-

int count_x(char* p, char x) {
  // count the number of occurrences of x in p[]
  // p is assumed to point to a zero-terminated array of char (or to nothing)

  if(p == nullptr) return 0;
  int count = 0;
  for(; p != nullptr; ++p)
      if(*p == x)
        ++count;
  return count;
}

int count_x(char* p, char x) {
  int count = 0;
  while(p) {
    if (*p == x)
      ++count;
    ++p;
  }
  return count;
}

bool accept2() {
  cout << "Do you want to proceed (y or n) ? \n";

  char answer = 0;
  cin >> answer;

  switch(answer) {
    case 'y': return true;
    case 'n': return false;
    default:
  }
}

struct Vector {
  int sz; // number of elements
  double* elem; // pointer to elements
}

Vector v;

void vector_init(Vector& v, int s) {
  v.elem = new double[s]; // allocate an array of s doubles
  v.sz = s;
}

double read_and_sum(int s) {
  Vector v;
  vector_init(v, s);
  for(int i = 0; i != s; ++i) {
      cin >> v.elem[i];
  }

  double sum = 0;
  for(int i = 0; i != s; ++i)
    sum += v.elem[i];
  return sum;
}

/*
 * unary suffix *  = pointer to
 * unary suffix &  = reference to
 * 
 * unary prefix *  = contents of
 * unary prefix & = address of
 */