#include <stdio.h>
#include <stdlib.h>

/**
 * bits - fun printing the bits of a number.
 */

/**
 * Procedure:
 *   show_int_bits
 * Parameters:
 *   i, an integer
 * Purpose:
 *   Show all the bits in i
 * Produces:
 *   [Nothing, called for the side effect.]
 * Preconditions:
 *   [No additional]
 * Postconditions:
 *   32 bits (character 0 or character 1) appear on output.
 *   (Explain output.)
 */
void
show_int_bits (int i)
{
  int j;
  int current;

  // For each bit position
  for (j = 31; j >= 0; j--)
    {
      // Check what the bit at position j is
      // Need the number corresponding to 00000100000000000, that is, 
      //    1 followed by j 0's
      // Can do it with expontentiation, but that's wasteful
      current = 0x1 << j;
      if ((i & current) == 0)
        printf ("0");
      else
        printf ("1");
    }
} // show_int_bits

/**
 * main
 */
int 
main (int argc, char *argv[])
{
  // Grab element 1 of argv as an integer
  int i = atoi (argv[1]);

  printf ("%d is ", i);
  show_int_bits (i);
  printf ("\n");

  return EXIT_SUCCESS;
} // main