Exemplo n.º 1
0
 @Override
 protected MoveValuePair ABMaxMinValue(
     Position position, int depth, int alpha, int beta, boolean maxTurn)
     throws IllegalMoveException {
   if (depth <= 0 || position.isTerminal()) {
     return handleTerminal(position, maxTurn, alpha, beta);
   } else {
     MoveValuePair bestMove = new MoveValuePair();
     LinkedList<MoveValuePair> sortedMoves = getSortedMoves(position, maxTurn);
     for (MoveValuePair movepair : sortedMoves) {
       short move = movepair.move;
       // collect values from further moves
       // get and update transposition table if possible
       position.doMove(move);
       if (this.p2tte.containsKey(position.getHashCode())
           && (this.p2tte.get(position.getHashCode()).depth >= depth)) {
         // System.out.println("trans table at level: " + depth);
         TransTableEntry tte = p2tte.get(position.getHashCode());
         bestMove.updateMinMax(move, tte.eval, maxTurn);
       } else {
         // recursive method
         MoveValuePair childMove = ABMaxMinValue(position, depth - 1, alpha, beta, !maxTurn);
         bestMove.updateMinMax(move, childMove.eval, maxTurn);
         p2tte.put(position.getHashCode(), new TransTableEntry(childMove.eval, depth, move));
       }
       position.undoMove();
       // update the alpha beta boundary
       if (maxTurn) alpha = bestMove.eval;
       else beta = bestMove.eval;
       // prune the subtree if needed
       if (alpha >= beta) return bestMove;
     }
     return bestMove;
   }
 }
Exemplo n.º 2
0
  //    protected MoveValuePair handleTerminal(Position position, boolean maxTurn) {
  //        MoveValuePair finalMove = new MoveValuePair();
  //        if (position.isTerminal() && position.isMate()) {
  //            this.terminalFound = position.isTerminal();
  //            finalMove.eval = (maxTurn ? BE_MATED : MATE);
  //        } else if (position.isTerminal() && position.isStaleMate())
  //            finalMove.eval = 0;
  //        else {
  //            finalMove.eval = (int) ( (position.getMaterial() + position.getDomination()));
  //        }
  ////        System.out.print(finalMove.eval + " ");
  //        return finalMove;
  //    }
  protected LinkedList<MoveValuePair> getCapturingSortedMoves(Position position, boolean maxTurn)
      throws IllegalMoveException {
    LinkedList<MoveValuePair> sortedMoves = new LinkedList<MoveValuePair>();
    short[] moves = position.getAllCapturingMoves();
    MoveValuePair theMove = null;
    ASCENDING = maxTurn ? false : true;

    for (short move : moves) {
      position.doMove(move);
      if (p2tte.containsKey(position.getHashCode())) {
        theMove = new MoveValuePair(move, p2tte.get(position.getHashCode()).eval);
      } else {
        // for max turn, I assign worst values those unvisited positions
        //                theMove = new MoveValuePair(move, maxTurn ? BE_MATED : MATE);
        int eval = (int) ((maxTurn ? -1 : 1) * (position.getMaterial() + position.getDomination()));
        theMove = new MoveValuePair(move, eval);
      }
      position.undoMove();
      sortedMoves.add(theMove);
    }
    Collections.sort(
        sortedMoves,
        new Comparator<MoveValuePair>() {
          @Override
          public int compare(MoveValuePair c1, MoveValuePair c2) {
            //                System.out.println(c1.eval + " vs " + c2.eval);
            return (int) ((ASCENDING ? 1 : -1) * Math.signum(c1.eval - c2.eval)); // use your logic
          }
        });
    return sortedMoves;
  }
Exemplo n.º 3
0
 /**
  * Returns whether the given position occurs in the main line of this game.
  *
  * @param position the position to look for, must not be null
  * @return whether the given position occurs in the main line of this game
  */
 public boolean containsPosition(ImmutablePosition position) {
   boolean res = false;
   int index = getCurNode();
   gotoStart(true);
   for (; ; ) {
     if (m_position.getHashCode() == position.getHashCode()) {
       res = true;
       break;
     }
     if (!hasNextMove()) break;
     goForward(true);
   }
   gotoNode(index, true);
   return res;
 }