A structured, hands-on repository of common DSA concepts, solved coding problems, and core logic building. Ideal for students and interview preparation.
| Topic | Covered Content | Why it’s Useful |
|---|---|---|
| Arrays | Basics, 2D arrays, sliding window, prefix sums, Kadane’s, etc. | Foundation for all other DSA problems. |
| Strings | Palindromes, anagrams, character frequency, pattern matching | Frequently asked in coding rounds. |
| Linked Lists | Singly, doubly, reversal, cycle detection | Important for pointer-based logic. |
| Stacks & Queues | Balanced parentheses, infix-postfix, LRU cache | Great for parsing and memory problems. |
| Recursion & Backtracking | Factorials, permutations, N-Queens | Builds problem-solving intuition. |
| Binary Trees & BST | Traversals, height, diameter, lowest common ancestor | Common in system design & tech interviews. |
| Hashing | HashMap, HashSet, frequency maps, custom hashing | Crucial for O(1) lookups & optimization. |
| Searching & Sorting | Binary search, merge sort, quicksort | Core algorithms asked everywhere. |
| Graphs | DFS, BFS, shortest path (Dijkstra, Bellman-Ford), union-find | Advanced problems & CP foundations. |
| Dynamic Programming | 0/1 Knapsack, LIS, LCS, memoization | Must-have skill for FAANG-level interviews. |
data-structure-and-algorithm/ ├── 01_arrays/ ├── 02_strings/ ├── 03_linked_lists/ ├── 04_stacks_queues/ ├── 05_recursion_backtracking/ ├── 06_trees_bst/ ├── 07_hashing/ ├── 08_sorting_searching/ ├── 09_graphs/ ├── 10_dynamic_programming/ └── 11_interview_questions/
yaml Copy Edit
Each folder contains:
- ✅ Concept notes (in
.mdformat) - 🧠 Solved problems with comments
- 🧪 Sample test cases (where applicable)
# Clone the repository
git clone https://github.com/sparshsharma81/DATA-STRUCTURE-AND-ALGORITHM.git
cd DATA-STRUCTURE-AND-ALGORITHM
# Open any topic folder and run `.java` files with your favorite IDE or terminal
Make sure you have Java 8 or higher installed. Some code uses Java Collections and lambda expressions.
💡 How to Use
Pick a topic you're weak in (e.g. Strings).
Read the summary markdown inside the folder.
Run and modify the example .java files to understand how it works.
Practice by solving additional problems in the interview_questions/ folder.
Track your progress!
🤝 Contributing
Pull requests are welcome.
Add new problems in the correct folder
Keep filenames descriptive (e.g., LongestPalindrome.java)
Comment your logic for clarity
👋 Author
Sparsh Sharma
Java Developer | Problem Solver | Lifelong Learner
LinkedIn · Portfolio
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