/**
* Causes a visitor to visit the nodes of this tree
* in depth-first traversal order starting from this node.
* This method invokes the preVisit, inVisit
* and postVisit methods of the visitor
* for each node in this tree.
*
* @param object IPrePostVisitor $visitor The visitor to accept.
*/
public function depthFirstTraversal(IPrePostVisitor $visitor)
{
if (!$this->isEmpty()) {
for ($i = 0; $i <= $this->count; ++$i) {
if ($i >= 2) {
$visitor->postVisit($this->key[$i - 1]);
}
if ($i >= 1 && $i <= $this->count) {
$visitor->inVisit($this->key[$i]);
}
if ($i <= $this->count - 1) {
$visitor->preVisit($this->key[$i + 1]);
}
if ($i <= $this->count) {
$this->subtree[$i]->depthFirstTraversal($visitor);
}
}
}
}
/**
* Causes a visitor to visit the nodes of this tree
* in depth-first traversal order starting from this node.
* This method invokes the preVisit, inVisit
* and postVisit methods of the visitor
* for each node in this tree.
* @param object IPrePostVisitor $visitor The visitor to accept.
*/
public function depthFirstTraversal(IPrePostVisitor $visitor)
{
if (!$this->isEmpty()) {
$visitor->preVisit($this->key);
$this->left->depthFirstTraversal($visitor);
$visitor->inVisit($this->key);
$this->right->depthFirstTraversal($visitor);
$visitor->postVisit($this->key);
}
}
/**
* Recursive depth-first traversal method.
*
* @param object IPrePostVisitor $visitor The visitor to accept.
* @param integer $start The vertex at which to start the traversal.
* @param object BasicArray $visited
* Used to keep track of the visited vertices.
*/
private function doDepthFirstTraversal(IPrePostVisitor $visitor, $v, $visited)
{
if ($visitor->isDone()) {
return;
}
$visitor->preVisit($v);
$visited[$v->getNumber()] = true;
foreach ($v->getSuccessors() as $to) {
if (!$visited[$to->getNumber()]) {
$this->doDepthFirstTraversal($visitor, $to, $visited);
}
}
$visitor->postVisit($v);
}
/**
* Causes a visitor to visit the nodes of this tree
* in depth-first traversal order starting from this node.
* This method invokes the preVisit
* and postVisit methods of the visitor
* for each node in this tree.
* The default implementation is recursive.
* The default implementation never invokes the InVisit method
* of the visitor.
* The traversal continues as long as the isDone
* method of the visitor returns false.
*
* @param object IPrePostVisitor $visitor The visitor to accept.
*/
public function depthFirstTraversal(IPrePostVisitor $visitor)
{
if ($visitor->isDone()) {
return;
}
if (!$this->isEmpty()) {
$visitor->preVisit($this->getKey());
for ($i = 0; $i < $this->getDegree(); ++$i) {
$this->getSubtree($i)->depthFirstTraversal($visitor);
}
$visitor->postVisit($this->getKey());
}
}
