用C++编写

以下是一个使用C++编写的学生成绩文件管理代码示例：

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

using namespace std;

class Student {
private:
    string name;
    int grade;
public:
    Student(string n, int g) {
        name = n;
        grade = g;
    }
    string get_name() {
        return name;
    }
    int get_grade() {
        return grade;
    }
};

class GradeBook {
private:
    vector<Student> students;
public:
    void add_student(Student s) {
        students.push_back(s);
    }
    void remove_student(Student s) {
        for (int i = 0; i < students.size(); i++) {
            if (students[i].get_name() == s.get_name()) {
                students.erase(students.begin() + i);
                break;
            }
        }
    }
    void save_grades(string filename) {
        ofstream fout(filename);
        for (int i = 0; i < students.size(); i++) {
            fout << students[i].get_name() << "," << students[i].get_grade() << endl;
        }
        fout.close();
    }
    void load_grades(string filename) {
        ifstream fin(filename);
        string line;
        while (getline(fin, line)) {
            string name = line.substr(0, line.find(","));
            int grade = stoi(line.substr(line.find(",") + 1));
            Student s(name, grade);
            add_student(s);
        }
        fin.close();
    }
    void print_grades() {
        for (int i = 0; i < students.size(); i++) {
            cout << students[i].get_name() << ": " << students[i].get_grade() << endl;
        }
    }
};

int main() {
    GradeBook book;

    // Add some students
    book.add_student(Student("Alice", 90));
    book.add_student(Student("Bob", 80));
    book.add_student(Student("Charlie", 70));

    // Save the grades to a file
    book.save_grades("grades.txt");

    // Remove a student
    book.remove_student(Student("Bob", 80));

    // Load the grades from the file
    book.load_grades("grades.txt");

    // Print the grades
    book.print_grades();

    return 0;
}

该代码包含两个类：`Student` 表示学生对象，包含姓名和成绩属性，`GradeBook` 表示成绩册对象，包含学生列表以及添加、删除、保存、加载和打印学生成绩的方法。

你可以根据自己的需求进行修改和扩展。