StudentSystem/StudentSystem.cpp

#include <iostream>
#include <map>
#include <fstream>
#include <string>
#include <unordered_map>

// 基类 Student
class Student {
	protected:
		std::string name;
		std::string id;
		float totalScore;

	public:
		Student(const std::string &name, const std::string &id) : name(name), id(id), totalScore(0.0f) {}
		virtual ~Student() {}

		virtual void calculateTotalScore() = 0;
		virtual void display() const = 0;

		const std::string &getName() const {
			return name;
		}
		const std::string &getId() const {
			return id;
		}
		float getTotalScore() const {
			return totalScore;
		}
};

// 本科生类 Undergraduate
class Undergraduate : public Student {
	private:
		float usualScore;
		float midtermScore;
		float finalScore;

	public:
		Undergraduate(const std::string &name, const std::string &id, float usual, float midterm, float final)
			: Student(name, id), usualScore(usual), midtermScore(midterm), finalScore(final) {}

		void calculateTotalScore() override {
			totalScore = usualScore * 0.3f + midtermScore * 0.3f + finalScore * 0.4f;
		}

		void display() const override {
			std::cout << "姓名: " << name << ", ID: " << id
			          << ", 平时成绩: " << usualScore
			          << ", 期中成绩: " << midtermScore
			          << ", 期末成绩: " << finalScore
			          << ", 总分: " << totalScore << std::endl;
		}
};

// 研究生类 Graduate
class Graduate : public Student {
	private:
		float writtenScore;
		float interviewScore;

	public:
		Graduate(const std::string &name, const std::string &id, float written, float interview)
			: Student(name, id), writtenScore(written), interviewScore(interview) {}

		void calculateTotalScore() override {
			totalScore = writtenScore * 0.7f + interviewScore * 0.3f;
		}

		void display() const override {
			std::cout << "姓名: " << name << ", ID: " << id
			          << ", 笔试成绩: " << writtenScore
			          << ", 面试成绩: " << interviewScore
			          << ", 总分: " << totalScore << std::endl;
		}
};

// 学生管理类 StudentManager
class StudentManager {
	private:
		std::map<std::string, Student *> students;

	public:
		void addStudent(Student *student) {
			students[student->getId()] = student;
		}

		void removeStudent(const std::string &id) {
			if (students.find(id) != students.end()) {
				delete students[id];
				students.erase(id);
				std::cout << "学生 " << id << " 成功删除." << std::endl;
			} else {
				std::cerr << "学生 " << id << " 不存在." << std::endl;
			}
		}

		void queryStudent(const std::string &id) {
			if (students.find(id) != students.end()) {
				students[id]->display();
			} else {
				std::cerr << "学生 " << id << " 不存在." << std::endl;
			}
		}

		void displayAllStudents() {
			for (const auto &pair : students) {
				pair.second->display();
			}
		}

		void saveToFile(const StudentManager &manager, const std::string &filename) {
			std::ofstream outfile(filename);
			if (!outfile.is_open()) {
				std::cerr << "文件不存在" << std::endl;
				return;
			}
			for (const auto &pair : manager.students) {
				pair.second->display();
				outfile << pair.second->getName() << "," << pair.second->getId() << "," << pair.second->getTotalScore() << std::endl;
			}
			outfile.close();
			std::cout << "数据成功录入." << std::endl;
		}

};

int main() {
	StudentManager manager;
	bool running = true;
	int choice;

	while (running) {
		std::cout << "学生成绩管理系统\n";
		std::cout << "输入1以添加学生\n";
		std::cout << "输入2以查询学生\n";
		std::cout << "输入3以删除学生\n";
		std::cout << "输入4以展示所有学生成绩\n";
		std::cout << "输入5以保存数据\n";
		std::cout << "输入6以退出\n";
		std::cout << "请输入你的指令: \n";
		std::cin >> choice;

		switch (choice) {
			case 1: {
				std::string name, id, type;
				float score1, score2, score3;
				std::cout << "输入学生姓名: ";
				std::cin >> name;
				std::cout << "输入学生ID: ";
				std::cin >> id;
				std::cout << "如果是本科生请输入u，研究生则输入g :";
				std::cin >> type;


				if (type == "u" || type == "U") {
					std::cout << "输入平时成绩: ";
					std::cin >> score1;
					std::cout << "输入期中成绩: ";
					std::cin >> score2;
					std::cout << "输入期末成绩: ";
					std::cin >> score3;
					std::cout << "添加成功\n"<<std::endl;
					Undergraduate *undergraduate = new Undergraduate(name, id, score1, score2, score3);
					undergraduate->calculateTotalScore();
					manager.addStudent(undergraduate);
				} else if (type == "g" || type == "G") {
					std::cout << "输入笔试成绩: ";
					std::cin >> score1;
					std::cout << "输入面试成绩: ";
					std::cin >> score2;
					std::cout << "添加成功\n"<<std::endl;
					Graduate *graduate = new Graduate(name, id, score1, score2);
					graduate->calculateTotalScore();
					manager.addStudent(graduate);
				} else {
					std::cerr << "不存在该类型. 请重试." << std::endl;
				}
				break;
			}
			case 2: {
				std::string id;
				std::cout << "输入需要查询的学生的ID: ";
				std::cin >> id;
				manager.queryStudent(id);
				break;
			}
			case 3: {
				std::string id;
				std::cout << "输入需要删除的学生的ID: ";
				std::cin >> id;
				manager.removeStudent(id);
				break;
			}
			case 4: {
				manager.displayAllStudents();
				break;
			}
			case 5: {
				std::string filename;
				std::cout << "输入文件名称: ";
				std::cin >> filename;
				manager.saveToFile(manager, filename);
				break;
			}
			case 6: {
				running = false;
				std::cout << "正在退出" << std::endl;
				break;
			}
			default: {
				std::cout << "不存在该选项，请重试." << std::endl;
			}
		}
	}
	return 0;
}