C++实现简单的学生管理系统

#include<iostream>
 
using namespace std;
 
struct Stu
{
  char no[10];
  char name[16];
  int math;
  int chi;
  double ave;
};
 
class Student
{
public:
  Stu st;
  Student * next;
public:
  Student(){}
  Student(Stu s)
  {
    st=s;
    next=NULL;
    st.ave=(st.math+st.chi)/2.0;
  }
  void setst(Stu s)
  {
    st=s;
    st.ave=(st.math+st.chi)/2.0;
  }
  Stu getst()
  {
    return st;
  }
  void show()
  {
    cout<<"----------------------------"<<endl;
    cout<<"学号:"<<st.no<<endl;
    cout<<"姓名:"<<st.name<<endl;
    cout<<"数学成绩:"<<st.math<<endl;
    cout<<"语文成绩:"<<st.chi<<endl;
    cout<<"平均成绩:"<<st.ave<<endl;
    cout<<"----------------------------"<<endl;
  }
};

#include<fstream>
#include"Student.cpp"
 
using namespace std;
 
Student * create_List();
void traverse_List(Student * pHead);
bool is_empty(Student * pHead);
int length_List(Student * pHead);
bool insert_List(Student * pHead,int position,Stu st);
bool delete_List(Student * pHead,int position,Stu * st);
void sort_List(Student * pHead); 
void menu_select();
void handle_menu(int s);
void outFile();
Student * inFile();
void delFile();
 
Student * pHead;
 
 
void main()
{
  menu_select();
}
 
void menu_select()
{
  int s;
  cout<<"请输入您要操作的选项:"<<endl;
  cout<<"1.增加原始记录"<<endl;
  cout<<"2.按平均分排序显示所有记录"<<endl;
  cout<<"3.保存原始文件"<<endl;
  cout<<"4.读取原始文件"<<endl;
  cout<<"5.删除原始文件"<<endl;
  cout<<"6.插入单条记录"<<endl;
  cout<<"7.删除单条记录"<<endl;
  cout<<"8.显示记录总条数"<<endl;
  cout<<"9.结束程序运行"<<endl<<endl;
  cout<<"左边数字对应功能选择,请选择1-9:";
  cin>>s;
  handle_menu(s);
}
 
void handle_menu(int s)
{
  switch (s)
  {
  case 1:
    {
      system("cls");
      pHead=create_List();
      system("cls");
      menu_select();
      break;
    }
  case 2:
    {
      if(NULL==pHead)
      {
        cout<<"记录总条数为零"<<endl;
        getchar();
        getchar();
        system("cls");
        menu_select();
      }
      system("cls");
      sort_List(pHead);
      traverse_List(pHead);
      getchar();
      getchar();
      system("cls");
      menu_select();
      break;
    }
  case 3:
    {
      if(pHead!=NULL)
      {
        system("cls");
        outFile();
        system("cls");
        menu_select();
      }
      system("cls");
      menu_select();
      break;
    }
  case 4:
    {
      system("cls");
      pHead=inFile();
      system("cls");
      menu_select();
      break;
    }
  case 5:
    {
      system("cls");
      delFile();
      system("cls");
      menu_select();
      break;
    }
  case 6:
    {
      if(NULL==pHead)
      {
        cout<<"记录总条数为零"<<endl;
        getchar();
        getchar();
        system("cls");
        menu_select();
      }
      system("cls");
      int num;
      Stu st;
      traverse_List(pHead);
      cout<<"您想在哪条记录后插入,请输入序号:";
      cin>>num;
      cout<<"编辑要插入的记录:"<<endl;
      cout<<"学号:";
      cin>>st.no;
      cout<<"姓名:";
      cin>>st.name;
      cout<<"数学成绩:";
      cin>>st.math;
      cout<<"语文成绩:";
      cin>>st.chi;
      if(insert_List(pHead,num-1,st))
      {
        cout<<"插入成功!"<<endl;
      }
      else
      {
        cout<<"插入失败!"<<endl;
      }
      getchar();
      getchar();
      system("cls");
      menu_select();
      break;
    }
  case 7:
    {
      if(NULL==pHead)
      {
        cout<<"记录总条数为零"<<endl;
        getchar();
        getchar();
        system("cls");
        menu_select();
      }
      int num;
      Stu * st=(Stu *)malloc(sizeof(Stu));
      traverse_List(pHead);
      cout<<endl<<"请输入您要删除的记录的序号:";
      cin>>num;
      if(delete_List(pHead,num,st))
      {
        cout<<endl<<"成功删除的记录如下:"<<endl;
        cout<<"学号:"<<st->no<<endl<<"姓名:"<<st->name<<endl;
      }
      else
      {
        cout<<"删除失败!"<<endl;
      }
      getchar();
      getchar();
      system("cls");
      menu_select();
      break;
    }
  case 8:
    {
      if(NULL!=pHead)
      {
        system("cls");
        cout<<"记录总条数:"<<length_List(pHead)<<"条"<<endl;
        getchar();
        getchar();
        system("cls");
        menu_select();
      }
      else
      {
        cout<<"记录总条数为零"<<endl;
        getchar();
        getchar();
        system("cls");
        menu_select();
      }
      break;
    }
  case 9:
    {
      system("cls");
      cout<<"成功退出!"<<endl;
      exit(0);
      break;
    }
  }
}
 
 
void delFile()
{
  ofstream fileout;
  fileout.open("c:\\kcsj.txt",ios_base::out);
  fileout<<"";
  fileout.close();
}
 
