开发一个简单的课表查询系统，实现以下基本功能： 【基本功能】 课表数据文件。每个课表的信息包括：学期、专业班级、时间、科目、教室等基本信息。 能够按给定班级、时间等信息进行查找并显示相关信息。 能够添加、删除或修改课表中的课程信息。 能够按照学期或班级信息对课表进行排序，并存入文件中。 【扩展功能】 可以按照自己对课表查询系统的需求理解进行扩展。比如：（1）权限处理 （2）模糊查询（3）综合查询（4）统计功能等。用c++写出完整代码

很好，这是一个比较实用的项目。以下是一个基本的课表查询系统的代码：

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

using namespace std;

struct Course {
    string semester;
    string major;
    string grade;
    string subject;
    string classroom;
    string time;
};

// 从文件中读取课程信息
void readCourses(vector<Course>& courses) {
    ifstream fin("courses.txt");
    if (!fin.is_open()) {
        cout << "Error opening file!" << endl;
        return;
    }

    Course course;
    while (fin >> course.semester >> course.major >> course.grade >> course.subject >> course.classroom >> course.time) {
        courses.push_back(course);
    }

    fin.close();
}

// 向文件中写入课程信息
void writeCourses(vector<Course>& courses) {
    ofstream fout("courses.txt");
    if (!fout.is_open()) {
        cout << "Error opening file!" << endl;
        return;
    }

    for (int i = 0; i < courses.size(); i++) {
        fout << courses[i].semester << " " << courses[i].major << " " << courses[i].grade << " " << courses[i].subject << " " << courses[i].classroom << " " << courses[i].time << endl;
    }

    fout.close();
}

// 根据班级和时间查询课程
void searchCourses(vector<Course>& courses) {
    string major, grade, time;
    cout << "Please enter major, grade and time:" << endl;
    cin >> major >> grade >> time;

    cout << "Search result:" << endl;
    for (int i = 0; i < courses.size(); i++) {
        if (courses[i].major == major && courses[i].grade == grade && courses[i].time == time) {
            cout << courses[i].semester << " " << courses[i].major << " " << courses[i].grade << " " << courses[i].subject << " " << courses[i].classroom << " " << courses[i].time << endl;
        }
    }
}

// 添加课程
void addCourse(vector<Course>& courses) {
    Course course;
    cout << "Please enter semester, major, grade, subject, classroom and time:" << endl;
    cin >> course.semester >> course.major >> course.grade >> course.subject >> course.classroom >> course.time;
    courses.push_back(course);
}

// 删除课程
void deleteCourse(vector<Course>& courses) {
    string major, grade, subject, classroom, time;
    cout << "Please enter major, grade, subject, classroom and time:" << endl;
    cin >> major >> grade >> subject >> classroom >> time;

    for (int i = 0; i < courses.size(); i++) {
        if (courses[i].major == major && courses[i].grade == grade && courses[i].subject == subject && courses[i].classroom == classroom && courses[i].time == time) {
            courses.erase(courses.begin() + i);
            cout << "Delete successfully!" << endl;
            return;
        }
    }

    cout << "Course not found!" << endl;
}

// 修改课程
void modifyCourse(vector<Course>& courses) {
    string major, grade, subject, classroom, time;
    cout << "Please enter major, grade, subject, classroom and time of the course you want to modify:" << endl;
    cin >> major >> grade >> subject >> classroom >> time;

    for (int i = 0; i < courses.size(); i++) {
        if (courses[i].major == major && courses[i].grade == grade && courses[i].subject == subject && courses[i].classroom == classroom && courses[i].time == time) {
            cout << "Please enter new semester, major, grade, subject, classroom and time:" << endl;
            cin >> courses[i].semester >> courses[i].major >> courses[i].grade >> courses[i].subject >> courses[i].classroom >> courses[i].time;
            cout << "Modify successfully!" << endl;
            return;
        }
    }

    cout << "Course not found!" << endl;
}

// 按照学期排序
bool sortBySemester(const Course& a, const Course& b) {
    return a.semester < b.semester;
}

// 按照班级排序
bool sortByMajor(const Course& a, const Course& b) {
    if (a.major != b.major) {
        return a.major < b.major;
    } else if (a.grade != b.grade) {
        return a.grade < b.grade;
    } else {
        return a.time < b.time;
    }
}

// 排序并存入文件
void sortAndSave(vector<Course>& courses) {
    int choice;
    cout << "Please choose the sort method (1 for semester, 2 for major):" << endl;
    cin >> choice;

    if (choice == 1) {
        sort(courses.begin(), courses.end(), sortBySemester);
    } else if (choice == 2) {
        sort(courses.begin(), courses.end(), sortByMajor);
    } else {
        cout << "Invalid choice!" << endl;
        return;
    }

    writeCourses(courses);
    cout << "Sort and save successfully!" << endl;
}

int main() {
    vector<Course> courses;
    readCourses(courses);

    int choice;
    while (true) {
        cout << endl << "Please choose an operation:" << endl;
        cout << "1. Search courses" << endl;
        cout << "2. Add course" << endl;
        cout << "3. Delete course" << endl;
        cout << "4. Modify course" << endl;
        cout << "5. Sort and save" << endl;
        cout << "6. Exit" << endl;

        cin >> choice;

        switch (choice) {
            case 1:
                searchCourses(courses);
                break;
            case 2:
                addCourse(courses);
                break;
            case 3:
                deleteCourse(courses);
                break;
            case 4:
                modifyCourse(courses);
                break;
            case 5:
                sortAndSave(courses);
                break;
            case 6:
                writeCourses(courses);
                cout << "Goodbye!" << endl;
                return 0;
            default:
                cout << "Invalid choice!" << endl;
        }
    }
}

这个代码可能还有一些不完善的地方，但是已经实现了基本的功能。你可以根据自己的需求进行扩展，加入更多的功能。