学生成绩管理程序：用面向对象的类设计一个菜单驱动的学生成绩管理程序。学生的基本信息包括学生的学号、姓名、数学、语文、英语等信息。实现如下管理功能：（1）能输入并显示n个学生的基本信息。（2）计算学生的平均分和总分。（3）按总分降序进行排序。（4）任意输入一个学号，能显示该学生的基本信息。（5）可添加学生信息到指定位置，亦可在最后追加一批学生信息。（6）文件的导入和导出（从文件中读取若干条学生信息，或者将学生信息输出到文件中）。
#include <iostream>
#include <fstream>
#include <string>
#include <cstdlib>
#include <algorithm>
#include <string.h>
using namespace std;
int num=0;
class Student
{
public:
int id;
string name;
int math;
int Chinese;
int English;
int sum;
int aver;
};
void ShowMenu();//显示菜单
void CreatList(Student str[],int num);//创建
void AddStu(Student str[],int num);//添加
void Gather(Student str[],int num);//查询
void Sort(Student str[],int num);//排序
bool Compare(Student p,Student q);
void Search(Student str[],int num);//查询
void display(Student str[],int num);//显示
void Fileinto(Student str[],int num);//Wenjian
void Fileout(Student str[],int num);//wenjian
int main()
{
Student str[1000];
ShowMenu();
while(1)
{
int n;
cin >> n;
switch (n)
{
case 1: //创建
{
CreatList(str,num);
break;
}
case 2: //添加
{
AddStu(str,num);
break;
}
case 3: //汇总
{
Gather( str,num);
break;
}
case 4: //修改
{
Sort(str,num);
break;
}
case 5: //删除
Search(str,num);
break;
case 6: //显示
display(str,num);
break;
case 7: //文件导入
Fileinto(str,num);
break;
case 8: //文件导出
Fileout(str,num);
break;
case 9:
exit(0);
default: cout << "输入错误，请重新输入 ： "; break;
}
}
return 0;
}
void ShowMenu()
{
cout << " 请选择下面的菜单 ：" << endl;
cout << " 1 创建" << endl;//创建
cout << " 2 添加" << endl;
cout << " 3 汇总" << endl;
cout << " 4 排序" << endl;
cout << " 5 查询" << endl;
cout << " 6 显示" << endl;
cout << " 7 文件导入" << endl;
cout << " 8 文件导出" << endl;
cout << " 9 退出" << endl;
cout << " 请选择 ：" ;//显示菜单
}
void CreatList(Student str[],int num)//创建
{
int i,n;
cout << "输入创建的学生的个数" << endl;
cin >> n;
cout << "请输入信息" << endl;
for (i = 0; i < n; i++)
{
cin >> str[i].id >> str[i].name >> str[i].math >> str[i].Chinese >> str[i].English ;
str[i].sum=str[i].math+str[i].English+str[i].Chinese;
str[i].aver=str[i].sum/3;
num++;
}
cout << "学生信息: " << endl;
for (i = 0; i < num; i++)
{
cout << str[i].id << " " << str[i].name << " " << str[i].math << " " << str[i].Chinese << " " << str[i].English << endl;
}
}
void AddStu(Student str[],int num)//添加
{
cout<<"最后追加or指定位置添加？（1/2）";
int m;
cin>>m;
if(m==1)
{
cout << "添加的通讯者的数目 : ";
int x;
cin >> x;
cout << "请输入" << endl;
for (int i = num; i < num + x; i++)
{
cin >> str[i].id >> str[i].name >> str[i].math >> str[i].Chinese >> str[i].English ;
str[i].sum=str[i].math+str[i].English+str[i].Chinese;
str[i].aver=str[i].sum/3;
}
cout << "以下是你输入的信息: " << endl;
for (int i = num; i < num + x; i++)
{
cout << str[i].id << " " << str[i].name << " " << str[i].math << " " << str[i].Chinese << " " << str[i].English<< endl;
}
num += x;
}
if(m==2)
{
cout << "添加的通讯者的数目 : ";
