AKTU Data Structure · Important Questions 2026Source: ryzenstudy.com PYQs
BCS301 Data Structure Important Questions 2026 (AKTU)
Repeat analysis + most-asked questions, unit-wise
What we did: built from all 5 AKTU Data Structure papers (2021-22–2025-26): 121 questions grouped into 74 distinct questions, 27 of which were asked in more than one paper.
- of marks were repeat questions
- 52%
- of marks were repeat questions
- questions asked in 2+ papers
- 27
- questions asked in 2+ papers
- papers analysed (2021-22–2025-26)
- 5
- papers analysed (2021-22–2025-26)
- units, mapped to current syllabus
- 5
- units, mapped to current syllabus
How much of the paper repeats?
- Repeats are real: when we checked each newer BCS301 paper against the papers before it, on average 52% of its marks were questions already asked in an earlier paper.
- 2023-24 paper: 32% of marks were repeats (5 of 6 repeated questions were in our top list).
- 2024-25 paper: 72% of marks were repeats (6 of 15 repeated questions were in our top list).
- 2025-26 paper: 53% of marks were repeats (7 of 15 repeated questions were in our top list).
- Topic weightage is a guide, not a guarantee: our Tier 1 + Tier 2 topics covered 62% of the next paper's marks — picking the same number of topics at random would have covered about 53%.
Across 10 subjects and 23 papers we tested, 43% of marks repeated earlier questions on average.
1.Unit-wise most-asked questions
Ranked by how many papers asked them, then by how recently. Click a paper to open it.
Unit 1: Introduction · Abstract Data Types (ADT) Arrays · Linked lists
21% of past marks| Question | Asked |
|---|---|
| Illustrate how to represent a polynomial using a linked list. Construct a C program to add two polynomials using a linked list. | Asked 4× |
| What do you mean by complexity? Describe the asymptotic notations with a suitable diagram. | Asked 3× |
| What is the difference between array implementation and linked list implementation? | Asked 3× |
| An array ARR[-5...15, 10...20] stores elements in Row Major order with each element requiring 2 bytes of storage. Evaluate the address of ARR[10][15] when the base address is 2500. | Asked 3× |
Unit 2: Stacks · Queues
19% of past marks| Question | Asked |
|---|---|
| Write an algorithm for converting an infix expression into postfix expression. Trace your algorithm for the given infix expression Q into its equivalent postfix expression P (see original paper). | Asked 4× |
| Write a C program to implement a stack using a single linked list. | Asked 3× |
| What do you mean by recursion? Discuss advantages and disadvantages of recursion. | Asked 2× |
| What do you understand by tail recursion? | Asked 2× |
Unit 3: Searching · Sorting
18% of past marks| Question | Asked |
|---|---|
| What is hashing? Explain the division method to compute the hash function and also explain the collision resolution strategies used in hashing. | Asked 2× |
| Write an algorithm for Heap Sort. Use the Heap sort algorithm to sort the following sequence: 18, 25, 45, 34, 36, 51, 43 (list may continue, see original paper). | Asked 2× |
| Write the algorithm of insertion sort and sort the following list of numbers using insertion sort: 70, 17, 30, 80, 55, 1, 29, 67, 15. | Asked 2× |
| Explain linear probing and quadratic probing in hashing with examples. | Asked 2× |
Unit 4: Trees
25% of past marks| Question | Asked |
|---|---|
| Insert the following sequence of elements into an AVL tree, starting with an empty tree: 71, 41, 91, 56, 60, 30, 40, 80, 50, 55. | Asked 3× |
| What do you mean by Binary Search Tree? Construct a Binary Search Tree by inserting the following sequence of numbers: 10, 12, 5, 4, 20, 8, 7, 15 (list may continue, see original paper). | Asked 3× |
| Construct a binary tree with the following traversals. Inorder: BCAEGDHFIJ. Preorder: ABCDEGFHIJ. | Asked 2× |
| Demonstrate B-Tree. Construct a B-Tree of order 4 with the letters arriving in the following sequence: a g f b k d h m j e s i r x c l n t u p. | Asked 2× |
Unit 5: Graphs · Graph Traversal
17% of past marks| Question | Asked |
|---|---|
| Use Prim's algorithm to compute the MST for the given weighted graph (see original paper). | Asked 4× |
| Explain the Depth-First Search (DFS) algorithm with the help of an example graph. Which data structure is used for DFS and BFS? | Asked 3× |
| Consider the following graph and use Dijkstra's algorithm to find the shortest path (see original paper). | Asked 3× |
| Write and explain the Floyd Warshall algorithm to find the all-pair shortest path. Use the Floyd Warshall algorithm to find shortest paths among all the vertices in the given graph (see original paper). | Asked 2× |
2.Topic weightage: which topics carry the marks
Blue = Tier 1 + Tier 2 (topics that carried ~80% of past marks). Grey = the rest. It shows where marks have gone, not a promise of what comes next.
