dom - PHP DOMDocument - URL の照合と削除

Question

DOMを使用してhtmlページからリンクを抽出しようとしています:

$html = file_get_contents('links.html');
$DOM = new DOMDocument();
$DOM->loadHTML($html);
$a = $DOM->getElementsByTagName('a');
foreach($a as $link){
    //echo out the href attribute of the <A> tag.
    echo $link->getAttribute('href').'<br/>';
}

出力：

http://dontwantthisdomain.com/dont-want-this-domain-name/
http://dontwantthisdomain2.com/also-dont-want-any-pages-from-this-domain/
http://dontwantthisdomain3.com/dont-want-any-pages-from-this-domain/
http://domain1.com/page-X-on-domain-com.html

http://dontwantthisdomain.com/dont-want-link-from-this-domain-name.html
http://dontwantthisdomain2.com/dont-want-any-pages-from-this-domain/
http://domain.com/page-XZ-on-domain-com.html

http://dontwantthisdomain.com/another-page-from-same-domain-that-i-dont-want-to-be-included/
http://dontwantthisdomain2.com/same-as-above/
http://domain3.com/page-XYZ-on-domain3-com.html

dontwantthisdomain.com、dontwantthisdomain2.com、および dontwantthisdomain3.com に一致するすべての結果を削除したいので、出力は次のようになります。

http://domain1.com/page-X-on-domain-com.html
http://domain.com/page-XZ-on-domain-com.html
http://domain3.com/page-XYZ-on-domain3-com.html

何か案は？:)