学生选课管理系统这个怎么搞啊

Question

假定有n门课程，每门课程有课程编号，课程名称，课程性质（必须/选修），学时，授课学时，实验或上机学时，学分等信息，学生按要求（总学分不得少于15，其中必修课不得低于10分）自由选课。试设计一个简单选修课程系统。

功能要求：

(1) 输入功能：可以完成若干条课程信息记录的输入。

(2) 显示功能：完成全部记录的显示。

(3) 插入功能：插入添加一条或多条记录。

(4) 查找功能：按课程编号查找并显示。

(5) 删除功能：按课程编号号进行删除。

(6) 修改功能：按课程编号进行修改。

(7) 排序功能：实现学分进行排序。

Answer 1

#include <iostream>
#include <fstream>
using namespace std;
#define Mc_CourseNameLength          61                  /*课程名称不超过30个字*/
#define Mc_FileName                  ("CourseData.csd")   /*存储课程信息的文件名称*/
#define Mc_OpenFileError             0                   /*打开文件失败*/
#define Mc_OpenFileSucceed           1                   /*打开文件成功*/
class ElectiveSystem /*选课系统*/
{
 protected:
  struct Course /*课程*/
  {
    long    ID;                         /*课程编号，0 到 65535*/
    char    name[Mc_CourseNameLength];  /*课程名称*/
    float   credit;                     /*学分*/
    short   TimeTotal;                  /*总学时*/
    short   TimeLesson;                 /*授课学时*/
    short   TimeExperiment;             /*实验学时*/
    short   nature;                     /*课程性质，值域为 1 到 3，每种数值代表一种性质。因为不知道什么是课程的性质，所以没给出具体的含义*/
    bool    term;                       /*为真表示上学期，为假表示下学期*/
    short   number;                     /*节点编号，从 1 开始*/
    struct  Course *next;               /*下一个节点*/
  } *PtHead;                            /*头结点*/
  int       AddNewCourse();                       /*增加新课程信息*/
  int       SaveCourseData(struct Course *cs);    /*保存单个课程信息*/
  int       LoadCourseData();                     /*加载课程信息*/
  void      ShowCourseData();          /*显示课程信息*/
  int       MainInterface();           /*系统主界面*/
  void      InputCourseData();         /*录入课程信息界面*/
  void      SelectCourse();            /*学生选课界面*/
  void      SearchCourse();            /*课程查询界面*/
  void      SearchCredit();            /*按学分查询*/
  void      SearchNature();            /*按性质查询*/
  void      FreePtHeadMemery();        /*释放PtHead指向的空间*/
 public:
  ElectiveSystem();                    /*构造函数*/
  ~ElectiveSystem();                   /*析构函数*/
  void      BeginRun();                /*开始运行此系统*/
};
int ElectiveSystem::AddNewCourse()
{
   struct Course cs;
   cout<<"请输入课程信息，每输入完一个项目按一次Enter键"<<endl<<endl<<endl;
   cout<<"课程编号 (0 到 65535，且必须是唯一的，不能与其他课程编号重复): ";
   cin>>cs.ID;
   cout<<endl;
   cout<<"课程名称 (不超过30个文字): ";
   cin>>cs.name;
   cout<<endl;
   cout<<"课程学分 (0.5 到 5): ";
   cin>>cs.credit;
   cout<<endl;
   cout<<"总学时 (0 到 300): ";
   cin>>cs.TimeTotal;
   cout<<endl;
   cout<<"授课学时: ";
   cin>>cs.TimeLesson;
   cout<<endl;
   cout<<"实验学时: ";
   cin>>cs.TimeExperiment;
   cout<<endl;
   cout<<"课程性质 ( 1 到 3): ";
   cin>>cs.nature;
   cout<<endl;
   cout<<"开课学期 (输入 1 表示上学期，0 表示下学期): ";
   cin>>cs.term;
   cout<<endl;
   return SaveCourseData(&cs);
}
int ElectiveSystem::SaveCourseData(struct Course *cs)
{
   fstream file;
   file.open(Mc_FileName, ios::binary | ios::out | ios::app);
   if (!file)
     return Mc_OpenFileError;
   file.write((char*)&cs->ID, sizeof(long));
   file.write(cs->name, Mc_CourseNameLength * sizeof(char));
   file.write((char*)&cs->credit, sizeof(float));
   file.write((char*)&cs->TimeTotal, sizeof(short));
   file.write((char*)&cs->TimeLesson, sizeof(short));
   file.write((char*)&cs->TimeExperiment, sizeof(short));
   file.write((char*)&cs->nature, sizeof(short));
   file.write((char*)&cs->term, sizeof(bool));
   file.close();
   return Mc_OpenFileSucceed;
}
int ElectiveSystem::LoadCourseData()
{
   ifstream file;
   FreePtHeadMemery();
   PtHead = NULL;
   file.open(Mc_FileName, ios::binary);
   if (!file)
     return Mc_OpenFileError;
   struct Course *cur, *New, test;
   short  num = 1;
   while (!file.eof())
   {
     if (PtHead == NULL)
     {
       test.nature = 0;
       file.read(reinterpret_cast<char*> (&test.ID), sizeof(long));
       file.read(reinterpret_cast<char*> (test.name), Mc_CourseNameLength * sizeof(char));
       file.read(reinterpret_cast<char*> (&test.credit), sizeof(float));
       file.read(reinterpret_cast<char*> (&test.TimeTotal), sizeof(short));
