Data Structures To Know For Coding Interviews

Describe The Different Kinds Of Tree Traversals For A Binary Search Tree

The 10 Most Important Concepts For Coding Interviews (algorithms and data structures)

There are three ways to traverse a tree. They are:

Inorder Traversal

Traverse the tree starting at the left subtree, then to the root of the tree, and finishing off at the right subtree.

Preorder Traversal

Preorder traversal starts at the root, then moves to the left subtree and finally the right subtree.

Postorder Traversal

This involves covering the tree starting from the left subtree and moving to the right subtree. You then move from the right subtree to the root to complete the traversal.

What Is A Queue Data Structure

In this data structure interview question, you can also discuss your experience and situations using queue. A queue is an abstract data type that specifies a linear data structure or an ordered list, using the First In First Out operation to access elements. Insert operations can be performed only at one end called REAR and delete operations can be performed only at the other end called FRONT.

How Should You Answer Why Should We Hire You As A Software Developer During An Interview

When recruiters ask this question, theyre looking to find out whether youre a good fit for the company. You need to show that you understand what the company does and what your role will be. Make sure that you research the company and know what it offers. If possible, connect to a developer in the company to learn about theyre work and the culture of the team. Include your findings in your answer and explain why you are the perfect candidate for the job.

Since youre hereConsidering a career in software engineering? Well help you build a CV that rivals experienced software engineers in 9 months flat with our Software Engineering Bootcamp. If youre still mulling, try our free software engineering learning path and check out our salary guide to see what you could be making.

About Sakshi Gupta

Sakshi is a Senior Associate Editor at Springboard. She is a technology enthusiast who loves to read and write about emerging tech. She is a content marketer and has experience working in the Indian and US markets.

Don’t Miss: How To Schedule Multiple Interviews

What Will Be The Output Of The Code Below

This question tests your knowledge of arrays and how they interact with different data types. In this case, you should understand that the length of the tree array will still be five, even after the delete function. The delete function simply takes the third indexed item and makes it undefined. The length of the underlying array is still the same, it just contains an undefined element instead of the string maple.

Define The Advantages And Disadvantages Of The Heap Compared To A Stack

Graph data structure cheat sheet for coding interviews.

The advantages of the heap compared to a stack are listed below:

Heap is more flexible when compared to a stack

Memory space of the heap can actually be allocated and de-allocated as per the need.

On the contrary, the disadvantages of the heap compared to a stack is listed below:

The memory of the heap is slower when compared to the memory of the stack

Don’t Miss: What Questions Should I Ask When Interviewing Someone

What Is The For

The for-in loop is a fundamental part of iterating through data structures. You should be able to describe its syntax to interviewers without hesitation.

This is the case for-in loop implementation in JavaScript. You would loop through an array by replacing the object name with the array name, and then place the piece of iterative code inside the block.

Tips For Cracking The Google Software Engineer Interview

Before going in, ensure that you keep the following in mind and put your best efforts into clearing the Google software engineer interview:

Have a thorough understanding of the work culture at Google because a good part of the interview process is focused on determining whether youâre a cultural fit for the company or not.

Practice data structures and algorithms questions and work on developing your knowledge. Google looks for problem solvers, so the quicker you are, the higher are your chances of getting selected.

When preparing for Google software engineer interview questions, use the STAR method . Start by describing the situation, the task you did, the action you took in response to the given task, and finally, explain your experience and the result.

Donât keep your strengths to yourself. Be bold and confidently describe your strengths using your past experiences. Even if you are answering a question where you have to describe a mistake youâve made in the past, be clear and own up to it.

Make the interviewer feel like theyâre a part of the communication and keep it going.

These tips will always come in handy â whether youâre appearing for the Google software engineer intern interview or youâre an experienced professional. You can learn more here.

If you want some more help, check out these articles:

Recommended Reading: How To Interview A Data Scientist

Misclellaneous Interview Questions On Algorithms

Explain the implementation process of a bubble sort algorithm.
How is an iterative quicksort algorithm implemented?
How to carry out a merge sort algorithm?
How do you implement an insertion sort algorithm?
Elaborate upon the implementation of the radix sort algorithm.

Studying data structures and algorithms together is the best way to go. Without a good understanding of data structures, youâll have a hard time grasping a particular algorithm in a specific condition.

What Are C++ Data Structures

Top 6 Coding Interview Concepts (Data Structures & Algorithms)

Data structures are formats used to organize, store, and manage data. You can use data structures to access and modify data efficiently. There are various types of data structures. The type you use will depend on the application youre using. Each data structure has its advantages and disadvantages.

