//  ShowbitsKL.java  Copyright (c) 2005 Kari Laitinen

//  http://www.naturalprogramming.com

//  2005-06-21   File created.
//  2005-06-21   Last modification.

//  A solution to exercises 16-3 and 16-4.

import java.util.* ;

class ShowbitsKL
{
   static void print_in_binary_form( int  given_integer )
   {
      int  bit_mask ;
      int   number_of_bits_to_print ;

      if ( given_integer  <  0x100 )
      {
         bit_mask  = 0x80 ;
         number_of_bits_to_print  =  8 ;
      }
      else if ( given_integer  <  0x10000 )
      {
         bit_mask  = 0x8000 ;
         number_of_bits_to_print  =  16 ;
      }
      else
      {
         bit_mask  = 0x80000000 ;
         number_of_bits_to_print  =  32 ;
      }

      int  one_bit_in_given_integer ;

      int bit_counter  =  0  ;

      while ( bit_counter  <  number_of_bits_to_print )
      {
         one_bit_in_given_integer  =  given_integer & bit_mask ;

         if ( one_bit_in_given_integer  ==  0 )
         {
            System.out.print( "0" ) ;
         }
         else
         {
            System.out.print( "1" ) ;
         }

         bit_mask  =  bit_mask  >>>  1 ;

         bit_counter  ++ ;

         if ( ( bit_counter  %  4 )  ==  0 )
         {
            //  Printing a space after each four bits.
            System.out.print( " " ) ;
         }
      }
   }

   public static void main( String[]  command_line_parameters )
   {
      Scanner keyboard = new Scanner( System.in ) ;

      if ( command_line_parameters.length  ==  1 )
      {
         String  given_number_as_string  = 
                          command_line_parameters[ 0 ] ;

         int  given_number ;

         if ( given_number_as_string.length()  >  1  &&
              ( given_number_as_string.charAt( 1 )  ==  'x'  ||
                given_number_as_string.charAt( 1 )  ==  'X'   ) )
         {
            //  A hexadecimal number was given
            given_number  =  Integer.parseInt(
                                 given_number_as_string.substring( 2 ), 16 ) ;

            // Alternatively, the following statement could be used
            // in place of the previous statement.

            // given_number  =  Integer.decode( given_number_as_string ) ;

            System.out.printf( "\n 0x%X  is  ",  given_number ) ;
            print_in_binary_form( given_number ) ;
            System.out.print( "(binary)    "
                        +  given_number  +  " (decimal)   " ) ;
         }
         else
         {
            //  We'll suppose that a decimal number was given.
            given_number  =  Integer.parseInt( given_number_as_string ) ;

            System.out.print( "\n "  +  given_number  +  "  is  " ) ;
            print_in_binary_form( given_number ) ;
            System.out.printf( "(binary)    %X (hexadecimal)   ",
                               given_number ) ;
         }

         //  We'll print the number as a character if it is less
         //  than 256.

         if ( given_number  <  0x100 )
         {
            System.out.print( "\'"  +  (char) given_number
                        +  "\' as  character  \n\n" ) ;
         }
         else
         {
            System.out.print( "\n\n" ) ;
         }
      }
      else
      {
         System.out.print( "\n\n Give a number on the command line.\n\n" ) ;
      }
   }
}