<?php
function permuteUnique($items, $perms = [], &$return = []) {
if (empty($items)) {
$return[] = $perms;
} else {
sort($items);
$prev = false;
for ($i = count($items) - 1; $i >= 0; --$i) {
$newitems = $items;
$tmp = array_splice($newitems, $i, 1)[0];
if ($tmp != $prev) {
$prev = $tmp;
$newperms = $perms;
array_unshift($newperms, $tmp);
permuteUnique($newitems, $newperms, $return);
}
}
return $return;
}
}
$permutations = permuteUnique(["x1", "x2", "x3"]);
var_dump($permutations);
- Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.30, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.12 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
- array(6) {
[0]=>
array(3) {
[0]=>
string(2) "x1"
[1]=>
string(2) "x2"
[2]=>
string(2) "x3"
}
[1]=>
array(3) {
[0]=>
string(2) "x2"
[1]=>
string(2) "x1"
[2]=>
string(2) "x3"
}
[2]=>
array(3) {
[0]=>
string(2) "x1"
[1]=>
string(2) "x3"
[2]=>
string(2) "x2"
}
[3]=>
array(3) {
[0]=>
string(2) "x3"
[1]=>
string(2) "x1"
[2]=>
string(2) "x2"
}
[4]=>
array(3) {
[0]=>
string(2) "x2"
[1]=>
string(2) "x3"
[2]=>
string(2) "x1"
}
[5]=>
array(3) {
[0]=>
string(2) "x3"
[1]=>
string(2) "x2"
[2]=>
string(2) "x1"
}
}
- Output for 4.4.2 - 4.4.9, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29
- Parse error: syntax error, unexpected '[' in /in/RLS36 on line 2
Process exited with code 255. - Output for 4.3.0 - 4.3.1, 4.3.5 - 4.3.11, 4.4.0 - 4.4.1, 5.0.0 - 5.0.5
- Parse error: parse error, unexpected '[' in /in/RLS36 on line 2
Process exited with code 255. - Output for 4.3.2 - 4.3.4
- Parse error: parse error in /in/RLS36 on line 2
Process exited with code 255.
preferences:
279.5 ms | 401 KiB | 371 Q