Data Structures & Algorithms Important Questions April 2026 | B.Sc Computer Science – MS University

📘 Data Structures & Algorithms — Important Questions for April 2026

Based on your syllabus and analysis of 2024 & 2025 previous year papers, this guide provides not only important questions but also key explanations and concepts to help you score high.

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⚠️ Disclaimer

This content is for educational purposes only. Questions are based on previous trends and syllabus analysis. There is no guarantee that the same questions will appear in the April 2026 examination. Students should prepare the full syllabus.

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✅ PART A — 1 Mark (MCQ Pattern)

• A queue follows FIFO principle
• A stack follows LIFO principle
• Push and pop relate to Stacks
• Traversal = processing each element in a list
• Trees = non-linear data structure
• BFS requires a Queue
• Regular graph = all vertices have equal degree
• Searching = finding location of an item
• Hashing = mapping large data to small tables

📌 Concept Quick Notes

• Stack: Used in recursion, expression evaluation
• Queue: Used in scheduling, BFS traversal
• Tree: Hierarchical data structure
• Hashing: Provides fast data access (O(1) average)

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⭐ PART B — 5 Marks (High Probability)

Topic	Question
Unit 1	What is ADT? / What is Doubly Linked List?
Unit 2	Applications of Queue / What is Circular Queue? / Priority Queue
Unit 3	Binary Tree vs Binary Search Tree / AVL Tree / Applications of Trees
Unit 4	Types of Graphs / Bi-connectivity
Unit 5	Open Addressing / Hashing / Hash functions

📌 Important Explanations

ADT (Abstract Data Type): A logical model that defines data and operations without specifying implementation.

Doubly Linked List: Each node contains data, previous pointer, and next pointer. Allows traversal in both directions.

Circular Queue: Last element connects back to first, avoiding memory wastage.

AVL Tree: Self-balancing binary search tree where height difference ≤ 1.

Hashing: Technique to map keys into table indices using hash functions.

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⭐⭐ PART C — 8 Marks (Most Important)

Unit	Must-Prepare Questions
Unit 1	Singly Linked List (detail) / Doubly Linked List / Polynomial manipulation
Unit 2	Stack operations + applications / Infix to Postfix conversion / Queue ADT
Unit 3	AVL Trees / Tree traversals / Expression Tree / Heap + applications
Unit 4	Breadth First Traversal / Depth First Traversal / Euler circuits + Cut vertex
Unit 5	Linear Search / Binary Search / Bubble Sort / Insertion Sort

📌 Key Concepts You Must Understand

Infix to Postfix Conversion:
Use a stack to convert expressions. Operators are pushed and popped based on precedence.
Example: A + B → AB+

BFS (Breadth First Search):
Uses queue. Traverses level by level.

DFS (Depth First Search):
Uses stack or recursion. Goes deep before backtracking.

AVL Rotations:
Includes LL, RR, LR, RL rotations to maintain balance.

Sorting Algorithms:

• Bubble Sort: Repeated swapping
• Insertion Sort: Insert elements in correct position
• Binary Search: Works on sorted data (O(log n))

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🔥 Top 5 "Sure Shot" Questions

1. Infix to Postfix conversion (with example) — appeared both years
2. BFS or DFS — appeared both years
3. AVL Tree — appeared both years
4. Doubly Linked List — appeared both years
5. Hashing / Separate Chaining / Open Addressing — appeared both years

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📌 Final Preparation Tips

• Focus on Part C (8 marks) for maximum score
• Practice algorithms with examples
• Revise definitions daily for MCQs
• Do not skip Trees and Graphs

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🎯 Conclusion

By preparing these questions along with concepts, you can confidently attempt 80–90% of the exam paper. Consistent practice and understanding will help you score high.

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