将一维数组压制成为树状结构，例如
1,11,111,1111
1,11,111,1112
1,11,112,1121
压制成为
1
_11
____111
_______1111
_______1112
____112
_______1121
以数组形式存储，最后一级（叶子节点）以一维数组存储，其余各级均以[id=>[],data=>[]]
的格式存储

<?php class array_2_tree {
//更改方案，使用直接暴力压制下去的方式
private $tree=[];
private $row=[];

private $id_names=false;
private $data_names=false;

private $row_keys=0;
private $row_size=0;

function __construct($opt){
$this->init($opt);
}

private function get_row_value($pos){
if(!$this->row_keys){
$this->row_keys=array_keys($this->row);
}
return $this->row[$this->row_keys[$pos]];
}

function init($opt){
if($opt['id_names'] && is_array($opt['id_names'])){
$this->id_names=$opt['id_names'];
}
if($opt['data_names'] && is_array($opt['data_names'])){
$this->data_names=$opt['data_names'];
}
}
function pick(&$row){
$this->row=$row;
$this->row_size=sizeof($row);
$this->smash($this->tree);
}
function get_tree(){
return $this->tree;
}
private function smash(&$node,$key_index=0){
$id_name=$this->get_id_name($key_index);
$data_name=$this->get_data_name($key_index);
if(sizeof($this->row)row)-1)==($key_index)){
$node[]=$this->get_row_value($key_index);
return;
}else{
$node[]=[
$id_name=>$this->get_row_value($key_index),
$data_name=>[]
];
}
$new_node=&$node[0][$data_name];
$node=&$new_node;
}else{
$size=sizeof($node);
if( ($this->row_size-1) == $key_index){
$node[]=$this->get_row_value($key_index);
return;
}
if( ($node[$size-1][$id_name]) == ($this->get_row_value($key_index)) ){
$next_node=&$node[$size-1][$data_name];
$node=&$next_node;
}else{
$node[]=[
$id_name=>$this->get_row_value($key_index),
$data_name=>[]
];
$size=sizeof($node);
$next_node=&$node[$size-1][$data_name];
$node=&$next_node;
}
}
$this->smash($node,++$key_index);
}
private function get_id_name($k){
if($this->id_names && $this->id_names[$k]){
return $this->id_names[$k];
}else{
return 'id';
}
}
private function get_data_name($k){
if($this->data_names && $this->data_names[$k]){
return $this->data_names[$k];
}else{
return 'data';
}
}
}

?>

$a=[
['depid'=>1,'uid'=>11,'ymd'=>1,'v'=>1],
['depid'=>1,'uid'=>11,'ymd'=>2,'v'=>2],
['depid'=>1,'uid'=>11,'ymd'=>3,'v'=>3],
['depid'=>1,'uid'=>11,'ymd'=>4,'v'=>4],
['depid'=>1,'uid'=>12,'ymd'=>2,'v'=>5],
['depid'=>1,'uid'=>12,'ymd'=>3,'v'=>6],
['depid'=>1,'uid'=>12,'ymd'=>4,'v'=>7],
['depid'=>1,'uid'=>12,'ymd'=>5,'v'=>8],
['depid'=>2,'uid'=>2,'ymd'=>1,'v'=>9],
['depid'=>2,'uid'=>2,'ymd'=>2,'v'=>10],
['depid'=>2,'uid'=>2,'ymd'=>3,'v'=>11],
['depid'=>2,'uid'=>2,'ymd'=>3,'v'=>12]
];
$r=[];
$t=new array_2_tree();
foreach($a as $k=>$v){
$t->pick($v);
}
$r=$t->get_tree();
debug($r);