This article has the dual purpose of introducing Binary Tree exercises in this website and presenting the implementation of the binary tree node that they use.

The following code snippet contains the Java code for the class ListNode used on a few exercises on my website.

Three main reasons explain why even the most experienced developers struggle with coding interviews:

What programming languages do you support ?

We only support Java for now.

The Fibonacci Sequence is sometimes referred to as “God’s sequence” as it is a naturally occurring sequence. If you are curious about it check it out here. It is also heavily used in interview code exercises, with many variations available.

Do you know what a prime number is ? Unless you work with cryptography algorithms or a similar field, chances are that you have not heard about prime number since the high school. A significant number of whiteboard coding questions rely on prime numbers, so this will be a good refresher. A prime number is a natural number that has no positive divisors other than 1 and itself.

In the first post of this series, we start with a simple concept: the integer division and modulo operator (also called remainder operation). To demonstrate these concepts, we will use a classic whiteboard exercise, the Fizz Buzz. This is possibly the most widely used coding exercise in telephone and shared screen interviews.

I’m starting a series of posts aimed at improving your coding interview skills, specifically the whiteboard exercise part of the interview. I have already covered some aspect of it in previous posts (here and here) However, this post series is meant to be a step-by-step guide for software developers and software engineers in test (SDETs) that want to excel in the technical coding interview.

A binary tree is strict when all nodes have either two or zero child nodes. The following binary tree is an example of a strict binary tree:

A binary tree is perfect when all levels are complete. In other words, all internal nodes have two child nodes, and the leaves have zero child nodes.