[plt-scheme] Re: Help: I want to travel a binary tree?

Thanks for all of your suggestions !!!
all of your codes enlighten me a lot!
I'm reading your codes carefully.
and I'm very sorry to give the two example,
actually, the second is what I really mean ?


firstly , I want to express the tree in s-exp , which you see before!
I don't want to give you two samples.
that's my first time! So I made a wrong expression .
yesterday evening , I sensed that fault, so I give the expression
again.
That made me feel ashamed.


Thanks Joshua!
I'm used to using C/C++ , and I agree with you .
These days , when I started FP , every function use recursion !
That makes things a little interesing.


I don't know if there is any time difference ,
my time is noon now, may be your time is nighttime!
So I may respond you very late according to your time!