make tree in scheme
- by ???
(define (entry tree) (car tree))
(define (left-branch tree) (cadr tree))
(define (right-branch tree) (caddr tree))
(define (make-tree entry left right) (list entry left right))
(define (mktree order items_list)
(cond ((= (length items_list) 1)
(make-tree (car items_list) '() '()))
(else
(insert2 order (car items_list) (mktree order (cdr items_list))))))
(define (insert2 order x t)
(cond ((null? t) (make-tree x '() '()))
((order x (entry t))
(make-tree (entry t) (insert2 order x (left-branch t)) (right-branch t)))
((order (entry t) x )
(make-tree (entry t) (left-branch t) (insert2 order x (right-branch t))))
(else t)))
The result is:
(mktree (lambda (x y) (< x y)) (list 7 3 5 1 9 11))
(11 (9 (1 () (5 (3 () ()) (7 () ()))) ()) ())
But I'm trying to get:
(7 (3 (1 () ()) (5 () ())) (9 () (11 () ())))
Where is the problem?
