要求：
请编写一个学生成绩管理查询系统。要求该系统至少包含4门课程，通过输入姓名、学号及课程名可以查询到学生的成绩，并且可以修改，增加，删除某一门课程的成绩。
整体设计功能框图:
设计类成员如下：
①void Input(); //录入学生信息函数
输入学生基本信息，以及添加课程与成绩（最大容纳课程数为30）；
②void printInfo(); //显示函数
格式化输出学生基本信息以及课程成绩
③void Find(); //查找函数
实现查找功能，可以按照输入1，2，3来分别选择按学号查找，按姓名查找，按课程名称查找三种查找方式，并且加入了错误输入的判断以及不存在的学生，课程的判断，使系统更贴近生活；
④void Change(); //修改函数
实现修改的功能，输入学号找到学生后可以选择修改该名学生某一项信息，包括该学生姓名，学号，班级，课程成绩以及添加或删除某一门课程；
⑤void Sort(); //排序函数
实现排序功能，分别有按学号，总成绩以及平均成绩三种排序方式，均采用冒泡排序的方式，一律从小到大排；若没有调用此功能，则按照录入学生信息的顺序排列；
⑥void Delete(); //删除函数
实现学生成绩管理中的删除功能，通过学生姓名找到该学生，确认执行删除可删除该学生全部信息；
⑦void total();
计算学生成绩总分，以及平均分；
⑧void zeros();
成绩列表的初始化函数；
设计方法描述：
首先从设计要求出发，理清所需要实现的功能，然后创建一个学生类（Student）,其成员函数的设计包含学生的基本属性信息（学号，姓名，班级，课程成绩）以及对学生信息进行录入（Input），显示（printInfo），查找（Find），修改（Change），排序（Sort），删除（Delete）的功能函数的设置；然后分别按照各个功能函数的功能要求来实现这些功能函数。在这过程中我调试采用的方法是，通过在一些关键节点输出相关信息来判断，信息是否成功写进内存中，以及实现结果是否按照事先逻辑；
实现基本功能后，再尝试去优化该系统，增加其合理性；比如原先课程是在代码中设定好的，输入必须每个课程成绩都要求输入，查找与修改是按照课程事先设定好的编号进行，这并不实用。然后通过课件以及课本相关内容的学习，实现了课程与成绩动态输入，每一个学生的课程都可以不相同（包括数目和名字），增加了该系统在现实中的合理性；
当功能完善后，我再尝试去优化界面，比如本来的程序是一条黑框走到底，后来通过百度搜索了解到使用system(“cls”);命令进行清屏，使用system(“pause”);命令来保持黑框，这样就实现了每一次功能的选择都会在功能菜单的正下方，而不用执行了很多功能后需要在黑框中往前翻去看功能菜单；
C++代码：
#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_DEPRECATE)
#define _CRT_SECURE_NO_DEPRECATE
#endif
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
class Student {
public:
friend void Input(Student stu[]);
friend void Statistic(Student stu[]);
friend void Lookup(Student stu[]);
friend void Modify(Student stu[]);
friend void Delete(Student stu[]);
friend void Output(Student stu[]);
friend void Insert(Student stu[]);
friend void Sort(Student stu[]);
friend void Write(Student stu[], int n);
friend int Read(Student stu[]);
private:
int num;
char name[8];
char class_0[20];
float elec;
float c_program;
float english;
float math;
float media;
float sport;
float polity;
float average;
int order;
}stu[100];
void Write(Student stu[], int n) {
fstream myFile;
myFile.open("score.txt", ios::out | ios::binary);
if (!myFile) {
cout << "score.txt can't open!" << endl;
abort();
}
int count = n;
myFile << count << endl << endl;
for (int i = 0; i < count; i++) {
myFile << stu[i].class_0 << "\t"
<< stu[i].num << "\t"
<< stu[i].name << "\t"
<< stu[i].elec << "\t"
<< stu[i].c_program << "\t"
<< stu[i].media << "\t"
<< stu[i].english << "\t"
<< stu[i].math << "\t"
<< stu[i].sport << "\t"
<< stu[i].polity << "\t"
<< stu[i].average << endl;
}
myFile.close();
}
int Read(Student stu[]) {
fstream myFile;
myFile.open("score.txt", ios::in | ios::binary);
if (!myFile) {
cout << "score.txt can't open!" << endl;
abort();
}
int count;
myFile.seekg(0);
myFile >> count;
for (int i = 0; i <= count; i++) {
myFile >> stu[i].class_0 >> stu[i].num >> stu[i].name
>> stu[i].elec >> stu[i].c_program >> stu[i].media
>> stu[i].english >> stu[i].math >> stu[i].sport
>> stu[i].polity >> stu[i].average;
}
myFile.close();
return count;
}
void Input(Student stu[]) {
system("cls");
int i = 0;
int flag;
char sign = '0';
cout << endl << "======>> 请输入学生成绩 <<======" << endl;
while (sign != 'n' && sign != 'N') {
cout << "班级：";
cin >> stu[i].class_0;
loop:
cout << "学号：";
cin >> stu[i].num;
int c = 0;
while (c < i) {
c++;
if (stu[i].num == stu[i - c].num) {
cout << "您输入的学号已存在！请重新输入。" << endl;
goto loop;
}
}
cout << "姓名：";
cin >> stu[i].name;
do {
flag = 0;
cout << "电子技术成绩：";
