multiplicative inverse of modulo m in scheme

Question

I\'ve written the code for multiplicative inverse of modulo m. It works for most of the initial cases but not for some. The code is below:

(define (inverse x m)
         


        

Answer 1

I think this is the Haskell code on that page translated directly into Scheme:

(define (inverse p q)
  (cond ((= p 0) #f)
        ((= p 1) 1)
        (else
          (let ((recurse (inverse (mod q p) p)))
             (and recurse
                  (let ((n (- p recurse)))
                    (div (+ (* n q) 1) p)))))))

It looks like you're trying to convert it from recursive to tail-recursive, which is why things don't match up so well.