C/C++

观察者模式定义了对象之间的一对多依赖，这样一来，当一个对象改变状态时，它的所有依赖者都会收到通知并自动更新。 Observer Pattern defines a one-to-many dependency between objects so that when one object changes state, all its dependents are updated automa

策略模式： 定义了算法族，分别封装起来，让它们之间可以互相替换，此模式让算法的变化独立于使用算法的客户。 The Strategy Pattern defines a family of algorithms, encapsulates each one, and makes interchangeable. Strategy lets the algorithm vary independe