求一个学生信息管理系统C++2022年12月22日要

学生信息管理系统的设计与实现
主要功能:
1.学籍信息管理
2.成绩信息管理
学籍信息:学号、姓名、性别、年龄、电话、专业等（学号不重复）。
学籍信息管理功能：
(1)输入功能：学生信息录入（学生信息用文件保存）
(2)浏览功能：完成对全部学生信息的显示。
(3)查找功能：
①完成按学生的学号查询学生的相关信息，并显示。
②完成按学生的电话号码查询学生的相关信息，并显示。
③完成按学生的姓名查询学生的相关信息，并显示，允许重名。
(4)删除功能：通过输入学生的姓名完成对该名学生的信息进行删除。
(5)添加功能：完成添加新学生的信息的任务。
(6)修改功能：通过输入学生的姓名完成对该名学生的信息进行修改。
成绩信息：学号，姓名，专业，语文成绩，数学成绩，英语成绩.
成绩信息管理提供以下功能：
(1)录入每个学生的学号、姓名和各科考试成绩。
(2)计算每门课程的总分和平均分
(3)计算每个学生的总分和平均分。
(4)按每个学生的总分由高到低排出名次表。
(5)按学号由小到大排出成绩表。
(6)按学号查询学生排名及其考试成绩。
(7)按姓名查询学生排名及其考试成绩。
(8)查询语文最高分的学生信息。
(9)查询总成绩最高的3名学生的学籍信息和总分。

https://blog.csdn.net/m0_62754376/article/details/125340297

这是我自己写的一个：

源码在这里：

基于C++实现的学生信息管理系统（源码+报告+截图）.zip-C++文档类资源-CSDN下载 本系统完成的主要功能有：1.从键盘录入学生个人信息并保存到文件中；2.从文件中读取学生个人信息；更多下载资源、学习资料请访问CSDN下载频道. https://download.csdn.net/download/qq_64505944/87260585

这是写的另一个：

源码：

基于C++实现的学生成绩管理系统（源码+课设）.zip_c++学生成绩管理系统代码-C++文档类资源-CSDN下载 本系统在设计时应该满足以下几点：（1）对学生信息操作简单，可以方便地进行添加，修改和输出操作。（c++学生成绩管理系统代码更多下载资源、学习资料请访问CSDN下载频道. https://download.csdn.net/download/qq_64505944/87256329

需要的话可以采纳

• 这有个类似的问题, 你可以参考下: https://ask.csdn.net/questions/7735170

C++课设-学生信息管理系统
借鉴下
https://blog.csdn.net/qq_41105058/article/details/105286837

#include "Stu_one.h"
#include "Stu_two.h"
#include <map>
#include <fstream>
using namespace std;
map<int,Stu> Stu_map;
 
void Reload();//加载当前所有记录
void SaveRecord();//保存当前所有记录
void Add_Stu();//添加学生模块
void Delete_Stu();//删除学生模块
void Traverse_Stu();//遍历所有学生
 
 
int main()
{
 
 
    int chioce=0;
    while(1){
    cout<<"--------------------------------学生管理系统----------------------------------------" << endl;
    cout<<"1.添加学生"<<endl;
    cout<<"2.删除学生"<<endl;
    cout<<"3.按年级输出学生信息"<<endl;
    cout<<"4.按性别输出学生信息"<<endl;
    cout<<"5.按姓名检索学生"<<endl;
    cout<<"6.输出学生的成绩情况"<<endl;
    cout<<"7.显示全部学生"<<endl;
    cout<<"8.保存当前记录"<<endl;
    cout<<"9.从文件中读取数据"<<endl;
    cout<<"请输入你的选择:"<<endl;
    cin>>chioce;
    switch(chioce){
        case 1:
            Add_Stu();
            break;
        case 2:
            Delete_Stu();
            break;
        case 3:
            break;
        case 4:
            break;
        case 5:
            break;
        case 6:
            break;
        case 7:
            Traverse_Stu();
        case 8:
            SaveRecord();
            break;
        case 9:
            Reload();
    }
 
