public class Test2DArray2 {

  public static void main (String[] argv)
  {
    int size = 5;
    int[][] triangle;

    // There are `size' rows.
    triangle = new int[size][];

    // Each row has a different number of elements.
    for (int i=0; i<size; i++)
      triangle[i] = new int[i+1];

    // Compute elements
    System.out.println ("Triangle of 1's:");

    for (int i=0; i<size; i++) {

      // Count enough blanks for i-th row.
      for (int j=0; j<size-i; j++)
        System.out.print (" ");

      // Print out 1's. Note length reference as an alternative.
      for (int j=0; j<triangle[i].length; j++) {
        triangle[i][j] = 1;
        System.out.print ("1 ");
      }

      System.out.println ();
    }
  }
}