nryoung/algorithms — pull request #67 by JoaoGFarias (2014-07-22 17:00:35+00:00)
Title: Implementation of a persistent binary tree

Implementaion of a binary tree, including the persistence characteristic, based on the implementation in ML made by [Okasaki](http://www.amazon.com/Purely-Functional-Structures-Chris-Okasaki/dp/0521663504).
A small reference can be found on [Wikipedia](http://en.wikipedia.org/wiki/Persistent_data_structure#Trees).