Lec-29: Regular Expressions for Infinite Languages Example 2 | TOC

[@kundangupta7403]

I don't like to read standard textbook..... But I see your every gate videos and make notes.... That is very helpful...... 👌👌

[@ayeshabilal275]

Same case with me

[@aditinageshwar3217]

Same here bro

[@lonelyboy4385]

Nice name bro😁

[@thanks283-v7f]

mujhe b notes de do please

[@akashkush6631]

gate exam diya kya bhai?

[@brahmanandakabi8796]

Honestly,you are one of best teacher in KZbin

[@nishantgaurav5007]

I have gone through all of your videos of TOC and DBMS both.I would like to thank you a lot for providing guidance and to make us understand the subject in easy way..........Thank you so much again.It was really very helpful.

[@keepsmiling6192]

you are my hero teacher sir i am following you from jan 2021 ....thanks for providing such great and helpful videos .....

[@SaumyaSharma007]

Thanks a lot sir 👌🔥 5.21 lac logo ki blessings saath h isliye apko aur apki family ko kuch nhi ho skta Sir 🌟🙏🤗 Very happy for you sir ki aap ab theek ho

[@69upasonabiswas88]

so close to 500K.. Damn excited sir ji..

[@ramankumar41]

Your videos are really very helpful. Thank you Sir.

[@VishalChauhan-ts9jm]

Sir aap jaise teachers hai tab hi ham students ka jeevan dhanya hai ❤❤❤❤❤❤❤❤

[@Swaroop_Rath]

Explanation level has no comparison, wowsome videos sir....

[@TarunDubey-ig2su]

10:45 starting with a and ending with a should be (a+ (a (a+b)* a) instead of a (a+b)* a

[@TarunDubey-ig2su]

because string " a " is also starting with a and ending with a , we can't write it with video's answer.......................

[@md.danish5612]

a*b^+(a+b)* for 2nd ques is correct?

[@17_jain_darsh65]

Perfect explaination sir

[@tayyab.sheikh]

Half concepts from Neso half from Gate Smashers, one is better than the other ❤

[@techbro5590]

your the best teacher 🙏

[@ravirajkudal5626]

How many times I should say thank you You are so awesome Thank you again🙏🙏

[@anubhav9158]

jo gate smashers ke videos dislike karte hain na unke liye garuda purana mein alag saja likhi hui hain.

[@seemadahiya432]

Best teacher ever for cs.....

[@EBKCS_DHRUV_SHARMA]

kya badhiya revision karwa diya sir

[@kaiserrashidofficial]

Amazing sir love from kashmir

[@kundangupta7403]

Great source of knowledge sir 👍

[@richardjones7726]

Sir you are legend !😍

[@darshanasonawane8699]

thank you very much sir..found it very useful

[@tufgaming7390]

1 year , 2 year now 3 year you are the best teacher

[@pkblaziken3585]

One question plz answer if i say All strings with odd number of a's and b's so what's the regular expression of it

[@yugpatel2759]

Sir thank you so much.. amazing explanation...

[@AbdulRehman-yb4zf]

Best teacher💚💕💕

[@netcracker7353]

Thanks sir actually I did my MCA from an open University from IGNOU but meine toc ko as subject nahi pada mca k baad m kai videos se sikne ki koshish bi ki meine i.t.i ke lec tak sune h online but aap k jitna acha India m to kya bahar bi koi nahi karva sakta . Thank you sir

[@hussainaslam5676]

the last trick of 2b's deserves a like👍👍

[@ramankumar41]

Very nice explanation. Thanks a lot Sir !!

[@just-trendingthings]

You simply Great sir 👏

[@pranavmehendale]

10:30 Sir I think for 6th L={a,aa,...} so to consider 'a' R=a+a(a+b)*a right?

[@vaishnavimore5888]

Sir You are you teaching very Exllent

[@renukajoshi3403]

Thank you Sir for these TOC videos

[@tyece75sayaligawali74]

Thank you so much sir your teaching a is fabulous....😊 I m getting all the concepts cleared regarding TOC through your vedio so thank you so much sir

[@mohammadhasnain4103]

I think regex for Q6 (begin and end with a) should be a + a (a+b)^* a because it contains a single ''a'' too which begins and ends with a.

