Push Down Automata (PDA).

Please support our Computer Science advertiser: Learn about neural networks and artificial intelligence.
Reply

Join Date: Mar 2005
Posts: 6
Reputation: acidburns is an unknown quantity at this point 
Solved Threads: 0
acidburns's Avatar
acidburns acidburns is offline Offline
Newbie Poster

Push Down Automata (PDA).

 
0
  #1
Nov 8th, 2006
Hello,
can someone please help with solving this problem regarding push down automata. I am to write a table for the following problem.

L={number of a's in (X) is not equal to number of b's in (X)l X is {a,b,c}* }.

I could really use some help planning the it, so i can write it myself.

The components of PDA are:
q=current state
t=input symbol
s=stack top symbol
q'=next state
i=movement over input tape.
d=operation over stack.

the operations only include [. , push, pop]
Reply With Quote Quick reply to this message  
Join Date: Jun 2005
Posts: 2,052
Reputation: Rashakil Fol is just really nice Rashakil Fol is just really nice Rashakil Fol is just really nice Rashakil Fol is just really nice 
Solved Threads: 139
Team Colleague
Rashakil Fol's Avatar
Rashakil Fol Rashakil Fol is offline Offline
Super Senior Demiposter

Re: Push Down Automata (PDA).

 
1
  #2
Nov 8th, 2006
What do you mean by 'a table'?
All my posts may be redistributed under the GNU Free Documentation License.
Reply With Quote Quick reply to this message  
Join Date: Mar 2005
Posts: 6
Reputation: acidburns is an unknown quantity at this point 
Solved Threads: 0
acidburns's Avatar
acidburns acidburns is offline Offline
Newbie Poster

Re: Push Down Automata (PDA).

 
0
  #3
Nov 9th, 2006
Originally Posted by Rashakil Fol View Post
What do you mean by 'a table'?

I mean a transition table which will show that after pushing or poping an input whether the given string is accepted or rejected.
Reply With Quote Quick reply to this message  
Join Date: Jun 2005
Posts: 2,052
Reputation: Rashakil Fol is just really nice Rashakil Fol is just really nice Rashakil Fol is just really nice Rashakil Fol is just really nice 
Solved Threads: 139
Team Colleague
Rashakil Fol's Avatar
Rashakil Fol Rashakil Fol is offline Offline
Super Senior Demiposter

Re: Push Down Automata (PDA).

 
1
  #4
Nov 11th, 2006
Oh, so you just mean a table with two columns: input strings and acceptance/rejection?

Well, anyway, you should probably think about information storage. When you're partway through the string, what piece of information will you need to have retained about the previously read parts of the string? How are you going to represent that information? You have two places to represent that information: your current node within the graph of the automaton, and your stack. What piece of information do you need to retain and update each step of the way?
All my posts may be redistributed under the GNU Free Documentation License.
Reply With Quote Quick reply to this message  
Join Date: Aug 2008
Posts: 1
Reputation: samerald is an unknown quantity at this point 
Solved Threads: 0
samerald samerald is offline Offline
Newbie Poster

Re: Push Down Automata (PDA).

 
-1
  #5
Aug 25th, 2008
hey guys!!! anyone can help me how to design a PDA that ask a string and the output should be accepted. The entire input string must be read before the machine can accept the word. It is in any language!! thnk you
Reply With Quote Quick reply to this message  
Reply

This thread is more than three months old.
Perhaps start a new thread instead?
Message:



Similar Threads
Other Threads in the Computer Science Forum
Thread Tools Search this Thread



About Us | Contact Us | Advertise | DaniWeb | Acceptable Use Policy | RSS Feed

©2003 - 2009 DaniWeb® LLC