PHP array combination problem?

How to put the following this array $arr=array (0=>array (' id ' =>1, ' pid ' = ' = '), 1=>array (' id ' =>208, ' pid ' = =), 2=>array (' Id ' =>3, ' pid ' =>208) 3=>array (' id ' =>4, ' pid ' =>208) '), and become such a form of $arr=array (0=>array (' id ' =>1, ' pid ') = =), 1=>array (' id ' =>208, ' pid ' =>, ' str ' =>array (             0=>array (  ' id ' =>1, ' pid ' =>208),             1=>array (' id ' =>4, ' pid ' =>208)));

Reply to discussion (solution)

http://bbs.csdn.net/topics/370094009

$BRR =array (), foreach ($arr as $k + $v) {if (Empty ($v [' pid])) if (Isset ($brr [$v [' ID ']]) {$BRR [$v [' id ']][]= $v [' id ']; $BRR [$v [' id ']][]= $v [' pid '];} else$brr[$v [' id ']]= $v else{if (!isset ($brr [$v [' pid]]) $brr [$v [' PID ']]=array () $brr [$v [' PID ']][' str '][]= $v;}} Sort ($BRR);

http://bbs.csdn.net/topics/370094009

Moderator this gets the result is this, if the build for 4 of the removal is good ah, because the 4 has been put into 208 inside, do not need

Array ([    1] = = Array        (            [id] = 1            [pid] = =         )    [4] = = Array        (            [id] = 4            [PID] + 208        )    [208] = =        array            ([ID] + 208            [pid] = = [Child             ] = array                (                    [4] = = Array                        (                            [id] = 4                            [PID] = 208                        )        )))

$BRR =array (), foreach ($arr as $k + $v) {if (Empty ($v [' pid])) {if (!isset ($brr [$v [' ID ']]) $BRR [$v [' id ']]= $v;} Else{if (!isset ($brr [$v [' pid]]) $brr [$v [' PID ']]=array (); $brr [$v [' PID ']][' str '][]= $v;}} Sort ($BRR);

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