@Override
	public int h(Node n) {
		int misplacedCell = 0;
		ArrayList<Integer> board = n.getState().getBoard();
		for (int i = 0; i < N * N; i++) {
			int k = board.get(i);
			if (k != (i + 1) && k != 0)
				misplacedCell++;
		}
		return misplacedCell;
	}