这个题我多次wrong answer 50%,后来同学提醒是精度控制的问题(虽然题目没说,但OJ却是有检测~~~)
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Problem E: 驾驶员与汽车
Submit: 819 Solved: 369
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Problem E: 驾驶员与汽车
Time Limit: 1 Sec Memory Limit: 128 MBSubmit: 819 Solved: 369
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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:
1. Automobile:抽象类,具有数据成员double speed,纯虚函数virtual void run() const = 0。
2. 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。
3. 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。
Append Code
#include<iostream> #include <typeinfo> #include<iomanip> using namespace std; class Automobile{ protected: double speed; Automobile *next; public: virtual void run()const =0; Automobile(double s=0):speed(s){} virtual ~Automobile(){cout<<"An automobile is erased!"<<endl;} }; class Benz:public Automobile{ protected: double speed; public: Benz(double s):speed(s){} void run()const{cout<<setiosflags(ios::fixed)<<"Benz at speed of "<<setprecision(2)<<speed<<"km/h."<<endl;} ~Benz(){cout<<"A Benz is erased!"<<endl;} }; class Buick:public Automobile{ protected: double speed; public: Buick(double s):speed(s){} void run()const{cout<<setiosflags(ios::fixed)<<"Buick at speed of "<<setprecision(2)<<speed<<"km/h."<<endl;} ~Buick(){cout<<"A Buick is erased!"<<endl;} }; class Zhongba:public Automobile{ protected: double speed; public: Zhongba(double s):speed(s){} void run()const{cout<<setiosflags(ios::fixed)<<"Zhongba at speed of "<<setprecision(2)<<speed<<"km/h."<<endl;} ~Zhongba(){cout<<"A Zhongba is erased!"<<endl;} }; class Beiqi:public Automobile{ protected: double speed; public: Beiqi(double s):speed(s){} void run()const{cout<<setiosflags(ios::fixed)<<"Beiqi at speed of "<<setprecision(2)<<speed<<"km/h."<<endl;} ~Beiqi(){cout<<"A Beiqi is erased!"<<endl;} }; class Dayu:public Automobile{ protected: double speed; public: Dayu(double s):speed(s){} void run()const{cout<<setiosflags(ios::fixed)<<"Dayu at speed of "<<setprecision(2)<<speed<<"km/h."<<endl;} ~Dayu(){cout<<"A Dayu is erased!"<<endl;} }; class Jianghuai:public Automobile{ protected: double speed; public: Jianghuai(double s):speed(s){} void run()const{cout<<setiosflags(ios::fixed)<<"Jianghuai at speed of "<<setprecision(2)<<speed<<"km/h."<<endl;} ~Jianghuai(){cout<<"A Jianghuai is erased!"<<endl;} }; class Driver{ protected: string name; char type; public: void Drive(Automobile *); Driver(string n,char t):name(n),type(t){} ~Driver(){} }; 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; }