Practice Questions
Duration: 6 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
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:
- Paper 2 - Full-length Mock Tests:
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
The video lecture provides a comprehensive guide on removing left recursion from Context-Free Grammars (CFGs), a fundamental requirement for constructing top-down parsers like recursive descent parsers. The instructor begins with the standard algorithm for immediate left recursion, demonstrating it on a classic arithmetic expression grammar. He then advances to more complex scenarios, including ambiguous grammars and indirect left recursion, illustrating how to substitute non-terminals to expose hidden recursion before applying the elimination technique. The visual board work clearly shows the step-by-step transformation of production rules, making the abstract process concrete for students.
Chapters
0:00 – 2:00 00:00-02:00
The instructor introduces a grammar with immediate left recursion: E -> E + T / T, T -> T * F / F, F -> (E) / id. He identifies E -> E + T as the source of left recursion. He applies the standard transformation algorithm: E -> T E' and E' -> + T E' / epsilon. Similarly, he transforms T -> F T' and T' -> * F T' / epsilon, while keeping F -> (E) / id unchanged. This section establishes the foundational method for eliminating immediate left recursion by factoring out the recursive part into a new non-terminal E'. The board clearly displays the original grammar in orange and the transformed grammar in blue. The instructor underlines the recursive part.
2:00 – 5:00 02:00-05:00
The lecture progresses to a more ambiguous grammar: E -> E + E / E * E / (E) / id. The instructor rewrites this to remove left recursion, resulting in E -> (E) E' / id E' and E' -> + E E' / * E E' / epsilon. He then tackles another example: R -> R * / R R / (R) / id. He transforms it into R -> (R) R' / id R' and R' -> * R' / R R' / epsilon. Finally, he addresses a list grammar: S -> (L) / a, L -> L, S / S. He transforms L into L -> S L' and L' -> , S L' / epsilon to remove the left recursion in L, ensuring the grammar is no longer left-recursive. The instructor uses underlining to highlight the recursive parts of the productions.
5:00 – 5:38 05:00-05:38
The final example involves indirect left recursion: S -> A a B, A -> S A c / a, B -> B a / b. The instructor substitutes S into A, revealing A -> A a B A c / a. He then removes left recursion from A, resulting in A -> a A' and A' -> a B A c A' / epsilon. He then substitutes A back into S. Alternatively, he substitutes A into S to get S -> S A c a B / a a B, then removes left recursion from S, resulting in S -> a a B S' and S' -> A c a B S' / epsilon. He also handles B -> B a / b by transforming it to B -> b B' and B' -> a B' / epsilon. The board shows the substitution process clearly. He underlines the recursive parts.
The lesson systematically builds from simple immediate left recursion to complex indirect cases. By substituting non-terminals, hidden left recursion is exposed and then eliminated using the standard algorithm, ensuring the grammar is suitable for recursive descent parsers. The visual progression on the whiteboard reinforces the logical steps required for each transformation, providing a clear roadmap for students to follow when dealing with similar grammatical structures in their own studies.

