PHP Infinitus Classification

Infinitus classification: recursive and iterative implementation

1. Find the sub-column of the specified column

2. Find the descendant columns of the specified column, which is a descendant tree

3. Find the parent directory, grandparent directory,... .,, top directory

欲处理的原始数据

$area=array(
array('id'=>1,'name'=>'山东','parent'=>0),
array('id'=>2,'name'=>'菏泽','parent'=>1),
array('id'=>3,'name'=>'定陶','parent'=>2),
array('id'=>4,'name'=>'青岛','parent'=>1),
array('id'=>5,'name'=>'莱西','parent'=>4),
array('id'=>6,'name'=>'烟台','parent'=>1),
array('id'=>7,'name'=>'南山','parent'=>6),
array('id'=>8,'name'=>'仿山','parent'=>3),
array('id'=>9,'name'=>'日照','parent'=>1),
array('id'=>10,'name'=>'济南','parent'=>1)

);

//找子栏目
function findSon($arr,$id=0){
	//查找$arr中元素的parent的值等于$id就是其子目录
	$s
	foreach ($arr as $v) {
	 	if($v['parent']==$id){
	 		$sons[]=$v;
	 		}
	} 
	return $sons;
}

//找子孙树

//利用<strong>静态变量</strong>
function findTree($arr,$id,$lev=1){
	static $subs=array();
	
	foreach ($arr as $v) {
	 	if($v['parent']==$id){
	 		$v['lev']=$lev;
	 		$subs[]=$v;
	 	    findTree($arr,$v['id'],$lev+1);
	 		}
	} 
	return $subs;
	
	}
方法二、
function findTree($arr,$id,$lev=1){
	 static $subs=array();
	
	foreach ($arr as $v) {
	 	if($v['parent']==$id){
	 		$v['lev']=$lev;
	 		$subs[]=$v;
	 	    $subs=$subs+findTree($arr,$v['id'],$lev+1);
	 		}
	} 
	return $subs;
	
	}
方法三、
function findTree($arr,$id,$lev=1){
	  $subs=array();
	
	foreach ($arr as $v) {
	 	if($v['parent']==$id){
	 		$v['lev']=$lev;
	 		$subs[]=$v;
	 	    $subs= array_merge( $subs,findTree($arr,$v['id'],$lev+1));
	 		}
	} 
	return $subs;
	
	}

//用迭代法来找子孙树

function subTree($arr,$parent=0){
	$task=array($parent);//任务表
	$tree=array();//地区表
	while(!empty($task)){
		
		$flag=false;
		foreach($arr as $k=>$v){
			
			if($v['parent']==$parent){
				$tree[]=$v;
				array_push($task,$v['id']);//最新的地区id入任务栈
				$parent=$v['id'];
				unset($arr[$k]);//把找到单元unset
				
				$flag=true;
				}
				
			}
			if($flag==false){
					
					array_pop($task);
					$parent=end($task);
		}
		}
		
	return $tree;
		
	}

//===
//无限极分类
//家谱树
//===
方法一、
function familyTree($arr,$id,$lev=1){
	
	//static $tree=array();
	 $tree=array();
	foreach($arr as $v){
		
	 	if($v['id']==$id){
	 		$v['lev']=$lev;
	 		
	 		//判断改子类是否存在父目录
	 		if($v['parent'] > 0){
	 			$tree=array_merge($tree,familyTree($arr,$v['parent'],$lev+1));
	 			//familyTree($arr,$v['parent']);
	 			
	 			
	 			}
	 			
	 			$tree[]=$v;
	 		}
	} 
	return $tree;
	}
方法二、
//用迭代法来找家谱树

function tree($arr,$id){
	$tree=array();

	while($id !==0){
		foreach ($arr as $v) {
			
		    if($v['id']==$id){
		    	
		    	$tree[]=$v;
		    	$id=$v['parent'];
		    	break;
		    	}
	        
		}
		
		}
 
	
	return $tree;
	}

The above has introduced the PHP Infinitus classification, including static variables. I hope it will be helpful to friends who are interested in PHP tutorials.