This tutorial series is a beginner’s guide to data structures and algorithms in Java. You’ll learn: How to recognize and use array and list data structures in your Java programs.

In contrast, a data structure is a concrete implementation of one or more ADTs, similar to how Java classes implement interfaces. Examples of ADTs include Employee, Vehicle, Array, and List.

First, they reasoned that to perform an insertion or a deletion, a hash table — or, really, any data structure — must access the computer’s memory some number of times. If they could figure out the ...

“Hash tables are among the oldest data structures we have. And they’re still one of the most efficient ways to store data.” Yet open questions remain about how they work, he said. “This paper answers ...