Skip lists are a fascinating data structure: very simple, and yet have the same asymptotic efficiency as much more complicated AVL trees and red-black trees. While many standard libraries for various programming languages provide a sorted set data structure, there are numerous problems that require more control over the internal data structure than a sorted set exposes. In this article, I will discuss the asymptotic efficiency of operations on skip lists, the ideas that make them work, and their interesting use cases. And, of course, I will give you the source code for a skip list in C#.

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