这个代码谁有 要用c加加写

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

#define null NULL

class student
{
    private:
        friend class studentMessage;
        student *next; //节点指针
        string name; //学生姓名
        int age; //年纪
        int id; //学号
        double score[3]; //三科成绩
        double total; //总分
        double average; //平均成绩
    public:
        student(string _name,int _age,int _id,double *_score)
        {
            name = _name;
            age = _age;
            id = _id;
            score[0] = _score[0];
            score[1] = _score[1];
            score[2] = _score[2];
            total = score[0]+score[1]+score[2];
            average = total/3;
            next = NULL;
        }
        student() //为studentMessage初始化头结点用
        {
            name = "null";
            age = 0;
            id = 0;
            score[0]=score[1]=score[2]=0;
            total = 0;
            average = 0;
            next = NULL;
        }
        ~student(){}
        void swap(student*);
};


void student::swap(student *q)
{
    string _name;
    int _age,_id;
    double _score[3],_total,_average;

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

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

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

    _score[0] = score[0];
    score[0] = q->score[0];
    q->score[0] = _score[0];

    _score[1] = score[1];
    score[1] = q->score[1];
    q->score[1] = _score[1];

    _score[2] = score[2];
    score[2] = q->score[2];
    q->score[2] = _score[2];

    _total = total;
    total = q->total;
    q->total = _total;

    _average = average;
    average = q->average;
    q->average = _average;
}






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 sortByLesson1(void); //按成绩一来排序
        void sortByLesson2(void); //按成绩二来排序
        void sortByLesson3(void); //按成绩三来排序
        void sortByTotal(void); //按总分来排序
        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
};


int studentMessage::menu(void)
{
    int ch;
    cout<<"**********************************************************************"<<endl;
    cout<<"======================================================================"<<endl;
    cout<<"***************************学生成绩管理系统***************************"<<endl;cout<<endl;
    cout<<"1.显示所有学生成绩"<<endl;
    cout<<"2.添加学生信息"<<endl;
    cout<<"3.查询学生信息"<<endl;
    cout<<"4.修改学生信息"<<endl;
    cout<<"5.删除最下面一个学生信息"<<endl;
    cout<<"6.删除所有信息"<<endl;
    cout<<"0.退出系统"<<endl;cout<<endl;
    cout<<"********************Copyright@ By Jeaven Wong**************************"<<endl;
    cout<<"======================================================================="<<endl;
    cout<<"***********************************************************************"<<endl;
    cin >> ch;
    cout<<"\n\n\n"<<endl;
    return ch;
}



//插入
void studentMessage::Insret(void)
{
    string name;
    int age;
    int id;
    double score[3];
    cout<<"请输入学生姓名: ";
    cin>>name;
    cout<<"请输入学生年龄: ";
    cin>>age;
    cout<<"请输入学生学号: ";
    cin>>id;
    cout<<"下面请输入学生三门课程成绩: ";
    cout<<endl;
    cout<<"请输入第一门课的成绩: ";cin>>score[0];
    cout<<"请输入第二门课的成绩: ";cin>>score[1];
    cout<<"请输入第三门课的成绩: ";cin>>score[2];
    cout<<endl;


    student *newstu = new student(name,age,id,score);
    student *p = first;
    while(p->next != NULL)
    {
        p = p->next;
    }
    p->next = newstu;
    newstu->next = null;
    num++;
}



void studentMessage::Display(void)
{
    if(num == 0)
    {
        cout<<"当前记录中无学生..."<<endl;
    }

    else
    {
        student *p = first->next;
        while(p != null)
        {
            cout<<"姓名:"<<p->name<<"  ";
            cout<<"年龄:"<<p->age<<"  ";
            cout<<"学号:"<<p->id<<"  ";
            cout<<"三门课程成绩: "<<p->score[0]<<" "<<p->score[1]<<" "<<p->score[2]<<"  ";
            cout<<"总分:"<<p->total<<"  ";
            cout<<"平均分:"<<p->average<<endl;
            p = p->next;
        }
    }
}


void studentMessage::Delete(void)
{
    student *p = first;
    student *pre = first;
    while(p->next != NULL)
    {
        pre = p;
        p = p->next;
    }
    pre->next = NULL;
    delete p;
    num--;
}


