Best Free Coding Interview Courses

Find the best online Free Coding Interview Courses for you. The courses are sorted based on popularity and user ratings. We do not allow paid placements in any of our rankings.

Cracking the Coding interview: Learn 5 Essential Patterns

Two pointers, Sliding window, Binary Search, Merge Intervals, Top K elements. Solution in (Java & Python)

Created by Fred Boundou - Software Engineer


Students: 15028, Price: Free

This course is for all those people who want improve their skills in problem solving. In this course I want you to focus on practice because I do believe that it is the better way to master technique for solving coding interview problems. By the end of this course you will be able to identify some coding interview problems so that you can use that pattern to solve it. Thanks!

What will you learn in this course?

You will learn and master 5 Patterns for coding interviews:  Solutions in Java & Python

  1. Pattern 1: Two Pointers Techniques

  2. Pattern 2: Sliding Window

  3. Pattern 3: Sorted Array & Binary Search

  4. Pattern 4: Merge Intervals

  5. Pattern 5: Heap & Top K elements

You will improve your problem solving skills

Your instructor, Fred Boundou, Energetic software engineer with 10+ years experience developing robust code for high-volume businesses.

Highly familiar with a wide variety of Software Engineering, Database, Web as well as Data Science.

Progressively engage my experience through my passion for creating application using best practice intuitive experience as focus.

Using my diverse skills set in order to provide a super service that will assist a range of clients...

I have been working for many Big tech companies include (Microsoft, Boeing...)

This means you are learning from someone who has all the professional training, skills,

and experience you need to teach you how to become master of solving interview questions in the fastest possible way.

Python String Coding Interview Questions In Simple Way

To improve your Logical Thinking and To clear Python Interviews

Created by DURGASOFT DURGA - Software Training Organization


Students: 14655, Price: Free

The following programs will be covered as the part of this course:

1. Write a Program To REVERSE content of the given String by using slice operator

2. Write a Program To REVERSE content of the given String by using reversed() function

3. Write a Program To REVERSE content of the given String by using while loop

4. Write a Program To REVERSE order of words present in the given string

5. Write a Program To REVERSE internal content of each word

6. Write a Program To REVERSE internal content of every second word present in the given string

7. Write a program to print the characters present at even index and odd index separately for the given string

8. Write a program to merge characters of 2 strings into a single string by taking characters alternatively

9. Program to sort characters of the string, first alphabet symbols followed by digits

10. Program for the requirement,input: a4b3c2 and expected output: aaaabbbcc

11. Program for the requirement,input: a3z2b4 and expected output: aaabbbbzz (sorted String)

12. Program for the requirement,input: aaaabbbccz and expected output: 4a3b2c1z

13. Program for the requirement,input: a4k3b2 and expected output: aeknbd

14. Program to remove duplicate characters from the given input String

15. Program to find the number of occurrences of each character present in the given string with count() method

16. Important Conclusions about dictionary

17. Program to find the number of occurrences of each character present in the given string without using count() method

18. Program for the requirement,input: ABAABBCA and expected output: 4A3B1C

19. Program for the requirement,input: ABAABBCA and expected output: A4B3C1

20. Program to find the number of occurrences of each vowel present in the given string?

21. Program to check whether the given two strings are anagrams or not?

22. Program to check whether the given string is palindrome or not?

23. Program to generate words from the given input strings by taking characters alternatively?

Java Coding Interview questions for freshers and experienced

Java Coding Interview Questions to crack any interview

Created by Krishna Sandeep - SoftwareEngineer


Students: 7016, Price: Free

This course contains various java programming questions and their solutions step by step. It covers String based,array based ,number based frequently asked programming interview questions for java freshers and experienced engineers. Every section starts with an introduction about the section and it provides clear learning path.

This course will be useful for Java developers,Automation testers and Bigdata Engineers to crack the interview.

