用链表做一个学生管理系统

 //Student.cpp
#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;
    }
};
 
 
 
 
//main.cpp
#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;
           }
        }
    }   
}