[@shutupandcode]

nice bro... I agree

[@mujeebtyagi4695]

Bro isme starting me b bhi aa skta h

[@bestofnow1162]

it (aaa) can come in this notation also "a(a+b)*a" so sir is right, we want to minimize the expression , no need to expand it or make it large

[@divyam5935]

I agree but there is an even smarter way to deal with the single 'a' problem we can simply write a(a+b)*a* or a*(a+b)*a

[@Dev77g]

​@@divyam5935the first example you give is wrong because string ab will be accepted and the second example is wrong because string ba will be accepted

[@ritikshrivastava9442]

10:31 laughed very hard

[@PriyaKumari-xj1ls]

Sir can you please make video lectures of compiler design for us so that we can utilize this lock down time for our studies by understanding concept and practical approaches of gate subjects Please make videos on that also as soon as possible. 😊

[@arshadshaik4961]

outstanding bro

[@alinajaved2165]

great teacher..

[@Sammy09s]

Mazza aaa gea 😍 Love from pakistan 🇵🇰❤️

[@shahraankashaan]

When your views become moree suddenly smjh jana hmari university k papaer start hn or hmari class y lectures smjh k phr prhtiii😂😂😂😂❤❤

[@chandnibhatia316]

Thankyou sir 💫

[@jasminerose5733]

Like your video... Thanks... From Pakistan 🎉

[@amantyagi4653]

Your Funda is always Great Keep it up!

[@simrinnaiyma6477]

Thank you so much sir 🥺💗

[@quark2248]

Sir at last you told that the regular expression of atleast two b is a*ba*ba*. But one string can also be possible i.e. bbb. But according to your expression, bbb can't be formed.

[@priyankpatel9134]

Thank you..Sir your videos is very usefull for us...

[@AmanpreetKaur-lf4ut]

Best channel

[@ratnakantahanse2661]

Thank you sir....

[@kirtipurohit1237]

I like your way of speaking

[@pradeeppradeepkanaujiya8990]

Great sir

[@saqibshinwari78]

Very helpful … thank u so much

[@akankshasharma5602]

Thank you soo much sir 🙏🙏🙏🙏🙏

[@thesandipsunar]

[@vaibhavambrale6805]

For regex of starting and ending with 'a' It should be "a(a+b)*a+a" , the "+a" will be added because a single "a" will be the smallest string that starts and ends with "a" , which cannot be generated by "a(a+b)*a" alone.

[@anaskaratela6851]

Kudos

[@itssomeoneyoudontneedtoknow]

correct

[@divyam5935]

​​@@akashgarg4043this works too but its just unnecessary. the simplest way to deal with single 'a' problem is to write it as a(a+b)*a* or a*(a+b)*a edit: this doesnt work, as for a*(a+b)*a the string ba can be accepted, which is wrong, therefore its imperative we write, ((a(a+b)*a)+a)

[@vikasphulriya1841]

​@@divyam5935 in a*(a+b)*a ba will pass which is wrong taking a* as empty string output (a+b)* taking b as output a is permanent then final output will be ba which is wrong

[@divyam5935]

@@vikasphulriya1841 yes u r correct. i will edit my reply.

[@golammuktadir4355]

Dear Sir, No.2 question: All strings having at least one 'b' = regex -> (a+b)*b^+(a+b)* is it correct ? because b^+ means = one or more . Thanks for your quality lecture .

[@md.danish5612]

can it be this == a*b^+(a+b)* ?

[@bleed0P]

what if we write (a+b)* b^+ (a+b)* or a* b^+ a* in time 8:32

[@anishagarwal6482]

abababa won't satisfy for your second solution

[@forkanfahimfhf6563]

tnq soooo much

[@ganeshnanhe9638]

Sir while designing what we have to use NFA Or DFA?❓❓❓

[@atik_tanim5991]

Love from Bangladesh

[@rexxter5718]

Sir 6th example beginning and ending with 'a' mai ye wala string bhi accept hona chahiye - {a} ie single 'a' but for expr- a (a+b)^* a we require atleast two 'a'. This expr will not accept single 'a'. Pls look into this. Thankyou

[@jayshrikhamk97]

Concept clear

[@kumartiwari6380]

Confused on -> For Begning and ending with a ; I think it will be a+a(a+b)*a because 'a' itself starts and ends with 'a' and your expression a(a+b)*a will have minimum of 2 a's so , whats the correct answer ????

[@shutupandcode]

correct

[@snazalsingh2465]

Can we put diffrent values of kleen closure in same string

[@anmolpandey7840]

thanks sir

[@dazewaker262]

Sir i got one question..Can {a} count as beginning with a and ending with a ?? If so then,R = a(a+b)*a already gives us minimum of 'a epsilon a' (.i.e. aa)

[@devanshramani]

RE for strings starts & ends with ‘a' is : “a(a+b)*a?” or “a?(a+b)*a”

[@jayshrikhamk97]

Thanks

[@praneetabisen9665]

thank u sir

[@aryanshirsat8160]

sir 2nd mai a*b^+a* nahi chaleg??

