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B-Tree in PHP test implementation
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<?php | |
declare(strict_types=1); | |
final class Node{ | |
public static function buildTree(int $size, ?Node $node = null) : self{ | |
$node ??= new Node(); | |
$node->entries[0] = new Node(); | |
$node->entries[1] = new Node(); | |
if($size <= 2){ | |
static $i = 0; | |
$node->entries[0] = $i++; | |
$node->entries[1] = $i++; | |
return $node; | |
} | |
$size /= 2; | |
self::buildTree($size, $node->entries[0]); | |
self::buildTree($size, $node->entries[1]); | |
return $node; | |
} | |
public array $entries; | |
public function __construct(array $entries = []){ | |
$this->entries = $entries; | |
} | |
} | |
final class Inventory{ | |
public int $size; | |
public Node $slots_tree; | |
public function __construct(int $size){ | |
$this->size = $size; | |
$this->slots_tree = Node::buildTree($this->size); | |
} | |
private function getNode(int $slot) : Node{ | |
$node = $this->slots_tree; | |
$size = $this->size; | |
for($i = $this->size / 2; $i >= 2; $i /= 2){ | |
$node = $node->entries[($slot & $i) > 0 ? 1 : 0]; | |
} | |
return $node; | |
} | |
public function get(int $slot){ | |
return $this->getNode($slot)->entries[$slot & 1]; | |
} | |
public function set(int $slot, $value) : void{ | |
$this->getNode($slot)->entries[$slot & 1] = $value; | |
} | |
} | |
$inventory = new Inventory(64); | |
var_dump($inventory->get(55)); |
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