#include <iostream>
#include <fstream>
#include <string>
#include <vector>

class Student {
private:
	std::string name;
	int age;
	int studentNumber;
	
public:
	Student(std::string n, int a, int sn) : name(n), age(a), studentNumber(sn) {}
	
	std::string getName() const {
		return name;
	}
	
	int getAge() const {
		return age;
	}
	
	int getStudentNumber() const {
		return studentNumber;
	}
};

void saveData(const std::vector<Student>& students) {
	std::ofstream file("student_data.txt");
	if (file.is_open()) {
		for (const auto& student : students) {
			file << student.getName() << " " << student.getAge() << " " << student.getStudentNumber() << std::endl;
		}
		file.close();
	} else {
		std::cout << "Error: Unable to open file for writing." << std::endl;
	}
}

void readData(std::vector<Student>& students) {
	std::ifstream file("student_data.txt");
	if (file.is_open()) {
		std::string name;
		int age, studentNumber;
		while (file >> name >> age >> studentNumber) {
			students.push_back(Student(name, age, studentNumber));
		}
		file.close();
	} else {
		std::cout << "No existing data found." << std::endl;
	}
}

int main() {
	std::vector<Student> students;
	
	// 读取文件中已存在的数据
	readData(students);
	
	int choice;
	do {
		std::cout << "1. Add student\n";
		std::cout << "2. Delete student\n";
		std::cout << "3. Update student\n";
		std::cout << "4. View all students\n";
		std::cout << "5. Save and exit\n";
		std::cin >> choice;
		
		switch (choice) {
			case 1: {
				std::string name;
				int age, studentNumber;
				std::cout << "Enter name, age, and student number: ";
				std::cin >> name >> age >> studentNumber;
				students.push_back(Student(name, age, studentNumber));
				break;
			}
			case 2: {
				// Delete student
				// Your code to delete a student here
				break;
			}
			case 3: {
				// Update student
				// Your code to update a student here
				break;
			}
			case 4: {
				// View all students
				for (const auto& student : students) {
					std::cout << student.getName() << " " << student.getAge() << " " << student.getStudentNumber() << std::endl;
				}
				break;
			}
			case 5: {
				// Save and exit
				saveData(students);
				std::cout << "Data saved. Goodbye!" << std::endl;
				break;
			}
		default:
			std::cout << "Invalid choice!" << std::endl;
		}
	} while (choice != 5);
	
	return 0;
}