# Basic data structures that every software developer should know

Many people flinch at the thought of a coding interview. It can be stressful, exhausting, and difficult. It is often difficult just to know what topics to prepare.

Today you will be introduced to the basic data structures and **algorithms online courses** that are tested in a coding interview. After reading this article, you should have a good idea of what you need to prepare for in order to land your dream job.

**Important data structures to learn**

In simple terms, data structures are ways to organize and store data on a computer so that you can access and edit it. You will **learn data structures online** the basics of important data structures that are tested in a coding interview.

**Array**

An array is a collection of elements of the same type of variable stored sequentially in memory. It is one of the most popular and simple data structures and is often used to implement other data structures.

Each element in the array is indexed starting at 0, and each element is known as an element. It is also important to note that in Java you cannot resize an array. It is recommended to use a list for dynamic dimensions.

**General interview questions:**

Find the first non-repeating integer in an array

Rearrange array in descending order

Rotate array right one index

Subarray of maximum sum using divide and conquer function

**Linked lists**

A linked list is a linear sequence of nodes linked together. Unlike arrays, linked lists are not indexed, so you must start at the first node and go through each node until you reach the nth node. Eventually, the last node will point to zero.

The first knot is called the head and the last knot is called the tail. Below is a list with individual links.

A linked list contains several useful applications:

Implement stacks, queues, and hash tables

Create directories

Polynomial representation and arithmetic operations

Dynamic memory allocation

**General interview questions:**

Reverse linked list

Find the mean in a linked list

Remove cycle in a linked list

**Stacks**

Stacks are linear data structures in LIFO (last in, first out) order. What does this mean? Imagine a stack of plates. The last plate you put on top of the pile is the first one you take away. Here's how stacks work - the last added value will be the first you remove. Think of a stack as a collection of items that we can add and remove.

The stack has a number of useful applications:

Return to the previous state

Evaluating and Converting an Expression

**General interview questions:**

Use a stack to check for balanced parentheses

Implement two stacks in an array

Next Largest Element Using the Stack

**Queues**

Queues are very similar to stacks, as they are linear and dynamically shaped **data structures online courses**. However, rows are FIFO data structures (first-come, first-served). To visualize this data structure template, imagine that you are waiting for a roller coaster ride. The first people to line up leave the line and drive.

There are many useful applications in a Queue:

When the resource is shared by multiple consumers

Create directories

When data is exchanged between two sources

**Common Interview Questions:**

Reverse the first nth elements of a row

Draw binary numbers from 1 to n using a row

**Graph**

A graph is a set of verticals (nodes) that are attached to one edge, forming a network. Graphs are very versatile data structures that can solve many real-world problems. Charts are often used on social networks like LinkedIn or Facebook. With the development of GraphQL, data is organized in the form of graphs or networks.

**General interview questions:**

Find the shortest path between two peaks

Check if a path exists between two vertices

Find the "mother node" in the graph

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