DFA

Question

Answer 1

.....

Comments

@leen in 3rd dfa on state q5 when 'b' is already defined then...then why u sent a,b,c on outgoing edge to trap state q6...u shud send only a,c from q5 to q6...not b..

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yes in 3rd too.

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ManojK Tauhin Gangwar Thank You.check it now.

Answer 2

(a+b)(a*+b*)

Answer 3

ab*c (aa+b*)

Answer 4

aa*b*b

Comments

From wikipedia

https://en.wikipedia.org/wiki/Deterministic_finite_automaton#Complete_and_incomplete_deterministic_finite_automata

According to the above definition, deterministic finite automata are always complete: they define a transition for each state and each input symbol.

While this is the most common definition, some authors use the term deterministic finite automaton for a slightly different notion: an automaton that defines at most one transition for each state and each input symbol; the transition function is allowed to be partial. When no transition is defined, such an automaton halts.

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if someone ask you what is the minimum number of states in DFA for regular expression aa*b*b then what will be your answer?

3 or 4?

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DFA should have transitions for all the inputs on all the states that's how it becomes deterministic