给定数列 1, 1, 1, 3, 5, 9, 17, …，从第 4 项开始，每项都是前 3 项的和。求第 20190324 项的最后 4 位数字。

public interface Map

The Strategy Pattern defines a family of algorithms, encapsulates each one, and makes them interchangeable. Strategy lets the algorithm vary independently from clients that use it.

The Command Pattern encapsulates a request as an object, thereby letting you parameterize other objects with different requests, qucue or log requests, and support undoable operations.