Data structures generally fall under these two categories:

Linear data structures: Elements are arranged sequentially
Non-linear data structures: Elements are not arranged sequentially, but are stored within different levels

Don’t Miss: How To Prepare For An Interview Questions And Answers

Google Software Engineer Interview Questions On Array

How do you find the duplicate number on a given integer array?
How do you find the largest and smallest number in an unsorted integer array?
How do you identify duplicate numbers in an array if it consists of multiple duplicates?
How will you remove duplicates from an array in place?
In Java, how will you reverse an array in place?

You need to be well-versed with the fundamentals of arrays to be able to solve array-based questions in the Google software engineer interview. Youâll also need to know basic programming constructors such as recursion, loop, and fundamental operators.

Check more here.

Define What Is An Array

While referring to array the data is stored and utilized based on the index and this number actually co-relates to the element number in the data sequence. So thus making it flexible to access data in any order. Within programming language, an array is considered as a variable having a certain number of indexed elements.

Also Check: Interview With The Vampire Movies

Explain Whether A Linked List Is Considered As A Linear Or Non

This is purely determined on the requirement basis, a linked list can be considered as a linear data structure or a non-linear data structure. For example: If the linked list is used on storage, then the linked list is considered as a nonlinear data structure.

If linked lists are used against access strategies then they are considered as a linear data structure.

Grokking The Coding Interview: Patterns For Coding Questions

Seven (7) Essential Data Structures for a Coding Interview and ...

This course on by Design Gurus expands upon the questions on the recommended practice questions but approaches the practicing from a questions pattern perspective, which is an approach I also agree with for learning and have personally used to get better at coding interviews. The course allows you to practice selected questions in Java, Python, C++, JavaScript and also provides sample solutions in those languages along with step-by-step visualizations. Learn and understand patterns, not memorize answers!Get lifetime access now

Recommended Reading: How To Nail A Nursing Interview

My Present Position Does Not Need Me To Work With Data Is It Logical For Me To Pursue This Data Science Program

Data rules businesses all around the world. The more data-driven you are, the better off your company will be. Using data insights, you can make meaningful decisions, create strategies, and help your organization accomplish its goals faster. Enrolling in this comprehensive Data Science curriculum will undoubtedly provide you with a competitive advantage.

Algorithm And Data Structure Problems For Interviews

Here are some sample data structures and algorithms programming problems for interviews see if you can solve them all:

Reverse an array in place.

Remove duplicate nodes in an unsorted linked list.

Find the fifth node from the end in a singly linked list.

Find the sum of two linked lists using a stack.

Check if two strings are a rotation of each other.

Print all nodes of a given binary tree using inorder traversal without using recursion.

Implement bucket sort, counting sort, and radix sort algorithms.

Check if two rectangles overlap with each other.

Check if a list is cyclic using a Hash Table.

Check if a graph contains a cycle.

For more problems and solutions, check out the Problems page.

Recommended Reading: What Questions They Ask In A Job Interview

Explain About Linked List Data Structure

A linked list is a series of data structures connected via links. In simple words, it’s a sequence of links that contain items. After the array, the linked list is the second most used data structure. The essential terms to understand the linked list are:

Link – In a linked list, each link stores data called an element.

Next – In a linked list, each link is connected to the following link called next.

LinkedList – It contains the connection link to the first link called first.

The below diagram depicts how nodes are connected in the Linked List:

Basic operations supported by a linked list:

Insertion – Inserts an element at the list beginning.
Deletion – Deletes an element at the list beginning.
Display – Displays the complete list.
Search – Searches an element using the given key.
Delete – Deletes an element using the given key.

What Is The Difference Between An Array And A Linked List

How to Learn Data Structures and Algorithms for Your Coding Interview

Array and Linked list are two ways of organizing the data in memory. The below table lists the various differences between the array and linked lists:

Array	Linked List
An array is a sequence of elements of a similar data type.	A Linked list is a set of objects known as a node, where it internally consists of two parts, i.e., data and address.
It can be accessed irregularly using the array index.	Linked lists support random access. Only supports sequential access.
Array elements store in contiguous locations in memory.	New elements can be stored anywhere, and a reference is created for the new element using pointers.
In arrays, memory allocation is done during compile time.	In linked lists, memory allocation is done during runtime.
Array size must be defined at the time of declaration/initialization.	Linked list size grows when new elements are inserted or deleted.

Recommended Reading: What To Ask Interviewer At The End

How Are Heaps Used In Coding Interviews

Heaps are really useful if we want to efficiently maintain multiple items in order. Specifically, if we want to be able to regularly reference the largest or smallest item in our collection.

For example, if were reading in a stream of values and want to be able to keep track of the max value as we go, a heap could be a good way to do that.

Often times, we wont be solving heap coding interview problems in our interviews but rather using heaps as a tool to solve other types of problems.

