Practice Questions

Duration: 6 min

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Module outline

  1. Quantitative Aptitude: Ratio and Proportion (Ratios), Data Interpretation, Mixture and Alligation, Permutation and Combination, Number System, Sequence and Series (Series), Speed Time and Distance, Speed Mathematics and Basic Mathematics, Algebra, Percentage, Profit and Loss, Simple Interest and Compound Interest, Powers and Exponents (Surds and Indices), Time and Work, Mensuration and Geometry, Partnership
  2. Reasoning Ability: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Seating Arrangements, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Directions (Direction Test), Ranking, Order and Sequence, Syllogisms, Blood Relations, Puzzle Solving (Puzzles), Inequality, Machine Input-Output
  3. English Language: Vocabulary, Noun, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Tenses, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Sentence Construction, Pronoun, Preposition, Conjunction, Adverb, Verb, Modals, Articles, Determiner, Interjection
  4. General Awareness: Evolution of Indian Banking (Banking & Financial Awareness), GK- Current Affairs, Static General Knowledge, Indian Economy
  5. C Concepts + MCQs (IT Specialist): C Programming by Yash Sir, C Language Core
  6. Java (IT Specialist): Java
  7. Python (IT Specialist): Python for Placements by Yash Sir, Python Basics
  8. OOPs (IT Specialist): Object Oriented Programming (OOPS)
  9. DBMS (IT Specialist): Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, ORDBMS, Database Security & Authorization, Query Processing & Optimization, Enhanced Data Models, Data Warehousing & Mining, Big Data Systems, NoSQL
  10. SQL (IT Specialist): SQL
  11. Software Engineering (IT Specialist): Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  12. Data Structure (IT Specialist): Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  13. Operating System (IT Specialist): Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS, Linux OS, Security, Distributed Systems, Virtual Machines
  14. Compiler Design (IT Specialist): 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
  15. Computer Architecture (IT Specialist): Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations, Multiprocessors, Programming the Basic Computer
  16. Data Communication & Networking (IT Specialist): 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
  17. Descriptive Test (Main Exam): English Writing Ability
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

  1. 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. 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.

  3. 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.

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