    }
    return 0;
}
//加载记录
void Reload(){
    ifstream savefile("save.txt",ios::in | ios::binary);
     string name;
     Stu stu;
     int b=0;
     while(savefile.eof()!=1) {
        savefile.read((char *)&stu,sizeof(Stu));
        Stu_map.insert(map<int, Stu>::value_type (stu.Get_Id(), stu));
    }
 
    savefile.close();
}
//保存记录
void SaveRecord(){
     ofstream savefile("save.txt",ios::out | ios::binary );
     map<int, Stu>::iterator iter;
     iter = Stu_map.begin();
     string name;
     while(iter != Stu_map.end()) {
       Stu stu=(Stu)iter->second;
       savefile.write((char*)&(stu),sizeof(Stu));
       iter++;
    }
    savefile.close();
 
 
}
//遍历
void Traverse_Stu(){
     map<int, Stu>::iterator iter;
     iter = Stu_map.begin();
     while(iter != Stu_map.end()) {
        cout<<iter->second<<endl;
        iter++;
    }
}
//删除
void Delete_Stu(){
    int id=0;
    cout<<"请输入欲删除学生的学号："<<endl;
    cin>>id;
    if(id!=0){
        Stu_map.erase(id);
    }
}
//添加
void Add_Stu(){//添加学生模块
 
    int chioce=0;
    cout<<"1.添加1年级学生"<<endl;
    cout<<"2.添加2年级学生"<<endl;
    cout<<"3.请输入你的选择: "<<endl;
    cin>>chioce;
    switch(chioce){
    case 1:
            {
            Stu_one stu;
            cin>>stu;
            Stu_map.insert(map<int, Stu>::value_type (stu.Get_Id(), stu));
 
        }
        break;
    case 2:
        {
            Stu_two stu;
            cin>>stu;
            Stu_map.insert(map<int, Stu>::value_type (stu.Get_Id(), stu));
        }
        break;
    }
 
}
 
 

#include <cstdlib>
#include <iostream>
#include <string>
#include<windows.h>
#include<conio.h>
#include <fstream>
using namespace std;
#define null NULL
class student
{
    private:
        int flag;
        friend class studentMessage;
        student *next; //节点指针
        string name; //学生姓名
        string address;  //家庭住址
        int age; //年龄
        int id; //学号
        string sex;
        char grade;                  班级
        //  A    代表大学生
        //  B    代表中学生
        //  C    代表小学生
        double chinese , math , english;  //语文 ， 数学 ， 英语
        double history , geography ;     //历史  ， 地理
        string major; long long int TL;     //  专业  ，  电话

    public:
        static int num_total;  //总数
        static int num_sex;
        static int num_age;

        //小学生初始化
        student(int _id,string _name,string _sex,int _age,char _grade,double _chinese,double _math,double _english)
        {
            name = _name;
            grade = _grade;
            age  = _age;
            sex = _sex;
            id = _id;

            chinese = _chinese;
            math    =  _math;
            english = _english;
            next = NULL;
        }

        //初中生初始化
        student(int _id,string _name,string _sex,int _age,char _grade,double _geography,double _history,string _address)
        {
            name = _name;
            grade = _grade;
            age  = _age;
            sex = _sex;
            id = _id;

            geography = _geography;
            history   = _history;
            address    = _address;
            next = NULL;
        }
        //大学生初始化
        student(int _id,string _name,string _sex,int _age,char _grade,string _major,string _address,long long int _TL)
        {
            name = _name;
            grade = _grade;
            age  = _age;
            sex = _sex;
            id = _id;

            major  = _major;
            address = _address;
            TL     = _TL;
            next = NULL;
        }

