C#经典机试题(猫叫)

猫大叫一声，所有的老鼠都开始逃跑，主人被惊醒。(C#语言)

　　1.要有联动性，老鼠和主人的行为是被动的。

　　2.考虑可扩展性，猫的叫声可能引起其他联动效应。

 public interface Observer
    {
        void Response();//观察者响应
    }

    public interface Subject
    {
        void AimAt(Observer obs); //针哪些观察者
    }

    public class Mouse : Observer
    {
        private string name;
        public Mouse(string _name, Subject sub)
        {
            this.name = _name;
            sub.AimAt(this);
        }
        public void Response()
        {
            Console.WriteLine(name + "开始逃跑...");
        }
    }

    public class Master : Observer
    {
        public Master(Subject sub)
        {
            sub.AimAt(this);
        }

        public void Response()
        {
            Console.WriteLine("主人惊醒...");
        }
    }

    public class Cat : Subject
    {
        private ArrayList observers;
        public Cat()
        {
            this.observers = new ArrayList();
        }
        public void AimAt(Observer obs)
        {
            this.observers.Add(obs);
        }

        public void Cry()
        {
            Console.WriteLine("猫叫");
            foreach (Observer obs in this.observers)
            {
                obs.Response();
            }
        }
    }



    class Program
    {
        static void Main(string[] args)
        {
            Cat cat = new Cat();
            Mouse mouse1 = new Mouse("老鼠1", cat);
            Mouse mouse2 = new Mouse("老鼠2", cat);
            Master master = new Master(cat);
            cat.Cry();

            Console.ReadKey();
        }
    }