k&r 2-7

#include <stdio.h>
#define bits(x) sizeof(x) * 8

void showBits(unsigned x) {
  for (int i = bits(x) - 1; i >= 0; i--) {
    printf("%d", 1 & (x >> i));
  }
  puts("");
}

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

int main() {
  unsigned x, p, n;
  printf("x="); scanf("%u", &x);
  printf("p="); scanf("%u", &p);
  printf("n="); scanf("%u", &n);
  showBits(x);
  showBits(invert(x, p, n));
  return 0;
}