Data Structures Unit 2 – Stacks, Recursion & Queues: AKTU previous year questions
37 AKTU questions from Unit 2 (Stacks, Recursion & Queues) asked in 2020–2026, tagged by marks, year and topic. In short: about 30 marks of every paper come from this unit; the most asked topic is Stacks (20 times); 17 questions came back in a later year. The latest ones are listed below; on the page you can filter them by 2-mark or long questions, topic and repeats.
Unit 2 previous year questions
- What is the difference between array implementation and linked list implementation? (2 marks, 2026, Stacks)
- What do you understand by polish notion? (2 marks, 2026, Stacks)
- Write the difference between stack and Queue in Data Structure. (2 marks, 2026, Stacks)
- What do you mean by recursion? Discuss advantages and disadvantages of recursion. (2 marks, 2026, Recursion)
- Write an algorithm for converting infix expression into postfix expression. Trace your algorithm for infix expression Q into its equivalent postfix expression P, Q: A + ( B * C – ( D / E ^ F) * G ) * H (7 marks, 2026, Stacks)
- Write an algorithm for finding a solution to the Tower of Hanoi problem. Explain the working of your algorithm (with 4 disks) with diagrams. (7 marks, 2026, Recursion)
- Write a C program to implement a stack using a single linked list. (7 marks, 2026, Stacks)
- Explain Priority Queue and its significance? (2 marks, 2025, Queues)
- The following sequence of operations is performed on stack: PUSH (10), PUSH (20), POP, PUSH (10), PUSH (20), POP, POP, POP, PUSH (20), POP. Demonstrate the sequence of the value popped out? (2 marks, 2025, Stacks)
- If a stack is implemented using Linked List, then show the logical representation of nodes as a stack. Illustrate PUSH and POP operations of this type of stack. (7 marks, 2025, Stacks)
- Construct a Queue using a linked list? Include functions insert(), delete(), print().Explain how a circular queue overcomes the limitations of a simple queue. (7 marks, 2025, Queues)
- Construct a C program to check whether the parentheses are balanced in an expression. (7 marks, 2025, Stacks)
Most asked Unit 2 topics
- Stacks – asked 20 times
- Recursion – asked 9 times
- Queues – asked 8 times
Unit 2 question pattern
- 2-mark questions: 17 asked in 2020–2026
- 7-mark questions: 9 asked in 2020–2026
- 10-mark questions: 11 asked in 2020–2026
- About 30 marks from Unit 2 in every paper
- 17 questions were asked again in a later year
Unit 2 questions year by year
- 2026: 7 Unit 2 questions asked (29 marks across that year's papers)
- 2025: 5 Unit 2 questions asked (25 marks across that year's papers)
- 2024: 4 Unit 2 questions asked (23 marks across that year's papers)
- 2023: 6 Unit 2 questions asked (36 marks across that year's papers)
- 2022: 4 Unit 2 questions asked (24 marks across that year's papers)
- 2021: 5 Unit 2 questions asked (34 marks across that year's papers)
- 2020: 6 Unit 2 questions asked (36 marks across that year's papers)