已知交通工具类定义如下。要求：（1)实现这个类；（2）定义并实现一个小车类car，是它的公有派生类，小车本身的私有属性有载人数，小车的函数有init(设置车轮数，重量和载人数），getpassenger(获取载人数)，print（打印车轮数，重量和载人数）。

class vehicle

{protected:

int wheels;//车轮数

float weight;//重量

public:

void init(int wheels,float weight);

int get_wheels();

float get_weight();

void print();

};

void vehicle::init(int wheels,float weight)

{this->wheels=wheels;

this->weight=weight;

cout<<wheels<<endl;

}

int vehicle::get_wheels()

{return wheels;

}

float vehicle::get_weight()

{return weight;}

void vehicle::print()

{cout<<"车轮数："<<wheels<<","<<"重量："<<weight<<endl;}

答案：class car:public vehicle

{private:int passengers;

public:

void init(int wheels,float weight,int pass);

int getpassenger();

void print();}；

void car::init(int wheels,float weight,int pass)

{vehicle::init(wheels,weight);

passengers=pass;}

int car::getpassenger()

{return passengers;}

void car::print()

{vehicle::print();

cout<<"可载人数："<<passengers<<endl;

}__