Data structures and algorithm questions are an important part of any programming job interview, be it a Java interview, C++ interview or any other programming language. Since data structures are core programming concept, it’s mandatory for all programmers, to know basic data structures like stack, linked list, queue, array, tree, and graph. Though tree and graph are on the tough side, I still see programmers get familiar will all these. Any list of programming job interview questions isincomplete without questions from data structures and algorithms. Similarly, while going on questions from data structure you may get some programming exercise as well e.g. swapping numbers without temp variable. The linked list and array are favorite topics in any data structure interview, questions like reversing linked list, traversing linked list or deleting nodes from linked list, which involves algorithm and data structures are quite common. Similarly, finding duplicates in an array, finding missing numbers, sorting arrays are very popular. You can also expect questions from the stack, queue, array, linked list, tree, graph and hash table are most common in any data structure interview. In this tutorial, we will see a couple of data structure questions answers from these topics. Let us know, if you have any interesting questions from data structures and algorithm, which you faced during any Java interviews. I also suggest to look on data structure and algorithm questions on “Cracking the Coding Interview book”, as this book contains some good questions with proper explanation. That will certainly help you to do better on programming job interviews. One more suggestion I have to make is whenever you get some time, just read the “Introduction to Algorithm by Thomas Cormen”, if you have not read already. This book is the bible of algorithm and IMHO every programmer should read this book.