New answers tagged regular-expressions
3
votes
Accepted
DFA and NFA with 2 Substrings
Find an automaton for $L_1= \{uopv\mid u,v\in \Sigma^*\}$ and an automaton for $L_2 = \{upqv\mid u,v\in\Sigma^*\}$ (this should be easy enough).
Then, you can compute the product automaton of the two ...
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0
votes
regex find substring matches in text
One approach is to match against the regexp .* E .*, then figure out how it matches. Whether you can figure out how that matched depends on the algorithm you are ...
D.W.♦
- 141k
0
votes
Showing that $(b^*a)^+.(b^*a) = (b^*a)^*$
let A=(b* a)+ ,B=(b* a) and C=(b* a)*
we have to show that whether A.B=C
here . indicates the concatenation of strings
'+' is known as Kleene plus which means all kinds of non empty strings are ...
-1
votes
Construct a regular expression for the set of strings over {a, b} that contain an odd number of a's and at most four b's
It says the constraints are
Odd number of A's and
At most 4 B's
let's start the expression
->string may start with both A & B
======>(A+B)
->say the first letter of the string be A
=====...
1
vote
Accepted
Why is $L'=\{u\#v^R ~|~ u,v \in L\}$ and $L\in RL$ a regular language?
Regular languages are closed under reversal, therefore $L^R = \{v^R \mid v \in L\}$ is regular. Moreover, regular languages are closed under concatenation, therefore $L' = L \circ \{\#\} \circ L^R$ is ...
- 23.4k
0
votes
Regular Expressions with at least 3 b's and at most 2 a's
A regular expression can be developed from the following finite state machine for at most 2 As and at least 3 Bs by using all possible paths separate by |, and using * where their is a loop edge.
...
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3
votes
Accepted
Are the set of all Bitcoin addresses a context-sensitive language?
Any answer I give you is likely to be unsatisfying and a little silly, both because we're squarely in theory-land here (and not the useful kind of theory, but theory that is irrelevant in practice), ...
D.W.♦
- 141k
0
votes
Regular Expressions with at least 3 b's and at most 2 a's
I don't think there is any simple solution.
There are 15 ways to write a word with 3 $b$'s and at most 2 $a$'s:
$bbb$, $abbb$, $babb$, $bbab$, $bbba$, $aabbb$, $ababb$, $abbab$, $abbba$, $baabb$, $...
- 7,107
1
vote
How would I design a State Diagram (FSM) for a AC unit?
Your question's answer could be solved by Finite Automata with output that is Moore Machine or Mealy Machine.
You have three cases:
$Case:1$ When temperature is equal or more than $80°$ then output is ...
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