Tree traversal Pseudocode (Inorder)
Duration: 10 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
Module outline
- Discrete Mathematics: Permutation, Combination and Probability / क्रमचय, संचय एवं प्रायिकता, Set Theory, Relations, Functions, Propositional and Predicate Logic, Graph Theory, Group Theory
- Digital Logic: Digital Systems & Boolean Basics, Boolean Expression, Boolean Minimization, Logic Gates & Hardware, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Floating Point Rep
- Computer Organization and Architecture: Basics of COA, Programming the Basic Computer, Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Register Transfer and Microoperations, Control Unit Design, Pipelining, Multiprocessors
- Programming: Language Design, C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, OOPS with C++
- Data Structures: Introduction to DS, Array, Linked List, Stack, Queue, Tree, Graphs, Hashing
- Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
- Theory of Computation: Grammar, Regular Language Properties, Moore & Mealy Machines, Turing Machines
- Compiler Design: Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization, Run Time Environment, Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Pushdown Automata & CFG, Complexity Theory
- Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Unix OS, Linux OS, Security
- Database Management Systems: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Relational Calculus, Transaction Management, Concurrency Control, ORDBMS, NoSQL
- Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
The video lecture explains how to determine the output of a recursive C function named `what` that operates on a binary tree. The instructor analyzes the code structure, specifically the recursive calls to left and right children and the print statement in between. He draws a sample binary tree with nodes A, B, C, D, and E to demonstrate the execution. By tracing the function call stack step-by-step, he shows that the function performs an in-order traversal, printing the nodes in the sequence D, B, E, A, C.
Chapters
0:00 – 2:00 00:00-02:00
The video begins with a slide displaying the question 'Find what this function is doing?' alongside a C code snippet `void what(struct Bnode *t)`. The instructor underlines `struct Bnode *t` to identify the data structure. He explains the `if (t)` condition which serves as a base case. To illustrate, he draws a binary tree on the right side of the screen, starting with a root node 'A', adding left child 'B' and right child 'C', and then adding children 'D' and 'E' to node 'B'.
2:00 – 5:00 02:00-05:00
The instructor begins tracing the function execution using a stack diagram. He draws a stack frame for the root node 'A' at address 1000, labeling fields 'LC', 'Data', and 'RC'. He explains that the first line `what(t -> LC)` triggers a recursive call to the left child 'B' at address 2000. He draws a new stack frame for B and continues the recursion to node 'D' at address 4000, writing `w(1000)`, `w(2000)`, and `w(4000)` to track the call stack depth.
5:00 – 10:00 05:00-10:00
The trace reaches the leaf node D. The instructor notes that D's left child is null, so the recursive call returns immediately. The `printf` statement executes, printing 'D'. He writes 'D' on the board. Control returns to B, where `printf` prints 'B'. Then, the function calls `what(t -> RC)` for B, moving to node E at address 5000. He traces E: left child null, print E, right child null. Control returns to A, `printf` prints 'A'. Finally, `what(t -> RC)` for A moves to node C at address 3000, which is traced similarly.
10:00 – 10:01 10:00-10:01
The video concludes with the final result. The instructor writes the sequence of printed values 'D B E A C' in a box at the bottom left. He explains that this specific order—Left subtree, Root, Right subtree—defines an in-order traversal. The final output is highlighted to confirm the function's behavior.
The lecture demonstrates a systematic approach to tracing recursive functions on tree data structures. By visualizing the call stack and following the order of operations (Left, Root, Right), the instructor proves that the function performs an in-order traversal. This method is essential for understanding recursion and tree algorithms in computer science.

