设计实验

有 3 个开关：a b c

有 3 个电灯：x y z

要求实现：

a 能控制 x

b 能控制 x, y

c 能 x

注意：1个灯泡可以被多个开关控制；1个开关可以同时控制多个灯泡

所谓“控制”：当开关操作时，当前灯泡的状态发生翻转。亮->灭 或 灭->亮

 
import java.util.*; 
 
class Light
{
	private boolean state;  // 灯的状态。true: 亮
	
	public String toString()
	{
		if(state)
			return "亮";
		else
			return "灭";
	}
	
	// 翻转状态
	public void change()
	{
		state = !state;
	}
}
	 
class Switch
{
	//Light[] a = ...
	Vector v = new Vector();
	
	public void addLight(Light x)
	{
		v.add(x);
	}
	
	// 按了一下开关
	public void press()
	{
		for(int i=0; i<v.size(); i++)
		{
			Light p = (Light)v.get(i);
			p.change();  // 反转电灯的当前状态
		}
	}
}
			
public class MyTest
{
	private static void show_light(Light x, Light y, Light z)
	{
		System.out.println(x + "," + y + "," + z);
		System.out.println("-----------------------");
	}
	
	public static void main(String[] args)
	{	
		Light x = new Light();
		Light y = new Light();
		Light z = new Light();
		
		Switch a = new Switch();
		Switch b = new Switch();
		Switch c = new Switch();
		
		a.addLight(x);
		b.addLight(x);
		b.addLight(y);
		c.addLight(x);
		
		show_light(x, y, z);
		
		a.press();
		show_light(x, y, z);
		
		b.press();
		show_light(x, y, z);
		
		c.press();
		show_light(x, y, z);
		
	}
}