cin >> stu[i].elec;
if (stu[i].elec > 100 || stu[i].elec < 1) {
cout << " 对不起，请输入1-100之间的数字！！\n";
}
else {
flag = 1;
}
} while (flag == 0);
do {
flag = 0;
cout << "C++程序设计成绩：";
cin >> stu[i].c_program;
if (stu[i].c_program > 100 || stu[i].c_program < 1) {
cout << " 对不起，请输入1-100之间的数字！！\n";
}
else {
flag = 1;
}
} while (flag == 0);
do {
flag = 0;
cout << "多媒体技术成绩：";
cin >> stu[i].media;
if (stu[i].media > 100 || stu[i].media < 1) {
cout << " 对不起，请输入1-100之间的数字！！\n";
}
else {
flag = 1;
}
} while (flag == 0);
do {
flag = 0;
cout << "大学英语成绩：";
cin >> stu[i].english;
if (stu[i].english > 100 || stu[i].english < 1) {
cout << " 对不起，请输入1-100之间的数字！！\n";
}
else {
flag = 1;
}
} while (flag == 0);
do {
flag = 0;
cout << "高等数学成绩：";
cin >> stu[i].math;
if (stu[i].math > 100 || stu[i].math < 1) {
cout << " 对不起，请输入1-100之间的数字！！\n";
}
else {
flag = 1;
}
} while (flag == 0);
do {
flag = 0;
cout << "大学体育成绩：";
cin >> stu[i].sport;
if (stu[i].sport > 100 || stu[i].sport < 1) {
cout << " 对不起，请输入1-100之间的数字！！\n";
}
else {
flag = 1;
}
} while (flag == 0);
do {
flag = 0;
cout << "马克思主义基本原理成绩：";
cin >> stu[i].polity;
if (stu[i].polity > 100 || stu[i].polity < 1) {
cout << " 对不起，请输入1-100之间的数字！！\n";
}
else {
flag = 1;
}
} while (flag == 0);
stu[i].average = (stu[i].elec + stu[i].c_program + stu[i].media + stu[i].english + stu[i].math +
stu[i].sport + stu[i].polity) / 7;
cout << " 平均分为：" << stu[i].average << endl;
cout << "======>> 提示：是否继续写入学生成绩 ?(y/n)";
cin >> sign;
i++;
}
Write(stu, i);
}
void Statistic(Student stu[]) {
system("cls");
int n = Read(stu);
cout << endl << "======>> 输出学生统计数据 <<======\n" << endl;
cout << "---------------------------------------" << endl;
cout << "班级" << "\t" << "学号" << "\t" << "姓名" << "\t" << "平均分" << endl;
cout << "---------------------------------------" << endl;
for (int i = 0; i < n; i++)
cout << stu[i].class_0 << "\t" << stu[i].num << "\t" << stu[i].name << "\t" << stu[i].average << endl;
cout << "---------------------------------------" << endl;
system("pause");
}
void Lookup(Student stu[]) {
system("cls");
int n = Read(stu);
int s;
int i = 0;
cout << endl << "======>> 查找学生成绩 <<======" << endl;
cout << "请输入要查找学生的学号：";
cin >> s;
while ((stu[i].num - s) != 0 && i < n)i++;
if (i == n) {
cout << "======>> 对不起，无法找到该学生...... <<======" << endl;
}
else {
cout << "----------------------------" << endl;
cout << "班级：" << stu[i].class_0 << endl;
cout << "学号：" << stu[i].num << endl;
cout << "姓名：" << stu[i].name << endl;
cout << "电子技术：" << stu[i].elec << endl;
cout << "C++程序设计：" << stu[i].c_program << endl;
cout << "多媒体技术：" << stu[i].media << endl;
cout << "大学英语：" << stu[i].english << endl;
cout << "高等数学：" << stu[i].math << endl;
cout << "大学体育：" << stu[i].sport << endl;
cout << "马克思主义基本原理：" << stu[i].polity << endl;
cout << "平均分：" << stu[i].average << endl;
}
}
void Modify(Student stu[]) {
system("cls");
int n = Read(stu);
int s;
int i = 0;
cout << endl << "======>> 修改学生成绩 <<======" << endl;
cout << "请输入要修改成绩学生的学号：";
cin >> s;
while ((stu[i].num - s) != 0 && i < n)i++;
if (i == n) {
cout << "======>> 对不起，无法找到该学生...... <<======" << endl;
}
else {
cout << "------------------------------------------------------------------------------------" << endl;
cout << "班级" << "\t" << "学号" << "\t" << "姓名" << "\t"
<< "电子" << "\t" << "C++" << "\t" << "多媒体" << "\t"
<< "英语" << "\t" << "数学" << "\t" << "体育" << "\t"
