Theory of Computation
Q201.
Which regular expression best describes the language accepted by the non-deterministic automaton below?Q202.
Consider the regular expression R = (a + b)^* \ (aa + bb) \ (a + b)^* Which one of the regular expressions given below defines the same language as defined by the regular expression R ?Q203.
Consider the Deterministic Finite-state Automaton (DFA) A shown below. The DFA runs on the alphabet {0, 1}, and has the set of states {s, p, q, r}, with s being the start state and p being the only final state.Which one of the following regular expressions correctly describes the language accepted by A?Q204.
The length of the shortest string NOT in the language (over \Sigma={a,b}) of the following regular expression is _________. a*b* (ba)* a*Q205.
Which one of the following regular expressions is NOT equivalent to the regular expression (a + b + c)^*?Q206.
Consider the regular expression R = (a + b)^* (aa + bb) (a + b)^* Which of the following non-deterministic finite automata recognizes the language defined by the regular expression R? Edges labeled \lambda denote transitions on the empty string.Q207.
In some programming language, an identifier is permitted to be a letter followed by any number of letters or digits. If L and D denote the sets of letters and digits respectively, which of the following expressions defines an identifier?Q208.
Which one of the following languages over the alphabet {0,1} is described by the regular expression: (0+1)*0(0+1)*0(0+1)*?Q209.
Let L = {w \in (0 + 1)*|w has even number of 1s}, i.e. L is the set of all bit strings with even number of 1s. Which one of the regular expressions below represents L?