int n,place;
cin >> n;
cout<<"请输入指定位置";
cin>>place;
for(int i=place;i<place+n;i++)
{
int id;
string name;
int math;
int Chinese;
int English;
str[i+n].id=str[i].id;
str[i+n].name=str[i].name;
str[i+n].math=str[i].math;
str[i+n].English=str[i].English;
cout<<"请输入信息"<<endl;
cin >> num >> name >> math >> Chinese >> English ;
str[i].id=id;
str[i].name=name;
str[i].math=math;
str[i].English=English;
}
cout << "以下是你输入的信息: " << endl;
for (int i = place; i < place+n; i++)
{
cout << str[i].id << " " << str[i].name << " " << str[i].math << " " << str[i].Chinese << " " << str[i].English<< endl;
}
num+=n;
}
}
void Gather(Student str[],int num)//汇总
{
for (int i = 0; i < num; i++)
{
str[i].sum=str[i].math+str[i].English+str[i].Chinese;
str[i].aver=str[i].sum/3;
cout << str[i].id << " " << str[i].name << " " << str[i].math << " " << str[i].Chinese << " " << str[i].English <<str[i].sum<<str[i].aver<< endl;
}
}
void Sort(Student str[],int num)//排序
{
for(int i=0;i<num;i++)
{
sort(str,str+num,Compare);
}
for(int j=0;j<num;j++)
{
cout << str[j].id << " " << str[j].name << " " << str[j].math << " " << str[j].Chinese << " " << str[j].English <<str[j].sum<<str[j].aver<< endl;
}
}
bool Compare(Student p, Student q)
{
return p.sum>q.sum;
}
void Search(Student str[],int num)//查询
{
int m(0), flag(0);
int ID;
cout << "请输入所查询的学号 ：";
cin >> ID ;
for (int i = 0; i < num; i++)
{
if (str[i].id == ID )
{
cout << str[i].id << " " << str[i].name << " " << str[i].math << " " << str[i].Chinese << " " << str[i].English <<str[i].sum<<str[i].aver<< endl;
flag = 1;
break;
}
}
if (flag == 0)
cout << "未找到所查学号，请重新查询 " << endl;
}
void display(Student str[],int num)//显示
{
for (int i = 0; i < num; i++)
{
cout << str[i].id << " " << str[i].name << " " << str[i].math << " " << str[i].Chinese << " " << str[i].English <<str[i].sum<<str[i].aver<< endl;
}
}
void Fileinto(Student str[],int num)
{
ifstream daoru("f_1.txt", ios::in);
if (!daoru)
{
cout << "文件导入失败" << endl;
}
else
{
cout << "请输入导入学生个数 ： ";
int n, i, j;
cin >> n;
int ru[1000] = { 0 };
Student stb[1000];
for (j = 0; j < n; j++)
{
daoru >> str[i].id >> str[i].name >> str[i].math >> str[i].Chinese >> str[i].English ;
}
for (int x = 0; x < n; x++)
{
for (int y = 0; y < num; y++)
{
if (stb[x].id == str[y].id)
{
ru[x] = 1;
break;
}
}
}
j = 0;
n = n + num;
for (i = num; i < n; i++, j++)
{
if (ru[j] == 0)
{
str[i] = stb[j];
num++;
}
}
daoru.close();
cout << "导入结束" << endl;
}
}
void Fileout(Student str[],int num)
{
ofstream daochu("f_1.txt", ios::out);
if (!daochu)
{
cout << "文件导出失败" << endl;
}
else
{
for (int i = 0; i < num; i++)
{
daochu << str[i].id << " " << str[i].name << " " << str[i].math << " " << str[i].Chinese << " " << str[i].English <<str[i].sum<<str[i].aver<< endl;
}
daochu.close();
}
}
