create the binary tree in least-common-ancestor.py

[jeff1evesque]

We need to take the binary search tree representation from the external file (input.txt), and create the tree representation in least-common-ancestor.py file.

[jeff1evesque]

b7ee086: In python, we need to define a class before we can create instances of it. Prior to ca1d481, the Node class was defined at the end of least-common-ancestor.py file -- however, we tried to use it prior to this. Ideally, we have to move the definition prior to creating the instance -- but, we decided to create a separate file to contain the definitions, class_definitions.py and import it within least-common-ancestor.py.

Note: we have to append the file name when we create instances of a specific class from class_definitions.py. For example:

root = class_definitions.Node(cast_type(data_root[0]))

[jeff1evesque]

380189a, eb2d6ca, 47d210a: in python, it's good practice to name variables and files using underscores, instead of dashes -- since dashes are typically interpreted as subtraction

[jeff1evesque]

9443288: we call the class methods imported from class_definitions.py in order to build the tree we need in least_common_ancestor.py. We also implemented a recursive breadth-first algorithm in order to print the binary search tree.

[jeff1evesque]

Note: since class_definitions.py is imported in least_common_ancestor.py, running the latter file creates a bytecode copy of the former file, specifically class_defintions.pyc. Bytecode files are represented by the file extension, pyc.