coin_toss.c

int fib(n) {
  return n < 2 ? n : fib(n-1) + fib(n-2);
}

int main() {
  int t, n;
  scanf("%d\n", &t);
  while (t--) {
    scanf("%d\n", &n);
    printf("%f\n", fib(n+2) / pow(2, n));
  }
  return 0;
}