you can implement it as follows.

int zeroProcedure(int i) {
  int check = !(i);
  //1 if all are 0, else 0
  check = ~check;
  //1..10 if all are 0, else all 1s.
  check += 1;
  //1...1 if all are 0, else 0.
  return check;
}

or simply:

int zeroProcedure(int i) {
  return (~(!i))+1;
}