Prefix and suffix
Duration: 3 min
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Inside: a video lesson and guided study material.
Module outline
- Discrete Mathematics: Permutation, Combination and Probability / क्रमचय, संचय एवं प्रायिकता, Set Theory, Relations, Functions, Propositional and Predicate Logic, Graph Theory, Group Theory
- Digital Logic: Digital Systems & Boolean Basics, Boolean Expression, Boolean Minimization, Logic Gates & Hardware, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Floating Point Rep
- Computer Organization and Architecture: Basics of COA, Programming the Basic Computer, Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Register Transfer and Microoperations, Control Unit Design, Pipelining, Multiprocessors
- Programming: Language Design, C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, OOPS with C++
- Data Structures: Introduction to DS, Array, Linked List, Stack, Queue, Tree, Graphs, Hashing
- Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
- Theory of Computation: Grammar, Regular Language Properties, Moore & Mealy Machines, Turing Machines
- 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, Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Pushdown Automata & CFG, Complexity Theory
- Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Unix OS, Linux OS, Security
- Database Management Systems: 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, ORDBMS, NoSQL
- Computer Networks: 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
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
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.
2:00 – 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.

