2-7

2-7.c

#include <stdio.h>

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

int main(){
  int x = 0b00011100;
  int y = 0b00010000;
  // x -> 0b00000000 = 0
  // y -> 0b00001100 = 12

  x = invert(x, 4, 3);
  printf("%d\n", x);
  y = invert(y, 4, 3);
  printf("%d\n", y);
}

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