Ex_2.7_invert.c

/**
 *
 * Exercise 2.7
 *
 * Write a function invert(x,p,n) that returns x with n bit starting at p
 * inverted .
 *
 **/

#include<stdio.h>

unsigned invert(unsigned x,int p,int n);

int main(void)
{
	printf("%u", (unsigned) invert((unsigned) 8, (int) 3, (int) 3));
}

unsigned invert(unsigned x, int p, int n)
{
	return   x ^ (~(~0 << n) << (p + 1 - n));
}