php遍历树的常用方法汇总

本文实例讲述了php遍历树的常用方法。分享给大家供大家参考。具体如下：

一、递归的深度优先的算法：

----------------------- Test run for '.$func.'() ';
  flush();
  $time_start = microtime(true);
  $list = $func($trydir);
  //print_r($list);
  $time = microtime(true) - $time_start;
  echo 'Finished : '.count($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('rec_list_files', "D:wwwserver"); ?>

二、递归的深度优先的算法（用了一个栈来实现）

----------------------- Test run for '.$func.'() ';
  flush();
  $time_start = microtime(true);
  $list = $func($trydir);
  //print_r($list);
  $time = microtime(true) - $time_start;
  echo 'Finished : '.count($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"); ?>

三、非递归的广度优先算法（用了一个队列来实现）

 NEXT CHILD
  }
  return $files; // end of tree, file not found
}
function profile($func, $trydir)
{
  $mem1 = memory_get_usage();
  echo '
----------------------- Test run for '.$func.'() ';
  flush();
  $time_start = microtime(true);
  $list = $func($trydir);
  //print_r($list);
  $time = microtime(true) - $time_start;
  echo 'Finished : '.count($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('breadth_first_files', "D:wwwserver");
?>

希望本文所述对大家的php程序设计有所帮助。