如果你想要说些什么，去问男人；如果你想要做些什么，去问女人。

史记

The Liskov Substitution Principle is a fundamental concept in object-oriented programming, stating that objects of a superclass should be replaceable with objects of a subclass without affecting the correctness of the program.

数学之美不仅在于其抽象的优雅，还在于其建模和解决现实世界问题的深刻能力。