Prefix and suffix

Duration: 3 min

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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, समुच्चय, संबंध, फलन और विविक्त गणित / Sets, Relations, Functions and Discrete Mathematics, व्यापार, विपणन एवं उपभोक्ता संरक्षण / Trade, Marketing and Consumer Protection, कंप्यूटर नेटवर्क / Computer Networks
  13. Digital Society & Cyber Law: Society, Law & Ethics, साइबर सुरक्षा / Cyber Safety and Security
  14. HPSC PGT Previous Year Paper:
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  17. Full Mock Test:
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AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The lecture focuses on string theory concepts, specifically calculating the number of prefixes and suffixes for a given string. The instructor uses the example string 'GATE' to demonstrate the enumeration process. He systematically lists all possible prefixes starting from the empty string (epsilon) up to the full string itself. Similarly, he lists all suffixes, ending with the full string. The core takeaway is establishing a general formula relating the length of a string to the count of its prefixes and suffixes. This is a fundamental concept in automata theory and formal languages.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor poses the question: 'Consider a string 'GATE' find the total number of prefix and suffix possible?' He begins by writing out the set of prefixes for 'GATE' on the whiteboard. He writes Prefix(GATE) = { epsilon, G, GA, GAT, GATE }. He counts these elements, noting there are 5 distinct prefixes. Next, he moves to suffixes, writing Suffix(GATE) = { epsilon, E, TE, ATE, GATE }. He again counts these, finding 5 distinct suffixes. He writes n -> n and n -> n+1 on the board, hinting at a relationship between string length and count. He writes GATE and lists G, GA, GAT, GATE to reinforce the concept of proper prefixes versus the full string.

  2. 2:00 – 2:48 02:00-02:48

    The instructor concludes the example by generalizing the observation. A text slide appears stating: 'If there is a string of length n then no of prefix or suffix will be n+1'. He verbally confirms that for 'GATE', which has a length of 4, the number of prefixes is 4 + 1 = 5. This establishes the fundamental rule that a string of length n always has n+1 prefixes and n+1 suffixes, including the empty string and the string itself. He emphasizes that this rule applies universally to any string of length n.

The lesson progresses from a specific example to a general rule. By manually enumerating the prefixes and suffixes of 'GATE', the instructor illustrates that the count includes the empty string. This leads to the derivation of the formula n+1, where n is the string length. This concept is foundational for understanding string properties in computer science and formal language theory, particularly in the context of finite automata and regular expressions.

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