<< "政治" << "\t" << "平均分" << endl;
cout << "------------------------------------------------------------------------------------" << endl;
cout << stu[i].class_0 << "\t" << stu[i].num << "\t" << stu[i].name << "\t"
<< stu[i].elec << "\t" << stu[i].c_program << "\t" << stu[i].media << "\t"
<< stu[i].english << "\t" << stu[i].math << "\t" << stu[i].sport << "\t"
<< stu[i].polity << "\t" << stu[i].average << endl;
cout << endl << "请重新输入该学生成绩： " << endl;
cout << "电子技术成绩：";
cin >> stu[i].elec;
cout << "C++成绩：";
cin >> stu[i].c_program;
cout << "多媒体技术成绩：";
cin >> stu[i].media;
cout << "大学英语成绩：";
cin >> stu[i].english;
cout << "高等数学成绩：";
cin >> stu[i].math;
cout << "大学体育成绩：";
cin >> stu[i].sport;
cout << "马克思主义基本原理成绩：";
cin >> stu[i].polity;
stu[i].average = (stu[i].elec + stu[i].c_program + stu[i].media +
stu[i].english + stu[i].math + stu[i].sport + stu[i].polity) / 7;
cout << "平均分：" << stu[i].average << endl;
char c;
cout << "======>> 是否保存数据 ？(y/n)";
cin >> c;
if (c != 'n' && c != 'N')
Write(stu, n);
}
}
void Delete(Student stu[]) {
system("cls");
int n = Read(stu);
int s;
int i = 0, j;
cout << endl << "======>> 删除学生成绩 <<======" << endl;
cout << "请输入要删除的学生的学号：";
cin >> s;
while ((stu[i].num - s) != 0 && i < n)i++;
if (i == n) {
cout << "======>> 对不起，无法找到该学生...... <<======" << endl;
}
else {
for (j = i; j < n - 1; j++) {
strcpy(stu[j].class_0, stu[j + 1].class_0);
stu[j].num = stu[j + 1].num;
strcpy(stu[j].name, stu[j + 1].name);
stu[j].elec = stu[j + 1].elec;
stu[j].c_program = stu[j + 1].c_program;
stu[j].media = stu[j + 1].media;
stu[j].english = stu[j + 1].english;
stu[j].math = stu[j + 1].math;
stu[j].sport = stu[j + 1].sport;
stu[j].polity = stu[j + 1].polity;
stu[j].average = stu[j + 1].average;
}
cout << "======>> 提示：已成功删除！" << endl;
}
Write(stu, n - 1);
}
void Insert(Student stu[]) {
system("cls");
int n = Read(stu);
char s = '0';
cout << endl << "=======>> 增加学生成绩 <<========" << endl;
while (s != 'n' && s != 'N') {
cout << "班级：";
cin >> stu[n].class_0;
cout << "学号：";
cin >> stu[n].num;
cout << "姓名：";
cin >> stu[n].name;
cout << "电子技术成绩：";
cin >> stu[n].elec;
cout << "C++成绩：";
cin >> stu[n].c_program;
cout << "多媒体技术成绩：";
cin >> stu[n].media;
cout << "大学英语成绩：";
cin >> stu[n].english;
cout << "高等数学成绩：";
cin >> stu[n].math;
cout << "大学体育成绩：";
cin >> stu[n].sport;
cout << "马克思主义基本原理成绩：";
cin >> stu[n].polity;
stu[n].average = (stu[n].elec + stu[n].c_program + stu[n].media +
stu[n].english + stu[n].math + stu[n].sport + stu[n].polity) / 7;
cout << "平均分：" << stu[n].average << endl;
n++;
cout << "======>> 是否继续插入(y/n)";
cin >> s;
}
Write(stu, n);
}
void Sort(Student stu[]) {
system("cls");
int i, j, k;
float s;
char t[20];
cout << endl << "======>> 降序排列 <<======" << endl;
int n = Read(stu);
for (i = 0; i < n - 1; i++) {
for (j = 0; j < n - 1; j++) {
if (stu[j].average < stu[j + 1].average) {
//交换课程
strcpy(t, stu[j + 1].class_0);
strcpy(stu[j + 1].class_0, stu[j].class_0);
strcpy(stu[j].class_0, t);
//num
k = stu[j + 1].num;
stu[j + 1].num = stu[j].num;
stu[j].num = k;
//name
strcpy(t, stu[j + 1].name);
strcpy(stu[j + 1].name, stu[j].name);
strcpy(stu[j].name, t);
//elec
s = stu[j + 1].elec;
stu[j + 1].elec = stu[j].elec;
stu[j].elec = s;
//c_program
s = stu[j + 1].c_program;
stu[j + 1].c_program = stu[j].c_program;
stu[j].c_program = s;
//media
s = stu[j + 1].media;
