PHP - How to create all possibility from a string - php

Question

Here, there is a example string "XjYAKpR" .. how to create all new string possibility with that string ??
I've tried before
function containAllRots($s, $arr) {
$n = strlen($s);
$a = array();
for ($i = 0; $i < $n ; $i++) {
$rotated = rotate(str_split($s), $i);
$a[] = $rotated;
}
print_r($a);die();
if (array_diff($arr, $a)) {
return True;
}
else
{
return False;
}
}
I make 2 function rotate and generate
function rotate($l, $n) {
$b = $l[$n];
$sisa = array_values(array_diff($l, array($b)));
for ($i = 0; $i < count($sisa) ; $i++) {
$random[] = generate($sisa, $b);
}
print_r($random);die();
$hasil = $l[$n] . implode("",$random);
return $hasil;
}
function generate($sisa, $b) {
$string = implode("",$sisa);
$length = count($sisa);
$size = strlen($string);
$str = '';
for( $i = 0; $i < $length; $i++ ) {
$str .= $string[ rand( 0, $size - 1 ) ];
}

Answer 1

Here there is a pair of functions that lets you calculate a permutation set
(no repetitions are taken in account)
function extends_permutation($char, $perm) {
$result = [];
$times = count($perm);
for ($i=0; $i<$times; $i++) {
$temp = $perm;
array_splice($temp, $i, 0, $char);
array_push($result, $temp);
}
array_push($result, array_merge($perm, [$char]));
return $result;
}
function extends_set_of_permutations($char, $set) {
$step = [];
foreach ($set as $perm) {
$step = array_merge($step, extends_permutation($char, $perm));
}
return $step;
}
you can use them to generate the required set of permutations. Something like this:
$seed = "XjYAKpR";
// the first set of permutations contains only the
// possible permutation of a one char string (1)
$result_set = [[$seed[0]]];
$rest = str_split(substr($seed,1));
foreach($rest as $char) {
$result_set = extends_set_of_permutations($char, $result_set);
}
$result_set = array_map('implode', $result_set);
sort($result_set);
At the end of the execution you will have the 5040 permutations generated by your string in the result_set array (sorted in alphabetical order).
Add a char and you will have more than 40000 results.
The functions are quite naive in implementation and naming, both aspects can be improved.