Question

Design finite automata (deterministic or nondeterministic) for each of the following

languages

1. All strings of digits with at most one repeated digit.

2. All strings of a's and b's with an even number of a's and an odd number of b's.

Answer 1

All strings of digits with at most one repeated digit.

Let us consider the digits 0,1,2

So the strings like 221100, 01212200 will be rejeced but the strings like 00101202 will be accepted.

output

2.