演示如何使用虚函数，实现运行时的多态功能-Polymorphic function demonstrates how to use the virtual function run

这是一个多态性链表，在一条链表上可以存在着不同的节点，不针对节点，对链表的处理还是比较全面的-This is a polymorphic list, the list can exist on a different node, the node is not targeted on the list is quite comprehensive treatment