Tree Traversal Pseudocode PQ
Duration: 6 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
Module outline
- About the Course: About the Course
- 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
- Section 1 | Language (उर्दू भाषा — 22 प्रश्न (निश्चित)): Spelling & Diacritics, Grammar (اسم, فعل, صفت, ضمیر), Vocabulary, Idioms & Proverbs, Comprehension
- Section 1 | Language (বাংলা / बांग्ला भाषा — 22 प्रश्न (निश्चित)): শব্দার্থ, বাগধারা ও ভাষাশুদ্ধি / Meaning, Idioms and Correct Usage, বাক্য ও বাচ্য / Sentences and Voice, শব্দগঠন ও শব্দভান্ডার / Word Formation and Vocabulary, অনুবাদ, বোধপরীক্ষণ ও রচনা / Translation, Comprehension and Composition
- 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
- 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, Number System & Place Value, Factors, Multiples, Divisibility, HCF & LCM, Coordinates & Graphs, Higher Mathematics — Trigonometry, Quadratics, Polynomials, Progressions, Statistics, Logarithms
- 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
- 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
- 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
- Section 3 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Process Synchronization
- 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
- 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
- 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
- Section 3 | Emerging Trends (AI, Societal Ethics & MS Office): Artificial Intelligence, Emerging Tech Trends, Society, Law & Ethics, MS Office Applications, Marketing and Consumer Studies, साइबर सुरक्षा / Cyber Safety and Security, कंप्यूटर सॉफ़्टवेयर / Computer Software, ऑपरेटिंग सिस्टम / Operating System, कंप्यूटर नेटवर्क / Computer Networks, वर्ड प्रोसेसिंग (MS Word) / Word Processing (MS Word), Terms & Abbreviations, प्रेज़ेंटेशन (MS PowerPoint) / Presentation Software (MS PowerPoint)
- 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
- Section 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
- Section 3 | OOPS, C++, JAVA, HTML: OOPS with C++, Java, HTML Basics, CSS
- Section 3 | Java: Java Fundamentals, Array, String, IO & References, OOPS with Java
- 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
- Section 3 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
- Section 3 | Multimedia: Multimedia
- BPSC Previous Year Papers:
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AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
This educational video provides a detailed step-by-step walkthrough of tracing the execution of two mutually recursive functions, A and B, operating on a binary tree data structure. The instructor begins by presenting the C-like pseudocode for both functions and a sample binary tree. He then manually simulates the function calls, drawing a call tree to visualize the recursion depth and order. The primary goal is to determine the sequence of integers printed to the console by the printf statements within the functions. The video serves as a practical example of understanding recursion and function call stacks in computer science, specifically focusing on how two functions can call each other. The instructor uses a whiteboard or digital canvas to draw the tree and the call stack.
Chapters
0:00 – 2:00 00:00-02:00
The video starts with the problem statement: "Find what this function is doing?" The code for Void A(struct Bnode *t) and Void B(struct Bnode *t) is displayed on the screen. Function A is defined to recursively call B on the left child, print the current node's data, and then call B on the right child. Conversely, Function B prints the current node's data, then recursively calls A on the left child, and finally calls A on the right child. The instructor draws a binary tree with root 10, left child 30, right child 30, and a left child of the left 30 which is 40. He initiates the trace by calling A(10) and explains the initial steps of the recursion, setting up the context for the detailed trace. He carefully follows the indentation and logic flow.
2:00 – 5:00 02:00-05:00
The instructor meticulously traces the execution on the right side of the screen, drawing a tree of function calls to keep track of the state. Starting with A(10), it calls B(30) (left child). Inside B(30), it prints 30. Then it calls A(40) (left child of 30). Inside A(40), it calls B(NULL) (left child of 40), which returns immediately because the node is null. Then A(40) prints 40. Then A(40) calls B(NULL) (right child of 40), which returns. A(40) returns. Back in B(30), it calls A(NULL) (right child of 30), which returns. B(30) returns. Back in A(10), it prints 10. Then it calls B(30) (right child of 10). Inside this B(30), it prints 30. Then it calls A(NULL) (left child) and A(NULL) (right child), both returning immediately. The instructor writes the final output sequence in a green box: 30 40 10 30. He underlines the printed values as he goes. He writes the numbers 30, 40, 10, 30 in a box at the bottom.
5:00 – 5:36 05:00-05:36
The instructor concludes the lesson by reviewing the code structure one last time. He highlights the mutual recursion where A calls B and B calls A. He points out the specific lines of code responsible for the printing and the recursive calls, emphasizing the order of operations. He confirms that the output sequence 30 40 10 30 is correct based on the trace. He emphasizes understanding the order of execution in mutually recursive functions and how the call stack unwinds. The video ends with the final answer clearly displayed and the instructor summarizing the key takeaway about the traversal order. The instructor ensures the student understands the base case where the node is null.
The video effectively demonstrates the concept of mutual recursion through a concrete example. By tracing the execution of functions A and B on a binary tree, the instructor clarifies how the call stack operates when functions call each other. The step-by-step visual aid of drawing the call tree helps students understand the order of operations and the final output sequence. This method is crucial for debugging and understanding complex recursive algorithms in computer science.