strings

[sheephat]

Hello Users,

Could someone please help me with this, I have a script in which I need to generate more strings from the first.

For example say my string is “cat”. I need this to somehow generate the strings:
cat
cta
atc
act
tac
tca

and then with capitals: eg

Cat
Cta
atC
aCt
taC
tCa
cAt
ctA
Atc
Act
tAc
tcA
caT
cTa
aTc
acT
Tac
Tca
CAt
CtA
AtC
ACt
tAC
tCS

Etc.etc to make every possible combination of the word cat including capitals.

I would be most appreciative of any help you may be able to give.

[nrg_alpha]

I think a good starting point would be to describe the goal / purpose of this script you seek.. by giving why you are looking for something like this might open the doors to other solutions. Perhaps what you are thinking of is not the best approach?

On the onset, having the 'why' aspect set aside, I would be prone to investigate putting your entry into an array, and look into playing around with keys and their values (example, the shuffle() function shuffles key values around randomly [not what you are looking for, I know]).. Arrays offer tons of functionality that you can look up on php.net.. perhaps there is built in functionlaity to do what it is you seek.

Cheers,

NRG

[Weedpacket]

For part of the job, here's a routine I keep handy

function LexicographicPermutations($l)
{
	$n = count($l);
	if($n == 0 || $n == 1)
		return array($l);
	if($n == 2)
		return array($l, array_reverse($l));
	$table = array();
	for($i = 0; $i < $n; ++$i)
	{
		$new = $l;
		$li = $new[$i];
		unset($new[$i]);
		$new = LexicographicPermutations(array_values($new));
		foreach($new as $k=>$v)
			array_unshift($new[$k], $li);
		$table[] = $new;
	}
	return call_user_func_array('array_merge', $table);
}



$array = str_split('rada');

print_r(array_map('join', LexicographicPermutations($array)));

It doesn't recognise duplicates, and works on arrays rather than strings (hence the splitting and joining) and of course doesn't do the different capitalisations, but of course its result can have those things done to it afterwards.

[nrg_alpha]

Here is what I came up with for the first part (which is in essence scrolling the array's values it seems).

*Edit: Realised the OP wanted new strings of each result.. so I reposted the new code:

$entry = '12345'; // some random entry
$stringArray = str_split($entry);

$newStringArray = array();

function leftScroll($scrollArrayLeft){
	global $newStringArray;
	for($i = 0; $i < count($scrollArrayLeft); ++$i){
		$first_to_last = reset($scrollArrayLeft); // grab first index key value
		array_shift($scrollArrayLeft); // remove first index/key and shift all others downwards
		array_push($scrollArrayLeft, $first_to_last); // append new last index/key to array
		foreach($scrollArrayLeft as $keyVal){
			$newStringArray[$i] .= $keyVal;
		}
	}
	unset($first_to_last, $keyVal, $scrollArrayLeft, $i); //clean up varaibles no longer in use...
}
leftScroll($stringArray);
for($x = 0; $x < count($newStringArray); ++$x){
	echo $newStringArray[$x] . '<br />';
}

Cheers,

NRG

**Edit.. oops.. my function does not do what the OP wanted for the first part.. I realised that simply 'scrolling' the keys/values doesn't work. Please disregard my post 🙁

[Weedpacket]

nrg_alpha wrote:

    unset($first_to_last, $keyVal, $scrollArrayLeft, $i); //clean up varaibles no longer in use... 

Incidentally, this is quite unnecessary: all local variables are unset when they go out of scope (as at the end of a function).

[nrg_alpha]

Good call.. I completely forgot about variable scope. :queasy:

Cheers,

NRG