# Finite automata for the language of all those strings starting and ending with different letters in theory of automata

## Built the FA for the language of all those strings in which all strings are starting and ending with different letters?

 Accepted Strings You should check some small, some medium and some large size strings that are part of the language and all of them(100% strings) should be accepted by our FA. Small strings: ab, ba, aab, abb, baa….. and all such strings that are starting and ending with different letters. Medium size strings: ababab, bababbaba …… and all such strings that are starting and ending with different letters. Large size strings: ababbababababbabababbabab,   bababababbabbbaaaaba……. and all such strings that are starting and ending with different letters.

 Rejected Strings You should check some small, some medium and some large size strings that are not part of the language and all of them(100% strings) should be rejected by our FA. Small strings: a, b, aa, bb, aba, bab….. and all such strings that are not starting and ending with different letters. Medium size strings: ababab, bababbaba ……and all such strings that are not starting and ending with different letters. Large size strings: ababbababababbabababbababa,   bababababbabbbaaaabab…….and all such strings that are not starting and ending with different letters.

## Finite Automata Exercise Solution

Here I am showing you a list of some more important Deterministic Finite Automata used in the theory of automata and theory of computation.

1. DFA for  (a+b)* (a+b)a .
2. DFA for (bb)*(aa)* .
3. DFA for  b+a(a+b)*+a.
4. DFA for (a+b)*b+(bb)*a.
5. DFA for bb+a(a+b)*+aa.
6. DFA for  a(a+b)*+bb(a)* .
7. DFA for  a(a+b)b*+bb(a)*.
8. DFA for  b(aa)*a+a(bb)*b.
9. DFA for a+a(aa+b)*(aa)b.
10. DFA for a+a(aa+b)*+(aa)b.
11. DFA for (a+b)b(a+b)*+(aa)*b.
12. FA for strings starting with a and ending with a.
13. FA for the language of all those strings starting with a.
14. FA for the language of all those strings containing aa as a substring.
15. DFA for the language of all those strings starting and ending with the same letters.
16. DFA for the language of all those strings starting and ending with different letters.
17. DFA for the language of all those strings having double 0 or double 1.
18. DFA for the language of all those strings starting and ending with b.
19. DFA for ending with b.
20. DFA for the string of even A’s and even b’s.
21. DFA for the regular expression of  a(a+b)*+(bb)+a(ba)*+aba+bb*(a+b)*.
22. RegExp and DFA for strings having triple a’s or triple b’s.