A DFA is a deterministic finite automaton, a simple model of computation. It is one way to model regular languages. Each DFA consists of a finite set of states and a transition function between those states describing how the state of the machine changes in response to new input. DFAs are closely related to regular expressions in the sense that they can be converted into each other. Thus, DFAs are often used to implement regular expression matchers.
Questions tagged [dfa]
569 questions
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Let Σ= {a}, assume language, L= { a^(2012.K) / K> 0}, what is minimum number of states needed in a DFA to recognize L
In my opinion it should be 2012 but I am not sure.Thanks for the help.
Akshat Sharma
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Difference Between KMP and Regex/DFA-based Searching
I am confused about the relation between KMP (Knuth–Morris–Pratt) and Regex (DFA-based) Searching.
My thought is that KMP cannot use regex notations (e.g., (A|B){2}C), so it can only search for a "single" string (e.g., AC or BC, but not AC|BC). Is…
JackWM
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What is this DFA means?
There is a DFA.
But I don't know this DFA means.
I want to know this DFA's Regular expression and description
(Description like 'this automata accept suffix is 011)
Blue state is start state and red states are accept states.
Jihoon Yoon
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minimum no of states required for A(BC)*D?
What are the minimum no. of states required in dfa of the language: A(BC)*D? Is it 3 or 4?
By 3 I mean, can I write "BC" on single arrow?
If possible please explain using a diagram.
Thank you in advance.
gmaster
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Mapping power state to unique number NFA to DFA
I am writing the code to convert NFA to DFA, if we have a power state {1,2,4}, I have to convert it into the some unique number, say x. Also I have to do the reverse mapping such that is I get x, I have to return the power state as {1,2,4}
I came up…
Vallabh Patade
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How can I tell a regular language?
As we know, using pumping lemma, we can easily prove the language L = {WW|W ∈ {a,b}*} is not a regular language.
However, The language, L1 = {W1W2| |W1| = |W2|} is a regular language. Because we can get the DFA like below,
My question is, L = {WW|W…
henry
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Is there an openly available implementation of the Hopcroft's DFA minimization algorithm?
Ditto. Java or C# would be best, but any imperative language will do.
Jakub Lédl
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By writing a regular expression or a grammar, describe the language accepted by the NFA
NFA diagram
the strings accepted are aaaaa which is pretty clear. The L = (111 + 1111)* is what I am getting but I need it in regular expression or grammar
coding12
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Regular Expression | Automata Theory
does anyone know about regular expressions of the following languages:
the set of all strings starting with 000 and not ending 11
the set of all strings with odd string length and ending in 111
L6 is the set of all strings ending in 00 and…
Apriana
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How can you identify whether the language is regular or context-free language
For example, is this language regular or context-free language?
On the one hand n can't be smaller than m but on the other hand you can't count n and m.
{(ab)^n (ab)^m | n>=m>=0}
Tomer Cher
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From a regular expression to NFA and to DFA
I have the following regular expression:
[A−Z]∗01∗[^A−Z]{3}
The alphabet is [A-Z][0-9].
Can someone explain the correct way to convert to a NFA and then to DFA.
And how can I implement the epsilon closure in C.
Nedo
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How to draw a dfa for this language :L={ w | w has an even number of a’s and one or two b’s}
I tried this problem but i get stuck everytime because i am unable to satisfy the second condition for b. Someone give the right dfa diagram for the language.
Prajwal K
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Find the DFA for the language L given
L is a language over {x,y,z} where x's are never preceded by y's and never followed by z's
Aastha Dahal
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Deterministic finite automaton for even zeroes and ones in multiples of 5
Given a binary string, create a DFA to check if the number of zeroes is even and the number of ones is a multiple of 5.
Avinash Kadimisetty
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DFA is not accepting strings
my program is supposed to implement a dfa for a binary string... dfa is a machine that can be in only one state at a time (when you enter a string the machine should use it and at the last step it should reach to the final state. if so, we say that…
Little Girl
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