#include <iostream>
#include <vector>

void checkGuest(std::vector<std::string> &guests) {
  std::cout << "Guest: ";
  std::string guest;
  std::cin >> guest;
  bool is_guest = false;

  for (std::vector<std::string>::iterator it = guests.begin(); it != guests.end();) {
    if (*it == guest) {
      is_guest = true;
      break;
    } else {
      ++it;
    }
  }

  std::cout << guest << " is " << ((is_guest) ? "" : "NOT ") << "on the guest list!" << std::endl;
}

void createGuest(std::vector<std::string> &guests) {
  bool keepInput = true;

  do {
    std::string guest;
    std::cout << "Guest: ";
    std::cin >> guest;
    guests.push_back(guest);
    std::cout << "More? (1 = Yes - 0 = No) ";
    std::cin >> keepInput;
  } while (keepInput);
}

void removeGuest(std::vector<std::string> &guests) {
  std::cout << "Guest: ";
  std::string guest;
  std::cin >> guest;

  for (std::vector<std::string>::iterator it = guests.begin(); it != guests.end();) {
    if (*it == guest) {
      it = guests.erase(it);
    } else {
      ++it;
    }
  }
}

void showGuests(std::vector<std::string> &guests) {
  std::cout << "-- List of all guests --" << std::endl;

  for (std::string &guest : guests) {
    std::cout << "\t" << guest << std::endl;
  }
}

int showMenuSelection() {
  std::cout << std::endl << std::endl;
  std::cout << "-- Menu (Guest list manager) --" << std::endl;
  std::cout << "\t 1 - New guest" << std::endl;
  std::cout << "\t 2 - Remove guest" << std::endl;
  std::cout << "\t 3 - Check guest" << std::endl;
  std::cout << "\t 4 - Show guests" << std::endl;
  std::cout << "\t 5 - Clear guest list" << std::endl;
  std::cout << "\t 9 - Exit" << std::endl;
  std::cout << std::endl << "Selection: ";
  int selection;
  std::cin >> selection;
  return selection;
}

int main() {
  std::vector<std::string> guests;

  while (int selection = showMenuSelection()) {
    switch (selection) {
      case 1:
        createGuest(guests);
        break;
      case 2:
        removeGuest(guests);
        break;
      case 3:
        checkGuest(guests);
        break;
      case 4:
        showGuests(guests);
        break;
      case 5:
        guests.clear();
        std::cout << "The guest list was cleared!" << std::endl;
        break;
      case 9:
        return 0;
        break;
    }
  }

  return 0;
}