problem 5.6

gistfile1.java

public class BitSwap {

  /**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		int a = 0b10001111;
		int b = a >> 1;
		int c = 0;
		int i = 0;
		int mask = ~ ( ( ~ 0 ) << 2 );
		while ( a != 0 ) {
			c = c | ( a << 1 & mask | b ) << i;
			i += 2;
			a = a >> 2;
			b = b >> 2;
		}		
		System.out.println( Integer.toBinaryString( c ) );
	}
}