Hi everyone,
Recently,Started learning c++. Can anyone help me in solving the following

consider the language in the alphabet {x,y} defined by the grammar: <S> =
x<S>x | y<S>y | x | y
list all the 3-charater strings that are on this language ,also write the
recursive function that,when passed a character array S, and integers First
and Last,determines whether S[First..Last]
is in this language.

Thank You in advance,