Tree method for conversion
Duration: 3 min
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Module outline
- General Intelligence & Reasoning: Analogy, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Logical Sequence Of Words, Syllogisms, Venn Diagram, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Data Sufficiency, Puzzle Solving (Puzzles), Data Arrangement, Cubes & Dices, Calendar, Clock, Arithmetic, Number System, HCF LCM, Verbal Analogy (Word Based Analogy), Visual Recognition and Figure Completion, Paper Folding and Cutting, Transformation of Shapes, Clocks and Calendars, Direction Sense, Cubes and Dice, Patterns in Two-Dimensional Figures, Seating Arrangements, Analogy and Classification, Logical Deduction and Induction, Alphabet and Word Tests, Mathematical Operations, Series Completion, Simplification and Approximation, Coding and Decoding, Numerical Reasoning, Assembling and Grouping of Shapes, Three-Dimensional Patterns and Visualization, Vocabulary, Number System, Averages, Mixtures and Alligation, Simple and Compound Interest, Percentages, Algebra, Speed, Time and Distance, Seating and Arrangement Puzzles, Traverse Surveying, Order, Ranking and Sequence, Constraint Puzzles, Syllogisms and Venn Diagrams, Reading Comprehension, Critical Reasoning, Permutations and Combinations, Narrative Sequencing, Project Monitoring, Resources and Safety, Profit, Loss and Discount, Ratio and Proportion, Time and Work, Mensuration, Data Interpretation, Powers, Surds and Logarithms, Sequences and Series, Articles and Determiners, Sentence Completion, Data Sufficiency, Blood Relations, Simple Interest and Compound Interest, Mixture and Alligation, Sequence and Series (Series), Speed Time and Distance, Algebra, Profit and Loss, Powers and Exponents (Surds and Indices), Permutation and Combination
- General Awareness: Physics, Chemistry, Biology, History, Geography, Polity, Indian Economy, Environment, Static General Knowledge, GK- Current Affairs, Artificial Intelligence, MS Office Applications, Terms & Abbreviations, Keyboard Shortcuts, Evolution of Indian Banking (Banking & Financial Awareness), Emerging Tech Trends
- Engineering Mathematics: Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic, Linear Algebra, Calculus, Probability, Statistics, Signal Space and Optimum Detection, Probability, Statistics
- Digital Logic: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Floating Point Rep, Number Systems and Codes, Registers and Counters, Boolean Algebra and Logic Gates, Microprocessors and Microcontrollers, Logic Families and CMOS Logic, Microprocessors, Logic Gates and Boolean Algebra, Minimization of Boolean Functions, Timing, Hazards and Testing, Logic Families, Combinational Logic Design, Arithmetic Circuits, Waveform Generators and Timer Circuits, Semiconductor Memories and Programmable Logic Devices, Combinational Logic Circuits, Latches and Flip-Flops, Finite State Machines, Sequential Circuits and State Machines, Minimization of Boolean Functions, Arithmetic Circuits, Latches and Flip-Flops, Number Systems and Codes, Registers and Counters
- Computer Organisation & Architecture: Basics of COA, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Programming the Basic Computer, Register Transfer and Microoperations, Semiconductor Memories and Programmable Logic, Processor Organization and Instructions, Memory Hierarchy and Input/Output, Registers and Counters
- Programming & Data Structures: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, HTML Basics, OOPS with C++, Java, Object Oriented Technology
- Databases: 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, Database Recovery, Database Security & Authorization
- Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos
- Theory of Computation: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Complexity Theory
- 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
- Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Security, Windows OS, Distributed Systems, Unix OS, Linux OS
- Computer Networks: Introduction to CN, 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, Data Communication, Website, Browser & Services, Web Design & Development, Network Security, Cyber Threats and Malware Attacks, Cyber Safety and Security
- Full Length Mock Tests:
- Sectional Tests:
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
This educational video features a lecture by Sanchit Jain from KnowledgeGate, focusing on converting an infix expression to postfix notation. The specific problem is from the GATE 2004 exam. The instructor systematically breaks down the expression `a + b * c - d ^ e ^ f` by constructing an expression tree based on operator precedence and associativity rules. He emphasizes that `+`, `-`, and `*` are left-associative, while `^` is right-associative, with precedence order `^` > `*` > `+` > `-`. The lecture demonstrates how to traverse the tree in post-order to derive the final postfix string.
Chapters
0:00 – 2:00 00:00-02:00
The instructor introduces the problem statement written on the whiteboard: convert the infix expression `a + b * c - d ^ e ^ f` to postfix. He lists the operator properties, noting that `+`, `-`, `*` are left-associative and `^` is right-associative. The precedence order is established as `^` (highest), `*`, `+`, `-` (lowest). He begins constructing the expression tree by identifying the operator with the lowest precedence, which is `-`. This splits the expression into a left sub-expression `a + b * c` and a right sub-expression `d ^ e ^ f`. He then recursively analyzes the left side, identifying `+` as the root for that section, separating `a` and `b * c`. The `b * c` part is resolved with `*` as the operator. Moving to the right side, he highlights the right associativity of `^`, explaining that `d ^ e ^ f` is grouped as `d ^ (e ^ f)`. This dictates that the first `^` is the root of the right subtree, with `d` as the left child and the second `^` as the right child.
2:00 – 3:12 02:00-03:12
The instructor completes the expression tree diagram on the board. The root is `-`. The left child is `+`, with `a` as its left child and `*` as its right child (which has `b` and `c` as children). The right child of the root is the first `^`, with `d` as its left child and the second `^` as its right child (which has `e` and `f` as children). He then performs a post-order traversal (Left, Right, Root) to generate the postfix expression. For the left subtree, the traversal yields `abc*+`. For the right subtree, the traversal yields `def^^`. Combining these parts with the root operator `-`, the final postfix expression is `abc*+def^^-`. He compares this result with the multiple-choice options, identifying Option (A) `abc x + def ^ ^ -` as the correct answer. He explicitly points out that Option (B) would be correct if `^` were left-associative, reinforcing the importance of the associativity rule.
The video provides a clear, step-by-step method for converting infix expressions to postfix notation using expression trees. The key learning points are the hierarchy of operator precedence and the impact of associativity on tree structure. Specifically, the right associativity of the exponentiation operator `^` causes the rightmost operator to become a child of the leftmost operator of the same precedence, resulting in the postfix sequence `def^^` rather than `de^f^`. This systematic approach ensures accurate conversion for complex expressions involving mixed operators.

