note 60994 deleted from ref.array by tularis
| From: | tularis@php.net | Date: | Mon, 23 Jan 2006 09:37:49 +0000 |
| Subject: | note 60994 deleted from ref.array by tularis | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-102268@lists.php.net to get a copy of this message | ||
Note Submitter: skondrat at finishedsolutions dot com
Reason: useless
----
Function returns all ways how elements can be ordered in array. Be careful number of ways increases
as factorial of number of elements:).
function all_orders(&$arr) {
$result=array();
if(count($arr)==1) {
$result[]=array($arr[0]);
} else {
for($i=0;$i<count($arr);$i++) {
$sub_arr=array();
for($j=0;$j<count($arr);$j++) {
if($i!=$j) {
$sub_arr[]=$arr[$j];
}
}
$sub_result=all_orders($sub_arr);
for($j=0;$j<count($sub_result);$j++) {
$new_order=array($arr[$i]);
foreach($sub_result[$j] as $val) {
$new_order[]=$val;
}
$result[]=$new_order;
}
}
}
return $result;
}
$arr=array('a','b','c');
print_r(all_orders($arr));
will produce
Array
(
[0] => Array
(
[0] => a
[1] => b
[2] => c
)
[1] => Array
(
[0] => a
[1] => c
[2] => b
)
[2] => Array
(
[0] => b
[1] => a
[2] => c
)
[3] => Array
(
[0] => b
[1] => c
[2] => a
)
[4] => Array
(
[0] => c
[1] => a
[2] => b
)
[5] => Array
(
[0] => c
[1] => b
[2] => a
)
)