C++小项目 学生成绩管理系统

#include<iostream>
#include<string>
#include<iomanip>
using namespace std;

int num;                                   //总学生人数

class student {
    friend class studentMessage;
private:
    string ID;
    string name;
    double score[5];                       //1-4代表math、English、OPP和总成绩  ，0号单元空出
    student * next;
public:
    student();
    string getName(){return name;}
    string getID(){return ID;}
    double getMath(){return score[1];}
    double getEnglesh(){return score[2];}
    double getOPP(){return score[3];}
    double gettotol(){return score[4];}
    student* getNext(){return next;}

    static void analyse(int ,student * ); //分析成绩
    void display();                          //打印成绩
    void swap();                          //交换对象和对象->next的信息
};

student::student()
{
    cout<<"请输入学生学号 : ";cin>>ID;
    cout<<"请输入学生姓名 : ";cin>>name;
    cout<<"请输入学生的数学、英语和OPP成绩 : "<<endl;
    int a,b,c;
    cin>>a;
    while(a<0||a>100)
    {
        cout<<"输入成绩有误，请重新输入: "<<endl;
        cin>>a;    
    }
    cin>>b;
    while(b<0||b>100)
    {
        cout<<"输入成绩有误，请重新输入: "<<endl;
        cin>>b;
    }
    cin>>c;
    while(c<0||c>100)
    {
        cout<<"输入成绩有误，请重新输入: "<<endl;
        cin>>c;        
    }
    score[1]=a;
    score[2]=b;
    score[3]=c;
    score[4]=a+b+c;
    next=NULL;
}

void student::analyse(int a,student * first)
{
    int you=0,liang=0,zhong=0,jige=0,bujige=0;
    student * t=first;
    double average=0;                   //平均分
    while(t)
    {
        int b = int(t->score[a]/10);
        switch(b)
        {
        case 10:
        case 9:you++;break;
        case 8:liang++;break;
        case 7:zhong++;break;
        case 6:jige++;break;
        default:bujige++;
        }
        average+=t->score[a];
        t=t->next;
    }
    average=average/num;
    cout<<" 考生总人数 : "<<num<<"        平均分 : "<<average<<endl;
    cout<<"\n 优     良      中     及格    不及格  "<<endl;
    cout<<" "<<you<<" \t"<<liang<<" \t"<<zhong<<"\t"<<jige<<"\t"<<bujige<<endl;
}

void student::display()
{
    cout<<" "<<setw(3)<<ID<<"     "<<setw(3)<<name<<"      ";
    for (int i=1;i<=4;i++)
    {
        cout<<setw(3)<<score[i]<<"      ";
    }
    cout<<endl; 
}

void student::swap()
{
    int j;
    string na,id;
    double sco[5];
    na=name;name=next->name;next->name=na;
    id=ID;ID=next->ID;next->ID=id;
    for(j=1;j<=4;j++)
    {                                            
        sco[j]=score[j];
        score[j]=next->score[j];    
        next->score[j]=sco[j];
    }
}

class studentMessage{
private:
    student * first;
    student * last;
public:
    studentMessage();
    student* getFirst(){return first;}
    student* getLast(){return last;}
    int getNum(){return num;}
    void add();                             //向表中增加学生成绩记录
    void search();                          //在表中查找学生成绩记录
    void del();                             //在表中删除学生成绩记录
    void showOne();                         //分析一门课的成绩
    void showAll();                         //输出所有同学所有科目的成绩
    void sort();                            //按一门课成绩或总成绩排序
    void clear();                           //清空所有信息并退出系统

};

studentMessage::studentMessage()
{
    first=NULL;
    last=NULL;
    num=0;
}

void studentMessage::add() 
{
    student * t =new student;
    student *p = first;
    while(p){
        if(p->ID==t->ID)
        {
            cout<<"\n学号输入错误或该学生成绩已经存在！(如需修改，请先删除再重新录入)"<<endl;
            return;
        }
        p=p->next;
    }
    num++;
    if(first==NULL)
    {
        first=last=t;
        
