From ac1bf1b75868c873037f742b727e79ee5a97bae2 Mon Sep 17 00:00:00 2001 From: Mike Vink Date: Fri, 24 Mar 2023 23:01:25 +0100 Subject: progress --- coding-exercises/2/64.rkt | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 coding-exercises/2/64.rkt (limited to 'coding-exercises/2/64.rkt') diff --git a/coding-exercises/2/64.rkt b/coding-exercises/2/64.rkt new file mode 100644 index 0000000..90994e8 --- /dev/null +++ b/coding-exercises/2/64.rkt @@ -0,0 +1,20 @@ +#lang racket +(define (list->tree elements) + (car (partial-tree elements (length elements)))) + +(define (partial-tree elts n) + (if (= n 0) + (let ((left-size (quotient (- n 1) + 2))) + (let ((left-result (partial-tree elts left-size))) + (let ((left-tree (car left-result)) + (non-left-elts (cdr left-result)) + (right-size (- n (+ left-size 1)))) + + (let ((this-entry (car non-left-elts)) + (right-result (partial-tree (cdr non-left-elts) + right-size))) + (let ((right-tree (car right-result)) + (remaining-elts (cdr right-result))) + (cons (make-tree thientry left-tree right-tree) + remaining-elts)))))))) -- cgit v1.2.3