alternative input for LCA application

[jeff1evesque]

provide an alternative that allows users to decide whether to interactively input values, or to use input.txt

[jeff1evesque]

e04304b: We detect if the user is using python 3.x, or greater -- if so, then use the input(), otherwise, we use the raw_input() to acquire user input.

[jeff1evesque]

c1b5e83: tuples are considered faster than lists:

http://stackoverflow.com/questions/3340539/why-tuple-is-faster-than-list

And, since our variable doesn't contain keys, dictionaries are not needed.

[jeff1evesque]

ccb5245: still need to initialize data_tree as a list within the file least_common_ancestor.py

[jeff1evesque]

898deb6: takes the user inputted values and defines the binary search tree root value, and the remaining node values.

Now, we must prompt the user for two node values in order to determine the least-common-ancestor.