42 votes 42 votes Consider the regular expression $R = (a + b)^* (aa + bb) (a + b)^*$ Which deterministic finite automaton accepts the language represented by the regular expression $R$? Theory of Computation gateit-2007 theory-of-computation finite-automata normal + – Ishrat Jahan asked Oct 30, 2014 • edited May 1, 2019 by Pooja Khatri Ishrat Jahan 7.9k views answer comment Share Follow See all 4 Comments See all 4 4 Comments reply raja11sep commented Dec 19, 2021 reply Follow Share B → “ab” C → “abb” D → “aa” 1 votes 1 votes ꧁༒☬ĿọŗԀ 🆂🅷🅸🆅🅰☬༒꧂ commented Oct 20, 2023 reply Follow Share B is still not a DFA coz of by the definition Dfa We can have exctly one transition from one state to any other state, but here in S3 there are 2 transitions on a which is not valid. 0 votes 0 votes Gopal Deshmuk commented Oct 21, 2023 reply Follow Share What is the proper way of solving these type of questions? Is trial and error the only way? 0 votes 0 votes ꧁༒☬ĿọŗԀ 🆂🅷🅸🆅🅰☬༒꧂ commented Oct 22, 2023 reply Follow Share @Gopal Deshmuk take strings which is accepting by the regular expression and check which string is accepted by the dfa is the easiest way . 1 votes 1 votes Please log in or register to add a comment.
0 votes 0 votes (B.) it accepts ab which is not in the language (C.) it is not accepting abb which is in language and also Is false since baa, abb not accepted (D.) it is not accepting aa and bb which is in language coming to option (A.) it accept Sandeep Suri answered Jan 1, 2018 Sandeep Suri comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes Here, Option B: it generates a string like ab which is not a part of our language, hence rejected. Option C and D: they don't even accept the minimal length strings aa and bb of our language, hence rejected. Option A is thus the right answer! TheAnteamatter answered Jun 20, 2020 TheAnteamatter comment Share Follow See all 0 reply Please log in or register to add a comment.
–2 votes –2 votes Option a and c both seems right anshu answered Feb 2, 2015 anshu comment Share Follow See all 2 Comments See all 2 2 Comments reply NERU.91 commented Apr 29, 2015 reply Follow Share I was also stuck between these two, but C does not accept 'abb' or 'baa'. 3 votes 3 votes raja11sep commented Dec 19, 2021 reply Follow Share Yes they seems but they are not. 0 votes 0 votes Please log in or register to add a comment.