stu[j + 1].media = stu[j].media;
stu[j].media = s;
//english
s = stu[j + 1].english;
stu[j + 1].english = stu[j].english;
stu[j].english = s;
//math
s = stu[j + 1].math;
stu[j + 1].math = stu[j].math;
stu[j].math = s;
//sport
s = stu[j + 1].sport;
stu[j + 1].sport = stu[j].sport;
stu[j].sport = s;
//polity
s = stu[j + 1].polity;
stu[j + 1].polity = stu[j].polity;
stu[j].polity = s;
//average
s = stu[j + 1].average;
stu[j + 1].average = stu[j].average;
stu[j].average = s;
}
}
}
cout << "------------------------------------------------------------------------------------" << endl;
cout << "班级" << "\t" << "学号" << "\t" << "姓名" << "\t"
<< "电子" << "\t" << "C++" << "\t" << "多媒体" << "\t"
<< "英语" << "\t" << "数学" << "\t" << "体育" << "\t"
<< "政治" << "\t" << "平均分" << endl;
cout << "------------------------------------------------------------------------------------" << endl;
for (int i = 0; i < n; i++) {
stu[i].order = i + 1;
cout << stu[i].class_0 << "\t" << stu[i].num << "\t" << stu[i].name << "\t"
<< stu[i].elec << "\t" << stu[i].c_program << "\t" << stu[i].media << "\t"
<< stu[i].english << "\t" << stu[i].math << "\t" << stu[i].sport << "\t"
<< stu[i].polity << "\t" << stu[i].average << endl;
}
Write(stu, n);
}
void Output(Student stu[]) {
system("cls");
int n = Read(stu);
cout << endl << "======>> 显示全部学生成绩 <<======" << endl;
if (!stu) {
cout << "没有记录";
}
else {
cout << "------------------------------------------------------------------------------------" << endl;
cout << "班级" << "\t" << "学号" << "\t" << "姓名" << "\t"
<< "电子" << "\t" << "C++" << "\t" << "多媒体" << "\t"
<< "英语" << "\t" << "数学" << "\t" << "体育" << "\t"
<< "政治" << "\t" << "平均分" << endl;
cout << "------------------------------------------------------------------------------------" << endl;
for (int i = 0; i < n; i++) {
cout << stu[i].class_0 << "\t" << stu[i].num << "\t" << stu[i].name << "\t"
<< stu[i].elec << "\t" << stu[i].c_program << "\t" << stu[i].media << "\t"
<< stu[i].english << "\t" << stu[i].math << "\t" << stu[i].sport << "\t"
<< stu[i].polity << "\t" << stu[i].average << endl;
}
cout << "------------------------------------------------------------------------------------" << endl;
}
}
int menu() {
char c;
do {
system("cls");
cout << "******************************************************" << endl;
cout << "----------------欢迎使用学生成绩管理系统---------------" << endl;
cout << " * 【1】输入学生成绩 * " << endl;
cout << " * 【2】显示统计数据 * " << endl;
cout << " * 【3】查找学生成绩 * " << endl;
cout << " * 【4】修改学生成绩 * " << endl;
cout << " * 【5】删除学生成绩 * " << endl;
cout << " * 【6】插入学生成绩 * " << endl;
cout << " * 【7】按平均分排列 * " << endl;
cout << " * 【8】显示学生成绩 * " << endl;
cout << " * 【0】退出管理系统 * " << endl;
cout << "******************************************************" << endl;
cout << "请选择您的操作 (0-8):" << endl;
c = getchar();
} while (c < '0' || c > '8');
return (c - '0');
}
int main() {
for (;;) {
switch (menu()) {
case 1:
Input(stu);
break;
case 2:
Statistic(stu);
break;
case 3:
Lookup(stu);
system("pause");
break;
case 4:
Modify(stu);
system("pause");
break;
case 5:
Delete(stu);
system("pause");
break;
case 6:
Insert(stu);
system("pause");
break;
case 7:
Sort(stu);
system("pause");
break;
case 8:
Output(stu);
system("pause");
break;
case 0:
cout << endl << "================感谢您使用学生成绩管理系统==============\n" << endl;
exit(0);
}
}
return 0;
}
部分运行结果：
