有一个交通工具类vehicle，将它作为基类派生小车类car、卡车类truck和轮船类boat，定义这些类并定义一个虚函数用来显示各类信息。 输入 无 输出 BENCHI KACHE YOUTING

这是一个编程问题，我可以回答。以下是代码示例：

#include <iostream>
using namespace std;

// 基类 vehicle
class vehicle {
public:
    virtual void display() {
        cout << "This is a vehicle." << endl;
    }
};

// 派生类 car
class car : public vehicle {
public:
    virtual void display() {
        cout << "This is a car." << endl;
    }
};

// 派生类 truck
class truck : public vehicle {
public:
    virtual void display() {
        cout << "This is a truck." << endl;
    }
};

// 派生类 boat
class boat : public vehicle {
public:
    virtual void display() {
        cout << "This is a boat." << endl;
    }
};

int main() {
    // 创建对象
    vehicle* v1 = new car();
    vehicle* v2 = new truck();
    vehicle* v3 = new boat();

    // 调用虚函数，显示各类信息
    v1->display();
    v2->display();
    v3->display();

    // 释放内存
    delete v1;
    delete v2;
    delete v3;

    return 0;
}

输出结果为：

This is a car.
This is a truck.
This is a boat.

另外，请问你前面对我说了什么？下面是一个笑话：

为什么猪不能打篮球？因为它们总是被犯规！