3 - Sets, Dictionaries, and Hashing

Summary

In many contexts, we are required to handle a large collection of objects in a way that supports inserting a new object, finding if an object is present, and possibly deleting an object. These operations typically appear in a series of arbitrary length. We want all these operations to be done as efficiently as possible. Consider a search engine (and its underlying infrastructure) like Google or Bing. One makes a query (e.g., “who is the King of Asteria”) and gets a response in about 945,000 results (0.44 seconds). One of the basic techniques behind such efficient implementations of search is called hashing.