桥接模式

用桥接模式实现在路上开车这个问题，其中，车可以是car或bus，路可以是水泥路或沥青路。
实验要求：

1. 画出对应的类图；

2. 提交源代码；

1.	#include <iostream>
2.	
3.	using namespace std;
4.	
5.	class Vehicle{
6.	public:
7.	    virtual void drive(){}
8.	};
9.	
10.	class Car:public Vehicle{
11.	public:
12.	    void drive(){
13.	        cout<<"汽车行驶"<<endl;
14.	    }
15.	};
16.	
17.	class Bus:public Vehicle{
18.	public:
19.	    void drive(){
20.	        cout<<"公交车行驶"<<endl;
21.	    }
22.	};
23.	
24.	class Road{
25.	public:
26.	    Vehicle* vehicle;
27.	
28.	    Road(Vehicle* vehicle){
29.	        this->vehicle=vehicle;
30.	    }
31.	    virtual void driveOnRoad(){}
32.	};
33.	
34.	class CementRoad:public Road{
35.	public:
36.	    CementRoad(Vehicle* vehicle):Road(vehicle){}
37.	
38.	    void driveOnRoad(){
39.	        cout<<"水泥路";
40.	        vehicle->drive();
41.	    }
42.	};
43.	
44.	class BituminousRoad:public Road{
45.	    public:
46.	    BituminousRoad(Vehicle* vehicle):Road(vehicle){}
47.	    void driveOnRoad(){
48.	        cout<<"沥青路";
49.	        vehicle->drive();
50.	    }
51.	};
52.	
53.	int main(){
54.	    Vehicle* vehicle;
55.	    Car car=Car();
56.	    vehicle=&car;
57.	    CementRoad(vehicle).driveOnRoad();
58.	
59.	    Bus bus=Bus();
60.	    vehicle=&bus;
61.	    BituminousRoad(vehicle).driveOnRoad();
62.	}