10 Most Important Data Structures For Coding Interviews

Last Updated : 03 May, 2023

Data structures are important for proficient and effective programming. In coding interviews, familiarity with common data structures and their operations is very important for solving problems efficiently and quickly. In this article, we will see the ten most critical data structures for coding interviews, examining their properties and practical applications for problem-solving.

There are many important data structures of which a few of them are mentioned below:

1. Array

Array is a sequential arrangement of elements of the same data type, stored in contiguous memory locations. It is an ordered collection that confers constant time access to individual elements and efficient memory usage. Arrays are fundamental for various purposes such as searching, sorting, and storing data, enabling quick and efficient data retrieval.

Array Data Structure

There are some standard questions on the array as mentioned below:

Must read: Most Commonly asked interview questions on Array

2. String

String is a collection of characters that represent text. Strings are conventionally implemented as arrays of characters, where each element represents a single character. They are essential for processing text data, forming the backbone of algorithms that deal with text, such as natural language processing and information retrieval.

String Data Structure

There are some standard questions on the strings as mentioned below:

Must read: Most Commonly asked interview questions on String

3. Stacks

Stacks are First Out (LIFO) data structures, that follow a specific principle of pushing elements onto the top of the stack and popping elements from the top. Stacks are implemented as linked lists, providing swift and efficient access to the most recently added elements, enabling practical applications such as memory allocation and syntax parsing.

Stack Data Structure

There are some standard questions on the stack as mentioned below:

Must read: Most Commonly asked interview questions on Stack

4. Queues

Queues follow the First In First Out (FIFO) principle, allowing for the orderly storage and retrieval of elements. Like stacks, they are implemented as linked lists and provide enqueue (adding elements to the back of the queue) and dequeue (removing elements from the front of the queue) operations, making them useful for real-time systems such as operating systems, message passing systems, and web servers.

Queue Data Structure

There are some standard questions on queues as mentioned below:

5. Linked List

Linked List is a data structure comprising a sequence of nodes, each containing a reference to the subsequent node in the sequence. Linked lists are vital for dynamic memory allocation and offer primary operations such as insertion, deletion, and traversal. They come in handy when working with variable data sizes, enabling the efficient management of data storage and retrieval.

Representation of Singly-linked list

There are some standard questions on the linked list as mentioned below:

Must read: Most Commonly asked interview questions on the linked list

6. Trees

Trees are hierarchical data structures that consist of nodes interconnected by edges. Trees enable the representation of hierarchical relationships such as family trees, and file systems. They also offer searching and sorting operations, making them useful for tasks such as traversing a directory structure, balancing a search tree, and constructing a decision tree.

Tree data structure

There are some standard questions on trees as mentioned below:

Must read: Most Commonly asked interview questions on Tree data structure

7. Heaps

Heaps are binary tree-based data structures, that adhere to the heap property, which implies that each node is either greater than or equal to (for max heap) or less than or equal to (for min heap) its child nodes. Heaps are utilized for priority queue operations, where elements are arranged in a specific order of priority, such as CPU scheduling, shortest path algorithms, and network routing.

Heap Data Structure

There are some standard questions on the heap as mentioned below:

Must read: Most Commonly asked interview questions on Heap data structure

8. Graphs

Graphs are collections of nodes interconnected by edges, where the edges represent relationships between the nodes. Graphs are crucial for modeling complex relationships between objects such as social networks, transportation systems, and electrical circuits. They are also useful for searching and sorting operations, such as traversing a network, finding the shortest path between two points, and identifying cycles in a network.

Graph Data structure

There are some standard questions on graphs as mentioned below:

Must read: Most Commonly asked interview questions on Graph

9. Hash tables

Hash tables are data structures that store data in key-value pairs, using a hash function to compute an index into an array of buckets or slots where the corresponding value can be found. Hash tables are useful for quick access to data and are widely used in databases and search engines.

Hash Table Data Structure

There are some standard questions on hashing as mentioned below:

Must read: Most Commonly asked interview questions on Hash data structure

10. Matrix

Matrix are two-dimensional arrays that represent a rectangular grid of values. Matrices are essential for operations that involve linear algebra, such as matrix multiplication, matrix inversion, and the solution of linear systems of equations. They are used in various fields such as computer graphics, data analysis, and numerical simulations.