Exercise 2-8. Write a function rightrot(x,n) that returns the value of the integer x rotated to the right by n positions.

/* Exercise 2-8. Write a function rightrot(x,n) that returns the value of the integer x rotated to the right by n positions. */

#include <stdio.h>

unsigned rightrot(unsigned x, int n);
int unsignedlength(void);

int main()
{
    unsigned x = 99;

    printf("x = %d\n", x);
    x = rightrot(x, 5);
    printf("modified x = %i\n", x);

    return 0;
}

unsigned rightrot(unsigned x, int n)
{
    int length = unsignedlength();
    printf("bit length of x = %d\n", length);

    return ((x >> n) | (((x) & (~(~0U << n))) << (length - n)));            
}

/* bitlength: count no of bits in x */
int unsignedlength(void)
{
    int b;
    unsigned y;

    y = (~0);                     /* sets every bit of y to 1*/
    for (b = 0; y != 0; y >>= 1)
        b++;

    return b;
}