Conversion of RE into finite automata

Question

Is this conversion of the regular expression L(((011 + 11)∗(00)∗)∗) into the transition diagram of a finite automata good? Please guide me into what could be wrong, I did it two times differently.

Answer 1

There can be multiple correct answers. Any good textbook will provide an algorithm for converting a regexp to a finite automaton. Follow that algorithm, one step at a time, and the result will be correct (if you followed the recipe correctly).

If you want to check whether your result is correct, a standard approach is to convert both the regexp and automaton to DFAs, then check whether they accept the same language by computing the symmetric difference (using the product construction). Or, you could convert both to regular expressions and test whether the two regular expressions are equivalent; both steps can be done mechanically using known algorithms.

Since this is a purely mechanical construction, I leave it to you to do the tedious work, as doing another worked example won't have any more value to others in the future than checking whether $230923 \times 9572 = 2210384956$.

I suggest reviewing a good textbook on automata theory / formal languages, and these resources: What is the correct way to draw NFA of RE (a|b|c)?, How to create DFA from regular expression without using NFA?, "Best" automaton for a regular language, Steps to convert regular expressions directly to regular grammars and vice versa, Proving Equivalence of Two Regular Expressions, Does Thompson's algorithm produce optimal NFAs?, How to prove a language is regular?, Does every regular expression describe only 1 language?, Check whether a regular expression is correct, Algorithm to determine whether two regexes are equivalent, Proving Equivalence of Two Regular Expressions, Equivalence of regular expressions.