// Exercise3_8.java: Print a pattern
public class Exercise3_8
{
  public static void main(String[] args)
  {
    int number = 0; // Number to print

    for (int row=0; row<=7; row++)
    {
      // Pad leading blanks
      for (int col=1; col<=7-row; col++)
        System.out.print("     ");

      // Print left half of the row
      for (int col=0; col<=row; col++)
      {
        number = (int)Math.pow(2, col);

        // You can write a method in Chapter 4 for this section
        if (number > 100)
        {
          System.out.print("  " + number);
        }
        else if (number > 10)
        {
          System.out.print("   " + number);
        }
        else
        {
          System.out.print("    " + number);
        }
      }

      // Print the right half of the row
      for (int col=row-1; col>=0; col--)
      {
        number = (int)Math.pow(2, col);

        // You can write a method in Chapter 4 for this section
        if (number > 100)
        {
          System.out.print("  " + number);
        }
        else if (number > 10)
        {
          System.out.print("   " + number);
        }
        else
        {
          System.out.print("    " + number);
        }
      }

      // Start a new line
      System.out.print('\n');
    }
  }
}