c++小实验：酒店住房退房，要求使用运算符重载，纯虚函数，多态c/c++qpfxgg的博客-

实验要求：
实现对抽象类的继承，通过operator函数调用的形式,实现运算符的重载

实验内容：
一个小型快捷酒店有5个房间，其中3个标准间，2个大床间，可在柜台办理入住或退房。

标准间180元/天，大床间120元/天，押金都是100元。 请利用类的多态特性实现该系统。

 
这个需要事先创建一个number.txt的文件，并在其中输入3 5,分别代表标准间个数和大床房个数

 
代码如下

#include<iostream> #include<fstream> using namespace std;  //房间的基类 class Room { public:   //预定房间  virtual void Reserve() = 0;   //退订房间  virtual void Cancel() = 0;   int m_Num;//房间剩余数  int m_Deposit;//押金 };  //标准间 class StandardRoom:public Room { public:   //预定房间  virtual void Reserve();   //退订房间  virtual void Cancel(); };  int stand;//标准间房间个数 int big;//大床房房间个数 int num;//顾客预定房间个数  //预定标准间 void StandardRoom::Reserve() {  //打开文件  fstream fs;  fs.open("number.txt", ios::in );  fs >> stand >> big;  cout << "标准间剩余：" << stand << "个！" << endl   << "请输入您要预定的房间个数！" << endl;  while (true)  {   cin >> num;   if (num > stand)   {    cout << "输入有误，请重新输入！" << endl;   }   else   {    stand -= num;    break;   }  }  //cout << "stand:" << stand << endl;  fs.close();  fs.open("number.txt", ios::trunc|ios::out);  fs << stand << " " << big;   cout << "标准间180元/天，押金100元" << endl;  cout << "预定成功!" << endl;    fs.close(); }  //退订标准间 void StandardRoom::Cancel() {  //打开文件  fstream fs;  fs.open("number.txt", ios::in);  fs >> stand >> big;  cout << "标准间剩余：" << stand << "个！" << endl   << "请输入您要退订的房间个数！" << endl;  while (true)  {   cin >> num;   if (num + stand>3)   {    cout << "输入有误，请重新输入！" << endl;   }   else   {    stand += num;    break;   }  }  //cout << "stand:" << stand << endl;  fs.close();  fs.open("number.txt", ios::trunc | ios::out);  fs << stand << " " << big;   cout << "退订成功，已退还押金！" << endl;  fs.close(); } //大床间 class BigBedRoom :public Room { public:   //预定房间  virtual void Reserve();   //退订房间  virtual void Cancel(); };  //预定大床间 void BigBedRoom::Reserve() {   //打开文件  fstream fs;  fs.open("number.txt", ios::in);  fs >> stand >> big;  cout << "大床间剩余：" << big << "个！" << endl   << "请输入您要预定的房间个数！" << endl;  while (true)  {   cin >> num;   if (num > big)   {    cout << "输入有误，请重新输入！" << endl;   }   else   {    big -= num;    break;   }  }  //cout << "stand:" << stand << endl;  fs.close();  fs.open("number.txt", ios::trunc | ios::out);  fs << stand << " " << big;   cout << "大床间120元/天，押金100元" << endl;  cout << "预定成功!" << endl;    fs.close(); }  //退订大床间 void BigBedRoom::Cancel() {  //打开文件  fstream fs;  fs.open("number.txt", ios::in);  fs >> stand >> big;  cout << "大床间剩余：" << big << "个！" << endl   << "请输入您要退订的房间个数！" << endl;  while (true)  {   cin >> num;   if (num + big>5)   {    cout << "输入有误，请重新输入！" << endl;   }   else   {    big += num;    break;   }  }  //cout << "stand:" << stand << endl;  fs.close();  fs.open("number.txt", ios::trunc | ios::out);  fs << stand << " " << big;   cout << "退订成功，已退还押金！" << endl;  fs.close(); } void ShowMenu() {  cout << " ------------------------------------" << endl;  cout << "|                                    |" << endl;  cout << "|        请输入您要进行的操作！      |" << endl;  cout << "|                                    |" << endl;  cout << "|            1、入住标准间           |" << endl;  cout << "|                                    |" << endl;  cout << "|            2、入住大床间           |" << endl;  cout << "|                                    |" << endl;  cout << "|            3、退订标准间           |" << endl;  cout << "|                                    |" << endl;  cout << "|            4、退订大床间           |" << endl;  cout << "|                                    |" << endl;  cout << "|            5、查看房间剩余         |" << endl;  cout << "|                                    |" << endl;  cout << "|            0、退出                 |" << endl;  cout << "|                                    |" << endl;  cout << " ------------------------------------" << endl; }  StandardRoom sm; BigBedRoom bbr;  ostream& operator<<(ostream& out, StandardRoom& s) {  out << "标准间剩余:" << s.m_Num << endl;  return out; }  ostream& operator<<(ostream& out, BigBedRoom& b) {  out << "大床间剩余:" << b.m_Num << endl;  return out; } void Check() {  //打开文件  fstream fs;  fs.open("number.txt", ios::in);  fs >> stand >> big;   sm.m_Num = stand;  bbr.m_Num = big;   cout << sm << bbr; }  int main() {     int choice;  //登陆界面  while (true)  {   ShowMenu();   cin >> choice;    //入住标准间   if (choice == 1)   {    sm.Reserve();    system("pause");    system("cls");   }   //入住大床间   else if (choice == 2)   {    bbr.Reserve();    system("pause");    system("cls");   }   //退订标准房   else if (choice == 3)   {    sm.Cancel();    system("pause");    system("cls");   }   //退订大床房   else if (choice == 4)   {    bbr.Cancel();    system("pause");    system("cls");   }   //查看房间余量   else if (choice == 5)   {    Check();    system("pause");    system("cls");   }   //退出   else if (choice == 0)   {    break;    cout << "欢迎您下次使用!" << endl;     system("pause");    system("cls");   }   else   {    cout << "输入错误！" << endl;    system("pause");    system("cls");   }  } }