The Comprehensive Set of 90 DSA Patterns That Cover 99% Coding Interviews
Even after solving hundreds of LeetCode questions, do you still struggle when faced with real coding interviews?
Here’s the secret: most coding interviews don’t test unique problems — they reuse established logical templates.
Major companies prefer problem templates that measure reasoning, not rote memory.
Master these 90 essential DSA patterns, and you’ll instantly recognize nearly every coding problem you encounter.
What You’ll Learn
You’ll explore 15 foundational categories containing 90 powerful coding patterns.
Learn how to train smarter through real-time AI-assisted exercises on Thita.ai.
Why Random LeetCode Grinding Doesn’t Work
Without pattern-based learning, random LeetCode practice fails to build adaptability.
Think of patterns as templates you can reuse for any similar scenario.
For instance:
– Sorted array with a target ? Two Pointers (Converging)
– Find longest substring without repeats ? Sliding Window (Variable Size)
– Detect loop in linked list ? Fast & Slow Pointers.
Elite developers rely on pattern familiarity, not brute-force memorization.
The 15 Core DSA Pattern Families
Every pattern family addresses specific classes of problems that recur across companies.
1. Two Pointer Patterns (7 Patterns)
Used for efficient array/string navigation and pair-based operations.
Examples: Converging pointers, expanding from center, and two-pointer string comparison.
? Hint: Look for sorted input or pairwise relationships between indices.
2. Sliding Window Patterns (4 Patterns)
Use Case: Optimize subarray or substring challenges dynamically.
Key Patterns: Fixed-size window, Variable-size window, Monotonic queue, Character frequency matching.
? Tip: Efficiency lies in the ability to manage window size dynamically.
3. Tree Traversal Patterns (7 Patterns)
Applicable in computing paths, depths, and relationships within trees.
4. Graph Traversal Patterns (8 Patterns)
Use Case: Connectivity, pathfinding, and topology analysis.
5. Dynamic Programming Patterns (11 Patterns)
Central to solving resource allocation and sequence-based problems efficiently.
6. Heap (Priority Queue) Patterns (4 Patterns)
Used for stream processing and efficient order maintenance.
7. Backtracking Patterns (7 Patterns)
Use Case: Recursive search and exhaustive solution exploration.
8. Greedy Patterns (6 Patterns)
Relies on sorted order or prioritization strategies.
9. Binary Search Patterns (5 Patterns)
Use Case: Efficient searching over sorted data or answer ranges.
10. Stack Patterns (6 Patterns)
Enables structured data management through stack logic.
11. Bit Manipulation Patterns (5 Patterns)
Applied in optimization and binary arithmetic problems.
12. Linked List Patterns (5 Patterns)
Focuses on optimizing node traversal and transformation.
13. Array & Matrix Patterns (8 Patterns)
Use Case: Handling multidimensional data, rotations, and prefix operations.
14. String Manipulation Patterns (7 Patterns)
Used for matching, substring searches, and string reconstruction.
15. Design Patterns (Meta Category)
Represents higher-order algorithmic design and data structure construction.
How to Practice Effectively on Thita.ai
Learning the 90 DSA patterns is only the beginning — mastering their application is the key.
Start) by reviewing the official 90 DSA pattern sheet on Thita.ai.
Choose one category (e.g., Sliding Window) DSA roadmap to practice related LeetCode-style problems.
Step 3: Solve with AI Coaching ? Receive real-time hints, feedback, and explanations.
Step 4: Track Progress ? Analyze performance and identify weak zones.
The Smart Way to Prepare
Traditional grinding wastes time — pattern-based learning delivers results.
With Thita.ai, you’ll follow a structured, AI-enhanced learning journey.
Why Choose Thita.ai?
Thita.ai empowers learners to:
– Master 90 reusable DSA patterns
– Practice interactively with AI feedback
– Experience realistic mock interviews
– Prepare for FAANG and top-tier interviews
– Build a personalized, AI-guided learning path.