public boolean isFeasible(Coordinate c) {
		
		boolean validI = c.i >= 0 && c.i < size;
		boolean validJ = c.j >= 0 && c.j < size;
		
		boolean validCell = false;
		if (validI && validJ) {
			validCell = (maze.get(c.i).get(c.j).val == 0);
		}
		
		return validI && validJ && validCell;
	}