This is a GRE practice question.
Which of the following regular expressions generate(s) no stringwith two consecutive 1’s? (Note that ? denotes the emptystring.)
I. (1 + ?)(01 + 0)*
II. (01+10)*
III. (0+1)*(0+?)
(A) I only
(B) II only
(C) III only
(D) I and II only
(E) II and III only
The correct answer is A, but I’m not sure what ‘*’ means in thiscontext and would like if someone can breakdown how each of theseregular expressions are added to each other and multiplied.
Expert Answer
An answer will be send to you shortly. . . . .