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joachimschmidt557 2019-08-23 21:10:46 +02:00
parent 8af00ba2d3
commit be36959f87
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bst.rkt Normal file
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#lang racket
(define-struct node (value left right))
(define (search node value) (cond
[(= (node-value node) value) #t]
[(empty? node) #f]
[(> (node-value node) value) (search (node-left node) value)]
[else (search (node-right node) value)]
))
(define (insert node value) (cond
[(empty? node) (make-node value empty empty)]
[(> (node-value node) value) (make-node (node-value node) (insert (node-left node) value) (node-right node))]
[else (make-node (node-value node) (node-left node) (insert (node-right node) value))]
))
(define (bst-from-list lst) (cond
[(empty? lst) empty]
[else (insert (bst-from-list (rest lst)) (first lst))]
))
(define (rotate-left node) (if (empty? node) empty (let
(
[x node]
[l (node-left node)]
[r (node-right node)])
(let (
[a (if (empty? l) empty (node-left l))]
[b (if (empty? l) empty (node-right l))]
[c (if (empty? r) empty (node-left r))]
[d (if (empty? r) empty (node-right r))]
) (
(make-node (node-value l)
a
(make-node (node-value x)
b
r)
)
)))))
(define (height node) (cond
[(empty? node) 0]
[else (+ 1 (max (height (node-left node)) (height (node-right node))))]
))
(define (avlcheck node) (cond
[(empty? node) 0]
[(= (height (node-left node)) -1) -1]
[(= (height (node-right node)) -1) -1]
[(< 1 (abs (- (height (node-left node)) (height (node-right node))))) -1]
[else (+ 1 (max (height (node-left node)) (height (node-right node))))]
))