如何在里面添加一个功能按学号删除学生记录？(语言-c++)

Question

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

using namespace std;

class Date
{
public:
    void SetDate()
    {
        cout << "请输入年份：";
        cin >> year;
        cout << "请输入月份：";
        cin >> month;
        cout << "请输入日期：";
        cin >> day;
    }

    int GetYear() { return year; }
    int GetMonth() { return month; }
    int GetDay() { return day; }

private:
    int year;
    int month;
    int day;
};

class Student
{
public:
    void InputStudent(Date &birthday)
    {
        ofstream outfile("student.txt", ios::app);

        cout << "请输入学号：";
        cin >> num;
        cout << "请输入姓名：";
        cin >> name;
        birthday.SetDate();

        cout << "请输入性别：";
        cin >> gender;

        cout << "请输入三门课成绩：";
        cin >> score1 >> score2 >> score3;

        double average = (score1 + score2 + score3) / 3.0;
        int max_score = max({score1, score2, score3});
        int min_score = min({score1, score2, score3});

        outfile << num << " " << name << " " << birthday.GetYear() << " " << birthday.GetMonth() << " " << birthday.GetDay()
                << " " << gender << " " << score1 << " " << score2 << " " << score3 << " " << average << " " << max_score << " " << min_score << endl;

        cout << "学生信息录入成功！" << endl;
        outfile.close();
    }

    void DisplayAllStudents()
    {
        ifstream infile("student.txt");
        string line;
        while (getline(infile, line))
        {
            cout << line << endl;
        }
        infile.close();
    }

    void FindStudentByNum(int findnum)
    {
        ifstream infile("student.txt");
        int num;
        string line;
        bool found = false;
        while (infile >> num)
        {
            if (num == findnum)
            {
                getline(infile, line);
                cout << num << " " << line << endl;
                found = true;
                break;
            }
            getline(infile, line);
        }

        infile.close();

        if (!found)
        {
            cout << "未找到学号为 " << findnum << " 的学生" << endl;
        }
    }

    void AlterDateByNum(int findnum)
    {
        // 实现修改日期的方法
        // 省略具体实现代码
         fstream file("student.txt");
    ofstream temp("temp.txt");
    int num;
    string name, gender, line;
    int year, month, day, score1, score2, score3;
    double average;
    bool found = false;

    while (file >> num >> name >> year >> month >> day >> gender >> score1 >> score2 >> score3 >> average)
    {
        if (num == findnum)
        {
            Date newDate;
            newDate.SetDate();

            temp << num << " " << name << " " << newDate.GetYear() << " " << newDate.GetMonth() << " " << newDate.GetDay()
                 << " " << gender << " " << score1 << " " << score2 << " " << score3 << " " << average << endl;

            found = true;
            cout << "已成功修改学号为 " << num << " 的学生的出生日期！" << endl;
        }
        else
        {
            temp << num << " " << name << " " << year << " " << month << " " << day << " " << gender << " "
                 << score1 << " " << score2 << " " << score3 << " " << average << endl;
        }
    }

    file.close();
    temp.close();

    remove("student.txt");
    rename("temp.txt", "student.txt");

    if (!found)
    {
        cout << "未找到学号为 " << findnum << " 的学生" << endl;
    }
    }

    void AlterScoreByNum(int findnum)
    {
        // 实现修改成绩的方法
        // 省略具体实现代码
         fstream file("student.txt");
    ofstream temp("temp.txt");
    int num;
    string name, gender, line;
    int year, month, day, score1, score2, score3;
    double average;
    bool found = false;

    while (file >> num >> name >> year >> month >> day >> gender >> score1 >> score2 >> score3 >> average)
    {
        if (num == findnum)
        {
            int newScore1, newScore2, newScore3;
            cout << "请输入新的三门课成绩: ";
            cin >> newScore1 >> newScore2 >> newScore3;

            double newAverage = (newScore1 + newScore2 + newScore3) / 3.0;
            int newMax = max({newScore1, newScore2, newScore3});
            int newMin = min({newScore1, newScore2, newScore3});

            temp << num << " " << name << " " << year << " " << month << " " << day << " " << gender << " "
                 << newScore1 << " " << newScore2 << " " << newScore3 << " " << newAverage << " " << newMax << " " << newMin << endl;

            found = true;
            cout << "已成功修改学号为 " << num << " 的学生成绩！" << endl;
        }
        else
        {
            temp << num << " " << name << " " << year << " " << month << " " << day << " " << gender << " "
                 << score1 << " " << score2 << " " << score3 << " " << average << endl;
        }
    }

    file.close();
    temp.close();

    remove("student.txt");
    rename("temp.txt", "student.txt");

