DFA Designing sting where number of a =0(mod3)

Duration: 3 min

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Module outline

  1. About Course: About the Course
  2. English Language: Vocabulary, Noun, Adjectives, Tenses, Pronoun, Adverb, Preposition, Conjunction, Active Passive Voice (Voice), Articles, Direct and Indirect Speech, Sentence Correction (Error Correction), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Sentence Completion (Fill in the blanks), Cloze Test (Cloze Passage)
  3. Reasoning: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Puzzle Solving (Puzzles), Seating Arrangements, Blood Relations, Syllogisms, Inequality, Directions (Direction Test), Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Clock, Calendar, Analytical Reasoning (Counting Figures Reasoning), Selection Decision Table (Decision Making), Cubes & Dices, Machine Input-Output
  4. Quantitative Aptitude: Ratio and Proportion (Ratios), Data Interpretation, Mixture and Alligation, Permutation and Combination, Number System, Sequence and Series (Series), Speed Time and Distance, Algebra, Speed Mathematics and Basic Mathematics, Percentage, Average, Time and Work, Simple Interest and Compound Interest, Profit and Loss, Age Problems, Partnership, Mensuration and Geometry, Probability, IBPS Specific Videos
  5. Data Structures - Professional Knowledge: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  6. Algorithms- Professional Knowledge: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos
  7. Python- Professional Knowledge: Python for Placements by Yash Sir, Python Basics
  8. Operating System- Professional Knowledge: Introduction to OS, Process Management, CPU Scheduling, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management
  9. DBMS + SQL- Professional Knowledge: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), File Organization & Indexing, SQL, Transaction Management, Concurrency Control
  10. Computer Networks- Professional Knowledge: Introduction to CN, Data Communication, Net Layer: IP Addressing, Net Layer: IPv4 & Proto, Application Layer, Hardware basics, Network Security
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  12. Computer Organization & Microprocessor- Professional Knowledge: Basics of COA, Cache Memory Organization, Programming the Basic Computer
  13. Digital Logic Design- Professional Knowledge: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  14. Theory of Computation- Professional Knowledge: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Regular Language Properties, Pushdown Automata & CFG, Turing Machines
  15. Compiler Design- Professional Knowledge: Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Intermediate Code Gen, Code Optimization
  16. Programming Languages- Professional Knowledge: C Programming by Yash Sir, Object Oriented Programming (OOPS), Programming in C++, Java, C Language Core
  17. Emerging Tech- Professional Knowledge: Emerging Tech Trends
  18. Artificial Intelligence: Artificial Intelligence
  19. Unit Test - Professional Knowledge:
  20. Full Length Mock Test:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The video presents a lecture on designing minimal Deterministic Finite Automata (DFA) for specific string conditions over the alphabet $\Sigma = \{a, b\}$. The instructor outlines four distinct problems involving modular arithmetic constraints on the count of 'a's and 'b's. He systematically constructs state diagrams for each condition, demonstrating how to track remainders using states and transitions. The lecture focuses on the independence of character counts in these specific modular problems, showing how to handle 'a' and 'b' transitions separately to satisfy the required modulo conditions.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor begins by listing four conditions on the whiteboard: i) $|w|_a = 0 \pmod 2$, ii) $|w|_b = 1 \pmod 2$, iii) $|w|_a = 2 \pmod 3$, and iv) $|w|_a = 1 \pmod 4$. He starts with the first two conditions. For condition (i), he draws two states, $q_0$ and $q_1$, representing even and odd counts of 'a'. He draws transitions $q_0 \xrightarrow{a} q_1$ and $q_1 \xrightarrow{a} q_0$, adding self-loops for 'b' on both states. Next, he addresses condition (ii), drawing states for even and odd counts of 'b'. He draws transitions $q_0 \xrightarrow{b} q_1$ and $q_1 \xrightarrow{b} q_0$, adding self-loops for 'a'. He marks the start state with an incoming arrow and the state with an odd number of 'b's as the final state with a double circle.

  2. 2:00 – 3:19 02:00-03:19

    The instructor proceeds to condition (iii), where the number of 'a's must be congruent to 2 modulo 3. He draws three states labeled $q_0, q_1, q_2$ to represent remainders 0, 1, and 2. He draws a cycle of transitions for 'a': $q_0 \xrightarrow{a} q_1 \xrightarrow{a} q_2 \xrightarrow{a} q_0$. He adds self-loops for 'b' on all three states and marks $q_2$ as the final state. Finally, he tackles condition (iv), requiring the number of 'a's to be congruent to 1 modulo 4. He draws four states $q_0, q_1, q_2, q_3$ and creates a cycle for 'a' transitions. He adds self-loops for 'b' on all states and marks $q_1$ as the final state. Throughout this section, he emphasizes that these are separate problems.

The lecture effectively demonstrates the standard method for constructing DFAs based on modular arithmetic constraints. By treating the count of each character independently, the instructor shows how to create minimal state machines where states represent remainders. The visual progression from 2 states to 3 and then 4 states clearly illustrates the relationship between the modulus and the number of required states. This approach is fundamental for solving regular language problems involving counting. It highlights the direct mapping between the modulus value and the state count.

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