        //构造函数
        student() //为studentMessage初始化头结点用
        {
            name = "null";
            sex = "null";
            address = "null";
            age = 0;
            id = 0;
            chinese = 0;
            math = 0;
            english = 0;
            grade = '0';
            geography = 0;
            history = 0;
            major = "null";
            TL = 0;
            next = NULL;
        }
        ~student(){}
        void swap(student*);
};
int student::num_total = 0; 初始化
int student::num_sex = 0;
int student::num_age = 0;

void student::swap(student *q)
{
    string _name,_sex,_address;
    int _age,_id;

     char grade;                  班级
        //  A    代表大学生
        //  B    代表中学生
        //  C    代表小学生
    double _chinese , _math , _english;  //语文 ， 数学 ， 英语
    double _history , _geography ;     //历史  ， 地理
    string _major; long long int _TL;     //  专业  ，  电话

    _chinese   = chinese;
    chinese    = q->chinese;
    q->chinese = _chinese;

    _math   =  math;
    math    =  q->math;
    q->math =  _math;

    _english   =  english;
    english    =  q->english;
    q->english =  _english;

    _history   = history;
    history    = q->history;
    q->history = _history;

    _geography   =  geography;
    geography    =  q->geography;
    q->geography =  _geography;

    _major   =  major;
    major    = q->major;
    q->major =  _major;

    _TL   = TL;
    TL    = q->TL;
    q->TL = _TL;

    _name   = name;
    name    = q->name;
    q->name = _name;

    _sex   = sex;
    sex    = q->sex;
    q->sex = _sex;

    _address   = address;
    address    = q->address;
    q->address = _address;

    _age   = age;
    age    = q->age;
    q->age = _age;

    _id   = id;
    id    = q->id;
    q->id = _id;



}
class studentMessage
{
    private:
      student *first; //头指针
      int num; //信息中的学生人数
    public:
        studentMessage()
        {
            num = 0; //初始化学生人数为0
            first = new student;  //初始化头结点
        }
        ~studentMessage(){delete first;}

        /*管理系统常规操作*/
        void Insret(void); //插入
        void Display(void); //显示
        void Delete(void); //删除
        void Search(void); //搜索
        void Change(void); //改动
        void SearchByid(void); //按照学号查找
        void SearchByname(void); //按照姓名查找
        int menu(void); //初始的菜单
        void clear(void); //清空列表
        void tongji(void);  //统计学生人数
        void save(void);
        void read(void);
};


int studentMessage::menu(void)
{
    system("cls");
    int ch;
    cout<<endl;cout<<endl;cout<<endl;cout<<endl;
    cout<<"**********************************************************************"<<endl;
    cout<<"======================================================================"<<endl;
    cout<<"***************************学生信息管理系统***************************"<<endl;cout<<endl;
    cout<<endl;
    cout<<"                            1.添加功能"<<endl;
    cout<<"                            2.查询功能"<<endl;
    cout<<"                            3.显示功能"<<endl;
    cout<<"                            4.编辑功能"<<endl;
    cout<<"                            5.删除功能"<<endl;
    cout<<"                            6.统计功能"<<endl;
    cout<<"                            7.保存功能"<<endl;
    cout<<"                            8.全部删除"<<endl;
    cout<<"                            0.退出系统"<<endl;cout<<endl;
    cout<<endl;
    cout<<"***********************************************************************"<<endl;
    cout<<"======================================================================="<<endl;
    cout<<"***********************************************************************"<<endl;
    cout<<endl;cout<<endl;cout<<endl;cout<<endl;cout<<endl;cout<<endl;
    cin >> ch;
    cout<<"\n\n\n"<<endl;
    return ch;
}

void studentMessage::save(void)
{
     system("cls");
     fstream f("student.txt",ios::out);
    int i;
    if(!f)
    {
        cout<<endl;cout<<endl;cout<<endl;
        cout<<"文件保存失败!！！！按任意键返回..."<<endl;
           if(i = getch()) return ;
    }

    if(student::num_total == 0)
        {
            f<<"当前记录中无学生..."<<endl;
        }

    else
        {
            student *p = first->next;
            while(p != null)
            {
                f<<"学号:"<<p->id<<"  "<<endl;
                f<<"姓名:"<<p->name<<endl;
                f<<"性别(boy/girl):"<<p->sex<<endl;
                f<<"年龄:"<<p->age<<endl;
                f<<"班级:"<<p->grade<<endl;

