能帮我写一段完整能用的vs代码，利用控制台做一个简单的选课系统吗，复制粘贴就能用的那种

好的，以下是一个简单的选课系统的VS代码。请注意，这仅仅是一个示例，你可能需要根据你的具体需求进行修改和调整。

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

using namespace std;

// 定义课程结构体
struct Course {
    string name;
    int credit;
};

// 定义学生结构体
struct Student {
    string name;
    int id;
    vector<Course> courses;
};

// 定义全局变量
vector<Course> all_courses = {{"数学", 3}, {"英语", 2}, {"物理", 4}, {"化学", 3}, {"计算机", 3}};
vector<Student> all_students;

// 显示主菜单
void show_menu() {
    cout << "==========================" << endl;
    cout << "欢迎使用选课系统" << endl;
    cout << "请选择以下操作：" << endl;
    cout << "1. 添加学生" << endl;
    cout << "2. 显示学生" << endl;
    cout << "3. 添加课程" << endl;
    cout << "4. 显示课程" << endl;
    cout << "5. 学生选课" << endl;
    cout << "6. 退出" << endl;
    cout << "==========================" << endl;
}

// 添加学生
void add_student() {
    Student student;
    cout << "请输入学生姓名：";
    cin >> student.name;
    cout << "请输入学生学号：";
    cin >> student.id;
    all_students.push_back(student);
    cout << "添加学生成功！" << endl;
}

// 显示学生
void show_students() {
    cout << "所有学生信息如下：" << endl;
    for (int i = 0; i < all_students.size(); i++) {
        cout << "姓名：" << all_students[i].name << "，学号：" << all_students[i].id << endl;
    }
}

// 添加课程
void add_course() {
    Course course;
    cout << "请输入课程名称：";
    cin >> course.name;
    cout << "请输入课程学分：";
    cin >> course.credit;
    all_courses.push_back(course);
    cout << "添加课程成功！" << endl;
}

// 显示课程
void show_courses() {
    cout << "所有课程信息如下：" << endl;
    for (int i = 0; i < all_courses.size(); i++) {
        cout << "课程名称：" << all_courses[i].name << "，课程学分：" << all_courses[i].credit << endl;
    }
}

// 学生选课
void select_course() {
    int student_id;
    cout << "请输入学生学号：";
    cin >> student_id;
    int course_index;
    cout << "请选择课程：" << endl;
    for (int i = 0; i < all_courses.size(); i++) {
        cout << i + 1 << ". " << all_courses[i].name << "（学分：" << all_courses[i].credit << "）" << endl;
    }
    cin >> course_index;
    if (course_index < 1 || course_index > all_courses.size()) {
        cout << "选择的课程不存在！" << endl;
        return;
    }
    int student_index = -1;
    for (int i = 0; i < all_students.size(); i++) {
        if (all_students[i].id == student_id) {
            student_index = i;
            break;
        }
    }
    if (student_index == -1) {
        cout << "输入的学生学号不存在！" << endl;
        return;
    }
    for (int i = 0; i < all_students[student_index].courses.size(); i++) {
        if (all_students[student_index].courses[i].name == all_courses[course_index - 1].name) {
            cout << "该学生已经选过该课程！" << endl;
            return;
        }
    }
    all_students[student_index].courses.push_back(all_courses[course_index - 1]);
    cout << "选课成功！" << endl;
}

int main() {
    while (true) {
        show_menu();
        int choice;
        cin >> choice;
        switch (choice) {
            case 1:
                add_student();
                break;
            case 2:
                show_students();
                break;
            case 3:
                add_course();
                break;
            case 4:
                show_courses();
                break;
            case 5:
                select_course();
                break;
            case 6:
                cout << "欢迎下次使用！" << endl;
                return 0;
            default:
                cout << "输入的选项不存在，请重新输入！" << endl;
                break;
        }
    }
    return 0;
}

这段代码可以在Visual Studio中直接复制粘贴并运行。当然，你需要根据你的需要进行修改和调整，使其符合你的具体需求。