53 lines
No EOL
2.5 KiB
Racket
53 lines
No EOL
2.5 KiB
Racket
#lang racket
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(define-struct node (value left right))
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(define (search node value) (cond
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[(= (node-value node) value) #t]
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[(empty? node) #f]
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[(> (node-value node) value) (search (node-left node) value)]
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[else (search (node-right node) value)]
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))
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(define (insert node value) (cond
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[(empty? node) (make-node value empty empty)]
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[(> (node-value node) value) (make-node (node-value node) (insert (node-left node) value) (node-right node))]
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[else (make-node (node-value node) (node-left node) (insert (node-right node) value))]
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))
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(define (bst-from-list lst) (cond
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[(empty? lst) empty]
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[else (insert (bst-from-list (rest lst)) (first lst))]
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))
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(define (rotate-left node) (if (empty? node) empty (let
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(
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[x node]
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[l (node-left node)]
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[r (node-right node)])
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(let (
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[a (if (empty? l) empty (node-left l))]
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[b (if (empty? l) empty (node-right l))]
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[c (if (empty? r) empty (node-left r))]
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[d (if (empty? r) empty (node-right r))]
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) (
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(make-node (node-value l)
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a
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(make-node (node-value x)
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b
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r)
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)
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)))))
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(define (height node) (cond
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[(empty? node) 0]
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[else (+ 1 (max (height (node-left node)) (height (node-right node))))]
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))
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(define (avlcheck node) (cond
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[(empty? node) 0]
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[(= (height (node-left node)) -1) -1]
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[(= (height (node-right node)) -1) -1]
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[(< 1 (abs (- (height (node-left node)) (height (node-right node))))) -1]
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[else (+ 1 (max (height (node-left node)) (height (node-right node))))]
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)) |