Data Structures Unit 4 – Trees: AKTU previous year questions
35 AKTU questions from Unit 4 (Trees) asked in 2020–2026, tagged by marks, year and topic. In short: about 31 marks of every paper come from this unit; the most asked topic is Trees & Binary Trees (10 times); 19 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 4 previous year questions
- Explain the term Complete Binary Tree. (2 marks, 2026, Trees & Binary Trees)
- 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 and 13. (7 marks, 2026, Binary Search Tree (BST))
- Write Short notes of following (a) Binary Search Trees (b) Complete Binary Tree (c) Extended Binary Tree (7 marks, 2026, Trees & Binary Trees)
- Insert the following sequence of elements into an AVL tree, starting with empty tree 71,41,91,56,60,30,40,80,50,55 (7 marks, 2026, AVL, B-Trees & Binary Heaps)
- Illustrate the significance of Threaded Binary Tree. (2 marks, 2025, Threaded Binary Trees)
- Construct a binary tree with the following traversals: Inorder: B C A E G D H F I J Preorder: A B C D E G F H I J (7 marks, 2025, Trees & Binary Trees)
- Construct an AVL Tree by inserting following sequence of elements, starting with an empty tree: 71,41,91,56,60,30,40,80,50,55 (7 marks, 2025, AVL, B-Trees & Binary Heaps)
- Demonstrate B-Tree? Construct a B-Tree of order 4 with the alphabets (letters) arrive in the sequence as follows: a g f b k d h m j e s i r x c l n t u p. (7 marks, 2025, AVL, B-Trees & Binary Heaps)
- Construct a Binary Search Tree (BST) using the following sequence of numbers: 50, 30, 70, 20, 40, 60, 80, 35, 45. Perform Inorder traversal of Tree. (7 marks, 2025, Binary Search Tree (BST))
- If E and I denotes the external and internal path length of a binary tree having n internal nodes then show that E=I+2n. (7 marks, 2024, Trees & Binary Trees)
- Suppose character a, b, c, d,e,f has probabilities 0.07, 0.09, 0.12, 0.22, 0.23, 0.27 respectively. Find an optional Huffman code and draw the Huffman tree. What is the average code length? (7 marks, 2024, Huffman Coding)
- Write C function for non-recursive post order traversal. (7 marks, 2024, Trees & Binary Trees)
Most asked Unit 4 topics
- Trees & Binary Trees – asked 10 times
- AVL, B-Trees & Binary Heaps – asked 10 times
- Binary Search Tree (BST) – asked 8 times
Unit 4 question pattern
- 2-mark questions: 13 asked in 2020–2026
- 7-mark questions: 10 asked in 2020–2026
- 10-mark questions: 12 asked in 2020–2026
- About 31 marks from Unit 4 in every paper
- 19 questions were asked again in a later year
Unit 4 questions year by year
- 2026: 4 Unit 4 questions asked (23 marks across that year's papers)
- 2025: 5 Unit 4 questions asked (30 marks across that year's papers)
- 2024: 4 Unit 4 questions asked (23 marks across that year's papers)
- 2023: 6 Unit 4 questions asked (36 marks across that year's papers)
- 2022: 5 Unit 4 questions asked (34 marks across that year's papers)
- 2021: 6 Unit 4 questions asked (36 marks across that year's papers)
- 2020: 5 Unit 4 questions asked (34 marks across that year's papers)