Week 8: linked structures

Brief Overview:

This week's lecture dived into the topic of linked data structures in programming. We first looked at the concept of a linked data structure represented as a linked list by analyzing the LLNode class and its associated wrapper class as provided in lecture. A handy diagram from the CS department at SFU provided below gives a visual representation of what a linked list looks like in the abstract.

We then moved on to the idea of a binary search tree, which was essentially a linked list, but with two children (see diagram provided below). The code implementation for both types of data structure was relatively simple. In the code provided during lecture, the implementation of a linked list and a binary search tree both used a wrapper class as a method of organization (BTNode and BST; LListNode and LinkedList).

"Flattened" binary tree?
I had noticed that a LLNode object was essentially a BTNode object, except for the small difference where LLNode has a single child whereas BTNode has two. In fact, had the instructors not explicitly stated the differences between the two through the use of descriptive names, it would have been very difficult to distinguish the differences between the two. This little observation made me realize the importance of having meaningful names when creating classes to represent linked data structures, since confusion can easily arise when we start naming attributes or methods in the LLNode class with names that are typically reserved for the BTNode class. At the same time, its interesting that from the perspective of the python interpreter (assuming that the interpreter was somehow sentient), how a LLNode or BTNode class functions is unrelated with respect to the names given to the various methods and attributes of that class; the names exist solely to infer meaning to the code for the person reading it. Its a simple observation, yet quite profound at the same time the more that I thought about it.

Final Thoughts
How is everybody else faring with the concept of linked structures? Do you think its difficult/easy? Confusing/clear? Leave your thoughts in the comment section below!

Image citation:
Recursive Definition of a Linked List:. Digital image. N.p., n.d. Web. 1 Apr. 2014. <http://www.cs.sfu.ca/~bbart/225-beta/ind5.png>.
Binary Search Tree. Digital image. N.p., n.d. Web. 1 Apr. 2014. <http://upload.wikimedia.org/wikipedia/commons/a/a9/Unbalanced_binary_tree.svg>.