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2 Questions

Posted by dve83

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dve83

2 Questions
May 12, 2010 08:06PM

Registered: 18 years ago
Posts: 129
Rating: 1

Hi Got two questions:
No getting my mind around it..

1. an FA not containg 'ba'?
2. an FA containing even number of substrings of 'ab'

appreciate your help

Danie van Eeden
------------------------

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Anonymous User

Re: 2 Questions
May 13, 2010 02:18PM

Rating: 0

FA not containing 'ba'

State - (1)
read a go to State 2
read b go to State 3

State +(2)
read a stay in State 2
read b go to State 3

State +(3)
read a go to State 4
read b stay in State 3

State (4) dead end state
read a stay in State 4
read b stay in State 4

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Anonymous User

Re: 2 Questions
May 13, 2010 02:45PM

Rating: 0

FA containing even number of substring 'ab'

State - (1)
read a go to State 2
read b stay in State 1

State (2)
read a stay in State 2
read b go to State 3

State (3)
read a go to State 4
read b stay in State 3

State (4)
read a stay in State 4
read b go to State 5

State +(5)
read a go to State 2
read b go to State 1

Think this is correct.

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slow_eddy

Re: 2 Questions
May 14, 2010 12:12AM

Registered: 15 years ago
Posts: 3,496
Rating: 1

In broader terms, actively Reject the strings you don't want. Send them to /dev/null on the picture.

ie. Create a Sackgasse/ Cul du Sac / Dead End into which the undesireable substring is forced to go to die.

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33076960

Re: 2 Questions
May 17, 2010 11:04AM

Registered: 16 years ago
Posts: 105
Rating: -1

This was a tricky question, however, gvs, never thought of working out an answer this way.