[plt-scheme] Combining digits to form numbers

From: Tim Wawrzynczak (inforichland at gmail.com)
Date: Mon Feb 16 20:21:56 EST 2009

I think you're looking for something like this?

(foldr (lambda (x y) ( + x (* y 10) )) 0 (reverse '(1 2 3)))
 = 123

 - inforichland

On Mon, Feb 16, 2009 at 7:08 PM, Thomas Chust <chust at web.de> wrote:

> 2009-02-16 aditya shukla <adityashukla1983 at gmail.com>:
> > [...]
> > (define guess (lambda(lsb csb msb)
> >         This is the part which i was not able to do , how can i combine
> lsb
> > , csb and msb so the number is of the form (msbcsblsb) .Is there any
> > function in scheme which can do this
> >
> >                          ))
> > [...]
>
> Hello,
>
> there are indeed functions in Scheme that can be used do this -- they
> are called + and * ;-)
>
> All you need to do is multiply each digit of the number with the value
> of its position and add up the results. If you want to create a more
> general solution for an arbitrary number of digits, a function like
> foldr comes in handy, too.
>
> cu,
> Thomas
>
>
> --
> When C++ is your hammer, every problem looks like your thumb.
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