Design a DFA that Every 00 is Immediately Followed by 1 Last Updated : 12 Jul, 2025 Comments Improve Suggest changes 5 Likes Like Report DFA Machines are designed to accept the specific kind of input whose output is generated by the transition of input alphabet from each state. We want to design a Deterministic Finite Automaton (DFA) that ensures every time the string contains "00," it is immediately followed by "1". This means:The DFA must allow valid sequences where:"00" is always followed by "1".Any sequence of 0s and 1s is fine, as long as it follows this rule.The DFA must reject invalid sequences where:"00" is followed by another 0 or the string ends after "00".ApproachIn this situation, strings all strings are acceptable except more than 3 zeros. In this kind of string, no three continuous zeros are acceptable. Create initial state and start with minimum length of possible string do transition of its input 0 and 1 to possible states. according to transition, notice the final state and mark it. Designing DFA Step-by-stepStep-1: Make a initial state,say "A", minimum possible strings are 1 and 0 and also any number of 1 are acceptable.To do this put self-loop of 1 on state "A" and make transition of input alphabet 0 to state "B".DFA Step 1Step-2: After a single zero, if again '0' comes, it will go to the next state otherwise, in the case of '1', it will return to the initial state. Transect input 0 from state "B" to state "C". DFA Step 2Step-3: As every 00 is immediately followed by 1 so now after state "C" do transition of input '1' from state "C" to state "D" and '0' to 'Dead State'. DFA Step 3Step-4: We are left with transition of input alphabet 1 and 0 of state "D" and also from the dead state. DFA Step 4Transition Table of above DFA State "A" is both final as well as the initial state, state "C" is final state, state "D" is Dead State. Initial state is depicted by ---> and final state ids depicted by *. StateInput (0)Input (1)--->A (Initial State)BABCACDead StateDD * (Final State)BADead State Dead StateDead StateQ': set of finite sets = {A, B, C, D, Dead} set of input alphabets = {0, 1} Conclusion The DFA designed for this problem ensures that every occurrence of "00" in the input is immediately followed by "1". It does this by carefully transitioning through states to track the sequence and also reject the invalid patterns. Only the patterns that are valid will reach to the final state. Create Quiz Comment _mridul_bhardwaj_ Follow 5 Improve _mridul_bhardwaj_ Follow 5 Improve Article Tags : GATE CS Theory of Computation Explore Automata _ IntroductionIntroduction to Theory of Computation5 min readChomsky Hierarchy in Theory of Computation2 min readApplications of various Automata4 min readRegular Expression and Finite AutomataIntroduction of Finite Automata3 min readArden's Theorem in Theory of Computation6 min readSolving Automata Using Arden's Theorem6 min readL-graphs and what they represent in TOC4 min readHypothesis (language regularity) and algorithm (L-graph to NFA) in TOC7 min readRegular Expressions, Regular Grammar and Regular Languages7 min readHow to identify if a language is regular or not6 min readDesigning Finite Automata from Regular Expression (Set 1)4 min readStar Height of Regular Expression and Regular Language4 min readGenerating regular expression from Finite Automata3 min readCode Implementation of Deterministic Finite Automata (Set 1)8 min readProgram for Deterministic Finite Automata7 min readDFA for Strings not ending with "THE"12 min readDFA of a string with at least two 0âs and at least two 1âs3 min readDFA for accepting the language L = { anbm | n+m =even }14 min readDFA machines accepting odd number of 0âs or/and even number of 1âs3 min readDFA of a string in which 2nd symbol from RHS is 'a'10 min readUnion Process in DFA4 min readConcatenation Process in DFA3 min readDFA in LEX code which accepts even number of zeros and even number of ones6 min readConversion from NFA to DFA5 min readMinimization of DFA7 min readReversing Deterministic Finite Automata4 min readComplementation process in DFA2 min readKleene's Theorem in TOC | Part-13 min readMealy and Moore Machines in TOC3 min readDifference Between Mealy Machine and Moore Machine3 min readCFGRelationship between grammar and language in Theory of Computation4 min readSimplifying Context Free Grammars6 min readClosure Properties of Context Free Languages11 min readUnion and Intersection of Regular languages with CFL3 min readConverting Context Free Grammar to Chomsky Normal Form5 min readConverting Context Free Grammar to Greibach Normal Form6 min readPumping Lemma in Theory of Computation4 min readCheck if the language is Context Free or Not4 min readAmbiguity in Context free Grammar and Languages3 min readOperator grammar and precedence parser in TOC5 min readContext-sensitive Grammar (CSG) and Language (CSL)2 min readPDA (Pushdown Automata)Introduction of Pushdown Automata5 min readPushdown Automata Acceptance by Final State4 min readConstruct Pushdown Automata for given languages4 min readConstruct Pushdown Automata for all length palindrome6 min readDetailed Study of PushDown Automata3 min readNPDA for accepting the language L = {anbm cn | m,n>=1}2 min readNPDA for accepting the language L = {an bn cm | m,n>=1}2 min readNPDA for accepting the language L = {anbn | n>=1}2 min readNPDA for accepting the language L = {amb2m| m>=1}2 min readNPDA for accepting the language L = {am bn cp dq | m+n=p+q ; m,n,p,q>=1}2 min readConstruct Pushdown automata for L = {0n1m2m3n | m,n ⥠0}3 min readConstruct Pushdown automata for L = {0n1m2n+m | m, n ⥠0}2 min readNPDA for accepting the language L = {ambncm+n | m,n ⥠1}2 min readNPDA for accepting the language L = {amb(m+n)cn| m,n ⥠1}3 min readNPDA for accepting the language L = {a2mb3m|m>=1}2 min readNPDA for accepting the language L = {amb2m+1 | m ⥠1}2 min readNPDA for accepting the language L = {aibjckdl | i==k or j==l,i>=1,j>=1}3 min readConstruct Pushdown automata for L = {a2mc4ndnbm | m,n ⥠0}3 min readNPDA for L = {0i1j2k | i==j or j==k ; i , j , k >= 1}2 min readNPDA for accepting the language L = {anb2n| n>=1} U {anbn| n>=1}2 min readNPDA for the language L ={wÐ{a,b}* | w contains equal no. of a's and b's}3 min readTuring MachineTuring Machine in TOC7 min readTuring Machine for addition3 min readTuring machine for subtraction | Set 12 min readTuring machine for multiplication2 min readTuring machine for copying data2 min readConstruct a Turing Machine for language L = {0n1n2n | nâ¥1}3 min readConstruct a Turing Machine for language L = {wwr | w ∈ {0, 1}}5 min readConstruct a Turing Machine for language L = {ww | w ∈ {0,1}}7 min readConstruct Turing machine for L = {an bm a(n+m) | n,mâ¥1}3 min readConstruct a Turing machine for L = {aibjck | i*j = k; i, j, k ⥠1}2 min readTuring machine for 1's and 2âs complement3 min readRecursive and Recursive Enumerable Languages in TOC6 min readTuring Machine for subtraction | Set 22 min readHalting Problem in Theory of Computation4 min readTuring Machine as Comparator3 min readDecidabilityDecidable and Undecidable Problems in Theory of Computation6 min readUndecidability and Reducibility in TOC5 min readComputable and non-computable problems in TOC6 min readTOC Interview preparationLast Minute Notes - Theory of Computation13 min readTOC Quiz and PYQ's in TOCTheory of Computation - GATE CSE Previous Year Questions2 min read Like