Ex_2.8_rightrot.c

/* write a function rightrot(x,n) that returns the value of the integer x rotated to rightby n bit positions */

#include<stdio.h>

unsigned rightrot(unsigned x,int n);

int main(void)
{
	printf("%u",(unsigned)rightrot((unsigned)8,(int)1));

	return 0;
}

/* rightrot: rotate x to right by n bit positions */

unsigned rightrot(unsigned x,int n)
{
	int wordlength(void);
	unsigned rbit;/* rightmost bit */
	
	rbit = x << (wordlength() - n);
   	x = x >> n;
   	x = x | rbit;
   	
	return x;
}

int wordlength(void)
{
	int i;
	unsigned v = (unsigned) ~0;

	for(i=1;(v=v>>1)>0;i++)
		;
	return i;
}