Tree Traversal Pseudocode (Post-Order )

Duration: 8 min

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Module outline

  1. About the Course: About the Course
  2. Section 1 | Language (Hindi): भाषा, लिपि, ध्वनि, वर्ण, अक्षर, स्वर, व्यंजन, मात्रा और संयुक्ताक्षर, वर्तनी, वर्ण-विन्यास, अनुस्वार, अनुनासिक, चंद्रबिंदु और ‘र’ के रूप, शब्द, पद और शब्द-भेद, संज्ञा और सर्वनाम, विशेषण और क्रिया, लिंग, वचन, पुरुष और कारक, काल, वाच्य, वाक्य और वाक्य-भेद, संधि, समास, विलोम शब्द, पर्यायवाची शब्द, सामान्य अशुद्धियाँ, अनेक शब्दों के लिए एक शब्द, मुहावरे और लोकोक्तियाँ, अपठित गद्यांश और अपठित पद्यांश, Multi-Topic Content (Cross-Concept Material), वर्णमाला
  3. Section 1 | Language (उर्दू भाषा — 22 प्रश्न (निश्चित)): Spelling & Diacritics, Grammar (اسم, فعل, صفت, ضمیر), Vocabulary, Idioms & Proverbs, Comprehension
  4. Section 1 | Language (বাংলা / बांग्ला भाषा — 22 प्रश्न (निश्चित)): Bangla Script and Sounds, Bangla Grammar and Usage, Bangla Word Formation and Vocabulary, Reading and Text Interpretation
  5. Section 1 | Language (English): Vocabulary, Noun, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Tenses, Pronoun, Verb, Adverb, Preposition, Articles, Determiner, Conjunction, Modals, Active Passive Voice (Voice), Direct and Indirect Speech, Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Construction, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Verbal Analogy (Word Based Analogy), Facts, Inference and Judgements
  6. Section 2 | Primary Maths & Reasoning: Ratio and Proportion (Ratios), Divisibility Rules, Mixture and Alligation, Permutation and Combination, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Percentage, Average, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Mensuration and Geometry, Age Problems, Arithmetic, Powers and Exponents (Surds and Indices), Algebra, Probability, Trigonometry, Syllogisms, Seating Arrangements, Blood Relations, Directions (Direction Test), Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Venn Diagram, Data Arrangement, Inequality, Analogy, Ranking, Order and Sequence
  7. Section 2 | General Awareness (GK + Current Affairs): Polity, Physics, Biology, State Wise GK, Chemistry, History, Geography, Indian Economy, Environment, GK- Current Affairs, Static General Knowledge
  8. Section 3 | Computer System and Org. (CSO): Basics of COA, Floating Point Rep, Cache Memory Organization, Instr Formats & Modes, Programming the Basic Computer, Input Output Organisation, Register Transfer and Microoperations, Control Unit Design
  9. Section 3 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, SQL, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control
  10. Section 3 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Process Synchronization
  11. Section 3 | Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics
  12. Section 3 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Minimum Spanning Trees, Shortest Path Algos
  13. Section 3 | Theory Of Computation & Compiler Design: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization
  14. Section 3 | Emerging Trends (AI, Societal Ethics & MS Office): Artificial Intelligence, Emerging Tech Trends, Society, Law & Ethics, MS Office Applications
  15. Section 3 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Maintenance and Configuration Management, Software Testing
  16. Section 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  17. Section 3 | OOPS, C++, JAVA, HTML: OOPS with C++, Java, HTML Basics, CSS
  18. Section 3 | Java: Java Fundamentals, Array, String, IO & References
  19. Section 3 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  20. Section 3 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  21. Section 3 | Multimedia: Multimedia
  22. BPSC Previous Year Papers:
  23. BPSC Full Mock Tests:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The video lecture analyzes a C function named `what` that performs a tree traversal. The instructor displays the code and draws a binary tree to trace the function's execution. He explains the recursive calls and the base case, then determines the output sequence. The final result is identified as a Post-Order Traversal, with the output sequence 10 8 9 5 12.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a programming problem displayed at the top: "Find what this function is doing?". The code snippet `void what(struct Bnode *t)` is shown in orange text on the left side. The instructor uses a digital pen to underline the function name `what` and the parameter `t`, emphasizing the recursive nature of the function. He explains the `if (t)` condition, which serves as the base case to prevent null pointer dereferencing. He then begins to draw a binary tree on the whiteboard space to the right. He draws a root node containing the value 12. From this root, he draws a left edge to a node with value 10 and a right edge to a node with value 5. This visual setup is crucial for understanding how the function traverses the data structure. The instructor's gestures guide the viewer's attention to the code and the diagram simultaneously. The background is white with a faint watermark "KnowledgeGate". The instructor is visible in the bottom right corner, wearing a black shirt. The code includes a `printf` statement which is not yet explained. The instructor's focus is on the code structure. The text "Find what this function is doing?" is clearly visible. The instructor's hand movements are deliberate.

  2. 2:00 – 5:00 02:00-05:00

    Continuing the diagram, the instructor adds the remaining nodes to the binary tree. Node 5 is shown to have a left child with value 8 and a right child with value 9. He starts the execution trace by writing `what(12)` at the top right. He explains that the function first calls itself on the left child, so he writes `what(10)`. He traces further down, noting that node 10 has no children, so he writes `w(NULL)` for both its left and right children. He moves to the right subtree, tracing `what(5)`. He then traces `what(8)` and writes `w(NULL)` for its children. Similarly, he traces `what(9)` and writes `w(NULL)` for its children. This detailed tracing shows the depth-first approach of the recursion. The instructor writes these calls in black ink, contrasting with the orange code. The tree structure is now fully drawn, showing a complete binary tree with 5 nodes. The instructor is methodically tracing the path of execution. The visual representation of the tree is key to understanding the recursion. The instructor's handwriting is legible. The tree nodes are clearly labeled with numbers.

  3. 5:00 – 7:37 05:00-07:37

    The instructor completes the execution trace by determining the order in which the `printf` statement executes. Since the print statement comes after the recursive calls, it executes when the recursion unwinds. He writes the final output sequence at the bottom: 10 8 9 5 12. He circles the `printf` line in the code to highlight that this is the action performed. He explicitly states that this traversal order, visiting the left subtree, then the right subtree, and finally the root, is known as Post-Order Traversal. He draws a green box around the final output sequence to emphasize the result. The video concludes with a clear explanation of the function's purpose, linking the code structure to the traversal algorithm. The final output is clearly visible in a green box at the bottom left. The instructor points to the code and the output to reinforce the connection. The code lines `what(t -> LC)` and `what(t -> RC)` are clearly visible. The instructor's explanation ties the visual trace to the theoretical concept. The green box is a strong visual cue. The instructor's final summary is clear.

The video provides a step-by-step analysis of a recursive C function that traverses a binary tree. By drawing the tree and tracing the function calls, the instructor demonstrates that the function performs a Post-Order Traversal. The key takeaway is that the root node is processed after its left and right subtrees, resulting in the output sequence 10 8 9 5 12 for the given tree structure.

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