C++学生成绩管理系统

以下是一个简单的C++学生成绩管理系统的代码，它使用了链表来存储学生信息和成绩，并提供了增删改查和文件保存功能：

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

// 定义学生类
class Student {
public:
    string name;
    int id;
    float score;
    Student* next;
};

// 定义教师类
class Teacher {
public:
    Student* head;
    Teacher() {
        head = new Student();
        head->next = NULL;
    }
    // 添加学生信息
    void addStudent() {
        Student* p = head;
        while (p->next != NULL) {
            p = p->next;
        }
        Student* newStudent = new Student();
        cout << "请输入学生姓名：";
        cin >> newStudent->name;
        cout << "请输入学生学号：";
        cin >> newStudent->id;
        cout << "请输入学生成绩：";
        cin >> newStudent->score;
        newStudent->next = NULL;
        p->next = newStudent;
        cout << "添加成功！" << endl;
    }
    // 删除学生信息
    void deleteStudent() {
        int id;
        cout << "请输入要删除的学生学号：";
        cin >> id;
        Student* p = head->next;
        Student* pre = head;
        while (p != NULL) {
            if (p->id == id) {
                pre->next = p->next;
                delete p;
                cout << "删除成功！ << endl;
                return;
            }
            pre = p;
            p = p->next;
        }
        cout << "未找到该学生！" << endl;
    }
    // 修改学生信息
    void modifyStudent() {
        int id;
        cout << "请输入要修改的学生学号：";
        cin >> id;
        Student* p = head->next;
        while (p != NULL) {
            if (p->id == id) {
                cout << "请输入学生姓名：";
                cin >> p->name;
                cout << "请输入学生成绩：";
                cin >> p->score;
                cout << "修改成功！ << endl;
                return;
            }
            p = p->next;
        }
        cout << "未找到该学生！ << endl;
    }
    // 查询学生信息
    void queryStudent() {
        int id;
        cout << "请输入要查询的学生学号：";
        cin >> id;
        Student* p = head->next;
        while (p != NULL) {
            if (p->id == id) {
                cout << "学生姓名：" << p->name << endl;
                cout << "学生学号：" << p->id << endl;
                cout << "学生成绩：" << p->score << endl;
                return;
            }
            p = p->next;
        }
        cout << "未找到该学生！" << endl;
    }
    // 保存学生信息到文件
    void saveToFile() {
        ofstream outfile("students.txt");
        Student* p = head->next;
        while (p != NULL) {
            outfile << p->name << " " << p->id << " " << p->score << endl;
            p = p->next;
        }
        outfile.close();
        cout << "保存成功！" << endl;
    }
};

int main() {
    Teacher teacher;
    int choice;
    while (true) {
        cout << "请选择操作：" << endl;
        cout << "1.添加学生信息" << endl;
        cout << "2.删除学生信息" << endl;
        cout << "3.修改学生信息" << endl;
        cout << "4.查询学生信息" << endl;
        cout << "5.保存学生信息到文件" << endl;
        cout << "6.退出" << endl;
        cin >> choice;
        switch (choice) {
        case 1:
            teacher.addStudent();
            break;
        case 2:
            teacher.deleteStudent();
            break;
        case 3:
            teacher.modifyStudent();
            break;
        case 4:
            teacher.queryStudent();
            break;
        case 5:
            teacher.saveToFile();
            break;
        case 6:
            return 0;
        default:
            cout << "输入有误，请重新输入！" << endl;
            break;
        }
    }
    return 0;
}