Book Image

The Complete Coding Interview Guide in Java

By : Anghel Leonard
Book Image

The Complete Coding Interview Guide in Java

By: Anghel Leonard

Overview of this book

Java is one of the most sought-after programming languages in the job market, but cracking the coding interview in this challenging economy might not be easy. This comprehensive guide will help you to tackle various challenges faced in a coding job interview and avoid common interview mistakes, and will ultimately guide you toward landing your job as a Java developer. This book contains two crucial elements of coding interviews - a brief section that will take you through non-technical interview questions, while the more comprehensive part covers over 200 coding interview problems along with their hands-on solutions. This book will help you to develop skills in data structures and algorithms, which technical interviewers look for in a candidate, by solving various problems based on these topics covering a wide range of concepts such as arrays, strings, maps, linked lists, sorting, and searching. You'll find out how to approach a coding interview problem in a structured way that produces faster results. Toward the final chapters, you'll learn to solve tricky questions about concurrency, functional programming, and system scalability. By the end of this book, you'll have learned how to solve Java coding problems commonly used in interviews, and will have developed the confidence to secure your Java-centric dream job.
Table of Contents (25 chapters)
1
Section 1: The Non-Technical Part of an Interview
7
Section 2: Concepts
12
Section 3: Algorithms and Data Structures
19
Section 4: Bonus – Concurrency and Functional Programming

Coding challenges

Now that we have had a brief overview of trees and graphs, it is time to challenge ourselves with the 25 most popular coding problems encountered in interviews about these topics.

As usual, we have a mix of problems that are usually encountered by the top companies of the world, including IT giants such as Amazon, Adobe and Google. So, let's get started!

Coding challenge 1 – Paths between two nodes

Problem: Consider you've been given a directed graph. Write a snippet of code that returns true if there is a path (route) between two given nodes.

Solution: Let's consider the directed graph shown in the following diagram:

Figure 13.15 – Paths from D to E and vice versa

If we consider nodes D and E, then we can see that from D to E, there are three paths, while from E to D, there are none. So, if we start from D and traverse the graph (via BFS or DFS) then, at some point, we have to pass through node E,...