Tree terminology & types · U4
7.1% (cum 7%)
Linked lists & operations · U1
6.3% (cum 13%)
Prefix & postfix expressions · U2
6.1% (cum 20%)
Arrays & index formulae · U1
5.9% (cum 25%)
Stack operations & implementation · U2
4.9% (cum 30%)
Polynomial using linked list · U1
4% (cum 34%)
Prim & Kruskal · U5
4% (cum 38%)
Binary search tree operations · U4
3.7% (cum 42%)
Collision resolution · U3
3.6% (cum 46%)
AVL trees · U4
3.5% (cum 49%)
Dijkstra shortest path · U5
3.4% (cum 53%)
Elementary sorting · U3
3.4% (cum 56%)
Asymptotic notations · U1
3.3% (cum 59%)
B-trees · U4
3% (cum 62%)
Recursion principles · U2
2.8% (cum 65%)
DFS & BFS · U5
2.8% (cum 68%)
Hashing concepts · U3
2.5% (cum 70%)
Graph representation · U5
2.4% (cum 73%)
Tree from traversals · U4
2.3% (cum 75%)
Binary search · U3
2.2% (cum 77%)
Merge sort · U3
2% (cum 79%)
Heap sort · U3
2% (cum 81%)
Warshall & all-pairs paths · U5
2% (cum 83%)
Quick sort · U3
1.8% (cum 85%)
Threaded binary trees · U4
1.8% (cum 87%)
Huffman coding · U4
1.6% (cum 88%)
Deque & priority queue · U2
1.5% (cum 90%)
Graph terminology · U5
1.5% (cum 91%)
Queue operations & implementation · U2
1.5% (cum 93%)
Circular queue · U2
1.4% (cum 94%)
Tree traversals · U4
1.2% (cum 96%)
Spanning trees & components · U5
1.1% (cum 97%)
Basic terminology & data types · U1
1.1% (cum 98%)
Hanoi, Fibonacci, recursive search · U2
1% (cum 99%)
Sequential & index sequential search · U3
0.5% (cum 99%)
Sparse matrices · U1
0.4% (cum 100%)
Algorithm complexity · U1
0.4% (cum 100%)
Binary heaps · U4
0.4% (cum 100%)
| Topic | Papers | Share |
|---|---|---|
| Tree terminology & types · Unit 4 · Tier 1 | 3/5 | 7.1% |
| Linked lists & operations · Unit 1 · Tier 1 | 5/5 | 6.3% |
| Prefix & postfix expressions · Unit 2 · Tier 1 | 5/5 | 6.1% |
| Arrays & index formulae · Unit 1 · Tier 1 | 5/5 | 5.9% |
| Stack operations & implementation · Unit 2 · Tier 1 | 4/5 | 4.9% |
| Polynomial using linked list · Unit 1 · Tier 1 | 4/5 | 4% |
| Prim & Kruskal · Unit 5 · Tier 1 | 4/5 | 4% |
| Binary search tree operations · Unit 4 · Tier 1 | 3/5 | 3.7% |
| Collision resolution · Unit 3 · Tier 1 | 4/5 | 3.6% |
| AVL trees · Unit 4 · Tier 1 | 4/5 | 3.5% |
| Dijkstra shortest path · Unit 5 · Tier 1 | 3/5 | 3.4% |
| Elementary sorting · Unit 3 · Tier 2 | 4/5 | 3.4% |
| Asymptotic notations · Unit 1 · Tier 2 | 4/5 | 3.3% |
| B-trees · Unit 4 · Tier 2 | 3/5 | 3% |
| Recursion principles · Unit 2 · Tier 2 | 3/5 | 2.8% |
| DFS & BFS · Unit 5 · Tier 2 | 3/5 | 2.8% |
| Hashing concepts · Unit 3 · Tier 2 | 3/5 | 2.5% |
| Graph representation · Unit 5 · Tier 2 | 3/5 | 2.4% |
| Tree from traversals · Unit 4 · Tier 2 | 2/5 | 2.3% |
| Binary search · Unit 3 · Tier 2 | 2/5 | 2.2% |
| Merge sort · Unit 3 · Tier 2 | 2/5 | 2% |
| Heap sort · Unit 3 · Tier 2 | 2/5 | 2% |
| Warshall & all-pairs paths · Unit 5 · Tier 3 | 2/5 | 2% |
| Quick sort · Unit 3 · Tier 3 | 2/5 | 1.8% |