void studentMessage::Search(void)
{
    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;
    cin>>temp;
    switch(temp)
    {
        case 1: SearchByid(); break;
        case 2: SearchByname(); break;
        default: cout<<"输入有误..."<<endl;
    }
}

void studentMessage::SearchByid(void)
{
    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<<"姓名:"<<p->name<<"  ";
            cout<<"年龄:"<<p->age<<"  ";
            cout<<"学号:"<<p->id<<"  ";
            cout<<"三门课程成绩: "<<p->score[0]<<" "<<p->score[1]<<" "<<p->score[2]<<"  ";
            cout<<"总分:"<<p->total<<"  ";
            cout<<"平均分:"<<p->average<<endl;
        }
        p = p->next;
    }
    if(flag == 0)
    {
        cout<<"抱歉，记录中没有查找匹配项..."<<endl;
    }
}

void studentMessage::SearchByname(void)
{
    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)
        {
            flag = 1;
            cout<<"下面是查找匹配结果："<<endl;
            cout<<"姓名:"<<p->name<<"  ";
            cout<<"年龄:"<<p->age<<"  ";
            cout<<"学号:"<<p->id<<"  ";
            cout<<"三门课程成绩: "<<p->score[0]<<" "<<p->score[1]<<" "<<p->score[2]<<"  ";
            cout<<"总分:"<<p->total<<"  ";
            cout<<"平均分:"<<p->average<<endl;
        }
        p = p->next;
    }

    if(flag == 0)
    {
        cout<<"抱歉，记录中没有查找匹配项..."<<endl;
    }
}



void studentMessage::Change(void)
{
    string _name;
    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<<"姓名:"<<p->name<<"  ";
            cout<<"年龄:"<<p->age<<"  ";
            cout<<"学号:"<<p->id<<"  ";
            cout<<"三门课程成绩: "<<p->score[0]<<" "<<p->score[1]<<" "<<p->score[2]<<"  ";
            cout<<"总分:"<<p->total<<"  ";
            cout<<"平均分:"<<p->average<<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】）修改成绩（输入【3】）"<<endl;
            cin >> temp;
            switch(temp)
            {
                case 1:
                    {
                        cout<<"请输入新的学号：";cin>>_id;
                        p->id = _id;
                    }
                    break;
                case 2:
                    {
                        cout<<"请输入新的年龄：";cin>>_age;
                        p->age = _age;
                    }
                    break;
                case 3:
                    {
                        cout<<"请按指示修改课程成绩..."<<endl;
                        cout<<"是否需要修改第一门课程成绩？（需要输入【1】不需要输入【0】）"<<endl;
                        cin >> course;
                        if(course == 1)
                        {
                            cout<<"请输入修改后的第一门课的成绩："; cin >> p->score[0];
                        }
                        course = 0;

                        cout<<"是否需要修改第二门课程成绩？（需要输入【1】不需要输入【0】）"<<endl;
                        cin >> course;
                        if(course == 1)
                        {
                            cout<<"请输入修改后的第二门课的成绩："; cin >> p->score[1];
                        }
                        course = 0;

                        cout<<"是否需要修改第三门课程成绩？（需要输入【1】不需要输入【0】）"<<endl;
                        cin >> course;
                        if(course == 1)
                        {
                            cout<<"请输入修改后的第三门课的成绩："; cin >> p->score[2];
                        }
                        course = 0;

                        p->total = p->score[0]+p->score[1]+p->score[2];
                        p->average = p->total/3;

                        cout<<"修改后的信息如下： "<<endl;
                        cout<<"姓名:"<<p->name<<"  ";
                        cout<<"年龄:"<<p->age<<"  ";
                        cout<<"学号:"<<p->id<<"  ";
                        cout<<"三门课程成绩: "<<p->score[0]<<" "<<p->score[1]<<" "<<p->score[2]<<"  ";
                        cout<<"总分:"<<p->total<<"  ";
                        cout<<"平均分:"<<p->average<<endl;
                    }
                    break;
                default:  cout<<"输入有误..."<<endl;
            }
        }
        p = p->next;
    }
    if(flag == 0)
        cout<<"当前记录中没有次学生..."<<endl;
}

