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

Stacks in a nutshell

A stack is a linear data structure that uses the Last-In-First-Out (LIFO) principle. Think of a stack of plates that needs to be washed. You take the first plate from the top (which was the last one to be added) and you wash it. Afterward, you take the next plate from the top and so on. This is exactly what a real-life stack is (for example, a stack of plates, a stack of books, a stack of CDs, and so on).

So, technically speaking, in a stack, the elements are only added (known as the push operation) and removed (known as the pop operation) to/from one end of it (known as the top).

The most common operations that are performed in a stack are as follows:

  • push(E e): Adds an element to the top of the stack
  • E pop(): Removes the top element from the stack
  • E peek(): Returns (but doesn't remove) the top element from the stack
  • boolean isEmpty(): Returns true if the stack is empty
  • int size(): Returns the size of the stack
  • boolean isFull...