How To Study Data Structures For Coding Interviews

Techie, Author, Entrepreneur, Trainer

Data structure and Algorithms is one of the most important subjects for coding interviews. Software developers, sometimes, tend to lose the command on the subject. This is especially true when they are working on some support project and are not in the habit of problem-solving and book-reading.

But more and more companies are now taking coding interviews. The jobs of individual software developers are increasing and other jobs are struggling to remain relevant in the times of automation and Lean development.

The way data structure subject is studies by a software developer/Architect is little different from the way it is studied in a college .

College syllabus is designed to be more research-oriented and includes a lot of mathematical calculations/equations. But, when you study data structure from an interview point of view you should be more focused on problem-solving.

It requires a lot of practice to find which data structure should be used in a particular situation . For example, consider the following question from our book:

You will be surprised that an optimal solution to this problem actually uses Array data structure.

In my book on Data Structure for Coding Interviews, I have discussed how different data structures are used in different problem-solving situations.

The following video has an introduction of the book:

Don’t Miss: Google System Design Interview Preparation

Linked List Programming Interview Questions

A linked list is another common data structure that complements the array data structure. Similar to the array, it is also a linear data structure and stores elements in a linear fashion.

However, unlike the array, it doesnt store them in contiguous locations instead, they are scattered everywhere in memory, which is connected to each other using nodes.

A linked list is nothing but a list of nodes where each node contains the value stored and the address of the next node.

Because of this structure, its easy to add and remove elements in a linked list, as you just need to change the link instead of creating the array, but the search is difficult and often requires O time to find an element in the singly linked list.

This article provides more information on the difference between an array and linked list data structures.

It also comes in varieties like a singly linked list, which allows you to traverse in one direction a doubly-linked list, which allows you to traverse in both directions and finally, the circular linked list, which forms a circle.

In order to solve linked list-based questions, a good knowledge of recursion is important, because a linked list is a recursive data structure.

If you take one node from a linked list, the remaining data structure is still a linked list, and because of that, many linked list problems have simpler recursive solutions than iterative ones.

How do you find the middle element of a singly linked list in one pass?

What Are Binary Trees

The top data structures you should know for your next coding interview

A binary tree is a tree data structure made up of nodes, each of which has two offspring, known as the left and right nodes. The tree begins with a single node called the root.

Each node in the tree carries the following information:

Data

A pointing device indicates the left kid.

An arrow pointing to the correct child

Don’t Miss: How To Master A Interview

How To Recognize When To Use A Tree

Most of the time, tree problems will be explicitly stated as such. The problem will come in the form of Given a tree, do X.

The most important thing when you see problems like this is to make sure that you understand what type of tree youre dealing with. If its a BST, that has different implications than if its just a binary tree that is not sorted.

The two other possible cases where youll use trees in problems are:

Storing data in a BST

Using a Trie to find string prefixes

Storing data in a BST is something that we may occasionally want to do, although its not usually the most efficient option. If you end up doing this, youll probably want to use a built in tree structure rather than implementing your own, since that will provide additional benefits like rebalancing.

If youre trying to find strings by their prefix, then tries are inherently a great way to do that. For example, if you wanted to implement an autocomplete tool, tries would be a good option.

Can You Differentiate Between A B Tree And B+ Tree

The following are the differences between B trees and B+ trees:

Both the internal and leaf nodes in a B tree have pointers. Only the leaf nodes in a B+ tree have pointers.
Searching a B+ tree is faster because the keys are always in the leaf nodes. The keys of a B tree are not necessarily in the leaf node and searching takes more time as a result.
B trees dont maintain a duplicate of the keys in the tree. B+ trees maintain duplicates of keys.
The lead nodes of B+ trees are stored in the form of structural linked lists. This is not the case for B trees.

Get To Know Other Software Engineering Students

Geraldo Gomes

Also Check: How To Prepare For Machine Learning Engineer Interview

The Definitive Guide To Data Structures For Coding Interviews

If youve been reading Byte by Byte for any length of time, then you know that I have one mantra that I repeat over and over again:

Strategy, Strategy, Strategy

This is the one biggest difference between those students who succeed and those who fail at their coding interview. Its not who has studied the most problems. Its not who grinds the most Leetcode. Its not who is naturally the smartest.

The biggest difference is having a strategy for solving ANY problem, not just the ones youve seen before. And this approach is why our students see such fantastic results.

But

Heres the thing about strategy: Without the proper building blocks in place, youll never succeed. Thats why Data Structures are so key.

Trying to nail a coding interview without having your Data Structures down cold is like trying to play basketball without knowing how to dribble. All the strategy in the world wont help you be successful.

So in this post, Im going to share with you ALL of the data structures and algorithms that you need to be successful in your coding interviews.