트리 순회 방법 2

非递归的深度优先的算法,用了一个栈来实现

define('DS', DIRECTORY_SEPARATOR);
function deep_first_list_files($from = '.')
{
    if(!is_dir($from)) {
        return false;
    }
    $files = array();
    $dirs = array($from);
    while(NULL !== ($dir = array_pop($dirs))) {
        if( $dh = opendir($dir)) {
            while( false !== ($file = readdir($dh))) {
                if($file == '.' || $file == '..') {
                    continue;
                }
                $path = $dir . DS . $file;
                if(is_dir($path)) {
                    $dirs[] = $path;
                } else {
                    $files[] = $path;
                }
            }
            closedir($dh);
        }
    }
    return $files;
}
function profile($func, $trydir)
{
    $mem1 = memory_get_usage();
    echo '----------------------- Test run for '.$func.'() ';</li>
<li>    flush();</li>
<li>    $time_start = microtime(true);</li>
<li>    $list = $func($trydir);</li>
<li>    //print_r($list);</li>
<li>    $time = microtime(true) - $time_start;</li>
<li>    echo 'Finished : '.count($list).' files';
    $mem2 = memory_get_peak_usage();
    printf('Max memory for '.$func.'() : %0.2f kbytes Running time for '.$func.'() : %0.f s',
    ($mem2-$mem1)/1024.0, $time);
    return $list;
}
profile('deep_first_list_files', "D:wwwserver");
?>