 
Student * inFile()
{
  Student * pHead=(Student *)malloc(sizeof(Student));
  if(NULL==pHead)
  {
    cout<<"分配失败,程序终止!"<<endl;
    exit(0);
  }
  Student * pTail=pHead;
  pTail->next=NULL;
  ifstream in("c:\\kcsj.txt");
  if (!in.is_open())
  {
    cout << "Error opening file"<<endl; 
    exit(0);
  }
  while (!in.eof())
  {
    Stu st;
    in.read(reinterpret_cast<char *>(&st), sizeof(st));
    if (in.fail()) 
    {
      break;
    }
    Student * pNew=new Student();
    if(NULL==pNew)
    {
      printf("分配失败,程序终止\n");
      exit(0);
    }
    pNew->setst(st);
    pTail->next=pNew;
    pNew->next=NULL;
    pTail=pNew;
  }
  in.close();
  return pHead;
}
 
 
void outFile()
{
  ofstream out;
  out.open("c:\\kcsj.txt",ios_base::out|ios_base::app|ios::binary);
  if(!out)
  {
    cout<<"文件不存在，退出时别忘记保存文件!"<<endl;
    out.close();
    out.open("stu.dat",ios_base::out|ios::binary);
  }
  else
  { 
    out.close();
    out.open("c:\\kcsj.txt",ios_base::out|ios_base::app|ios::binary);
  }
  Student * temp=pHead->next;
  while(temp!=NULL)
  {
    Stu st=temp->getst();
    out.write(reinterpret_cast<char *>(&st), sizeof(st));
    temp=temp->next;
  }  
  out.close();
}
 
Student * create_List()
{
  int len;
  Student * pHead=(Student *)malloc(sizeof(Student));
  if(NULL==pHead)
  {
    cout<<"分配失败,程序终止!"<<endl;
    exit(0);
  }
  Student * pTail=pHead;
  pTail->next=NULL;
  cout<<"请输入要存储的学生人数:";
  cin>>len;
  for(int i=0;i<len;i++)
  {
    Stu st;
    cout<<"请输入第"<<i+1<<"个学生的学号:";
    cin>>st.no;
    cout<<"请输入第"<<i+1<<"个学生的姓名:";
    cin>>st.name;
    cout<<"请输入第"<<i+1<<"个学生的数学成绩:";
    cin>>st.math;
    cout<<"请输入第"<<i+1<<"个学生的语文成绩:";
    cin>>st.chi;
    Student * pNew=new Student();
    if(NULL==pNew)
    {
      printf("分配失败,程序终止\n");
      exit(0);
    }
    pNew->setst(st);
    pTail->next=pNew;
    pNew->next=NULL;
    pTail=pNew;
  }
  return pHead;
}
 
void traverse_List(Student * pHead)
{
  int i=1;
  Student * temp=pHead->next;
  while(temp!=NULL)
  {
    cout<<endl<<"序号:"<<i<<endl;
    temp->show();
    temp=temp->next;
    i++;
  }
}  
 
bool is_empty(Student * pHead)
{
  if(NULL==pHead->next)
  {
    return true;
  }
  else
  {
    return false;
  }
}
 
int length_List(Student * pHead)
{
  int len=0;
  Student * temp=pHead->next;
  while(temp)
  {
    len++;
    temp=temp->next;
  }
  return len;
}
 
bool insert_List(Student * pHead,int position,Stu st)
{
  int i=0;
  Student * p=pHead;
 
  while(NULL!=p&&i<position-1)
  {
    p=p->next;
    i++;
  }
  if(i>position-i||NULL==p)
  {
    return false;
  }
  Student * pNew=(Student *)malloc(sizeof(Student));
  if(NULL==pNew)
  {
    cout<<"分配失败,程序终止"<<endl;
    exit(0);
  }
  pNew->setst(st);
  pNew->next=p->next;
  p->next=pNew;
  return true;
}
 
bool delete_List(Student * pHead,int position,Stu * st)
{
  int i=0;
  Student * p=pHead;
 
  while(NULL!=p->next&&i<position-1)
  {
    p=p->next;
    i++;
  }
  Student * q=p->next;
  *st=q->getst();
  p->next=p->next->next;
  free(q);
  q=NULL;
  return true;
}
 
void sort_List(Student * pHead)
{
  Student * p,* q;
  Stu temp;
  int i,j;
  int len=length_List(pHead);
  for(i=0,p=pHead->next;i<len-1;i++,p=p->next)
  {
    for(j=i+1,q=p->next;j<len;j++,q=q->next)
    {
      if(q->st.ave>p->st.ave)
      {
        temp=q->st;
        q->st=p->st;
        p->st=temp;
      }
    }
  }  
}