Реализация алгоритма alpha-beta для шашек на Ява.

void doMakeMove(CheckersMove move) {
             // This is called when the current player has chosen the specified
             // move.  Make the move, and then either end or continue the game
             // appropriately.

         board.makeMove(move);

         /* If the move was a jump, it's possible that the player has another
            jump.  Check for legal jumps starting from the square that the player
            just moved to.  If there are any, the player must jump.  The same
            player continues moving.
         */

         if (move.isJump()) {
            legalMoves = board.getLegalJumpsFrom(currentPlayer,move.toRow,move.toCol);
            if (legalMoves != null) {
               if (currentPlayer == CheckersData.RED)
                  message.setText("RED:  You must continue jumping.");
               else
                  message.setText("BLACK:  You must continue jumping.");
               selectedRow = move.toRow;  // Since only one piece can be moved, select it.
               selectedCol = move.toCol;
               repaint();
               return;
            }
         }

         /* The current player's turn is ended, so change to the other player.
            Get that player's legal moves.  If the player has no legal moves,
            then the game ends. */

         if (currentPlayer == CheckersData.RED) {
            currentPlayer = CheckersData.BLACK;
            legalMoves = board.getLegalMoves(currentPlayer);
            if (legalMoves == null)
               gameOver("BLACK has no moves.  RED wins.");
//==ALL CHANGES WERE MADE HERE====================
            else/* if (legalMoves[0].isJump())
               message.setText("BLACK:  Make your move.  You must jump.");
            else*/
            {
               //message.setText("BLACK:  Make your move.");
               doMakeMove(legalMoves[0]);
            }
//==============================================
         }
         else {
            currentPlayer = CheckersData.RED;
            legalMoves = board.getLegalMoves(currentPlayer);
            if (legalMoves == null)
               gameOver("RED has no moves.  BLACK wins.");
            else if (legalMoves[0].isJump())
               message.setText("RED:  Make your move.  You must jump.");
            else
               message.setText("RED:  Make your move.");
         }

         /* Set selectedRow = -1 to record that the player has not yet selected
             a piece to move. */

         selectedRow = -1;

         /* As a courtesy to the user, if all legal moves use the same piece, then
            select that piece automatically so the use won't have to click on it
            to select it. */

         if (legalMoves != null) {
            boolean sameStartSquare = true;
            for (int i = 1; i < legalMoves.length; i++)
               if (legalMoves.fromRow != legalMoves[0].fromRow
                                    || legalMoves.fromCol != legalMoves[0].fromCol) {
                   sameStartSquare = false;
                   break;
               }
            if (sameStartSquare) {
               selectedRow = legalMoves[0].fromRow;
               selectedCol = legalMoves[0].fromCol;
            }
         }

         /* Make sure the board is redrawn in its new state. */

         repaint();

      }  // end doMakeMove();