       file.read(reinterpret_cast<char*> (&test.TimeLesson), sizeof(short));
       file.read(reinterpret_cast<char*> (&test.TimeExperiment), sizeof(short));
       file.read(reinterpret_cast<char*> (&test.nature), sizeof(short));
       file.read(reinterpret_cast<char*> (&test.term), sizeof(bool));
       if (test.nature != 0)
       {
         cur = PtHead = new struct Course;
         *cur = test;
         cur->number = num ++;
       }
       else
         break;
     }
     else
     {
       test.nature = 0;
       file.read(reinterpret_cast<char*> (&test.ID), sizeof(long));
       file.read(reinterpret_cast<char*> (test.name), Mc_CourseNameLength * sizeof(char));
       file.read(reinterpret_cast<char*> (&test.credit), sizeof(float));
       file.read(reinterpret_cast<char*> (&test.TimeTotal), sizeof(short));
       file.read(reinterpret_cast<char*> (&test.TimeLesson), sizeof(short));
       file.read(reinterpret_cast<char*> (&test.TimeExperiment), sizeof(short));
       file.read(reinterpret_cast<char*> (&test.nature), sizeof(short));
       file.read(reinterpret_cast<char*> (&test.term), sizeof(bool));
       if (test.nature !=0)
       {
         New = new struct Course;
         *New = test;
         cur->next = New;
         cur = New;
         cur->number = num ++;
       }
       else   /*nature的值域为1 到 3。之前有test.nature  = 0，如果能正确读到数据，那么不应该是0；如果是0，表明到了文件尾部*/
         break; /*因为eof()这个函数到了文件尾部会多停留一次，所以为了解决这个问题，采用此策略*/
     }
   }
   cur->next = PtHead;
   file.close();
   return Mc_OpenFileSucceed;
}
void ElectiveSystem::ShowCourseData()
{
   bool flag = true;
   if (PtHead == NULL)
   {
     LoadCourseData();
     if (PtHead == NULL)
     {
       flag = false;
       cout<<endl<<"管理员尚未录入任何课程信息! 请管理员录入课程信息后，再来浏览!"<<endl;
       system("pause");
     }
   }
   if (flag)
   {
     struct Course *cs = PtHead->next;
     cout<<"编号     学分     总学时   授课学时 实验学时 性质     开课学期 名称"<<endl<<endl;
     cout.precision(2);
     cout.setf(ios::left);
     while (cs->number != 1)
     {
       cout.width(9);
       cout<<cs->ID;
       cout.width(9);
       cout<<cs->credit;
       cout.width(9);
       cout<<cs->TimeTotal;
       cout.width(9);
       cout<<cs->TimeLesson;
       cout.width(9);
       cout<<cs->TimeExperiment;
       cout.width(9);
       cout<<cs->nature;
       if (cs->term == 1)
         cout<<"上学期   ";
       else
         cout<<"下学期   ";
       cout<<cs->name<<endl<<endl;
       cs = cs->next;
     }
     cout.width(9);
     cout<<cs->ID;
     cout.width(9);
     cout<<cs->credit;
     cout.width(9);
     cout<<cs->TimeTotal;
     cout.width(9);
     cout<<cs->TimeLesson;
     cout.width(9);
     cout<<cs->TimeExperiment;
     cout.width(9);
     cout<<cs->nature;
     if (cs->term == 1)
       cout<<"上学期   ";
     else
       cout<<"下学期   ";
     cout<<cs->name<<endl<<endl;
     system("pause");
   }
}
ElectiveSystem::ElectiveSystem()
{
   PtHead = NULL;
   LoadCourseData();
}
ElectiveSystem::~ElectiveSystem()
{
   FreePtHeadMemery();
}
int ElectiveSystem::MainInterface()
{
   short selection = 0;
   cout<<"学生选课系统: 请输入相应的序号，然后按Enter键"<<endl<<endl<<endl;
   cout<<"1.课程录入"<<endl<<endl;
   cout<<"2.浏览课程信息"<<endl<<endl;
   cout<<"3.学生选课"<<endl<<endl;
   cout<<"4.课程查询"<<endl<<endl;
   cout<<"5.退出"<<endl<<endl;
   cout<<"请在此输入你的选择: ";
   cin>>selection;
   return selection;
}
void ElectiveSystem::InputCourseData()
{
   LoadCourseData();
   if (PtHead == NULL)
   {
     short CourseCount = 0;
     int   loop = 0;
     cout<<"你将要录入多少个课程的信息？请输入课程个数，然后按Enter键"<<endl<<endl<<endl;
     cout<<"请在此输入你要录入的课程的个数: ";
     cin>>CourseCount;
     system("cls");
     for ( ; loop < CourseCount; loop ++)
     {
       cout<<"正在录入第 "<<loop + 1<<" 个课程信息，共 "<<CourseCount<<" 个课程信息"<<endl<<endl;
       AddNewCourse();
       system("cls");
     }
     cout<<"录入完成 ! 按任意键返回主界面 ......"<<endl;
     system("pause");
   }
   else
   {
     cout<<"你已经进行过数据录入，要想重新录入数据请将文件 "<<Mc_FileName<<" 删除!"<<endl<<endl<<endl;
     cout<<"按任意键返回主界面 ......"<<endl<<endl;
     system("pause");
   }
}
void main()
{
   ElectiveSystem es;
   es.BeginRun();
}