資料的格式話有關問題

求教：資料的格式話問題
資料來源格式：

$data = array(
  array('id' => 1,'pid' => 0,'name' => 'a'),
  array('id' => 2,'pid' => 0,'name' => 'b'),
  array('id' => 3,'pid' => 1,'name' => 'c'),
  array('id' => 4,'pid' => 1,'name' => 'd'),
  array('id' => 5,'pid' => 3,'name' => 'e'),
  array('id' => 6,'pid' => 3,'name' => 'f'),
  array('id' => 7,'pid' => 6,'name' => 'g'),
  array('id' => 8,'pid' => 6,'name' => 'h'),
  array('id' => 9,'pid' => 8,'name' => 'i'),
  array('id' => 10,'pid' => 8,'name' => 'j'),
  array('id' => 11,'pid' => 9,'name' => 'l'),
  array('id' => 12,'pid' => 9,'name' => 'm'),
);

需要將資料格式話成如下格式：

Array(
'a' => Array(
'c' => 'c',
'd' => Array(
'e' => 'e',
'f' => Array(
'g' => 'g'
'h' => Array(
'i' => Array(
'l' => 'l',
'm' => 'm'
),
'j' => 'j'
),
)
)
),
'b' => 'b'
)
求各位大神幫忙

------解決方案--------------------

$data = array(
  array('id' => 1,'pid' => 0,'name' => 'a'),
  array('id' => 2,'pid' => 0,'name' => 'b'),
  array('id' => 3,'pid' => 1,'name' => 'c'),
  array('id' => 4,'pid' => 1,'name' => 'd'),
  array('id' => 5,'pid' => 3,'name' => 'e'),
  array('id' => 6,'pid' => 3,'name' => 'f'),
  array('id' => 7,'pid' => 6,'name' => 'g'),
  array('id' => 8,'pid' => 6,'name' => 'h'),
  array('id' => 9,'pid' => 8,'name' => 'i'),
  array('id' => 10,'pid' => 8,'name' => 'j'),
  array('id' => 11,'pid' => 9,'name' => 'l'),
  array('id' => 12,'pid' => 9,'name' => 'm'),
);
/********我是YD的分割線*************/
$pid = 1000000;
//$mark = 'c';
foreach ($data as $key => $value){

if ($value[pid] == $pid) { 
