protected static function climbUpAndRight(BinaryTreeNodeWithParent $node)
{
$parent = $node;
while (($parent = $node->getParent()) !== null) {
if ($node === $parent->getLeft()) {
return $node;
}
$node = $parent;
}
return $node;
}
public function testFindSuccessor()
{
$n1 = new BinaryTreeNodeWithParent(1);
$n2 = new BinaryTreeNodeWithParent(2);
$n3 = new BinaryTreeNodeWithParent(3);
$n4 = new BinaryTreeNodeWithParent(4);
$n5 = new BinaryTreeNodeWithParent(5);
$n6 = new BinaryTreeNodeWithParent(6);
$n7 = new BinaryTreeNodeWithParent(7);
$n8 = new BinaryTreeNodeWithParent(8);
$n9 = new BinaryTreeNodeWithParent(9);
$n10 = new BinaryTreeNodeWithParent(10);
$n11 = new BinaryTreeNodeWithParent(11);
$n12 = new BinaryTreeNodeWithParent(12);
$n13 = new BinaryTreeNodeWithParent(13);
$n14 = new BinaryTreeNodeWithParent(14);
$n15 = new BinaryTreeNodeWithParent(15);
$n8->setLeft($n4);
$n8->setRight($n12);
$n4->setLeft($n2);
$n4->setRight($n6);
$n12->setLeft($n10);
$n12->setRight($n14);
$n2->setLeft($n1);
$n2->setRight($n3);
$n6->setLeft($n5);
$n6->setRight($n7);
$n10->setLeft($n9);
$n10->setRight($n11);
$n14->setLeft($n13);
$n14->setRight($n15);
$this->assertSame($n2, SuccessorNodeFinder::findSuccessor($n1));
$this->assertSame($n3, SuccessorNodeFinder::findSuccessor($n2));
$this->assertSame($n4, SuccessorNodeFinder::findSuccessor($n3));
$this->assertSame($n5, SuccessorNodeFinder::findSuccessor($n4));
$this->assertSame($n6, SuccessorNodeFinder::findSuccessor($n5));
$this->assertSame($n7, SuccessorNodeFinder::findSuccessor($n6));
$this->assertSame($n8, SuccessorNodeFinder::findSuccessor($n7));
$this->assertSame($n9, SuccessorNodeFinder::findSuccessor($n8));
$this->assertSame($n10, SuccessorNodeFinder::findSuccessor($n9));
$this->assertSame($n11, SuccessorNodeFinder::findSuccessor($n10));
$this->assertSame($n12, SuccessorNodeFinder::findSuccessor($n11));
$this->assertSame($n13, SuccessorNodeFinder::findSuccessor($n12));
$this->assertSame($n14, SuccessorNodeFinder::findSuccessor($n13));
$this->assertSame($n15, SuccessorNodeFinder::findSuccessor($n14));
$this->assertNull(SuccessorNodeFinder::findSuccessor($n15));
}
public function getRandomNode()
{
$left = parent::getLeft();
$right = parent::getRight();
$leftNodeCount = $left !== null ? $left->getNodeCount() : 0;
$rightNodeCount = $right !== null ? $right->getNodeCount() : 0;
$random = mt_rand(-$leftNodeCount, $rightNodeCount);
if ($random < 0) {
return $left->getRandomNode();
} elseif ($random > 0) {
return $right->getRandomNode();
}
// $random == 0
return $this;
}
