MisplacedHeuristic.java

import java.lang.Math;
import java.util.Comparator;

public class MisplacedHeuristic implements Comparator<Board> {
	public int compare(Board x, Board y) {
		if ((misplacedTile(x) + x.getCost()) < (misplacedTile(y) + y.getCost())) {
			return -1;
		} else if ((misplacedTile(x) + x.getCost()) > (misplacedTile(y) + y.getCost())) {
			return 1;
		} else {
			return 0;
		}
	}

	public int misplacedTile(Board board) {
		int count = 0;
		String[] boardState = new String[9];
		boardState[0] = board.topLeft.getValue();
		boardState[1] = board.topMid.getValue();
		boardState[2] = board.topRight.getValue();
		boardState[3] = board.midLeft.getValue();
		boardState[4] = board.midMid.getValue();
		boardState[5] = board.midRight.getValue();
		boardState[6] = board.botLeft.getValue();
		boardState[7] = board.botMid.getValue();
		boardState[8] = board.botRight.getValue();
		for (int i = 1; i < boardState.length; i++) {
			if (!boardState[i].equals(Integer.toString(i))) count++;
		}
		return count;
	}
}