| Threaded binary trees · Unit 4 · Tier 3 | 2/5 | 1.8% |
| Huffman coding · Unit 4 · Tier 3 | 1/5 | 1.6% |
| Deque & priority queue · Unit 2 · Tier 3 | 2/5 | 1.5% |
| Graph terminology · Unit 5 · Tier 3 | 2/5 | 1.5% |
| Queue operations & implementation · Unit 2 · Tier 3 | 2/5 | 1.5% |
| Circular queue · Unit 2 · Tier 3 | 1/5 | 1.4% |
| Tree traversals · Unit 4 · Tier 3 | 1/5 | 1.2% |
| Spanning trees & components · Unit 5 · Tier 3 | 2/5 | 1.1% |
| Basic terminology & data types · Unit 1 · Tier 3 | 2/5 | 1.1% |
| Hanoi, Fibonacci, recursive search · Unit 2 · Tier 3 | 1/5 | 1% |
| Sequential & index sequential search · Unit 3 · Tier 3 | 1/5 | 0.5% |
| Sparse matrices · Unit 1 · Tier 3 | 1/5 | 0.4% |
| Algorithm complexity · Unit 1 · Tier 3 | 1/5 | 0.4% |
| Binary heaps · Unit 4 · Tier 3 | 1/5 | 0.4% |
3.Paper pattern (2025-26)
| Section | Questions | Rule |
|---|---|---|
| A | 7 × 2 marks | Attempt all |
| B | 5 × 2.3333333333333335 marks | Attempt any 3 |
| C | 15 × 7 marks | Attempt any 1 |
4.In the syllabus, never asked yet
Low priority, but read them once — a new paper can always start here.
- Iteration vs recursion · U2
- Radix sort · U3
- Binary tree representation · U4
5.Study order
- 1Tree terminology & types (Unit 4, Tier 1)
- 2Linked lists & operations (Unit 1, Tier 1)
- 3Prefix & postfix expressions (Unit 2, Tier 1)
- 4Arrays & index formulae (Unit 1, Tier 1)
- 5Stack operations & implementation (Unit 2, Tier 1)
- 6Polynomial using linked list (Unit 1, Tier 1)
- 7Prim & Kruskal (Unit 5, Tier 1)
- 8Binary search tree operations (Unit 4, Tier 1)
- 9Collision resolution (Unit 3, Tier 1)
- 10AVL trees (Unit 4, Tier 1)
- 11Dijkstra shortest path (Unit 5, Tier 1)
- 12Elementary sorting (Unit 3, Tier 2)
- 13Asymptotic notations (Unit 1, Tier 2)
- 14B-trees (Unit 4, Tier 2)
- 15Recursion principles (Unit 2, Tier 2)
- 16DFS & BFS (Unit 5, Tier 2)
- 17Hashing concepts (Unit 3, Tier 2)
- 18Graph representation (Unit 5, Tier 2)
- 19Tree from traversals (Unit 4, Tier 2)
- 20Binary search (Unit 3, Tier 2)
- 21Merge sort (Unit 3, Tier 2)
- 22Heap sort (Unit 3, Tier 2)
FAQ
Which units of BCS301 carry the most marks?
Unit 4 (Trees, 25% of past marks) and Unit 1 (Introduction · Abstract Data Types (ADT) Arrays · Linked lists, 21% of past marks).
Do AKTU Data Structure questions repeat?
Yes. On average 52% of the marks in each newer BCS301 paper came from questions already asked in an earlier paper, and 27 questions have appeared in more than one paper.
How is this list made?
Every question from the 5 papers (2021-22–2025-26) was mapped to the current AKTU syllabus and grouped with the same question from other years. Questions are ranked by how many papers they appeared in, then by how recently.
Study this subject
Note: this is based on past AKTU papers, not a guarantee. Questions are mapped to the current syllabus; topics that are no longer in the syllabus are left out.