            if(p->grade == 'A')
            {
                f<<"专业："<<p->major<<endl;
                f<<"家庭住址："<<p->address<<endl;
                f<<"联系方式："<<p->TL<<endl;
            }

            else if(p->grade == 'B')
            {
                f<<"地理成绩："<<p->geography<<endl;
                f<<"历史成绩："<<p->history<<endl;
                f<<"家庭住址："<<p->address<<endl;
            }

            else
            {
                f<<"语文成绩："<<p->chinese<<endl;
                f<<"数学成绩："<<p->math<<endl;
                f<<"英语成绩："<<p->english<<endl;
            }
        f<<"------------------------------------------------"<<endl;
            p = p->next;
            }

        }
         f.close();
            cout<<endl;cout<<endl;cout<<endl;
            cout<<"学生信息文件已创建，按任意键继续"<<endl;
            i = getch();

}

void studentMessage::read(void)
{
    system("cls");
    string name;
    int age;
    int id;
    char grade;
    string sex,address;
    double chinese , math , english;  //语文 ， 数学 ， 英语
    double history , geography ;     //历史  ， 地理
    string major; long long int TL;     //  专业  ，  电话
    int i;
    char ch;
   ifstream f("student.txt");
    while(1)
    {
        f>>ch;
        if(f.eof())
        {
            cout<<"文件为空！按任意键返回"<<endl;
            if(i = getch()) return ;
        }

            f>>name;
            f>>sex;
            f>>age;
            f>>id;
            f>>grade;
        if(grade=='A')
        {
            f>>major;
            f>>address;
            f>>TL;
        }

        else if(grade == 'B')
        {

            f>>geography;
            f>>history;
            f>>address;
        }
        else
        {
            f>>chinese;
            f>>math;
            f>>english;
        }
        student::num_total ++;

        if(sex=="boy") student::num_sex++;
        if(age>=18) student::num_age ++;
        student *newstu = new student();
        if(grade == 'A')    newstu = new student(id,name,sex,age,grade,major,address,TL);
        else if(grade == 'B')    newstu = new student(id,name,sex,age,grade,geography,history,address);
        else if(grade == 'C')    newstu = new student(id,name,sex,age,grade,chinese,math,english);
    student *p = first;
    while(p->next != NULL)
        {
            p = p->next;
        }
        p->next = newstu;
        newstu->next = null;
    }

}
/统计
void studentMessage::tongji(void)
{
    system("cls");//
    cout<<"学生人数一共为：" <<student::num_total<<endl;
    cout<<"男生一共有："<<student::num_sex<<endl;
    cout<<"女生一共有："<<student::num_total-student::num_sex<<endl;
    cout<<"成年人有："<<student::num_age<<endl;
    int i;
            cout<<endl;cout<<endl;cout<<endl;
            cout<<"按任意键继续"<<endl;
            i = getch();
}


//插入
void studentMessage::Insret(void)
{
    system("cls");//
    string name;
    int age;
    int id;
    char grade;
    string sex,address;
    double chinese , math , english;  //语文 ， 数学 ， 英语
    double history , geography ;     //历史  ， 地理
    string major; long long int TL;     //  专业  ，  电话

    cout<<"请输入学生姓名: ";
    cin>>name;
    cout<<"请输入学生性别(boy/girl): ";
    cin>>sex;
    cout<<"请输入学生年龄: ";
    cin>>age;
    cout<<"请输入学生学号: ";
    cin>>id;
    cout<<"下面请输入学生班级(大学生输入'A'，初中生输入'B',小学生输入'C'): ";
    cout<<endl;
    cin>>grade;
    cout<<endl;
    if(grade=='A')
    {

        cout<<"请输入专业："<<endl;
        cin>>major;
        cout<<"请输入家庭住址："<<endl;
        cin>>address;
        cout<<"请输入联系电话："<<endl;
        cin>>TL;
    }

