Problem B: 不同交通工具的速度
Time Limit: 1 Sec Memory Limit: 128 MB
Submit: 3916 Solved: 1884
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Description
不同交通工具的速度是不同的。针对自行车、摩托车和汽车分别建立类，来模拟这一情况。
定义Vechicle类，是所有交通工具的父类：
1. 属性int speed表示交通工具的一般速度。
2. 静态数据成员int numOfVechicles，表示创建的交通工具的数量。这个值只增不减。
3. 静态成员函数int getNumOfVechicles()，用于获取交通工具的数量。
4. 析构函数。输出“A vechicle is deleted.”
5. 纯虚函数void show().
定义Bike、MotoBike和Car三个类，它们都是Vechicle的子类，且具有：
1. 构造函数。
2. 重写show()函数，输出“A *'s speed is ？ km/h.”，其中“*”是bike、motobike或car，根据所在类不同而不同。“？”是speed属性的值。
3. 析构函数。输出“A * is deleted.”，“*”的含义同上。
定义Person类，表示司机：
1. 数据成员string name，是人的姓名。
2. void drive(Vechicle&)方法，输出“$ drives”， 并调用Vechicle类的show()方法。其中“$”是name的值。
Input
第1行N>0，表示有N个测试用例。
每个测试用例包括一个不含空白符的字符串、一个字符和一个整数。
Output
见样例及题目描述。
Sample Input
3Tom B 15Jack M 50Mary C 100
Sample Output
In beginning, we have 0 vechicles.Tom drives. A bike's speed is 15km/h.A bike is deleted.A vechicle is deleted.Jack drives. A motobike's speed is 50km/h.A motobike is deleted.A vechicle is deleted.Mary drives. A car's speed is 100km/h.A car is deleted.A vechicle is deleted.At the end, we have 3 vechicles.
HINT
Append Code
#include <iostream>
#include <cstdio>
using namespace std;
class Vechicle {
protected:
int speed;
static int numOfVechicles;
public:
Vechicle(int x = 0) : speed(x) {
numOfVechicles++;
}
virtual ~Vechicle() {
cout << "A vechicle is deleted." << endl;
}
virtual void show() = 0;
static int getNumOfVechicles() { return numOfVechicles; }
};
class Bike : public Vechicle {
public:
Bike(int s) : Vechicle(s) {}
~Bike() {
cout << "A bike is deleted." << endl;
}
void show() {
cout << "A bike's speed is "<<speed<<"km/h." << endl;
}
};
class MotoBike : public Vechicle {
public:
MotoBike(int s) : Vechicle(s) {}
~MotoBike() {
cout << "A motobike is deleted." << endl;
}
void show() {
cout << "A motobike's speed is "<<speed<<"km/h." << endl;
}
};
class Car : public Vechicle {
public:
Car(int s) : Vechicle(s) {}
~Car() {
cout << "A car is deleted." << endl;
}
void show() {
cout << "A car's speed is "<<speed<<"km/h." << endl;
}
};
class Person
{
private:
string name;
public:
Person(string s) : name(s) {}
void drive(Vechicle &v) {
cout << name << " drives. ";
v.show();
}
};
int Vechicle::numOfVechicles = 0;
int main()
{
int cases, n;
char c;
string name;
Vechicle* vechicle;
cout<<"In beginning, we have "<<Vechicle::getNumOfVechicles()<<" vechicles."<<endl;
cin>>cases;
for (int i = 0; i < cases; i++)
{
cin>>name>>c>>n;
Person person(name);
switch (c)
{
case 'B':
vechicle = new Bike(n);
break;
case 'M':
vechicle = new MotoBike(n);
break;
case 'C':
vechicle = new Car(n);
break;
}
person.drive(*vechicle);
delete vechicle;
}
cout<<"At the end, we have "<<Vechicle::getNumOfVechicles()<<" vechicles."<<endl;
return 0;
}