Сформировать массив структур (записей) для автоматизации работы автостоянки

#include <vector>
#include <string>
#include <iostream>
 
struct Driver
  {
  std::string name;
  std::string car_name;
 
  unsigned parking_id;
 
  bool is_parking_now;
  bool is_paid;
  };
 
void print(const std::vector<Driver>& drivers)
  {
  for (int i = 0; i < drivers.size(); ++i)
    {
      std::cout << "Name: " << drivers[i].name
        << "Car name: " << drivers[i].car_name
        << "Parking id: " << drivers[i].parking_id
        << "Is parking now " << drivers[i].is_parking_now
        << "Is paid " << drivers[i].is_paid << std::endl;
    }
  }
 
std::vector<unsigned> get_free(const std::vector<Driver>& drivers)
  {
  std::vector<unsigned> ret;
 
  for (int i = 0; i < drivers.size(); ++i)
    {
    if (!drivers[i].is_parking_now)
      ret.push_back(drivers[i].parking_id);
    }
 
  return ret;
  }
 
std::vector<std::string> get_paid(const std::vector<Driver>& drivers)
  {
  std::vector<std::string> ret;
 
  for (int i = 0; i < drivers.size(); ++i)
    {
    if (!drivers[i].is_paid)
      ret.push_back(drivers[i].name);
    }
 
  return ret;
  }
 
int main()
  {
  Driver one = {"one", "one_car", 1, true, true };
  Driver two = {"two", "two_car", 2, true, false };
  Driver three = {"three", "three_car", 3, false, false };
 
  std::vector<Driver> drivers;
  drivers.push_back(one);
  drivers.push_back(two);
  drivers.push_back(three);
 
  print(drivers);
 
  std::cout << "Free for now: " << std::endl;
  std::vector<unsigned> free = get_free(drivers);
  for (int i = 0; i < free.size() - 1; ++i)
    std::cout << free[i] << " ";
  std::cout << free[free.size() - 1] << std::endl;
 
  std::cout << "Not paid: " << std::endl;
  std::vector<std::string> not_paid = get_paid(drivers);
  for (int i = 0; i < not_paid.size() - 1; ++i)
    std::cout << not_paid[i] << " ";
  std::cout << not_paid[not_paid.size() - 1] << std::endl;
 
 
  return 0;
  }