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Data Structures Unit 4 – Trees: important questions for AKTU

Unit 4 (Trees) questions that AKTU repeats most often. This unit carries about 31 marks per paper. Start with the repeated questions, then the most asked topics.

Most repeated Unit 4 questions

  • What is the significance of maintaining threads in Binary Search Tree? Write an algorithm to insert a node in thread binary tree. (10 marks, 2022, Threaded Binary Trees) – also asked in 2020, 2021, 2025
  • 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) – also asked in 2020, 2023
  • The order of nodes of a binary tree in inorder and postorder traversal are as follows: In order : B, I, D, A, C, G, E, H, F. Post order: I, D, B, G, C, H, F, E, A. (i) Draw the corresponding binary tree. (ii) Write the pre order traversal of the same tree. (10 marks, 2023, Trees & Binary Trees) – also asked in 2020, 2025

Most important Unit 4 topic

  • Trees & Binary Trees (Unit 4: Trees) – asked 10 times in 2020, 2021, 2023, 2024, 2025, 2026

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

More 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)

Unit 4 syllabus topics

  • Trees & Binary Trees
  • Binary Search Tree (BST)
  • Threaded Binary Trees
  • AVL, B-Trees & Binary Heaps
  • Huffman Coding