RE to DFA by direct method(Compiler Design) Example 1

RE to DFA by direct method(Compiler Design), Regular Expression to DFA by computing Nullable, Firstpos, Lastpos and Followpos functions. Here we are converting Regular Expression to DFA by direct method. We generate syntax tree for Firstpos, Lastpos, then we compute followpos using algorithm. Using followpos we design DFA, for this you can refer book "Compilers" by Aho, Lam, Ullman, Sethi.

[surajkumar-cvxb]

really very well explained. Better than IIT Kharagpur's professors.

[rupaktiwari]

This is gold. Best video on RE to DFA direct conversion.

[shristisisodiya]

you explained better than most of the youtubers but hesitating so much as a first timer knowing rules I had to repeat, if possible please retake this video explaining rules, btw thanks for the explanation.

[salmansamikhan]

very calm easy and clear explanation. Best video I found on this topic so far. Thank you so much mam

[anaskhan]

In second example {1, 2, 3, 5} is not showing transition for c, then how can we call it a dfa? Is there something that i dont know ?

[abhijeetbatra]

Thanks mam, understood better than our class lecture

[malikkhan]

In * node 3 and 4 we are adding the last pos in 1 pos
But you add 3 in 4 its wrong.

[padmalochanmaiti]

How's the second example a dfa when there are no transitions on c input from so many states??

[srivenkatanathann]

Slow, easy and understandable!! Thank u mam👌

[vishwaknama]

really well explained, thanks a lot
But for the last example shouldn't we be considering a dead state? As some of the states doesn't have transitions to some inputs so the answer is not a complete DFA

[RubelTube]

it's really understandable! thank you mam

[bahraebrahimkhalid]

Please answer the questions
Convert regular expressions to dfa directly (a|ab) ^*bb(a|b) ^*

[kalgikansara]

How you created diagram please explain

[sharanpreetkaur]

mam you saved me, , , video was so guddd, thankyou!!!

[JayDee-bu]

I have come up with an algorithm that is much much much faster than this. No graph creation necessary. Everything can be done with a binary tree.

[shlokgandhi]

I'm getting confused after 16:50, please help.

[kaushalniroula]

In second example I think it should be {1, 2, 3 } not {1, 2, 3, 5}

[PREETHAM-mp]

Ma'am how to draw Tree for (a/b)*ab*

[aksharkottuvada]

thank you mam it helped me understand this concept

[Lakshmi_Krishna]

Mam is it good to do it as same as in formal language automata theory (flat) our lecturer said you can do it can anybody plz help with this question