Practice Question

Duration: 4 min

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Inside: a video lesson and guided study material.

Module outline

  1. About Course: About the Course
  2. Paper 1 | General Studies: State Wise GK
  3. Paper 1 | Information and Communication Technology: Role of Internet and Web Services, Security in Mobile and Wireless Computing
  4. Paper 1 | Current Affairs: GK- Current Affairs
  5. Paper 2 | Discrete Mathematical Structure: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic, Probability
  6. Paper 2 | Digital Computer Organization And Architecture: Number System, Number Representation, Sequential Circuits, Combinational Circuit, Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Register Transfer and Microoperations, Control Unit Design, Programming the Basic Computer
  7. Paper 2 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  8. Paper 2 | Programming Languages & Object-Oriented Programming Concepts: Java, OOPS with C++, Java Fundamentals, Array, String, IO & References
  9. Paper 2 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  10. Paper 2 | Data Structure And Algorithms: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Minimum Spanning Trees, Advanced Algorithms
  11. Paper 2 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Unix OS
  12. Paper 2 | 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
  13. Paper 2 | 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
  14. Paper 2 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Algebra, SQL, Transaction Management, Concurrency Control, Database Recovery, Database Security & Authorization, Enhanced Data Models
  15. Paper 2 | Computer Network And Information Security: Introduction to CN, Data Communication, Application Layer, Hardware basics, Cyber Threats and Malware Attacks, Network Security, 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
  16. Paper 2 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  17. Paper 2 | Current Trends & Technologies: Emerging Tech Trends, Approaches to AI, Search Algorithms, Game Playing, Knowledge Representation, Planning, Multi Agent Systems, Fuzzy Sets, Natural Language Processing, Artificial Neural Networks, Genetic Algorithms, Artificial Intelligence, Data Warehousing & Mining, Electronic Data Interchange and E-Commerce, Terms & Abbreviations
  18. Paper 2 | Full Length Mock Tests:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The lecture focuses on converting a non-deterministic context-free grammar into a deterministic one using the left factoring technique. The problem statement presents the grammar S -> aAb / aABc / aABcd / aA / a. The instructor explains that this grammar is non-deterministic because multiple productions begin with the terminal 'a', creating ambiguity for a predictive parser. He systematically applies left factoring to resolve this. The process involves identifying common prefixes, extracting them into new non-terminals, and repeating the process until no common prefixes remain among the alternatives of any non-terminal. The final output is a set of productions where each rule starts with a unique terminal, ensuring determinism.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor begins by analyzing the initial grammar S -> aAb / aABc / aABcd / aA / a. He identifies 'a' as the common prefix for all productions. He rewrites the rule as S -> aS'. The alternatives for S' are derived by removing the 'a': Ab, ABc, ABcd, A, and epsilon (representing the original a production). He then observes that Ab, ABc, ABcd, and A all start with the non-terminal 'A'. He factors out 'A' to create S' -> AS'' / epsilon. Next, he looks at S'' alternatives: b, Bc, Bcd, epsilon. He identifies 'B' as a common prefix for Bc and Bcd, rewriting S'' as S'' -> BS''' / b / epsilon. This window establishes the hierarchical structure of the factored grammar.

  2. 2:00 – 3:33 02:00-03:33

    The instructor finalizes the grammar by factoring the remaining alternatives for S'''. The current alternatives are c and cd. He identifies 'c' as the common prefix and introduces a new non-terminal S''''. He writes S''' -> cS''''. The new non-terminal S'''' handles the suffixes: epsilon (for the c case) and d (for the cd case), written as S'''' -> epsilon / d. He then organizes the final grammar by numbering the productions: 1. S -> aS', 2. S' -> AS'' / epsilon, 3. S'' -> BS''' / b / epsilon, 4. S''' -> cS'''', 5. S'''' -> epsilon / d. He reviews these steps to ensure the grammar is now deterministic and free of left recursion or common prefixes.

The video effectively demonstrates the iterative nature of left factoring. By breaking down the grammar into layers of non-terminals (S', S'', S''', S''''), the instructor removes ambiguity at each level. The final grammar is suitable for LL(1) parsing because the FIRST sets of the alternatives for each non-terminal are disjoint. This transformation is a fundamental step in compiler design for constructing efficient parsers.

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