Tree data structure is a crucial interview concept that is centered around testing your technical knowledge!
Tree interview questions are an integral data structure part with a comprehensive set of questions.
Mastering these questions would be the key to unlock success for the upcoming coding interview.
Though, the tricky and uncertain questions may give jitters to the candidates. There is always a nervousness on what kind of questions would appear in the interview.
To help you in this regard, we have curated this blog post.
Learn how to ace tree interview questions with ease and excel at any kind of interview question that may appear in front of you.
Let’s get started!
Binary tree interview questions - key to excel
Binary tree is touted as the data structure where each node will be having at most two children called the left or the right child. Also, the topmost node is called the root node.
From binary tree concepts to binary heap to binary tree traversal to its implementation, there are multiple questions related to this topic that can be asked from the candidates.
You can be preparing for the Optum interview questions, Google interview questions or any other tech giant interview questions, the tree interview questions will appear in your interview.
To master the tree interview questions you should follow the below-mentioned pointers
Keep your basics clear
Basics or fundamental concepts of every topic should be clear to you. And binary tree topics are no exception. You should make your fundamentals clear in regards to this topic.
When you start doing your interview preparation, you always take up the most asked topic. Pick the tree topics, clear your fundamentals and brush up your knowledge on the said topic.
Learn the problems in-depth
Learn about all the tree related problems in-depth. Though binary tree is regarded as a comprehensive topic and you can’t ace it in one day, you can pick each concept a day and know about it in-depth.
Moving to advanced questions
You can only move to the advanced level tree interview questions if the basics are clear to you. Learn to write programs, codes and how to implement the binary tree by practicing religiously,
Practice previous year questions
Practice all the previous year questions related to the tree topic. This will give you an idea of what kind of questions generally appear in the coding interviews. Ultimately, your interview preparation will go on in full swing.
Tree Interview Questions
Keep a snapshot of the most commonly asked tree interview questions in order to crack the Optum interview questions, Google interview questions, Microsoft interview questions and any other tech giant’s interview questions.
How can a binary heap be implemented?
A binary heap is generally implemented with the help of an array. Any type of binary tree can be stored in the array because it can easily be stored. No spaces are needed for the pointers as the parent and its children node can be found on the array indices by the arithmetic.
How to implement the pre-order binary tree traversal with the help of recursion?
In order to traverse the non-empty binary tree in the pre-order fashion, you can do the following things for the node N which starts from the root of a tree:
- The N process starts with the N itself
- L will recursively traverse from the left subtree. When the step is finished we can be back it at the N again
- R will recursively traverse the right subtree. When this step is complete, you will be back with the N again
What do you know about the binary heap?
A binary heap in the binary tree is one that is known as the complete tree with all the levels filled completely except its last possible level that has all the possible keys left in it. This one property of the binary tree will make it ideal to get stored in the array. The binary heap can be either the min or the max heap. In the min binary heap, the key at its root will be minimum among all its roots present in the binary tree heap. This property must be recursively true with all the nodes of your binary tree.
How to do the interactive pre-order traversal of the tree without the recursion?
Given the binary tree, return its pre-order traversal with the help of node values. You can do it by setting the current node as the root node. Check in case the current node is null, return it. Store the value of the current node in the container. Put right and left on a stack. If the stack is not empty, pop it from the stack into the current node. Note that the left would be at the top of the stack and will be taken at first. Repeat all the steps again.
Define variants of DFS.
The three important variants of the DFS are:
- Pre-order traversal: Here visit the current node before you visit the node inside the left or the right subtrees
- Inorder traversal: Visit all the current nodes after you visit all the nodes inside your left subtree but before visiting the nodes in the right subtree
- Post order traversal: Visit your current node after you visit all the nodes of the left and the right subtrees
Name different ways to implement the priority queue
In order to implement the priority queue, you can make use of different data structures. It can be implemented [ including heaps] with the:
- Unsorted arrays
- Ordered arrays
- Unorder list
- Ordered list
- Binary tree
- Balanced binary tree
- Binary heap
Wrapping Up
Binary search trees are an essential part of the coding interviews. Tree interview questions are one of the commonly asked questions in the Optum interview questions, Google interview questions , Amazon interview questions and all the top company’s interview questions.
Your basic and advanced knowledge of these questions is tested by the interview. Keep this guide as your mentor and learn all the concepts properly.
