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<?php $arr = array(); $arr[] = array('p' => 3, 'id' => 4); $arr[] = array('p' => 3, 'id' => 5); $arr[] = array('p' => 3, 'id' => 6); $arr[] = array('p' => 2, 'id' => 3); $arr[] = array('p' => 1, 'id' => 2); $arr[] = array('p' => 1, 'id' => 7); $arr[] = array('p' => 0, 'id' => 1); $mas = array(); foreach($arr as $ind => $itm) { if(isset($mas[$itm['id']])) { if($itm['p'] == 0) { $mas[$itm['id']]['elements'] = $mas[$itm['id']]; $mas[$itm['id']]['name'] = 'aaa'.$ind; }else{ $mas[$itm['p']][$itm['id']]['elements'] = $mas[$itm['id']]; unset($mas[$itm['id']]); $mas[$itm['p']][$itm['id']]['name'] = 'aaa'.$ind; } } } print_r($mas);

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