public function test_that_left_holds_reference_to_left_node() { $monday = WeekDay::MONDAY(); $node = new RedBlackNode($monday, 'Monday', 1, RedBlackNode::RED); $sunday = WeekDay::SUNDAY(); $left = new RedBlackNode($sunday, 'Sunday', 1, RedBlackNode::RED); $node->setLeft($left); $this->assertSame($left, $node->left()); }
/** * Restores red-black tree invariant on insert * * @codeCoverageIgnore * * @param RedBlackNode $node The subtree root * * @return RedBlackNode */ protected function balanceOnInsert(RedBlackNode $node) : RedBlackNode { if ($this->isRed($node->right()) && !$this->isRed($node->left())) { $node = $this->rotateLeft($node); } if ($this->isRed($node->left()) && $this->isRed($node->left()->left())) { $node = $this->rotateRight($node); } if ($this->isRed($node->left()) && $this->isRed($node->right())) { $this->flipColors($node); } $node->setSize(1 + $this->nodeSize($node->left()) + $this->nodeSize($node->right())); return $node; }