驾驶员与汽车
Description
我们知道，目前我国的驾照大致可分为A、B、C三种，其中C证只能开小型客车（货车），B证可开中、小型客车（货车），A证没有限制。现在请定义如下几个类：
Automobile：抽象类，具有数据成员double speed，纯虚函数virtual void run() const = 0。
六种车型，即小型车Benz、Buick；中型车Zhongba、Beiqi；以及大型车Dayu、Jianghuai。它们都是Automobile的子类。
Driver类，具有string name和char type两个数据成员，前者是司机的名字，后者是司机持有的驾照类型（A、B或C）。提供Drive(Automobile *)方法，根据驾照类型判定该司机是否可以驾驶指定的汽车。
Input
输入分多行。第一行是一个整数M>0，表示之后有M个测试用例。
每个测试用例包括四部分：司机姓名（不含空白符）、驾照类型（A、B或C）、车型（分别用字母a~f表示六种车型，对应的车型可以从main()中看出）以及该车的行驶速度（double类型范围内的正数）。
Output
输出共M行，每个测试用例对应一行输入，具体格式参见样例。
Sample Input
4
zhangsan C a 100.33
lisi C d 100.33
wangwu B f 100.33
Tom A e 300.00
Sample Output
Driver zhangsan can drive Benz at speed of 100.33km/h.
A Benz is erased!
An automobile is erased!
Driver lisi cannot drive bus.
A Beiqi is erased!
An automobile is erased!
Driver wangwu cannot drive large bus.
A Jianghuai is erased!
An automobile is erased!
Driver Tom can drive Dayu at speed of 300.00km/h.
A Dayu is erased!
An automobile is erased!
HINT
1.使用typeid来判定一个基类指针实际指向的对象的类型。
2.注意：append.cc中已经给出了Driver类的一个方法，不要在Driver类重复定义了。
题目给定代码
void Driver::Drive(Automobile *automobile)
{
switch (type)
{
case 'A':
cout<<"Driver "<<name<<" can drive ";
automobile->run();
break;
case 'B':
if (typeid(*automobile) == typeid(Dayu) || typeid(*automobile) == typeid(Jianghuai))
cout<<"Driver "<<name<<" cannot drive large bus."<<endl;
else
{
cout<<"Driver "<<name<<" can drive ";
automobile->run();
}
break;
case 'C':
if (typeid(*automobile) != typeid(Benz) && typeid(*automobile) != typeid(Buick))
cout<<"Driver "<<name<<" cannot drive bus."<<endl;
else
{
cout<<"Driver "<<name<<" can drive ";
automobile->run();
}
break;
}
}
int main()
{
string name;
char type;
double speed;
char automobileType;
int cases;
Automobile *automobile;
cin>>cases;
for (int i = 0; i < cases; i++)
{
cin>>name>>type>>automobileType>>speed;
Driver driver(name, type);
switch (automobileType)
{
case 'a':
automobile = new Benz(speed);
break;
case 'b':
automobile = new Buick(speed);
break;
case 'c':
automobile = new Zhongba(speed);
break;
case 'd':
automobile = new Beiqi(speed);
break;
case 'e':
automobile = new Dayu(speed);
break;
case 'f':
automobile = new Jianghuai(speed);
break;
}
driver.Drive(automobile);
delete automobile;
}
return 0;
}
code：
#include<iostream>
#include<typeinfo>
#include<iomanip>
using namespace std;
class Automobile{
protected:
double speed;
public:
Automobile(double s):speed(s){
}
virtual void run()=0;
virtual ~Automobile(){
cout<<"An automobile is erased!"<<endl;
}
};
class Benz:virtual public Automobile{
public:
Benz(double s):Automobile(s){
}
void run(){
cout<<fixed<<setprecision(2)<<"Benz at speed of "<<speed<<"km/h."<<endl;
}
~Benz(){
cout<<"A Benz is erased!"<<endl;
}
};
class Buick:virtual public Automobile{
public:
Buick(double s):Automobile(s){
}
void run(){
cout<<fixed<<setprecision(2)<<"Benz at speed of "<<speed<<"km/h."<<endl;
}
~Buick(){
cout<<"A Buick is erased!"<<endl;
}
};
class Zhongba:virtual public Automobile{
public:
Zhongba(double s):Automobile(s){
}
void run(){
cout<<fixed<<setprecision(2)<<"Zhongba at speed of "<<speed<<"km/h."<<endl;
}
~Zhongba(){
cout<<"A Zhongba is erased!"<<endl;
}
};
class Beiqi:virtual public Automobile{
public:
Beiqi(double s):Automobile(s){
}
void run(){
cout<<fixed<<setprecision(2)<<"Beiqi at speed of "<<speed<<"km/h."<<endl;
}
~Beiqi(){
cout<<"A Beiqi is erased!"<<endl;
}
};
class Dayu:virtual public Automobile{
public:
Dayu(double s):Automobile(s){
}
void run(){
cout<<fixed<<setprecision(2)<<"Dayu at speed of "<<speed<<"km/h."<<endl;
}
~Dayu(){
cout<<"A Dayu is erased!"<<endl;
}
};
class Jianghuai:virtual public Automobile{
public:
Jianghuai(double s):Automobile(s){
}
void run(){
cout<<fixed<<setprecision(2)<<"Jianghuai at speed of "<<speed<<"km/h."<<endl;
}
~Jianghuai(){
cout<<"A Jianghuai is erased!"<<endl;
}
};
class Driver{
string name;
char type;
public:
Driver(string N,char C){
name=N;
type=C;
}
void Drive(Automobile *automobile);
};
void Driver::Drive(Automobile *automobile)
{
switch (type)
{
case 'A':
cout<<"Driver "<<name<<" can drive ";
automobile->run();
break;
case 'B':
if (typeid(*automobile) == typeid(Dayu) || typeid(*automobile) == typeid(Jianghuai))
cout<<"Driver "<<name<<" cannot drive large bus."<<endl;
else
{
cout<<"Driver "<<name<<" can drive ";
automobile->run();
}
break;
case 'C':
if (typeid(*automobile) != typeid(Benz) && typeid(*automobile) != typeid(Buick))
cout<<"Driver "<<name<<" cannot drive bus."<<endl;
else
{
cout<<"Driver "<<name<<" can drive ";
automobile->run();
}
break;
}
}
int main()
{
string name;
char type;
double speed;
char automobileType;
int cases;
Automobile *automobile;
cin>>cases;
for (int i = 0; i < cases; i++)
{
cin>>name>>type>>automobileType>>speed;
Driver driver(name, type);
switch (automobileType)
{
case 'a':
automobile = new Benz(speed);
break;
case 'b':
automobile = new Buick(speed);
break;
case 'c':
automobile = new Zhongba(speed);
break;
case 'd':
automobile = new Beiqi(speed);
break;
case 'e':
automobile = new Dayu(speed);
break;
case 'f':
automobile = new Jianghuai(speed);
break;
}
driver.Drive(automobile);
delete automobile;
}
return 0;
}
思路：
1）注意fixed与setprecision的用法，在头文件：
里面；
用法：
cout<<fixed<<setprecision(2)<<....
2）注意关键字typeid()关键字的用法：
用来判断一个对象是不是一个类的实例化！
typeid(*对象名)==typeid(子类名)
注意声明头文件：
3)抽象类的析构函数要执行必须将父类的析构函数声明未virtual
4）注意一般抽象函数定义方法
virtual 返回类型 函数名(参数列表)=0；
5)子类的构造函数执行前先执行父类的构造函数！！！