Data Structures and Algorithms in Java
Stop memorizing patterns. Build real problem-solving skill with 56 LeetCode labs, interview prep, and a clear path from Big O to Hard problems.
The DSA Course Built for Java Interviews
Most DSA courses tell you to memorize patterns and grind LeetCode until something sticks. That is why so many students feel stuck. They can recognize a solution after seeing it, but they freeze when the problem changes. This course is built differently. You learn the concept, understand the theory, implement it in Java, and then solve a hands-on lab that applies exactly what you just learned. No hidden prerequisites. No random problem dumps. No guessing what to study next. With 56 LeetCode-style labs, built-in interview prep, and a difficulty path from Easy to Hard, this course trains you to think through problems — not just remember answers.
The course mirrors a real interview journey. You start with Big O, arrays, strings, and search. Then you build toward linked lists, stacks, queues, trees, graphs, dynamic programming, and advanced interview patterns. By the final capstone, Trapping Rain Water, you will have practiced the core thinking skills companies actually test.
What you'll actually learn
- 56 Hands-on LeetCode LabsEvery major topic includes a lab chosen to match the lesson. You learn the idea, implement it in Java, then immediately apply it to a real coding problem.
- Interview Prep Built InYou will practice explaining your approach, analyzing time and space complexity, testing edge cases, and improving solutions the way interviewers expect.
- Algorithmic Thinking from Big O UpStart with algorithm analysis, time complexity, space complexity, and memory foundations so every later topic makes sense instead of feeling memorized.
- Every Core Data Structure in JavaArrays, linked lists, stacks, queues, trees, heaps, hash tables, and graphs — implemented and practiced in Java so you understand the mechanics behind the API.
- The Patterns Companies Actually TestTwo pointers, sliding window, binary search, recursion, backtracking, BFS, DFS, heaps, hash maps, dynamic programming, greedy, intervals, Trie, and Union-Find.
- A 5-Step Interview FrameworkLearn how to approach unseen problems using a repeatable process: Understand → Plan → Code → Test → Optimize. Then apply it to a final Hard capstone.
Who should take this course
- ✓ Full course access
- ✓ 56 LeetCode-style labs
- ✓ Interview prep built in
- ✓ Run Java in your browser
- ✓ Instant coding environment
- ✓ Step-by-step progression
- ✓ Full Java library
What students say
"I failed three coding screens before this course. The labs forced me to stop memorizing and actually explain my thinking. Module 12 changed the way I approach problems out loud."
"Every lab matches what was just taught. That matters. I wasn’t thrown into random LeetCode problems with no context. I finally had a path."
"Dynamic Programming finally clicked. The recurrence-first approach helped me understand the problem before touching code. That was the missing piece."
Course Curriculum
Build the mathematical and memory foundation behind every data structure. Learn Big O, Java arrays, strings, and prefix sums through runnable examples and hands-on labs.
| Unit | Lesson | What You'll Learn |
|---|---|---|
| 1 | Algorithm Analysis and Big O Notation | Define Big O, classify algorithms by time and space complexity, solve your first lab, and explain why brute force is often not enough in interviews |
| 2 | Array Memory Representation | Explain how contiguous memory enables O(1) array access, trace address calculation, and understand stack vs heap memory in Java |
| 3 | 1D Array Operations | Implement insert, delete, and update operations, understand why shifting costs O(n), and practice in-place array modification |
| 4 | 2D Arrays and Multi-dimensional Arrays | Declare and traverse 2D arrays, use boundary tracking, and solve a matrix traversal lab |
| 5 | String Fundamentals | Understand Java string immutability, reverse characters with two pointers, and choose between String and StringBuilder |
| 6 | Prefix Sum | Build prefix sum arrays, answer range queries in O(1), and apply running sums to interview-style array problems |
Frequently Asked Questions
Build Real Problem-Solving Skill in Java
Join 4,100+ developers practicing DSA with hands-on labs, interview prep, and a step-by-step path from fundamentals to Hard problems.