kerash

function strangeArray($array) {
    $original = $array;
    $uniq = array_unique($original);
    $output_array = array();
    $append_array = array();
    $dup_status = false;

    foreach($uniq as $uniq_index => $uv) {

            $origIndex = array_search($uv, $original);

            unset($original[$origIndex]);

            if( ( $dup_status or $uniq_index==0 ) and in_array ($uv, $original) )
            {
                    $dup_status = true;
                    array_push($output_array,$uv);
                    $dupOrigIndex = array_search($uv, $original);
                    unset($original[$dupOrigIndex]);

            } else if(in_array( $uv, $original ) ) {
                    array_push($output_array,$uv);
                    array_push($append_array,$uv);

                    $dupOrigIndex = array_search($uv, $original);
                    unset($original[$dupOrigIndex]);

            } else if(!$dup_status) {

                    array_push($output_array,$uv);

                    $dupOrigIndex = array_search($uv, $original);
                    if($dupOrigIndex) {
                            unset($original[$dupOrigIndex]);
                    }

            } else {
                break;
            }
    }

    if($dup_status) {
            foreach($uniq as $uv) {
                    array_push($output_array,$uv);
            }
    } else {
            foreach($append_array as $apv) {
                    array_push($output_array,$apv);
            }
    }
    return $output_array;
}

$o_arr1 = array(2,2,3,3,4,4,5,5,6,7,8,9,10,11,12);
$arr1 = strangeArray($o_arr1);
$o_arr2 = array(2,3,4,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12);
$arr2 = strangeArray($o_arr2);
echo json_encode($o_arr1)."<br />".json_encode($arr1);
echo "<hr />";
echo json_encode($o_arr2)."<br />".json_encode($arr2);

/* --- print out result
[2,2,3,3,4,4,5,5,6,7,8,9,10,11,12]
[2,3,4,5,2,3,4,5,6,7,8,9,10,11,12]
-----------------------------------
[2,3,4,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12]
[2,3,4,5,6,7,8,9,10,11,12,6,7,8,9,10,11,12]
*/