bool Robot::step()
{
	// If the robot has no energy left, return false
	// if (FULL_ENERGY == 0)
	//	return false;
	
       // Otherwise,
	else
	{	
		//    Randomly change direction with probability 1/3
		if (rand() % 3 == 0)    // 1/3 probability to pick a direction
			m_dir = Dir(rand() % 4);    // pick a random direction
		
	        //    Attempt to move one step in the direction we're currently facing.
		//      (E.g., to move north, decrement the row coordinate.)  If we can't
		//      move in that direction, don't move.
               if (r < 0  ||  r >= NROWS  ||  c < 0  ||  c >= NCOLS)
	    {
		cout << "***** Robot created with invalid coordinates (" << r << ","
			<< c << ")!" << endl;
		exit(1);
	    }
		switch (m_dir)
		{
		case NORTH:
			// TODO: Move one step north, if possible.
                        r--;
			break;
		case SOUTH:
                        r++;
		case WEST:
                        c++;
		case EAST:
                        c--;