SiroDiaz / DataStructures

        return new AVLNode($key, $data, $parent, $left, $right);

    }

    private function rightRotation(AVLNode $node) {

        $tempParent = &$node->parent;

        $tempRight = &$node->right;

        $veryChildren = &$tempRight->left;

        if($tempParent === null) {

            $this->root = &$tempRight;

            $tempRight->parent = null;

        } else {

            $tempRight->parent = &$tempParent;

            if($tempRight->key < $tempParent->key) {

                $tempParent->left = &$tempRight;

            } else {

                $tempParent->right = &$tempRight;

            }

        }

        $parentRight->left = &$node;

        $node->parent = &$tempRight;

        $node->right = &$veryChildren;

    }

    private function leftRotation(AVLNode $node) {

        $tempParent = &$node->parent;

        $node->right = &$veryChildren;

    }

    private function leftRotation(AVLNode $node) {

        $tempParent = &$node->parent;

        $tempLeft = &$node->left;

        $veryChildren = &$tempLeft->right;

        if($tempParent === null) {

            $this->root = &$tempLeft;

            $tempLeft->parent = null;

        } else {

            $tempLeft->parent = &$tempParent;

            if($tempLeft->key < $tempParent->key) {

                $tempParent->left = &$tempLeft;

            } else {

                $tempParent->right = &$tempLeft;

            }

        }

        $tempLeft->right = &$node;

        $node->parent = &$tempLeft;

        $node->left = &$veryChildren;

    }

    private function doubleRightRotation(AVLNode $node) {

        $node->right = $this->rightRotation($node->right);