    else if(grade == 'B')
    {

        cout<<"请输入地理成绩："<<endl;
        cin>>geography;
        cout<<"请输入历史成绩："<<endl;
        cin>>history;
        cout<<"请输入家庭住址："<<endl;
        cin>>address;
    }
    else
    {
        cout<<"请输入语文成绩："<<endl;
        cin>>chinese;
        cout<<"请输入数学成成绩："<<endl;
        cin>>math;
        cout<<"请输入英语成绩："<<endl;
        cin>>english;
    }
    student::num_total ++;
    if(sex=="boy") student::num_sex++;
    if(age>=18) student::num_age ++;
    student *newstu = new student();
         if(grade == 'A')    newstu = new student(id,name,sex,age,grade,major,address,TL);
    else if(grade == 'B')    newstu = new student(id,name,sex,age,grade,geography,history,address);
    else if(grade == 'C')    newstu = new student(id,name,sex,age,grade,chinese,math,english);


    student *p = first;
    while(p->next != NULL)
    {
        p = p->next;
    }
    p->next = newstu;
    newstu->next = null;
}
//00000000000000000000000/
void studentMessage::Display(void)
{
    system("cls");
    if(student::num_total == 0)
    {
        cout<<"当前记录中无学生..."<<endl;
    }

    else
    {
        student *p = first->next;
        while(p != null)
        {
            cout<<"学号:"<<p->id<<"  "<<endl;
            cout<<"姓名:"<<p->name<<endl;
            cout<<"性别(boy/girl):"<<p->sex<<endl;
            cout<<"年龄:"<<p->age<<endl;
            cout<<"班级:"<<p->grade<<endl;

            if(p->grade == 'A')
            {
                cout<<"专业："<<p->major<<endl;
                cout<<"家庭住址："<<p->address<<endl;
                cout<<"联系方式："<<p->TL<<endl;
            }

            else if(p->grade == 'B')
            {
                cout<<"地理成绩："<<p->geography<<endl;
                cout<<"历史成绩："<<p->history<<endl;
                cout<<"家庭住址："<<p->address<<endl;
            }

            else
            {
                cout<<"语文成绩："<<p->chinese<<endl;
                cout<<"数学成绩："<<p->math<<endl;
                cout<<"英语成绩："<<p->english<<endl;
            }
    cout<<"------------------------------------------------"<<endl;
            p = p->next;
        }
    }
    int i;
            cout<<endl;cout<<endl;cout<<endl;
            cout<<"按任意键继续"<<endl;
            i = getch();
}

//删除功能~~~~~~~~~~~~~~~~
void studentMessage::Delete(void)
{
    string _name;
    system("cls");
    cout<<"请输入需要删除的同学姓名："<<endl;
    cin>>_name;
    int k=0;
    student *p = first;
    student *pre = first;
    while(p->next)
    {
        pre=p->next;
        if(pre->name == _name)
        {
            p->next=pre->next;
            k=1;
            delete pre;
        }
        p=p->next;
    }
     if(k==0&&p->name!=_name)   cout<<"记录为空!"<<endl;
     else
    {
        student::num_total--;
        if(p->sex=="boy") student::num_sex--;
        if(p->age>=18)   student::num_age--;
    }


    int i;
            cout<<endl;cout<<endl;cout<<endl;
            cout<<"按任意键继续"<<endl;
            i = getch();
}


void studentMessage::Search(void)
{
    system("cls");/
    int temp = 0;
    cout<<"请输入查找的条件，有如下选项..."<<endl;
    cout<<"按照学号查找（请输入【1】） 按照姓名查找（请输入【2】） "<<endl;
    cout<<" 退出（请输入【666】）"<<endl;
    cin>>temp;
    switch(temp)
    {
        case 1: SearchByid(); break;
        case 2: SearchByname(); break;
        case 666: return;
        default: cout<<"输入有误..."<<endl;
    }
}

