Relevant data structures you should know before your next coding interview

coding interview at algo monster

For most machine learning, data science, or software engineering jobs, coding interviews are almost unavoidable. In several cases, we’ve seen candidates who are excellent at utilizing programming as a practical solution to daily life research concerns. Also some are mess things up in an interview. Thus, when it comes to coding interviews. There are some fundamentals you need to brush up on, and one of such is the concept of various data structures . After all, a significant percentage of problems focus on picking out the most fitting data structure for a specific problem.

Algo.Monster will examine 7 distinct data structures necessary for any coding interview alongside their pertinent coding interview questions.

coding interview at algo monster

Data structures & 20 Pertinent Coding Interview Questions Linked List

Linked List

A linked list is one of the most common data structures, complementing the array/list data structure. The array data structure, a linked list is linear, and as such, stores elements linearly. But as opposed to what is the array. A linked list doesn’t store these elements in contagious locations. Rather, it scatters them across diverse locations in the memory, and connects these elements with nodes.

Thus, a linked list is all about a list of nodes. Every node has comprised the value stred as well as the next node’s address. Due to its framework and design, it makes it easy to include or get rid of elements from a linked list. All you need to do is change the link, rather than developing the array. Nonetheless, search is pretty arduous with this structure and as such, usually demands 0(n) time to locate elements from the linked list.

Popular coding interview questions on linked lists

  • Reverse a linked list
  • In one pass, provide practical means to locating mid elements for a linked list
  • With no recursion, reverse a linked list
  • For an unsorted linked list, remove duplicate nodes.
  • With the aid of Stack, determine the sum of two linked lists

List or Array

The list comprises a sequential arrangement of data values in an organized and orderly system. It positions in memory.

An array remains the most basic data structure that oversees element storage at contagious locations on memories. Of course, it is one of the beloved topics of most interviewers. For any coding interview questions, whether system design interview questions or SQL interview questions. You’d come across several tests about an array, including sorting, reversing, or seeking some elements on the array. Suppose you are aware of the index, one fundamental advantage array data structure embodies is in its ability to offer a fast 0(1) search. However, including or subtracting specific elements from an array tends to be slow as you can’t alter its size on creation. In a situation whereby there is a need to create a longer or shorter array, you have to create a new one and paste all the elements into it.

One practical key to approaching array-centric questions is equipping yourself with the right knowledge of the array data structure and fundamental programming constructors. It includes recursion, loop, among others. With this ultimate coding interview cheat sheet, you’d be cracking the coding interview in no time.

Popular coding interview questions on Array

  • With these questions, you will not only enhance your problem-solving prowess, but also build up your understanding of array data structure.
  • Identify approaches to locating the missing number for a specific integer array of one to a hundred
  • Ways to reverse a list/array on Java
  • In what way can you eliminate duplicates from an array in place?
  • Identify the practical approaches to finding the smallest and the largest number for a specific unsorted integer array
  • Without the use of any library, how can you make an array devoid of duplicates?


No coding interview is complete without a string-centric question. 

It is an integral part of every programming job interview. If you look forward to cracking the coding interview, you must equip yourself with a robust knowledge of strong. One good thing about this data structure is that once you are accustomed to the array, and you have what it takes to solve every string-related question as they are nothing but character arrays.  Thus, you can ally every technique adopted to solve array questions to solve string questions.

Here are some common interview questions on string

  • For a specific string, count the number of consonants and vowels
  • Provide a step-by-step approach to printing duplicate characters in the string
  • How can you confirm whether two strings are anagrams of one another
  • Reverse a string with recursion
  • Find a duplicate character in a string,

Binary Tree

All the previously examined data structures revolve around linear data structures. However, we cannot represent all information linearly, ultimately calling for a need for the tree data structure. This data structure lets you store data hierarchically. Based on your approach to data storage, there are various types of trees. It includes a binary tree, featuring a node with a maximum of two child nodes. One fundamental point to approach binary tree-centric problems, and questions is equipping yourself with robust theoretical knowledge, such as definitions of a leaf, size/depth for a binary tree, coupled with an understanding of the most common traversing algorithms.

Common Interview Questions on Binary tree

  • Expatiate the implementation of a binary tree
  • Perform a binary search for a specific array
  • Traverse a specific binary tree preorder or postorder with no recursion
  • Implementation of postorder traversal algorithm
  • Highlight practical means of printing leaves of a binary search tree

Bottom Line: Is cracking the coding interview enough?

Cracking the coding interview is just the genesis of a long journey that lies beyond. If perhaps, you are listed as one of the successful candidates of the programming interview. Now is the time to equip yourself with more knowledge of various algorithms, designs, manipulations, and other topics pertinent to your job description.


Please enter your comment!
Please enter your name here