Solved

regular expression to DFA

Posted on 2008-09-30
8
462 Views
Last Modified: 2011-10-19
How do you draw this in a DFA?

w | each 1 in w is immediately preceded and immediately followed by a 0
0
Comment
Question by:kuntilanak
  • 5
  • 2
8 Comments
 
LVL 1

Accepted Solution

by:
yans earned 500 total points
ID: 22610815
0
 

Author Comment

by:kuntilanak
ID: 22610840
how does :

 b* + b*a(ba)*

satisfies my question, please explain
0
 
LVL 1

Expert Comment

by:yans
ID: 22610882
The question deals with regular expression. b* + b*a(ba)* is a regular expression representation and the solution demostrates how to draw it.

If you may check some reference on reading regular expression syntax.

http://en.wikipedia.org/wiki/Regular_expression
0
Gigs: Get Your Project Delivered by an Expert

Select from freelancers specializing in everything from database administration to programming, who have proven themselves as experts in their field. Hire the best, collaborate easily, pay securely and get projects done right.

 

Author Comment

by:kuntilanak
ID: 22610905
I don't understand how b* + b*a(ba)* represents each 1 in w is immediately preceded and immediately followed by a 0
0
 

Author Comment

by:kuntilanak
ID: 22610911
if 1 is equal to b here, then one possibility that regex gives me is 1* which can be an empty string and it is not followed immediately by a 0.
0
 
LVL 84

Expert Comment

by:ozo
ID: 22611143
0* (0 1 0 0*)*
0
 

Author Comment

by:kuntilanak
ID: 22611151
ozo can you please explain that a bit
0
 

Author Comment

by:kuntilanak
ID: 22616778

on the picture below, the start state is when given an input b, what if the input at the start state is a? It doesn't covers that..
dfa.png
0

Featured Post

Courses: Start Training Online With Pros, Today

Brush up on the basics or master the advanced techniques required to earn essential industry certifications, with Courses. Enroll in a course and start learning today. Training topics range from Android App Dev to the Xen Virtualization Platform.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Regex to get defined term and meaning from contract 39 69
Mod rewrite 3 58
REGEX HELP 11 40
How come this regular expression allows "e"? 14 35
by Batuhan Cetin Regular expression is a language that we use to edit a string or retrieve sub-strings that meets specific rules from a text. A regular expression can be applied to a set of string variables. There are many RegEx engines for u…
Whatever be the reason, if you are working on web development side,  you will need day-today validation codes like email validation, date validation , IP address validation, phone validation on any of the edit page or say at the time of registration…
Learn how to match and substitute tagged data using PHP regular expressions. Demonstrated on Windows 7, but also applies to other operating systems. Demonstrated technique applies to PHP (all versions) and Firefox, but very similar techniques will w…
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions. Consider email address RFCs: Look at HTML5 form input element (with type=email) regex pattern: T…

776 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question