12.3 摩托车的虚基类

/* (程序头部注释开始)
* 程序的版权和版本声明部分
* Copyright (c) 2011, 烟台大学计算机学院学生
* All rights reserved.
* 文件名称： 第十二周 任务三 
* 作 者： 杨森

* 完成日期： 2012 年 05 月 09 日
* 版 本 号： v.1.0

 

源程序：

 

;">#include <iostream>  #include<conio.h>   #include <windows.h>   using namespace std;  enum vehicleStaus {rest, running};  //车辆状态：泊车、行进   class vehicle //车辆类   {  protected:      int maxSpeed;       //最大车速       int currentSpeed;   //当前速度       int weight;         //车重       vehicleStaus status; //rest-泊车状态；running-行进状态   public:      vehicle(int maxS, int w); //构造函数，初始时，当前速度总为0且处在停车状态       void start();  //由rest状态到running, 初速为1       void stop(); //由running状态到rest, 当前速度小于5时，才允许停车       void speed_up();  //加速，调用1次，速度加1       void slow_down(); //减速，调用1次，速度减1，速度为0时，停车   };    class bicycle :virtual public vehicle//（1）自行车类的虚基类为车辆类   {   protected:      double height; //车高   public:      bicycle(int maxS=10, int w=50, int h=0.7);   //定义构造函数   };    class motorcar : virtual public vehicle//（2）机动车类的虚基类也为车辆类   {   protected:      int seatNum; //座位数       int passengerNum; //乘客人数   public:      motorcar(int maxS=150, int w=1500, int s=5, int p=1);   //定义构造函数       void addPassenger(int p=1);   //搭载乘客，超员要拒载，有人下车时，p为负数。当然车上乘客至少有1个（司机）。上下车时要保证安全……   };    class motorcycle: public bicycle,public motorcar //（3）摩托车类的基类为自行车类和机动车类{    {public:      motorcycle(int maxS=90, int w=100, int s=3, int p=1, int h=0.7);   //定义构造函数       void show(); //显示摩托车的运行状态   };    int main( )  {      motorcycle m;      bool end=false;      while (!end)      {          cout<<"请操作：1-启动  2-加速  3-减速  4-有人上车  5-有人下车  6-停车 0-结束"<<endl;          char keydown= _getch(); //_getch()返回键盘上读取的字符,应包含头文件<conio.h>           switch(keydown)          {          case '1':               cout<<"操作(启动)\t"; m.start(); break;          case '2':                                       cout<<"操作(加速)\t"; m.speed_up(); break;          case '3':                                        cout<<"操作(减速)\t"; m.slow_down(); break;          case '4':                                      cout<<"操作(有人上车)\t"; m.addPassenger(); break;          case '5':                                    cout<<"操作(有人下车)\t"; m.addPassenger(-1); break;          case '6':                                    cout<<"操作(停车)\t"; m.stop(); break;          case '0':                             end=true; break;          }          m.show();          cout<<endl;          Sleep(200);  //要包含头文件<windows.h>       }      system("pause");      return 0;  }  vehicle::vehicle(int maxS, int w)    {        maxSpeed = maxS;        weight = w;        currentSpeed = 0;        status = rest;    }        void vehicle::start()    {        if(status == rest)        {            status = running;            currentSpeed = 1;                cout << "车速为:" << currentSpeed << endl;        }        else        {            cout << "车辆已经启动！无需再次启动！" << endl;        }    }        void vehicle::stop()    {        if(currentSpeed < 5)        {            status = rest;            currentSpeed = 0;                cout << "车速为:" << currentSpeed << endl;        }        else        {            cout << "高速行驶！禁止停车！" << endl;        }    }        void vehicle::speed_up()    {        if(currentSpeed < maxSpeed)        {            ++currentSpeed;              status = running;                cout << "车速为:" << currentSpeed << endl;        }        else        {            cout << "已经达到最高车速！禁止加速！" << endl;        }    }        void vehicle::slow_down()    {        if(currentSpeed > 0)        {            --currentSpeed;                cout << "车速为:" << currentSpeed << endl;                if(currentSpeed == 0)            {                status = rest;            }        }        else        {            cout << "当前车速为0，已停车！禁止减速！" << endl;                status = rest;        }    }        bicycle::bicycle(int maxS, int w, int h):vehicle(maxS, w)    {        height = h;    }        motorcar::motorcar(int maxS, int w, int s, int p):vehicle(maxS, w)    {        seatNum = s;        passengerNum = p;    }        void motorcar::addPassenger(int p)   //搭载乘客，超员要拒载，有人下车时，p为负数。当然车上乘客至少有1个（司机）。上下车时要保证安全      {        if(p < 0 && passengerNum > 1 && status == rest)        {            --passengerNum;                cout << "当前车内人数：" << passengerNum << endl;        }        else if(passengerNum >= seatNum && p > 0 && status == rest)        {            cout << "车辆超载！禁止搭载乘客！" << endl;        }        else if(passengerNum <= 1 && p < 0 && status == rest)        {            cout << "已达到最低人数！除司机外无乘客！" << endl;        }        else if(status == running && p < 0)        {            cout << "车辆正在行驶！为保证安全，禁止乘客下车！" << endl;        }        else if(status == running && p > 0)        {            cout << "车辆正在行驶！为保证安全，禁止搭载乘客！" << endl;        }        else         {            ++passengerNum;                 cout << "当前车内人数：" << passengerNum << endl;        }            cout << "车速为:" << currentSpeed << endl;    }        motorcycle::motorcycle(int maxS, int w, int s, int p, int h):vehicle(maxS, w), bicycle(maxS, w, h), motorcar(maxS, w, s, p){}      void motorcycle::show()    {        cout << "当前车辆状态： ";            if(status == rest)        {            cout << "停车" << endl;        }        else        {            cout << "行驶" << endl;        }    }

运行结果：

小感：声明虚基类后，基类成员只保留一次