Data Structures & Algorithms in Python – Coding Interview

Learn all the data structures and algorithms in a simplified way. Practice questions and master coding interviews.

Created by Aakash Sachdeva - Programming Instructor


Students: 5582, Price: Free

This course will start from the very basics of algorithms and data structures and cover all the advanced data structures. We will discuss all the concepts that you need to learn and dive deeper into popular coding questions. You do not need any pre-requisite knowledge in data structures before taking this course. So, if you are a newbie or an advanced programmer looking to refresh your knowledge, this is the course for you. Moreover, it is in Python and the solutions to all the coding problems are given in Python, which makes it more interesting and gives you the opportunity to learn Python as well.

The highlight will be the coding problems that will be explained as well as given as exercise in this course. You will learn the following concepts in this course:

1. Big O

2. Arrays

   o Basics

   o Traverse an array in reverse

   o Traverse from both ends

3. Linked List

   o Implementation

   o Add and delete nodes

4. Stack

   o Implementation

5. Queues

   o Implementation

6. Hash Maps

   o Implementation

   o Hash Functions

7. Binary Trees

   o Traversal

   o Top to Bottom

   o Bottom to Top

8. Binary Search Tree

   o Implementation

9. Heap

   o Implementation

10. Graphs

   o Basics

   o DFS

   o BFS

11. Tries

   o Implementation

The following algorithms will be included in these topics:

- Searching

- Sorting

- Recursion

- Tree Traversal

- Breadth First Search

- Depth First Search

- Dynamic Programming

Java Basic Object Oriented Programing Coding Interview Guide

Prepare for your Java Basic Object Oriented Programming Coding Interview

Created by Jitendra Panigrahy - Associate Technical Architect | Professional Instructor


Students: 3076, Price: Free

This course will Guide you to learn Java Basic Object Oriented Programming and prepare for the interview

This course covers 50+ Java Basic Object Oriented Coding Interview Questions and Answers with real world code examples.

It covers the topics related to Basics of Object Oriented Programming  in Java listed below :

- How Object Oriented Programming is different from Procedure Oriented Programming

- What is Object Oriented Programming

- Why was Object Oriented Programming developed

- Why do we need Class in Object Oriented Programming

-  Why do we need to create Object of class in Object Oriented Programming

- What are the States and Behaviors of Object in Object Oriented Programming

- Define Class and Object in Java

- Code to develop Class and Object in Java ( With ECLIPSE IDE )

- What is and How to use encapsulation in Object Oriented Programming

- Why encapsulation used in Object Oriented Programming

- what is abstraction

- How to identify and build Abstraction in java with real world code example

- Benefits of Abstraction in java

- what is Inheritance

- Purpose of Inheritance in java with real world code example

- Pros and cons of Inheritance

- Types of Inheritance used in java

- What is Polymorphism

- Types of Polymorphism

- Compile time and Runtime Polymorphism in java with real world code examples

- Benefits of Polymorphism in java with with real wold examples

- 50+ Interview Questions and Answers based on Inheritance, Method Overloading and Method Overriding, Downcasting, Upcasting  and use of this and super keyword

Ace the Coding Interview

Top 14 coding problems reviewed and explained

Created by Elie Toubiana - Ex Uber


Students: 728, Price: Free

In my experience in interviewing over 150 engineers in big tech companies and startups, I noticed that most questions were only a variation of a small subset of questions and concepts. The goal of this class is to give candidates a guide and a list of questions to study to set them up for success in the coding and system design interviews.

How do you find the missing number in a given integer array of 1 to 100?

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 find all pairs of an integer array whose sum is equal to a given number?

How do you find duplicate numbers in an array if it contains multiple duplicates?

How are duplicates removed from a given array in Java?

How is an integer array sorted in place using the quicksort algorithm?

How do you remove duplicates from an array in place?

How do you reverse an array in place in Java?

How are duplicates removed from an array without using any library?

These are the types of questions you will learn to solve in minutes!