递归 迭代 得到家谱树 子孙树

<?php 
   $arr=array(
     array('id'=>'1','name'=>'吉林','parent'=>0),
	 array('id'=>'2','name'=>'北京','parent'=>0),
	 array('id'=>'3','name'=>'辽宁','parent'=>0),
	 array('id'=>'4','name'=>'吉林市','parent'=>1),
	 array('id'=>'5','name'=>'长春','parent'=>1),
	 array('id'=>'6','name'=>'海淀','parent'=>2),
	 array('id'=>'7','name'=>'大连','parent'=>3),
	 array('id'=>'8','name'=>'船营区','parent'=>4),
	 array('id'=>'9','name'=>'丰满区','parent'=>4)
   );
   //找子栏目

   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));
   
   //找子孙树
   //用静态变量
   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);
			 //不用静态变量
			// $subs=array_merge($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/>";
 }
 */
 /**
 家谱树应用
 面包屑导航
 首页>手机类型>诺基亚>
 
 
 **/
 
 function familytree($area,$id){
	 static $tree=array();
	 foreach($area as $v){
		 if($v['id']==$id){
			 $tree[]=$v;
			 //判断要不要继续找父栏目
			 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));
/*用迭代找家谱树(推荐)*/
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));
?>