PHP输出多个元素的排列或组合的方法

function getunique($t){
$t2 = array();
//print_r($t);
for($i=0;$i<count($t);$i++){
$count_list = array_count_values($t[$i]);
$flag = 1;
foreach($count_list as $ck=>$cv){
if($cv>1){
$flag = 0;
break;
}
}
if($flag){
sort($t[$i]);
$flag2 = 1;
if($t2){
foreach($t2 as $t2k=>$t2v){
if($t[$i]==$t2v){
$flag2 = 0;
break;
}
}
}
if($flag2){
$t2[] = $t[$i];
}
}
}
return $t2;
}

function getCombinationToString($arr,$m) {
if ($m ==1) {
return $arr;
}
$result = array();

$tmpArr = $arr;
unset($tmpArr[0]);
for($i=0;$i<count($arr);$i++) {
    $s = $arr[$i];
    $ret = getCombinationToString(array_values($tmpArr),($m-1),$result);

    foreach($ret as $row) {
        //$result[] = $s . $row;
        $temp = array();
        $temp[] = $s;
        if(is_array($row)){
            $temp = array_merge($temp,$row);
        }else{
            $temp[] = $row;
        }
        sort($temp);
        $result[] = $temp;
    }
}

return $result;
}

?>