Implementing Mergesort

• The list is empty

• The list has one element

Recall that mergesort uses a divide and conquer strategy.

Suppose we divide the list using one-part and the-other-part, and we merge them with merge:

     (define mergesort
       (lambda (lst)
         (cond ((null? lst) '())       ; first base case
               ((null? (cdr lst)) lst) ; second base case
               (else (merge (mergesort (one-part lst))
                            (mergesort (the-other-part lst)))))))