void studentMessage::SearchByid(void)
{
    system("cls");//
    int _id;
    int flag = 0;
    cout<<"请输入待查找学生的学号：";
    cin >> _id;
    student *p = first->next;
    while(p != null)
    {
        if(p->id == _id)
        {
            flag = 1;
            cout<<"下面是查找匹配结果："<<endl;
            cout<<endl;cout<<endl;cout<<endl;

            cout<<"学号:"<<p->id<<"  "<<endl;
            cout<<"姓名:"<<p->name<<endl;
            cout<<"性别(boy/girl):"<<p->sex<<endl;
            cout<<"年龄:"<<p->age<<endl;
            cout<<"班级:"<<p->grade<<endl;

            if(p->grade == 'A')
            {
                cout<<"专业："<<p->major<<endl;
                cout<<"家庭住址："<<p->address<<endl;
                cout<<"联系方式："<<p->TL<<endl;
            }
            else if(p->grade == 'B')
            {
                cout<<"地理成绩："<<p->geography<<endl;
                cout<<"历史成绩："<<p->history<<endl;
                cout<<"家庭住址："<<p->address<<endl;
            }
            else
            {
                cout<<"语文成绩："<<p->chinese<<endl;
                cout<<"数学成绩："<<p->math<<endl;
                cout<<"英语成绩："<<p->english<<endl;
            }
        }
        p = p->next;
    }
    if(flag == 0)
    {
        cout<<"未找到匹配项..."<<endl;
    }
     int i;
            cout<<endl;cout<<endl;cout<<endl;
            cout<<"按任意键继续"<<endl;
            i = getch();
}

void studentMessage::SearchByname(void)
{
    system("cls");/
    string _name;
    int flag = 0;
    cout<<"请输入待查找的学生姓名: ";
    cin >> _name;
    student *p = first->next;
    while(p != null)
    {
        if(p->name == _name)
        {
            cout<<"下面是查找匹配结果："<<endl;
            cout<<endl;cout<<endl;cout<<endl;

            cout<<"学号:"<<p->id<<"  "<<endl;
            cout<<"姓名:"<<p->name<<endl;
            cout<<"性别(boy/girl):"<<p->sex<<endl;
            cout<<"年龄:"<<p->age<<endl;
            cout<<"班级:"<<p->grade<<endl;
            if(p->grade == 'A')
            {
                cout<<"专业："<<p->major<<endl;
                cout<<"家庭住址："<<p->address<<endl;
                cout<<"联系方式："<<p->TL<<endl;
            }
            else if(p->grade == 'B')
            {
                cout<<"地理成绩："<<p->geography<<endl;
                cout<<"历史成绩："<<p->history<<endl;
                cout<<"家庭住址："<<p->address<<endl;
            }
            else
            {
                cout<<"语文成绩："<<p->chinese<<endl;
                cout<<"数学成绩："<<p->math<<endl;
                cout<<"英语成绩："<<p->english<<endl;
            }
        }
        p = p->next;
    }

    if(flag == 0)
    {
        cout<<"未找到匹配项..."<<endl;
    }
     int i;
            cout<<endl;cout<<endl;cout<<endl;
            cout<<"按任意键继续"<<endl;
            i = getch();
}

void studentMessage::Change(void)
{
    system("cls");//
    string _name,_sex,_address,_major;
    char _grade; long long int _TL;
    double _chinese , _math , _english;  //语文 ， 数学 ， 英语
    double _history , _geography ;     //历史  ， 地理

    int flag = 0,temp;
    int _id,_age;
    int course = 0;
    cout<<"请输入需要改动信息的学生的姓名: ";
    cin >> _name;
    student *p = first->next;
    while(p != null)
    {
        if(p->name == _name)
        {
            flag = 1;
            cout<<"该学生当前信息如下："<<endl;
            cout<<"学号:"<<p->id<<"  "<<endl;
            cout<<"姓名:"<<p->name<<endl;
            cout<<"性别(boy/girl):"<<p->sex<<endl;
            cout<<"年龄:"<<p->age<<endl;
            cout<<"班级:"<<p->grade<<endl;

