Online PHP editor | rfc for pmKqN

<?php class Node { public $color; public $key; public $value; public $left; public $right; public function __construct($key, $value, $color) { $this->key = $key; $this->value = $value; $this->color = $color; } public function compare($key) { if ($this->key < $key) return -1; elseif ($this->key > $key) return 1; else return 0; } } class RBTree { const RED = true; const BLACK = false; private $root; public function isEmpty() { return $this->root == null; } public function put($key, $value) { $this->root = $this->insert($this->root, (int)$key, $value); $this->root->color = self::BLACK; } public function get($key) { $x = $this->search($this->root, (int)$key); return $x ? $x->value : null; } private function isRed($h) { return $h ? $h->color : false; } private function insert($x, $key, $value) { if (!$x) return new Node($key, $value, self::RED); $cmp = $x->compare($key); if ($cmp > 0) $x->right = insert($x->right, $key, $value); elseif ($cmp < 0) $x->left = insert($x->left, $key, $value); else $x->value = $value; if ($this->isRed($x->right) && !$this->isRed($x->left)) $x = $this->rotateLeft($x); if ($this->isRed($x->left) && $this->isRed($x->left->left)) $x = $this->rotateRight($x); if ($this->isRed($x->left) && $this->isRed($x->right)) $this->flipColors($x); return $x; } private function search($x, $key) { while ($x) { $cmp = $x->compare($key); if ($cmp > 0) $x = $x->right; elseif ($cmp < 0) $x = $x->left; else return $x; } return null; } private function flipColors($h) { $h->color = !$h.color; $h->left->color = !$h->left->color; $h->right->color = $h->right->color; } private function rotateLeft($h) { $x = $h->right; $h->right = $x->left; $x->left = $h; $x->color = $x->left->color; $x->left->color = self::RED; return $x; } private function rotateRight($h) { $x = $h->left; $h->left = $x->right; $x->right = $h; $x->color = $x->right->color; $x->right->color = self::RED; return $x; } }

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