数组遍历问题

$arr=array(	'10'=>array(		'12'=>0	),	'15'=>array(		'30'=>array(			'35'=>0		),		'31'=>array(			'40'=>0		)	))

有以上这个数组，怎样才能得到从顶端到每一个根节点的路径？

比如最后得到这样的结果：

$a[]='10,12';$a[]='15,30,35';$a[]='15,31,40';

回复讨论(解决方案)

$arr=array('10'=>array('12'=>0),'15'=>array('30'=>array('35'=>0),'31'=>array('40'=>0)));				$a=array();		foreach ($arr as $k=>$v){			$a[$k][]=$k;			if(is_array($v)){				foreach ($v as $kk=>$vv){					$a[$k][]=$kk;				}			}				}		var_dump($a);

$arr=array('10'=>array('12'=>0),'15'=>array('30'=>array('35'=>0),'31'=>array('40'=>0),'33'=>array('42'=>0)));				$a=array();		$i=0;		foreach ($arr as $k=>$v){						$a[$i][]=$k;			if(is_array($v)){				foreach ($v as $kk=>$vv){					$a[$i][]=$kk;					if(is_array($vv)){						foreach ($vv as $kkk=>$vvv){							$j=0;							if($j==0){								unset($a[$i]);								$a[$i.'-'.$i][]=$k;								$a[$i.'-'.$i][]=$kk;								$a[$i.'-'.$i][]=$kkk;							}else{								$a[$i][]=$kkk;							}						}					}					$i++;				}			}			$i++;		}		var_dump($a);

最后是这样$arr=array('10'=>array('12'=>0),'15'=>array('30'=>array('35'=>0),'31'=>array('40'=>0),'33'=>array('42'=>0)));				$a=array();		$i=0;		foreach ($arr as $k=>$v){						$a[$i][]=$k;			if(is_array($v)){				foreach ($v as $kk=>$vv){					$a[$i][]=$kk;					if(is_array($vv)){						foreach ($vv as $kkk=>$vvv){														unset($a[$i]);							$a[$i.'-'.$i][]=$k;							$a[$i.'-'.$i][]=$kk;							$a[$i.'-'.$i][]=$kkk;						}					}					$i++;				}			}		}		var_dump(array_values($a));

$arr=array(  '10'=>array(    '12'=>0  ),  '15'=>array(    '30'=>array(      '35'=>0    ),    '31'=>array(      '40'=>0    )  ));print_r(foo($arr));function foo($ar) {  $res = array();  foreach($ar as $k=>$v) {    if(is_array($v)) {      foreach(foo($v) as $r) $res[] = "$k,$r";    }else $res[] = $k;  }  return $res;}

Array(    [0] => 10,12    [1] => 15,30,35    [2] => 15,31,40)

版主也太牛叉了！昨天我只想到用递归但是没有弄出来…

写了个方法

$arr=array(    '10'=>array(        '12'=>0,        '13'=>array(            '14' => 0,            '16' => array(                '17' =>0            )        )    ),    '15'=>array(        '30'=>array(            '35'=>0        ),        '31'=>array(            '40'=>0        )    ));function foo( $arr, &$str = '' ){    foreach($arr as $key => $value)    {        $str .= "," . $key;        if(is_array($value))        {            foo($value, $str);        }else{            print_r( ltrim($str,',') );            echo '
';        }        $str = rtrim( $str, ','.$key);    }}foo($arr);

$arr=array(    '10'=>array(        '12'=>0,        '13'=>array(            '14' => 0,            '16' => array(                '17' =>0            )        )    ),    '15'=>array(        '30'=>array(            '35'=>0        ),        '31'=>array(            '40'=>0        )    ));function foo( $arr, &$str = '' ){    foreach($arr as $key => $value)    {        $str .= "," . $key;        if(is_array($value))        {            foo($value, $str);        }else{            print_r( ltrim($str,',') );            echo '
';        }        $str = rtrim( $str, ','.$key);    }}foo($arr);

$arr=array(    '10'=>array(        '12'=>0,        '13'=>array(            '14' => 0,            '16' => array(                '17' =>0            )        )    ),    '15'=>array(        '30'=>array(            '35'=>0        ),        '31'=>array(            '40'=>0        )    ));function foo( $arr, &$str = '' ){    foreach($arr as $key => $value)    {        $str .= "," . $key;        if(is_array($value))        {            foo($value, $str);        }else{            print_r( ltrim($str,',') );            echo '
';        }        $str = rtrim( $str, ','.$key);    }}foo($arr);

$arr=array(  '10'=>array(    '12'=>0  ),  '15'=>array(    '30'=>array(      '35'=>0    ),    '31'=>array(      '40'=>0    )  ));function my($arr,$pid=10){    static $item=array();    static $s='';    foreach($arr as $k=>$v){         if(is_array($v)){            foreach($v as $key=>$value){                $s.=$key.',';                if(is_array($value)){                    my($value,$k);                }            }         }else{            $s.=$k;         }         $s=$pid.','.$s;         $item[]=$s;         $s='';    }    return $item;}$arr=my($arr);array_pop($arr);print_r($arr);

Array(    [0] => 10,12,    [1] => 15,30,35    [2] => 15,31,40)

太感谢版主了！