CA 1 PRESENTATION
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    NAME:Sumit Prasad
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    ROLL NO:10200223053
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    SUBJECT:FORMAL LANGUAGE AND & AUTOMATA
    THOERY
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    SUBJECT CODE:PCC-CS403
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    TOPIC:CONSTRUCT A DFA THAT ACCEPTS ALL
    BINARY STRINGS EXCEPT ‘000’ AND ‘111’.
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    BRANCH:IT
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    SEM:4TH
                                             1
                 Introduction
• Deterministic Finite Automata (DFA) is a
  theoretical machine used to recognize patterns in
  strings.
                                                      2
             Problem Statement
• Construct a DFA that accepts all binary strings
  except '000' and '111'.
                                                    3
           Basic Concepts of DFA
•   A DFA consists of:
•   - A finite set of states
•   - An alphabet (Σ={0,1})
•   - A transition function
•   - An initial state
•   - A set of accepting states
                                   4
   Understanding the Exclusions
• The DFA must reject '000' and '111', meaning it
  should track the last three bits of the string.
                                                    5
         State Diagram Concept
• A state diagram represents how the DFA
  transitions between states based on inputs.
                                                6
           State Representation
• Each state should store the last three bits
  processed to detect '000' and '111'.
                                                7
  Transition Table
• A transition table helps
  in defining how the
  DFA moves from one
  state to another based
  on input symbols.
                             8
   State Diagram
• The DFA will have
  transitions that ensure
  it rejects '000' and
  '111' while accepting
  all other strings.
                            9
       Explanation of Transitions
• Each transition ensures the last three bits are
  checked, moving to accepting or rejecting states.
                                                      10
         Testing with Examples
• Example 1: 101 (Accepted)
• Example 2: 000 (Rejected)
• Example 3: 1101 (Accepted)
                                 11
          Minimization of DFA
• The DFA can be optimized by merging equivalent
  states to reduce complexity.
                                                   12
           Real-world Applications
•   DFAs are used in:
•   - Lexical analysis in compilers
•   - Pattern matching
•   - Network protocol design
                                      13
                  Conclusion
• We successfully designed a DFA that accepts all
  binary strings except '000' and '111'.
                                                    14
  References & Acknowledgment
• 1. Hopcroft, Ullman - Automata Theory
• 2. Lecture Notes on DFAs
• 3. Online DFA Simulators
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