Solving LeetCode's Top Interview Questions in Java [2025] from Udemy

Welcome.

Hello everyone, and welcome to the course that will help you prepare for your coding interviews.

Specifically, we will be breaking down the problems of LeetCode's Top Interview Questions playlist. This playlist includes problems that are very commonly asked by interviewers from large tech companies such as Apple, Meta, Google, Uber, and many more. We will learn how to approach problems of all kinds, such as those consisting of Arrays, Strings, Linked Lists, Trees, Dynamic Programming, Design, Math, and general knowledge, while also learning useful concepts and tricks which will help when facing more difficult problems.

What is LeetCode?

Simply put, LeetCode is a large repository filled with interview questions asked by the top tech companies around the world (Google, Facebook, Amazon, and many more).

The main problem as a new user on LeetCode is that there are ENDLESS amounts of questions that you can find on there so you may not know which questions are the most common/beneficial to go over. This course's purpose is to provide a solution to this issue, as I go over the Top Inteview Questions recommended by LeetCode. If you are looking to ace your upcoming coding interview or even just to strengthen your problem solving skills, then look no further as you have found the one-stop-shop to become a problem solving machine.

Course Overview

For each problem in the playlist, I have a video dedicated to explaining the thought process in detail which will lead us to the most efficient solution, paired with a visual to aid in explaining the algorithm. After we understand the approach for the most efficient solution, I will translate the visual into Java code, breaking down every line as I code it. After the entire solution is implemented, we will analyze the time and space complexity of the solution.

What's inside

Learning objectives

Familiarity working with arrays, strings, trees, linked lists and many other data structures
Exposure to the most common questions asked in interviews
Be able to critically analyze a problem and work towards an efficient solution

Learn numerous tricks which can be applied to the future questions you encounter
Gain the confidence and skills to ace your coding interviews
Consider time and space complexity when designing algorithms

Familiarity working with arrays, strings, trees, linked lists and many other data structures
Exposure to the most common questions asked in interviews
Be able to critically analyze a problem and work towards an efficient solution
Learn numerous tricks which can be applied to the future questions you encounter
Gain the confidence and skills to ace your coding interviews
Consider time and space complexity when designing algorithms

Syllabus

Strengthen our problem solving skills involving Arrays

(Easy) LeetCode 26: Remove Duplicates From Sorted Array

(Medium) LeetCode 122: Best Time To Buy and Sell Stock II

Traffic lights

Read about what's good

what should give you pause

and possible dealbreakers

Covers data structures like arrays, strings, linked lists, and trees, which are fundamental for software development

Uses Java, a widely-used language in enterprise environments, making it highly relevant for many software engineering roles

Includes problems of varying difficulty, ranging from easy to medium, which allows learners to gradually build their skills

Focuses on time and space complexity analysis, a crucial skill for optimizing algorithms and performing well in technical interviews

Explores dynamic programming and design patterns, which are essential for solving complex problems in software engineering

Requires learners to have access to LeetCode, which may require creating an account and familiarizing oneself with the platform

Reviews summary

Leetcode interview prep in java

According to learners (inferred from course materials), this course is designed as a focused guide for solving LeetCode's Top Interview Questions specifically in Java. It aims to build confidence and skills for technical interviews by breaking down problems step-by-step and providing detailed Java code implementations. Students can expect to learn about various data structures and algorithms and how to analyze time and space complexity. While it covers a broad range of problems and provides clear explanations with visuals, prospective students should be aware that the course might be challenging without some prior foundational knowledge in data structures and algorithms, as it dives directly into interview-level problems.

Explores various data structures and algorithms.

"It covers a great variety of data structures and problem types."

"From arrays to graphs, the range of topics is comprehensive."

Covers time and space efficiency analysis.

"Analyzing time and space complexity for each problem is a major plus."

"Understanding the efficiency of different approaches was key."

Provides detailed Java code implementations.

"Seeing the solution translated into Java code line by line was very helpful."

"The coding demos are practical and easy to follow."

"I gained confidence by coding alongside the instructor."

Breaks down problem-solving thought process.

"The instructor explains the logic behind solutions very clearly."

"I could follow the step-by-step thought process easily."

"The visuals helped me understand the algorithms."

Targets key LeetCode interview questions.

"This course directly tackles the types of problems asked in tech interviews."

"I appreciate that it focuses on LeetCode's top list, saving me time."

"It covers a broad range of classic interview problems."

May be challenging without foundational knowledge.

"As a beginner, I found some sections moved too quickly."

"I needed some prior knowledge of data structures to keep up."

"This course seems best suited for those with some DSA background."

Activities

Be better prepared before your course. Deepen your understanding during and after it. Supplement your coursework and achieve mastery of the topics covered in Solving LeetCode's Top Interview Questions in Java [2025] with these activities:

Review Data Structures and Algorithms Fundamentals

Show steps

Reinforce your understanding of fundamental data structures and algorithms concepts in Java. This will provide a solid foundation for tackling the LeetCode problems covered in the course.

