Class Board

java/Chapter 8/Question8_8/Board.java:3–138

package Question8_8;

public class Board {
	private int blackCount = 0;
	private int whiteCount = 0;
	private Piece[][] board;
	
	public Board(int rows, int columns) {
		board = new Piece[rows][columns];
	}
	
	public void initialize() {
		/* initial board has a grid like the following in the center:
		 *     WB
		 *     BW
		 */
		int middleRow = board.length / 2;
		int middleColumn = board[middleRow].length / 2;
		board[middleRow][middleColumn] = new Piece(Color.White);
		board[middleRow + 1][middleColumn] = new Piece(Color.Black);
		board[middleRow + 1][middleColumn + 1] = new Piece(Color.White);
		board[middleRow][middleColumn + 1] = new Piece(Color.Black);
		blackCount = 2;
		whiteCount = 2;
	}
	
	public boolean placeColor(int row, int column, Color color) {
		if (board[row][column] != null) {
			return false;
		}
		
		/* attempt to flip each of the four directions */
		int[] results = new int[4];
		results[0] = flipSection(row - 1, column, color, Direction.up);
		results[1] = flipSection(row + 1, column, color, Direction.down);
		results[2] = flipSection(row, column + 1, color, Direction.right);
		results[3] = flipSection(row, column - 1, color, Direction.left);
		
		/* compute how many pieces were flipped */
		int flipped = 0;
		for (int result : results) {
			if (result > 0) {
				flipped += result;
			}
		}
		
		/* if nothing was flipped, then it's an invalid move */
		if (flipped < 0) {
			return false;
		}
		
		/* flip the piece, and update the score */
		board[row][column] = new Piece(color);
		updateScore(color, flipped + 1);
		return true;
	}
	
	private int flipSection(int row, int column, Color color, Direction d) {
		/* Compute the delta for the row and the column. At all times, only the row or the column
		 * will have a delta, since we're only moving in one direction at a time.