    }
    else
    {    
        last->next=t;
        last=last->next;
    }
}

void studentMessage::search()
{
    string a;
    cout<<"\n请输入要查找的学生的学号:";cin>>a;
    student *t = first;
    while(t){
        if(t->ID==a)
            break;
        t=t->next;
    }
    if(!t)
    {
        cout<<"\n未找到要查找学生！"<<endl;
        return;
    }
    cout<<"\n查找成功！"<<endl;
    cout << " 学号    姓名     数学     英语     OPP     总成绩" << endl;
    t->display();        
}

void studentMessage::del()    
{
    string a;
    cout<<"\n请输入要删除的学生的学号: ";cin>>a;
    student *t = first;
    student *p=NULL;
    while(t){
        if(t->ID==a)
            break;
        p=t;
        t=t->next;
    }
    if(!t)
    {
        cout<<"\n未找到要删除学生！"<<endl;
        return;
    }
    if(!p)
    {
        first=first->next;
        cout<<"\n成功删除学生"<<a<<endl;
        delete t;
    }
    else
    {
        p->next=t->next;
        cout<<"成功删除学生"<<a<<endl;
        delete t;
    }
    
    num--;
}

void studentMessage::showOne()
{
    int a;
    while(1)
    {
        cout<<"\n想要分析哪一门成绩？请输入相应序号(1:math 2:English 3:OPP):  ";cin>>a;
        if(a!=1&&a!=2&&a!=3)
            cout<<"\n输入序号有误，请重新输入！"<<endl;
        else 
            break;
    }
    cout<<"\n\t成绩分析如下: \n"<<endl;
    student::analyse(a,first);
}

void studentMessage::showAll()
{
    cout << "---------------------成绩列表----------------------"<< endl;
    cout << " 学号    姓名     数学     英语     OPP     总成绩" << endl;
    student *t = first;
    while(t){
        t->display();
        t=t->next;
    }
}

void studentMessage::sort()
{
    int a,n=0;                  //n--排名
    cout<<"想要按照什么成绩排序？请输入相应序号(1.数学 2.英语 3.OPP 4.总成绩): ";
    while(1)
    {
        cin>>a;
        if (a!=1&&a!=2&&a!=3&&a!=4)
            cout<<"\n输入序号有误，请重新输入 : ";
        else
            break;
    }
    student *t=first;
    student *p=t;
    while(p->next)
    {
        t=first;
        while(t->next)
        {
            if(t->next->score[a]>=t->score[a])
            {
                t->swap();
            }
            t=t->next;
        }
        p=p->next;
    }
    t = first;
    cout<<"\n\t 成绩表如下: "<<endl;
    cout<<"学号    姓名    成绩    排名"<<endl;
    while(t){
        n++;
        cout<<" "<<t->getID()<<"  \t"<<t->getName()<<"  \t";
        switch(a)
        {
            case 1 :cout<<t->getMath()<<"  \t"<<n<<endl;break;
            case 2 :cout<<t->getEnglesh()<<"  \t"<<n<<endl;break;
            case 3 :cout<<t->getOPP()<<"  \t"<<n<<endl;break;
            case 4 :cout<<t->gettotol()<<"  \t"<<n<<endl;break;
        }
        t=t->next;    
    }
}

void studentMessage::clear()
{
    int x;
    cout<<"确认要清空所有信息？请输入1或2 (1:确认 2:取消) : ";cin>>x;
    if (x==2) 
    {
        cout<<"\n取消清空\n"<<endl;
        return;
    }
    student *t = first;
    student *p; 
    while(t){
        p=t;
        t=t->next;
        delete p;
    }
    cout<<"\n清空成功！\n";
    cout<<"退出成功！\n";
}

void showMenu()
{
    cout << "                               \n";
    cout << "===============================\n";
    cout << "      学生成绩管理系统\n\n";
    cout << "      1.显示所有学生成绩\n";
    cout << "      2.添加信息\n";
    cout << "      3.查询信息\n";
    cout << "      4.删除信息\n";
    cout << "      5.成绩排序\n";
    cout << "      6.单科成绩分析\n";
    cout << "      7.清空所有信息并退出系统\n";
    cout << "      0.退出系统\n";
    cout << "===============================\n";
    cout << "                               \n";
}

int main()
{
    int h;
    studentMessage stuM=studentMessage();
    while(1)
    {
        showMenu();
        cout << "请输入操作对应的序号 : ";
        cin >>h;
        cout<<endl;
        switch(h)
        {
            case 1: stuM.showAll(); break;
            case 2: stuM.add(); break;
            case 3: stuM.search(); break;
            case 4: stuM.del(); break;
            case 5: stuM.sort(); break;
            case 6: stuM.showOne(); break;
            case 7: stuM.clear(); return 0;
            case 0: cout<<"\n退出成功！";return 0;
            default:cout<<"\n输入序号有误！请输入正确的序号。"<<endl;
        }
    }
}

历时两天整 重要把C++的课设做出来啦！吼开心！   第一次写课设  有不完善的还请多多指教哈