I send two programs, and both got accepted.
But for test "(0)**" first program answered "N", second "F".

By statement, power of set (0)* is 1, but what is power of set (0)**? 1 or infinity?

Edited by author 23.09.2007 20:47

You are wrong. Jury has this test, and all your programs output F on it. F is a correct answer, of course. For any set A, if a power of set A is 1, then power of set A* is infinity.

Oh, sorry.
This test looks like "(0*)*", and for it both my programs really gives different answers.

P.S.
hmmm...
>>For any set A, if a power of set A is 1, then power of set A* is infinity.
But if power of set A=(0)* is 1 (contains one empty word), then power of A* should be infinity, so answer N, isn't it? Or i misunderstand something?

Edited by author 25.09.2007 13:32

Empty word + Empty word = Empty word, so we have only one element in (0)*

Edited by author 25.09.2007 17:28

Sorry, I was wrong. "For any set A, if a power of set A is 1, then power of set A* is infinity." is correct for A!={empty_word} only. And {empty_word}* = {empty_word}. So (0)* = {empty_word}, and (0)** = {empty_word}, so answer is F.