/*排序我均采用冒泡排序法，均是从小到大排序*/


//按照科目一排序
void studentMessage::sortByLesson1(void)
{
    student *p = first->next;
    while(p->next != null)
    {
        student *q = p->next;
        while(q != null)
        {
            if(p->score[0] > q->score[0])
            {
                p->swap(q);
            }
            q = q->next;
        }
        p = p->next;
    }
}

//按照科目二排序
void studentMessage::sortByLesson2(void)
{
    student *p = first->next;
    while(p->next != null)
    {
        student *q = p->next;
        while(q != null)
        {
            if(p->score[1] > q->score[1])
            {
                p->swap(q);
            }
            q = q->next;
        }
        p = p->next;
    }
}

//按照科目三排序
void studentMessage::sortByLesson3(void)
{
    student *p = first->next;
    while(p->next != null)
    {
        student *q = p->next;
        while(q != null)
        {
            if(p->score[2] > q->score[2])
            {
                p->swap(q);
            }
            q = q->next;
        }
        p = p->next;
    }
}

//按照总成绩排序
void studentMessage::sortByTotal(void)
{
    student *p = first->next;
    while(p->next != null)
    {
        student *q = p->next;
        while(q != null)
        {
            if(p->total > q->total)
            {
                p->swap(q);
            }
            q = q->next;
        }
        p = p->next;
    }
}

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

参考：

#include<stdio.h>
 
#include<string.h> 
 
#include<stdlib.h> 
 
#define N 100 //最大输入
int n = 0; //总数
struct students
{
    int num; //学号
    char name[8]; //姓名
    int chinese; //语文
    int math; //数学
    int english; //英语
    int sum; //总成绩
    int ave; //平均分
}
student[N],student1; 
 
void count()
{
    struct students stu1;
    FILE * fp; //定义一个文件指针fp
    fp = fopen("students.txt", "at+"); //以"追加"方式打开students文本文件
    if (fp == NULL) //判断文件是否为空
    	printf("Cannot open file!");
    n = 0; //初始化
    while (1)
    {
        if (feof(fp)) //检测文件是否结束
        break;
        fread( & stu1, sizeof(struct students), 1, fp); //读取文件
        n++; //读取文件数
    }
    n--; //关闭文件数
    fclose(fp); //关闭文件
}
/*成绩输入*/
void input()
{
    int i = 0; //学生人数初始化//
    char c;
    FILE * fp; //定义一个文件指针fp//
    count(); //实时检测总数n//
    fp = fopen("students.txt", "at+"); //以"追加"方式打开students文本文件
    do
    {
        printf("请输入学生的个人信息:\n");
        printf("\n请输入第%d学生的信息:\n", n + 1);
        printf("请输入学生的学号:");
        scanf("%d", &student[i].num);
        printf("请输入学生的姓名:");
        scanf("%s", student[i].name);
        printf("请输入学生的语文成绩:");
        scanf("%d", &student[i].chinese);
        printf("请输入学生的数学成绩:");
        scanf("%d", &student[i].math);
        printf("请输入学生的英语成绩:");
        scanf("%d", &student[i].english);
		
        student[i].sum = student[i].chinese + student[i].math + student[i].english;
        student[i].ave = student[i].sum / 3;
		
