<?php
class CategoryTree
{
public $roots = [];
public function addCategory($category, $parent)
{
if ($this->categoryExists($this->roots, $category)) {
throw new InvalidArgumentException("Category: $category already exists.");
}
if ($parent === null) {
$this->roots[$category] = [];
return;
}
$node = &$this->findNode($parent, $this->roots);
if(!isset($node)) {
throw new InvalidArgumentException("Parent node: $parent not found.");
}
$node[$category] = [];
}
public function getChildren($parent)
{
$node = $this->findNode($parent, $this->roots);
if(!isset($node)) {
throw new InvalidArgumentException("Parent node: $parent not found.");
}
return array_keys($node);
}
protected function &findNode($node, &$root) {
if (in_array($node, array_keys($root))) {
return $root[$node];
}
foreach ($root as $n) {
return $this->findNode($node, $n);
}
}
public function categoryExists($nodes, $category) {
$exists = 'test';
if (in_array($category, array_keys($nodes))) {
return true;
}
foreach($nodes as $key => $node) {
$exists = $this->categoryExists($node, $category);
}
return $exists;
}
}
// For testing purposes (do not submit uncommented):
$c = new CategoryTree;
$c->addCategory('A', null);
$c->addCategory('B', 'A');
$c->addCategory('C', 'A');
echo implode(',', $c->getChildren('A'));
echo "\n". $c->categoryExists($c->roots, 'D');
preferences:
32.77 ms | 402 KiB | 5 Q