270 lines
7.1 KiB
Haxe
270 lines
7.1 KiB
Haxe
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/*
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* Copyright (C)2005-2019 Haxe Foundation
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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* DEALINGS IN THE SOFTWARE.
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*/
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package haxe.ds;
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/**
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BalancedTree allows key-value mapping with arbitrary keys, as long as they
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can be ordered. By default, `Reflect.compare` is used in the `compare`
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method, which can be overridden in subclasses.
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Operations have a logarithmic average and worst-case cost.
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Iteration over keys and values, using `keys` and `iterator` respectively,
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are in-order.
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**/
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class BalancedTree<K, V> implements haxe.Constraints.IMap<K, V> {
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var root:TreeNode<K, V>;
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/**
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Creates a new BalancedTree, which is initially empty.
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**/
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public function new() {}
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/**
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Binds `key` to `value`.
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If `key` is already bound to a value, that binding disappears.
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If `key` is null, the result is unspecified.
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**/
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public function set(key:K, value:V) {
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root = setLoop(key, value, root);
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}
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/**
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Returns the value `key` is bound to.
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If `key` is not bound to any value, `null` is returned.
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If `key` is null, the result is unspecified.
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**/
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public function get(key:K):Null<V> {
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var node = root;
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while (node != null) {
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var c = compare(key, node.key);
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if (c == 0)
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return node.value;
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if (c < 0)
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node = node.left;
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else
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node = node.right;
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}
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return null;
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}
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/**
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Removes the current binding of `key`.
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If `key` has no binding, `this` BalancedTree is unchanged and false is
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returned.
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Otherwise the binding of `key` is removed and true is returned.
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If `key` is null, the result is unspecified.
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**/
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public function remove(key:K) {
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try {
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root = removeLoop(key, root);
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return true;
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} catch (e:String) {
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return false;
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}
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}
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/**
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Tells if `key` is bound to a value.
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This method returns true even if `key` is bound to null.
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If `key` is null, the result is unspecified.
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**/
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public function exists(key:K) {
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var node = root;
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while (node != null) {
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var c = compare(key, node.key);
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if (c == 0)
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return true;
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else if (c < 0)
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node = node.left;
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else
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node = node.right;
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}
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return false;
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}
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/**
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Iterates over the bound values of `this` BalancedTree.
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This operation is performed in-order.
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**/
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public function iterator():Iterator<V> {
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var ret = [];
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iteratorLoop(root, ret);
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return ret.iterator();
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}
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/**
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See `Map.keyValueIterator`
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**/
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@:runtime public inline function keyValueIterator():KeyValueIterator<K, V> {
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return new haxe.iterators.MapKeyValueIterator(this);
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}
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/**
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Iterates over the keys of `this` BalancedTree.
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This operation is performed in-order.
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**/
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public function keys():Iterator<K> {
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var ret = [];
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keysLoop(root, ret);
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return ret.iterator();
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}
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public function copy():BalancedTree<K, V> {
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var copied = new BalancedTree<K, V>();
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copied.root = root;
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return copied;
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}
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function setLoop(k:K, v:V, node:TreeNode<K, V>) {
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if (node == null)
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return new TreeNode<K, V>(null, k, v, null);
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var c = compare(k, node.key);
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return if (c == 0) new TreeNode<K, V>(node.left, k, v, node.right, node.get_height()); else if (c < 0) {
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var nl = setLoop(k, v, node.left);
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balance(nl, node.key, node.value, node.right);
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} else {
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var nr = setLoop(k, v, node.right);
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balance(node.left, node.key, node.value, nr);
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}
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}
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function removeLoop(k:K, node:TreeNode<K, V>) {
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if (node == null)
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throw "Not_found";
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var c = compare(k, node.key);
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return if (c == 0) merge(node.left,
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node.right); else if (c < 0) balance(removeLoop(k, node.left), node.key, node.value,
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node.right); else balance(node.left, node.key, node.value, removeLoop(k, node.right));
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}
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static function iteratorLoop<K,V>(node:TreeNode<K, V>, acc:Array<V>) {
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if (node != null) {
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iteratorLoop(node.left, acc);
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acc.push(node.value);
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iteratorLoop(node.right, acc);
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}
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}
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function keysLoop(node:TreeNode<K, V>, acc:Array<K>) {
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if (node != null) {
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keysLoop(node.left, acc);
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acc.push(node.key);
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keysLoop(node.right, acc);
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}
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}
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function merge(t1, t2) {
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if (t1 == null)
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return t2;
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if (t2 == null)
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return t1;
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var t = minBinding(t2);
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return balance(t1, t.key, t.value, removeMinBinding(t2));
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}
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function minBinding(t:TreeNode<K, V>) {
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return if (t == null) throw "Not_found"; else if (t.left == null) t; else minBinding(t.left);
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}
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function removeMinBinding(t:TreeNode<K, V>) {
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return if (t.left == null) t.right; else balance(removeMinBinding(t.left), t.key, t.value, t.right);
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}
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function balance(l:TreeNode<K, V>, k:K, v:V, r:TreeNode<K, V>):TreeNode<K, V> {
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var hl = l.get_height();
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var hr = r.get_height();
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return if (hl > hr + 2) {
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if (l.left.get_height() >= l.right.get_height())
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new TreeNode<K, V>(l.left, l.key, l.value, new TreeNode<K, V>(l.right, k, v, r));
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else
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new TreeNode<K, V>(new TreeNode<K, V>(l.left, l.key, l.value, l.right.left), l.right.key, l.right.value,
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new TreeNode<K, V>(l.right.right, k, v, r));
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} else if (hr > hl + 2) {
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if (r.right.get_height() > r.left.get_height())
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new TreeNode<K, V>(new TreeNode<K, V>(l, k, v, r.left), r.key, r.value, r.right);
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else
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new TreeNode<K, V>(new TreeNode<K, V>(l, k, v, r.left.left), r.left.key, r.left.value,
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new TreeNode<K, V>(r.left.right, r.key, r.value, r.right));
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} else {
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new TreeNode<K, V>(l, k, v, r, (hl > hr ? hl : hr) + 1);
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}
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}
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function compare(k1:K, k2:K) {
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return Reflect.compare(k1, k2);
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}
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public function toString() {
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return root == null ? '{}' : '{${root.toString()}}';
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}
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/**
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Removes all keys from `this` BalancedTree.
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**/
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public function clear():Void {
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root = null;
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}
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}
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/**
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A tree node of `haxe.ds.BalancedTree`.
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**/
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class TreeNode<K, V> {
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public var left:TreeNode<K, V>;
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public var right:TreeNode<K, V>;
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public var key:K;
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public var value:V;
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var _height:Int;
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public function new(l, k, v, r, h = -1) {
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left = l;
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key = k;
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value = v;
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right = r;
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if (h == -1)
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_height = (left.get_height() > right.get_height() ? left.get_height() : right.get_height()) + 1;
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else
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_height = h;
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}
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extern public inline function get_height()
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return this == null ? 0 : _height;
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public function toString() {
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return (left == null ? "" : left.toString() + ", ") + '$key=$value' + (right == null ? "" : ", " + right.toString());
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}
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}
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