Automata Theory - DFAs

Deterministic Finite Automata (DFA) are defined. An intuitive understanding is provided.

This video is especially useful for beginners.

NOTE: In the example: "strings that start and end with an a", there is an implicit assumption that the length of a word is two or more. We address the situation where no such restriction exists in the following short clip:

[uprprsn]

Wait, what about the string "a"? It starts with and ends with "a". Shouldn't the (q1, a) arrow point to q3 instead?

[slackerengi]

Watching this during class
Better explanations online

[infamousgabriel]

So I just stumbles on to this video when I was learning programming languages, and this got my interests, can you help me. I don't have any idea what is this nor what is this for.

[abhishekmakam]

plz explain on what basis u drew the transition system..

[KTM_Trooper]

My qn is that cant the a and b from q4 be supplied to q2? It would be the same result ultimately the dfa ending with a! Correct me if im wrong im very much a newbie to this subject!

[-lv]

If you use this DFA, what happens if you have a string that starts with 'a' but ends with 'b'? You will be stuck in state q2. What do you do then?

[kirtidev]

can u plz explain on what basis u got the conclusion of desirable and undesirable states?

[likhithareddy]

very informative ....nice understanding...

[david.kizivat]

The automaton doesn't accept string 'a' which should be in L as it is defined. There should be one more final state, say q5, and transition function should exclude transition (q1, a) -> q2 and include transitions (q1, a) -> q5; (q5, a) -> q2; and (q5, b) -> q2... :) Or the language should have restriction to only include strings with length greater than 1. :)

[sgnlx_ai]

what does that * mean at w € {a, b}* ?

[saimashaheen]

ThankU sir...this video helped me a lot!

[sohamshah]

kuch samaj ni aa raha ghuma ghuma ke chala rahe ho