[@Spoorti123-r4w]

For all strings having at least 1 b....can we write b^+?bcz + includes any no. Of b but except null Plz clear this sir

[@adarshkumar3518]

No because aap a ke saath kuch nhi kr rhe ho. Agar 'a' aa jaata hai to wo accept hi nhi hoga. Only b, bb, bbb. . . hi accept honge.

[@bijayasharma480]

For all strings having at least 1 b. We need atleast 1 'b' anywhere in the expression so we write (a+b)* which signifies we can get anything and also it can end with anything too so we put (a+b)* at the end too. Then we need atleast one b so we put one b in between (a+b)* and (a+b)*. i.e; (a+b)* b (a+b)*

[@ManishKumarSahu-jd2ww]

@@bijayasharma480 we can write a*b+a* too, right?

[@ashleshakedare22]

@@ManishKumarSahu-jd2ww I think no, because it won't accept strings such as "ababbab".

[@ManishKumarSahu-jd2ww]

@@ashleshakedare22 ohh truuu, completely agreed, btw, have already passes that sem hehe, which sem this subject is in for you

[@30benasabu65]

Sir i have a doubt regarding question 4 as end with ab means there must be something preceeding it to end with ab, so shouldn't it be (a+b)^+(ab), avoiding the epsilon

[@sk-ie9xr]

Sir can we use b+ at the place of b at least one

[@c9m111]

i was also thinking the same

[@sanjughosh5127]

Could you please say the RE for the language containing strings ab,acb,accb,adb,addb,adddb,....

[@HybridCollege]

Question sir! (a+b) yahn + means k 'ya' yaa 'a' hogi string m yaa phr 'b' to sir AP ik string m dono sath de rahey hein... {ab , bb , bab} ... 😕 Confused ... Sir kindly guide

[@harshiyanasm1192]

Can anyone tell in starting and ending with different symbol, does ab accept in such expression?

[@yehumang8361]

nc explanation sir

[@shaffi1104]

Sir, kya aap telegram ya unacademy pr ho?

[@HarshitSharma-cj8ri]

in ques 2 can i write a^* b^+ a^* ?

[@mustafai1863]

your explaination method is so good

[@vikassen73]

Sir isi lockdown me syllabus complete karwa dijiye

[@jaskaransandhu1889]

👍

[@ek_bangali_engineer]

(a+b)*b(a+b)* can also be written as a*b(+)a* . Please some one help me at 7:16

[@shahinparween5560]

No

[@ek_bangali_engineer]

@@shahinparween5560 give me an example

[@muhammadzulqarnain2025]

a) Give the regular expression RE over Σ={a,b} for the language of all words having b as a second letter.

[@amanta6675]

I think it could be: (a+b)b(a+b)*

[@muhammadzulqarnain2025]

@@amanta6675 Thanks🥰

[@diptiprangya3008]

a to the power zero is 1 which is a value it can't be null

[@johnvick8861]

U made it so ezzz

[@asthajain5282]

thank you for providing guidance for this monster subject ,you helped me a lot and make all the subjects easier

[@Mystical_Moments]

7:00

[@adityatathod5440]

L = {x | x ε {a, b}* and x is a string with odd number of ‘a’s and any number of ‘b’s} whats the regular expression for this ??

[@gameplayy7329]

Is aba or aab or bba or bab is a part of (a+b)*. kindly, tell !

[@sidmadkaikar1216]

Legend

[@hussainabbas9060]

in the regular expression containing 'a' , can the RE be "(B*) A (A+B)* "

[@ProgrammingwithGautam]

Can a*b+a* be an answer for atleast b one case

[@ArnabJhaYT]

❤

[@dilwaralam8461]

SIR 2nd question can we write b power +

[@subhroacharjee1562]

in the second question can the RE be (a* + b+)* ? if not why?

[@ArnabJhaYT]

no, because the outside star will make epsilon acceptable in your string. Because we won't choose either a* or b+, and we know epsilon is an empty string but the question says at least one b. Therefore, it will be wrong.

[@ArnabJhaYT]

And if I keep on taking a*, I will get a string full of a, with no b.

[@rahulbiswas5346]

bhaiya koi question paper hein sample? im planning to give gate next year

[@asutoshdubey1388]

Web technology course bhi parallel start karo

[@fatemavadnagarwala1634]

Containing 2b the answer should be (a+b)*+b+(a+b)*+b+(a+b)*

[@CoderInTheNorth]

for 7th example... there should be [a + a(a+b)*a] coz single 'a' also starts and ends with 'a'.

[@JIGARSINGTHAKOR-yy6qp]

for second can we write a*b+a*?

[@Apnasonapunjab]

Not end with "ba" is ka regular expressions kya ho ga

[@ashugarg3196]

starting and ending with a mai only 'a' bhi toh hoga