        fwrite( & student[i], sizeof(struct students), 1, fp); //以方式将其写入students文本文件
        i++;
        n++;
        printf("\n\n\t\t\t\t是否继续输入(Y/N):");
        getchar(); //提示是否继续，从键盘获得一个字符
        scanf("%c", &c);
    }
    while ( c == 'y' || c == 'Y');
    fclose(fp);
}
/*成绩输出*/
void output()
{
    int i;
    char c;
    FILE * fp; //定义一个文件指针fp
    fp = fopen("students.txt", "rt"); //以"读取的" 方式打开students文本文件
    system("cls"); //清屏//
    getchar();
    printf("|#学号\t姓名\t语文\t数学\t英语\t总成绩\t平均分\t#|\n");
    do {
        for (i = 0; i < n; i++)
        {
            fread(&student[i], sizeof(struct students), 1, fp);
            printf(" %d ", student[i].num);
            printf(" %s ", student[i].name);
            printf(" %d ", student[i].chinese);
            printf(" %d ", student[i].math);
            printf(" %d ", student[i].english);
            printf(" %d ", student[i].sum);
            printf(" %d \n", student[i].ave);
        }
        printf("\n\n\t\t\t\t是否继续其它操作(Y/N):"); //提示是否继续
        scanf("%c", &c);
        c = getchar();
    } while ( c == 'y' || c == 'Y');
    fclose(fp); //关闭文件//
}
/*成绩修改*/
void xiugai() {
    int i,
    tp,
    num1;
    char c;
    FILE * fp; //定义一个文件指针fp//
    lb:
    printf("\n按学号修改\n\n");
    printf("请输入要修改的学生学号\n");
    scanf("%d", &num1);
    for (i = 0; i < n; i++)
    {
        if (num1 == student[i].num)
        {
            printf("要修改的学生信息为：\n");
            printf("学号\t姓名\t语文成绩\t数学成绩\t英语成绩\t总成绩\t平均分\n");
            printf(" %d ", student[i].num);
            printf(" %s ", student[i].name);
            printf(" %d ", student[i].chinese);
            printf(" %d ", student[i].math);
            printf(" %d ", student[i].english);
            printf(" %d ", student[i].sum);
            printf(" %d ", student[i].ave);
            do {
                printf("请选择要修改项：\n");
                printf("1学号\n2姓名\n3语文成绩\n4数学成绩\n5总成绩\n6平均分\n");
                scanf("%d", &tp);
                switch (tp)
                {
                case 1:
                    {
                        printf("请输入学号:\n");
                        scanf("%d", &student[i].num);
                        goto la;
                    }
                case 2:
                    {
                        printf("请输入姓名:\n");
                        scanf("%s", student[i].name);
                        goto la;
                    }
                case 3:
                    {
                        printf("请输入语文成绩:\n");
                        scanf("%d", &student[i].chinese);
                        goto la;
                    }
                case 4:
                    {
                        printf("请输入数学成绩:\n");
                        scanf("%d", &student[i].math);
                        goto la;
                    }
                case 5:
                    {
                        printf("请输入英语成绩:\n");
                        scanf("%d", &student[i].english);
                        goto la;
                    }
                case 6:
                    {
                        printf("请输入总成绩:\n");
                        scanf("%d", &student[i].sum);
                        goto la;
                    }
                case 7:
                    {
                        printf("请输入平均分:\n");
                        scanf("%d", &student[i].ave);
                        goto la;
                    }
                }
            } 
			while ( tp < 8 );
           	la: 
				printf("是否继续修改(y/n)\n"); //提示是否继续
            	getchar();
				scanf("%c", &c);
            if (c == 'y' || c == 'Y') 
				goto lb;
        }
    }
    fp = fopen("students.txt", "w+"); //以"读写" 方式打开students文本文件
    for (i = 0; i < n; i++)
    fwrite( & student[i], sizeof(struct students), 1, fp); //以 方式将其写入student文本文件
    fclose(fp); //关闭文件
}
/*成绩查询*/
void query()
{
    int querymode; //子菜单选择
    int i,
    j = 0,
    findnum;
    char findname[20];
    int findok,
    t = 0; //定义一个判断标志的整型变量findok
    char findct; //定义一个用于判断是否继续查找的字符变量findct
    FILE * fp; //定义一个文件指针fp
    count(); //实时检测总数
    fp = fopen("students.txt", "r"); //以"只读" 方式打开students文本文件
    system("cls"); //清屏
    /*查询菜单*/
