遞歸 迭代 得到家譜樹 子孫樹

<?php 
   $arr=array(
     array('id'=>'1','name'=>'吉林','parent'=>0),
	 array('id'=>'2','name'=>'北京','parent'=>0),
	 array('id'=>'3','name'=>'遼寧','parent'=>0),
	 array('id'=>'4','name'=>'吉林市','parent'=>1),
	 array('id'=>'5','name'=>'長春','parent'=>1),
	 array('id'=>'6','name'=>'海淀','parent'=>2),
	 array('id'=>'7','name'=>'大連','parent'=>3),
	 array('id'=>'8','name'=>'船營區','parent'=>4),
	 array('id'=>'9','name'=>'豐滿區','parent'=>4)
   );
   //找子欄目

   function findson($arr,$id=0){
	  $sons=array();
	  foreach($arr as $v){
		 if($v['parent']==$id){
			 $sons[]=$v;
		 }
	  }
       return $sons;
   }
   //var_dump(findson($arr,$id=1));
   
   //找子孫樹
   //用靜態變量
   function subtree($arr,$id,$lev=1){
	   static $subs=array();  //static 只初始化一次
	   
	  foreach($arr as $v){
		 if($v['parent']==$id){
			 $v['lev']=$lev;
			 $subs[]=$v;
			 subtree($arr,$v['id'],$lev+1);
			 //不用靜態變量
			// $subs=array_merge($subs,subtree($arr,$v['id'],$lev+1));
		 }
	  }
       return $subs;
   }
   /*
 $tree=subtree($arr,$id=0,1);
 foreach ($tree as $v){
	 echo str_repeat('  ',$v['lev']).$v['name']."<br/>";
 }
 */
 /**
 家譜樹應用
 麪包屑導航
 首頁>手機類型>諾基亞>
 
 
 **/
 
 function familytree($area,$id){
	 static $tree=array();
	 foreach($area as $v){
		 if($v['id']==$id){
			 $tree[]=$v;
			 //判斷要不要繼續找父欄目
			 if($v['parent']>0){
			 familytree($area,$v['parent']);
			 //不用static
			 //array_merge($area,familytree($area,$v['parent']));
			 }
		 }
		 
	 }
	 return $tree;
 }
 echo "<hr>";
//print_r(familytree($arr,9));
/*用迭代找家譜樹(推薦)*/
function familytree2($arr,$id){
	 $tree=array();
	 while($id!==0){
		 foreach($arr as $v){
			 if($v['id']==$id){
			    $tree[]=$v;	
                $id=$v['parent'];	
                 break;				
			 }
 
	 }
	 }
	 return $tree;
}
	print_r(familytree2($arr,9));
?>