Practice Questions

Duration: 2 min

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Inside: a video lesson and guided study material.

Module outline

  1. HPSC Interview Preparation: Interview Preparation
  2. Python Language: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis, DSA using Python
  3. Data Structure & Algorithms: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Sorting Algorithms, Minimum Spanning Trees, Time Complexity Analysis, Graph Theory, Shortest Path Algos
  4. Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security
  5. Computer System & Organisation: Basics of COA, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Programming the Basic Computer
  6. 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, Transaction Management, Concurrency Control
  7. Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling
  8. Digital Logic & Circuits: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  9. Theory Of Computation: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Pushdown Automata & CFG, Turing Machines, Moore & Mealy Machines
  10. 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
  11. Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management, Data Warehousing & Mining
  12. Introduction to Emerging Trends: Emerging Tech Trends
  13. Digital Society & Cyber Law: Society, Law & Ethics
  14. HPSC PGT Previous Year Paper:
  15. HPSC Assistant Professor Previous Year Paper:
  16. Live Sessions: HPSC Live Sessions, EMRS TGT/PGT Live Class
  17. Full Mock Test:
  18. HPSC PGT - MOCK Test Series:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video provides a step-by-step tutorial on eliminating left recursion from Context-Free Grammars (CFGs), a crucial step in compiler design and parsing theory. The instructor begins with the grammar `S -> SSS / 0`. He identifies `S -> SSS` as the left-recursive production and `S -> 0` as the non-recursive alternative. By applying the standard algorithm, he introduces a new non-terminal `A'` to handle the recursion. The original start symbol `S` is rewritten as `S -> 0A'`, while the new non-terminal `A'` is defined by the recursive part `SS` followed by `A'`, plus the epsilon production: `A' -> SSA' / epsilon`.

Next, the instructor moves to a slightly more complex example: `S -> S0S1 / 0 / 1`. He underlines the recursive `S` in `S0S1` to identify `alpha` as `0S1`. The non-recursive parts `0` and `1` become `beta`. The transformation yields `S -> 0S' / 1S'` and `S' -> 0S1S' / epsilon`.

Finally, the lecture addresses a grammar with multiple non-terminals: `S -> A a B`, `A -> A a / b B / a`, and `B -> b B / c`. The focus shifts to eliminating left recursion from `A`. The instructor isolates the recursive production `A a` (where `alpha` is `a`) and the non-recursive productions `b B` and `a` (where `beta` is `b B` and `a`). He writes the new rules: `A -> b B A' / a A'` and `A' -> a A' / epsilon`.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with the instructor analyzing the grammar `S -> SSS / 0`. He underlines the first `S` in `SSS` to mark the recursive part, labeling it `A`. He then constructs the transformed rules `S -> 0A'` and `A' -> SSA' / epsilon`. Moving to the next example, `S -> S0S1 / 0 / 1`, he underlines the recursive `S` and writes `S -> 0S' / 1S'` and `S' -> 0S1S' / epsilon`. He then transitions to a multi-rule grammar, underlining `A` in `A -> A a / b B / a` to identify the recursive component `a` and the non-recursive components `b B` and `a`.

  2. 2:00 – 2:20 02:00-02:20

    The instructor finalizes the left-recursion elimination for the non-terminal `A`. He formulates the new production rules `A -> b B A' / a A'` and `A' -> a A' / epsilon` on the whiteboard. The original grammar `S -> A a B`, `A -> A a / b B / a`, and `B -> b B / c` remains visible as he concludes this segment, setting the stage for the next step involving non-terminal `B`.

The lecture systematically applies the left-recursion elimination algorithm to three distinct grammars. It progresses from simple unary recursion to mixed recursion and finally to a multi-non-terminal grammar, illustrating how to isolate recursive and non-recursive productions to construct equivalent right-recursive forms.

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