问题
I know it is possible to create a self referencing list in languages like Python:
>>> my_list = [1,2]
>>> my_list.append(my_list)
>>> print my_list
[1,2,[...]]
>>> print my_list[0]
1
>>> print my_list[2]
[1,2,[...]]
What algorithms benefit from self referencing lists? I cannot think of one.
Thanks.
回答1:
Self-referencing lists, and, generally speaking, circular data structures, can be caused when representing a graph using data structures.
For example, consider this naive representation of a graph: Each node is either an atomic value, or a list of nodes that it is linked to. A circle may cause a list to contain another list that contains the list. A self-circle, i.e., an edge from a node to itself, will cause a self-referencing list.
回答2:
If you are asking just about lists, then I can't think of something right now, except for maybe recursively creating/searching in a data structure modeled as list.
But one application of a self-referencing could be this Self Referencing Class Definition in python
回答3:
Most recursive problem definition uses some kind of self refrential objects or a data with self-referential definition.
I would add the wikipedia link as it provides a good readup:
- http://en.wikipedia.org/wiki/Recursion_(computer_science)
Others on SO
- What is recursion and when should I use it?
- Recursive Sets vs Recursive Functions
- Understanding recursion
- Recursive Splay Tree
- https://stackoverflow.com/questions/2085834/how-did-you-practically-use-recursion
来源：https://stackoverflow.com/questions/3728667/uses-of-self-referencing-lists