1;
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      return 2;
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  }
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  }
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  return 0;
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  return 0;
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}
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}
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/* last modified 05/08/14 */
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/* last modified 08/03/16 */
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/*
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/*
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 *******************************************************************************
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 *******************************************************************************
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 *                                                                             *
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 *                                                                             *
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 *   Repeat3x() is used to detect a real draw by repetition.  This routine is  *
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 *   Repeat3x() is used to detect a real draw by repetition.  This routine is  *
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 *   only called from Main() and simply scans the complete list searching for  *
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 *   only called from Main() and simply scans the complete list searching for  *