Count.java

/*
  Enumerate all possible 0's and 1's in an n-digit binary string.
*/

public final class Count {

   public static void main (final String[] args) {
      final int digits = Integer.parseInt(args[0]);

      for (int i=0; i < (1<<digits); i++) {
         System.out.printf ("%6d: %12s%n", i, Integer.toString(i, 2));
      }
   }

}