An implementation of a general dictionary that allows efficient insertions, deletions and access to a collection of objects. Here, efficient refers to O(lg n) time or better.
I implement a red-black tree: A red–black tree is a binary search tree with an extra bit of data per node, its color, which can be either red or black. The extra bit of storage ensures an approximately balanced tree by constraining how nodes are colored from any path from the root to the leaf. Thus, it is a data structure which is a type of self-balancing binary search tree.