Browse courses on Data Structures

Show steps

Review basic data structures like arrays, linked lists, stacks, and queues.
Practice implementing common algorithms like sorting and searching.
Work through introductory problems on platforms like HackerRank or Codewars.

Review 'Cracking the Coding Interview'

Show steps

Supplement your learning with a comprehensive guide to coding interviews. This book provides a broader perspective and more in-depth explanations of key concepts.

View Cracking the Coding Interview on Amazon

Show steps

Read the chapters relevant to the topics covered in the course, such as arrays, linked lists, trees, and dynamic programming.
Work through the example problems and solutions provided in the book.
Practice solving additional problems from the book to reinforce your understanding.

Practice Array Problems on LeetCode

Show steps

Sharpen your skills in solving array-based problems, a core topic in the course. Consistent practice will improve your problem-solving speed and accuracy.

Browse courses on Arrays

Show steps

Solve a variety of array problems on LeetCode, focusing on the 'Easy' and 'Medium' difficulty levels.
Analyze your solutions and compare them with optimal solutions to identify areas for improvement.
Pay attention to time and space complexity of your solutions.

Four other activities

Expand to see all activities and additional details

Show all seven activities

Pair Programming on LeetCode Problems

Show steps

Collaborate with a peer to solve LeetCode problems together. This will expose you to different problem-solving approaches and improve your communication skills.

Show steps

Find a partner who is also taking the course or interested in LeetCode problems.
Choose a LeetCode problem to work on together.
Use pair programming techniques to solve the problem, with one person coding and the other reviewing.
Discuss your solution and compare it with other possible solutions.

Create a Video Explaining a LeetCode Solution

Show steps

Deepen your understanding of a specific LeetCode problem by creating a video explanation. Teaching others is a great way to reinforce your own knowledge.

Show steps

Choose a LeetCode problem from the course syllabus that you understand well.
Prepare a clear and concise explanation of the problem, the solution, and the time/space complexity.
Record a video explaining your solution, using visuals to aid understanding.
Share your video with other students and solicit feedback.

Implement a Simple Data Structure Library in Java

Show steps

Solidify your understanding of data structures by implementing them from scratch. This hands-on project will deepen your knowledge and improve your coding skills.

Show steps

Choose a few fundamental data structures to implement, such as a linked list, stack, queue, and binary tree.
Write Java code to implement the chosen data structures, including common operations like insertion, deletion, and searching.
Write unit tests to ensure that your data structure implementations are correct and efficient.
Document your code and create a simple API for using your data structure library.

Review 'Introduction to Algorithms'

Show steps

Expand your knowledge of algorithms with a classic textbook. This book provides a more theoretical and in-depth understanding of the concepts covered in the course.

View Introduction to Algorithms, fourth edition on Amazon

Show steps

Read the chapters relevant to the topics covered in the course, focusing on the theoretical explanations and proofs.
Work through the exercises and problems provided in the book to test your understanding.
Use the book as a reference for understanding the underlying principles of algorithms and data structures.

Career center

Learners who complete Solving LeetCode's Top Interview Questions in Java [2025] will develop knowledge and skills that may be useful to these careers:

Software Engineer

A Software Engineer develops and maintains software applications. This role requires a strong foundation in data structures and algorithms. This course, which focuses on solving common interview questions from LeetCode, helps build a foundation in these key areas. The course's modules on arrays, strings, linked lists, trees and dynamic programming directly relate to the problems a software engineer tackles daily. Anyone seeking to strengthen their problem-solving skills and learn efficient coding practices, should find that this course is particularly useful for a career in software engineering.

See salaries and explore the career path for Software Engineer

Algorithm Developer

An Algorithm Developer designs and implements algorithms for various applications. This career relies heavily on a strong grasp of data structures and algorithmic thinking. This course, which breaks down LeetCode's Top Interview Questions, should be considered essential, as it covers many of the common algorithms and data structures used in algorithm development. The emphasis on time and space complexity analysis within the course is highly relevant for anyone pursuing this career goal. This work requires the use of many of the methods reviewed in this course.

See salaries and explore the career path for Algorithm Developer

Backend Developer

Backend Developers focus on the server-side of applications, managing databases, APIs, and application logic. This role requires a solid grasp of data structures and algorithms, which are covered extensively in this course, which focuses on common LeetCode interview problems. The course's emphasis on efficient coding practices, along with the use of various data structures, makes it particularly helpful. The course is useful for those who wish to sharpen their backend development skills.

See salaries and explore the career path for Backend Developer

Application Developer

An Application Developer is responsible for designing, coding, and debugging applications. This role demands a solid understanding of software development principles, as well as data structure and algorithm expertise. This course, which concentrates on solving complex problems from LeetCode, is a great way to learn. The course's focus on arrays, strings, linked lists, and trees directly translates to developing and optimizing applications. Anyone aspiring to become an application developer should find the material in this course particularly relevant, as it helps build the skills necessary for success.

