/**
* @param Digraph $graph
* @param int $vertex
*/
private function depthSearch(Digraph $graph, int $vertex)
{
$this->onStack[$vertex] = true;
$this->marked[$vertex] = true;
foreach ($graph->adjacent($vertex) as $item) {
if ($this->hasCircle()) {
return;
} else {
if (!isset($this->marked[$item])) {
$this->edgeTo[$item] = $vertex;
$this->depthSearch($graph, $item);
} else {
if ($this->onStack[$item]) {
$this->circle = new Stack();
for ($x = $vertex; $x !== $item; $x = $this->edgeTo[$x]) {
$this->circle->add($x);
}
$this->circle->add($vertex);
$this->circle->add($item);
}
}
}
}
$this->onStack[$vertex] = false;
}
/**
* @param int $vertex
* @return Iterator|null
*/
public function pathTo(int $vertex)
{
if (!$this->hasPathTo($vertex)) {
return null;
}
$path = new Stack();
for ($x = $vertex; $x != $this->startVertex; $x = $this->edgeTo[$x]) {
$path->add($x);
}
$path->add($this->startVertex);
return $path;
}
<?php
use Base\Stack;
spl_autoload_register(function ($class) {
$file = str_replace('\\', '/', $class);
require "../{$file}.php";
});
$stack = new Stack();
$stack->add(1);
$stack->add(2);
$stack->add(3);
foreach ($stack as $key => $value) {
echo "{$key} => {$value}\n";
}
$stack->add(7);
$stack->add(8);
$stack->add(9);
foreach ($stack as $key => $value) {
echo "{$key} => {$value}\n";
}
