public static void main(String[] args) 
    {
        String strStars  = "*";
        String strSpaces = " ";
        int i, j;
        int nRow = 64;
        for (i = 0; i <= Math.log(nRow + 2) / Math.log(2); i++)
        {
            strStars += strStars;
            strSpaces += strSpaces;
        }
        for (i = 0, j = 0; i < nRow; i++)
        {
            System.out.print(strSpaces.substring(0, (nRow - 1) / 2 - j));
            System.out.println(strStars.substring(0, (j * 2 + 1)));
            if (nRow < (i * 2 + 2))
                j--;
            else if (nRow > (i * 2 + 2))
                j++;
        }
    }