    printf("\t\t成绩查询");
    printf("\n\t1按姓名查询");
    printf("\n\t2按学号查询");
    printf("\n\t0返回上级菜单");
    printf("\n请输入您的操作:");
    scanf("%d", &querymode);
    /*查询操作*/
    switch (querymode)
    {
    case 1:
        {
            printf("请输入要查询学生的姓名:\n");
            getchar();
            scanf("%s", findname);
            for (i = 0; i < N; i++)
            {
                fread( & student[i], sizeof(struct students), 1, fp); //以方式将其读入students 文本文件
                if (strcmp(student[i].name, findname) == 0) //比较字符串
                {
                    j++;
                    printf("\n查寻到的学生为:\n");
                    if (j == 1)
                    printf("|#学号\t姓名\t语文\t数学\t英语\t总成绩\t平均分\t#|\n");
                    printf("%4d%s%d%d%d%d%d", student[i].num, student[i].name, student[i].chinese, student[i].math, student[i].english,student[i].sum, student[i].ave);
                }
            }
            if (j == 0)
            printf("\n>>>查无此人！");
            //提示是否继续// 
            printf("\n是否继续查找(Y/N)?");
            getchar();
            getchar();
        }
        break;
    case 2:
        {
            printf("请输入要查询学生的学号:");
            scanf("%d", &findnum);
            for (i = 0; i < n; i++)
            {
                fread( & student[i], sizeof(struct students), 1, fp); //以结构体students的方式从文件fp中读取,将其读入students文本文件,每次读入一个 学生的信息
                if (student[i].num == findnum) //整型数字的比较/
                {
                    findok = 1;
                    break;
                }
                else findok = 0;
            }
            if (!findok)
            printf("\n>>>查无此人！");
            else
            {
                printf("\n查寻到的学生为:\n");
                if (j == 1)
                printf("|学号\t姓名\t语文\t数学\t英语\t总成绩\t平均分\t|\n");
                printf("%4d%s%d%d%d%d%d", student[i].num, student[i].name,student[i].chinese, student[i].math,student[i].english, student[i].sum, student[i].ave);
            }
            //提示是否继续//
            printf("\n是否继续查找(Y/N)?");
            getchar();
            findct = getchar(); //从键盘输入一个判断字符，并将它赋值给字符变量 findct,用于以下的if语句的判断
            if (findct == 'Y' || findct == 'y')
            query();
        }
    }
    fclose(fp); //关闭文件//
}
/*成绩排序*/
void paixu()
{
    int i,
    j;
    FILE * fp; //定义一个文件指针fp//
    system("cls"); //清屏//
    count(); //实时检测总数n// 
    for (i = 0; i < n - 1; i++)
    for (j = 0; j < n - 1 - i; j++) //按学号对学生信息进行排序
    {
        if (student[j].num > student[j + 1].num) //整型数字的比较
        {
            student1 = student[j];
            student[j] = student[j + 1];
            student[j + 1] = student1;
        }
    }
    fp = fopen("students.txt", "w+"); //以 "读写"方式打开students文本文件
    for (i = 0; i < n; i++)
    fwrite( & student[i], sizeof(struct students), 1, fp); 
    fclose(fp); //关闭文件//
}
/*退出系统*/
void tuichu()
{
    char c;
    system("cls"); //清屏
    printf("\n\n\t\t谢谢使用\n\n\n");
    printf("\n\n\t\t制作人：唐璐 李泓娴\n");
    getchar();
    c = getchar(); //取用户输入，回显  
}
/*菜单*/
void main()
{
    int i=1; //获取用户在菜单中的选择 
    while (i != 0)
    {
        printf("\t\t欢迎进入学生成绩管理系统\n");
        printf("\t\t==============================\n");
        printf("\t\t*选择操作                    *\n");
        printf("\t\t*1输入学生信息               *\n");
        printf("\t\t*2输出学生信息               *\n");
        printf("\t\t*3修改学生信息               *\n");
        printf("\t\t*4查询学生信息               *\n");
        printf("\t\t*5排序学生信息               *\n");
        printf("\t\t*0退出系统                   *\n");
        printf("\t\t==============================\n");
        scanf("%d", &i);
        system("cls"); //清屏
        count(); //实时检测总数
        switch (i)
        {
        case 1:
            input();
            break; //输入学生信息
        case 2:
            output();
            break; //输出学生信息
        case 3:
            xiugai();
            output();
            break; //修改学生信息
        case 4:
            query();
            break; //查询学生信息
        case 5:
            paixu();
            output();
            break; //成绩排序
        default:
            printf("输入有错\n"); //错误纠正
        }
    }
    if (i == 0)
    tuichu(); //退出系统
}