CS402 assignment-1 discussion and Solution fall 2014

[education-2014]

Q.1. Write a Regular Expression (RE) for the language of all strings defined over Σ = {x, y, z} which begins with z, x in the middle and ends with y. The minimum length of all strings must be 4.

[Marks 6]



Q.2.

a) Make a transition table for RE in Q.1.

b) Draw a Finite Automaton (FA) for part(a)

[Marks 7+7]


1) You should concern recommended books to clarify your concepts as handouts are not sufficient.

2) You are supposed to submit your assignment in .doc format. Any other formats like scan images, PDF, zip, rar, bmp etc will not be accepted.



Note:

No assignment will be accepted after the due date via email in any case (whether it is the case of load shedding or internet malfunctioning etc.). Hence refrain from uploading assignment in the last hour of deadline. It is recommended to upload solution file at least two days before its closing date.

[Vuhelper]

As the given condition dictates: "begins with z, x in the middle and ends with y" and the min_length = 4 characters...

Here is your regex without commas:
RE = ( z x x y )*

The language over Σ = {x, y, z} according to this RE will be:
L = { ^, zxxy, zxxyzxxy, zxxyzxxyzxxy, ... }

The length of first string is ZERO because null string doesn't have any characters in it i.e. condition violated...

Second string is okay...
Third string has y and z along with x's in it...
Fourth string also has y's and z's along with x's in it...
And, so on...

It is quite obvious that the RE: ( z x x y )* cannot generate the required language as described in the problem statement...

i hav found ds solutn. if there is any mstak plz reply

[zain2014]

this expression will generate strings as below
^, z x x y, z x x yz x x y, z x x yz x x yz x x y, z x x yz x x yz x x yz x x y, .......and so on that is why seems faulty

[zain2014]

because it is not creating all strings defined over x,y,z

[Xpert]

you want discussion i can help..................its not that much hard....simple assignment. But instead of giving solution if u do discussion i will help u.