DSA Forge: Learn DSA in Java

DSA Forge is a complete Java DSA app: learn Data Structures and Algorithms in Java through 204 curated DSA problems, each with a full Java solution and its time and space complexity. One DSA sheet you can actually finish

LEARN DSA IN JAVA, TOPIC BY TOPIC

13 DSA topics, each a complete unit with theory before practice:

• Arrays: Two pointers, sliding window, prefix sums, in-place rearrangement.
• Linked Lists : Fast/slow pointers, cycle detection, reversal, merging.
• Stacks: Monotonic stacks, parsing, expression evaluation.
• Queues: Deques, circular buffers, BFS, priority queues, streaming.
• Trees: DFS and BFS traversal, BSTs, recursion on hierarchies.
• Graphs: BFS, DFS, topological sort, Dijkstra, Union-Find, Bellman-Ford.
• Sorting: Merge sort, quicksort, counting and bucket sort, custom comparators.
• Searching: Binary search, binary search on the answer, quickselect.
• Backtracking: Subsets, permutations, combinations, constraint pruning.
• Greedy Algorithms: Exchange arguments, interval scheduling, sweeps.
• Dynamic Programming: Memoization, tabulation, 1D and 2D DP, knapsack.
• LLD, Low-Level Design
• HLD, High-Level Design

EVERY DSA TOPIC IS A LESSON, NOT JUST A PROBLEM LIST

Before you solve anything, each topic gives you a written overview of how the structure actually works in memory, 8 to 10 key points and interview gotchas, a complexity table covering every operation, and runnable Java code examples across the app, from building a dynamic array from scratch to writing Dijkstra with a PriorityQueue.

DSA AND SYSTEM DESIGN

Most DSA apps stop at algorithms. This one also covers low-level design and high-level system design covering sharding, consistent hashing, fan-out, message queues and CDNs.

TRACK YOUR DSA PROGRESS

Tick problems off as you solve them and watch each topic fill up. Finish a topic and you get a share card. Clear all 204 and you earn a certificate of completion Works signed out; create a free account and your progress follows you across devices.

NO SIGNUP WALL

Open the app and start solving. No account required, no lesson gate, no unlock-the-next-topic drip. All 13 topics and all 204 DSA problems are open from the first launch.

WHO THIS DSA APP IS FOR

Students preparing for campus placements. Developers targeting SDE 1, SDE 2 and product-based companies. Anyone revising DSA in Java before a technical round. Computer science students studying Data Structures and Algorithms for semester exams. Self-taught programmers who want an ordered path through arrays, recursion, trees, graphs, DP and system design.

Starting DSA from scratch, or revising Java DSA the week before an interview same path: 13 topics, 204 problems, one certificate.

Start with Arrays. Finish with a certificate. Forge your DSA in Java, one problem at a time.