            if(p->grade == 'A')
            {
                cout<<"专业："<<p->major<<endl;
                cout<<"家庭住址："<<p->address<<endl;
                cout<<"联系方式："<<p->TL<<endl;
            }
            else if(p->grade == 'B')
            {
                cout<<"地理成绩："<<p->geography<<endl;
                cout<<"历史成绩："<<p->history<<endl;
                cout<<"家庭住址："<<p->address<<endl;
            }
            else
            {
                cout<<"语文成绩："<<p->chinese<<endl;
                cout<<"数学成绩："<<p->math<<endl;
                cout<<"英语成绩："<<p->english<<endl;
            }

            cout<<"请指明哪一项需要修改..."<<endl;
            cout<<"修改学号（输入【1】） 修改年龄（输入【2】）修改班级信息（输入【3】） "<<endl;
            cout<<" 退出（输入【666】）"<<endl;
            cin >> temp;
            switch(temp)
            {
                case 1:
                    {
                        cout<<"请输入新的学号："<<endl;cin>>_id;
                        p->id = _id;
                    }
                    break;
                case 2:
                    {
                        cout<<"请输入新的年龄："<<endl;;cin>>_age;
                        p->age = _age;
                    }
                    break;
                case 3:
                    {
                        cout<<"请输入新的班级信息(大学生输入'A'，初中生输入'B',小学生输入'C')："<<endl;;cin>>_grade;
                        p->grade = _grade;

                         if(_grade=='A')
                            {

                                cout<<"请输入专业："<<endl;
                                cin>>_major;
                                p->major = _major;
                                cout<<"请输入家庭住址："<<endl;
                                cin>>_address;
                                p->address = _address;
                                cout<<"请输入联系电话："<<endl;
                                cin>>_TL;
                                p->TL = _TL;
                            }
                        else if(_grade == 'B')
                            {

                                cout<<"请输入地理成绩："<<endl;
                                cin>>_geography;
                                p->geography = _geography;
                                cout<<"请输入历史成绩："<<endl;
                                cin>>_history;
                                p->history = _history;
                                cout<<"请输入家庭住址："<<endl;
                                cin>>_address;
                                p->address = _address;
                            }
                            else
                            {
                                cout<<"请输入语文成绩："<<endl;
                                cin>>_chinese;
                                p->chinese = _chinese;
                                cout<<"请输入数学成成绩："<<endl;
                                cin>>_math;
                                p->major = _math;
                                cout<<"请输入英语成绩："<<endl;
                                cin>>_english;
                                p->english = _english;
                            }
                    }
                    break;
                    case 666: return ;
                    cout<<"修改后的信息如下： "<<endl;
                    cout<<"姓名:"<<p->name<<"  "<<endl;
                    cout<<"性别:"<<p->sex<<"  "<<endl;
                    cout<<"年龄:"<<p->age<<"  "<<endl;
                    cout<<"学号:"<<p->id<<"  "<<endl;
                    cout<<"地址:"<<p->address<<"  "<<endl;

                default:  cout<<"输入有误..."<<endl;
            }
        }
        p = p->next;
    }
    if(flag == 0)
        cout<<"当前记录中没有此学生..."<<endl;
}

void studentMessage::clear(void)
{
    student *p = first->next;
    while(p != null)
    {
        first->next = p->next;
        p->next = null;
        delete p;
        p = first->next;
    }
}

int main()
{
    studentMessage stulist;
    int ch;
    while(ch = stulist.menu())
    {
        switch(ch)
        {

            case 1: stulist.Insret();  break;
            case 2: stulist.Search();  break;
            case 3: stulist.Display(); break;
            case 4: stulist.Change();  break;
            case 5: stulist.Delete();  break;
            case 6: stulist.tongji();  break;
            case 7: stulist.save();    break;
            case 8: stulist.clear();   break;
            case 0: return 0;
            default: cout<<"请按要求输入..."<<endl;
        }
    }
    return 0;
}