    if (!found)
    {
        cout << "未找到学号为 " << findnum << " 的学生" << endl;
    }
    }

private:
    int num;
    string name;
    string gender;
    int score1, score2, score3;
};

int main()
{
    Student stu;
    Date birthday;
    int findnum;
    int choice;

    while (true)
    {
        cout << "***欢迎进入学生管理系统***" << endl;
        cout << "1. 录入学生信息" << endl;
        cout << "2. 浏览全部学生记录" << endl;
        cout << "3. 按学号查找学生记录" << endl;
        cout << "4. 按学号修改出生日期" << endl;
        cout << "5. 按学号修改学生成绩" << endl;
        cout << "6. 退出系统" << endl;
        cout << "请选择功能：";
        cin >> choice;

        switch (choice)
        {
        case 1:
            stu.InputStudent(birthday);
            break;
        case 2:
            stu.DisplayAllStudents();
            break;
        case 3:
            cout << "请输入要查找的学生学号：";
            cin >> findnum;
            stu.FindStudentByNum(findnum);
            break;
        case 4:
            cout << "请输入要修改日期的学生学号：";
            cin >> findnum;
            stu.AlterDateByNum(findnum);
            break;
        case 5:
            cout << "请输入要修改成绩的学生学号：";
            cin >> findnum;
            stu.AlterScoreByNum(findnum);
            break;
        case 6:
            cout << "感谢使用，再见！" << endl;
            return 0;
        default:
            cout << "无效的选项，请重新选择。" << endl;
            break;
        }
    }

    return 0;
}

在里面添加一个功能按学号删除学生记录另外使这个代码更加简洁

Answer 1

以下内容由CHATGPT及阿里嘎多学长共同生成、有用望采纳：

---

要在现有的C++学生管理系统中添加一个按学号删除学生记录的功能，并优化现有代码，以下是一些建议和代码示例：

1. 添加删除学生记录的功能

你可以添加一个新的成员函数DeleteStudentByNum到Student类中，这个函数将遍历文件，将不匹配指定学号的学生记录写入一个临时文件，然后替换原文件。

void DeleteStudentByNum(int delnum) {
    fstream file("student.txt");
    ofstream temp("temp.txt");
    string line;
    bool shouldDelete = false;

    while (getline(file, line)) {
        int num;
        istringstream iss(line);
        iss >> num;
        if (num != delnum) {
            temp << line << endl;
        } else {
            shouldDelete = true;
        }
    }

    file.close();
    temp.close();

    if (shouldDelete) {
        remove("student.txt");
        rename("temp.txt", "student.txt");
        cout << "已成功删除学号为 " << delnum << " 的学生记录！" << endl;
    } else {
        cout << "未找到学号为 " << delnum << " 的学生记录" << endl;
    }
}

2. 优化AlterDateByNum和AlterScoreByNum函数

你可以创建一个通用的函数AlterStudentRecord来避免代码重复，这个函数可以接收一个修改函数作为参数，然后应用这个函数到找到的学生记录上。

template<typename Func>
void AlterStudentRecord(int findnum, Func modifyFunc) {
    fstream file("student.txt");
    ofstream temp("temp.txt");
    bool found = false;

    while (getline(file, line)) {
        istringstream iss(line);
        int num;
        if (!(iss >> num)) break; // 错误的数据格式

        if (num == findnum) {
            modifyFunc(iss, temp);
            found = true;
        } else {
            temp << line << endl;
        }
    }

    file.close();
    temp.close();

    if (found) {
        remove("student.txt");
        rename("temp.txt", "student.txt");
    } else {
        cout << "未找到学号为 " << findnum << " 的学生" << endl;
    }
}

// 修改日期的函数
void ModifyDate(istringstream &iss, ofstream &temp) {
    Date newDate;
    newDate.SetDate();
    // 构造新的记录并写入temp
}

// 修改成绩的函数
void ModifyScore(istringstream &iss, ofstream &temp) {
    // 读取当前成绩并提示用户输入新成绩
    // 构造新的记录并写入temp
}

然后在AlterDateByNum和AlterScoreByNum中调用AlterStudentRecord：

void AlterDateByNum(int findnum) {
    AlterStudentRecord(findnum, ModifyDate);
}

void AlterScoreByNum(int findnum) {
    AlterStudentRecord(findnum, ModifyScore);
}

3. 改进文件操作

确保在文件操作中使用异常处理来处理可能的I/O错误，并且在删除和重命名文件之前检查操作是否成功。

4. 优化用户界面和交互流程

提供一个清晰的菜单，让用户可以容易地选择他们想要的操作。同时，确保所有的输入都有错误检查，以避免无效或恶意的输入。

最后，确保你的代码风格一致，使用适当的变量名和函数名，这样可以提高代码的可读性和可维护性。