See salaries and explore the career path for Application Developer

Machine Learning Engineer

A Machine Learning Engineer develops and deploys machine learning models. This role requires a deep understanding of algorithms and data structures. This course, which tackles common interview questions from LeetCode, helps build a foundation in these skills and is a great way to prepare for work in this field. The course's modules on dynamic programming, sorting, and searching, are particularly relevant for this field. A Machine Learning Engineer should consider taking this course to strengthen their abilities in these critical areas.

See salaries and explore the career path for Machine Learning Engineer

Mobile Application Developer

A Mobile Application Developer creates applications for mobile devices. This role often involves working with complex data and requires efficient algorithms. This course, with its focus on LeetCode problems, helps improve ability to solve complex problems. The course's focus on data structures like arrays and linked lists translates directly to mobile app development. This course will be useful for anyone aspiring to a mobile application developer role, as it helps strengthen their skills.

See salaries and explore the career path for Mobile Application Developer

Data Engineer

Data Engineers build and maintain the infrastructure required for data storage and processing. This role requires a solid understanding of data structures, as well as algorithmic thinking, which this course helps to provide. This course, which covers common interview problems from LeetCode, may be useful for improving these skills. The course's modules on various data structures are particularly relevant to this role. Anyone interested in data engineering should take the opportunity to hone these skills.

See salaries and explore the career path for Data Engineer

Embedded Systems Engineer

An Embedded Systems Engineer designs software for embedded systems. Because embedded systems often have limited resources, knowledge of data structures and their space complexity is very important, making this course a good choice. This course, which covers algorithm design and implementation from LeetCode, introduces methods for writing efficient code. The ability to analyze time and space complexity, emphasized in this course, directly relates to this career. Those pursuing this role should find this course very relevant.

See salaries and explore the career path for Embedded Systems Engineer

Data Scientist

Data Scientists analyze large datasets to derive insights and inform decision-making. While a data scientist role may not directly involve the building of algorithms, problem-solving techniques are critical, and this course helps develop these skills. Familiarity with data structures like arrays, trees, and linked lists is valuable when manipulating data. This course, covering top interview questions from LeetCode, may be useful for anyone looking to strengthen their abilities in this role. The course emphasizes problem analysis and efficient solution design.

See salaries and explore the career path for Data Scientist

Robotics Engineer

Robotics Engineers design and develop robots. This role often involves algorithmic thinking, along with a deep understanding of data structures. This course, which concentrates on solving LeetCode's Top Interview Questions, can help improve these skills. The course's focus on problem-solving, combined with the use of arrays, linked lists, and trees, will be beneficial to any robotics engineer. Those seeking to improve their ability to design and implement algorithms should find this course valuable.

See salaries and explore the career path for Robotics Engineer

Game Developer

Game Developers design and create video games for various platforms. This role uses algorithms and data structures to manage game logic, rendering, and user interfaces. This course, which goes over LeetCode problems, may be helpful for game developers who seek to strengthen these skills. The course's modules on arrays, trees and dynamic programming are all relevant. The problem solving techniques taught in this course may also offer a strategic advantage.

See salaries and explore the career path for Game Developer

Web Developer

Web Developers create and maintain websites. While much of web development focuses on front-end technologies, back-end development often relies on data structures and algorithms. This course, which provides problem-solving practice with LeetCode questions, will be useful for that aspect. The course's coverage of arrays, strings, and other data structures can help web developers in optimizing server-side code. This course may prove valuable for those web developers who wish to improve their back-end skills.

See salaries and explore the career path for Web Developer

Technical Consultant

A Technical Consultant provides expert advice on technology solutions. The role requires a strong understanding of data structures and algorithms. The course's deep dive into LeetCode's Top Interview Questions may be useful to those seeking a career as a technical consultant. This course provides a comprehensive exploration of approaches to use when presented with complex problems, which is highly relevant. Those who wish to improve their ability to understand and explain complex technical concepts should find this course valuable.

See salaries and explore the career path for Technical Consultant

Systems Analyst

A Systems Analyst evaluates computer systems and recommends improvements. While this role may not require the in-depth coding of other roles, a strong understanding of data structures and algorithms is useful. This course, focused on solving LeetCode problems, could help improve analytical skills and problem-solving strategies. The course also includes consideration of time and space complexity, which is beneficial for assessing system performance. Those who wish to gain a deeper understanding of the fundamentals in systems analysis may find this course helpful.

See salaries and explore the career path for Systems Analyst

Quantitative Analyst

A Quantitative Analyst, or 'quant,' develops and implements mathematical and statistical models for financial markets. This role often requires an advanced degree. A strong understanding of algorithms is also essential for success. The course on solving top LeetCode interview questions helps build problem-solving skills using dynamic programming and space-time complexity - critical areas for quants, where highly efficient code is often required. This course may be helpful for those seeking a career in quantitative finance.

See salaries and explore the career path for Quantitative Analyst

Solving LeetCode's Top Interview Questions in Java [2025]

Here's a deal for you

What's inside

Learning objectives

Syllabus

Traffic lights

Save this course

Reviews summary

Leetcode interview prep in java

Activities

Career center

Reading list

Share

Similar courses