To past the time a friend and mine play a game in which we are choose a word (such as "ETHIOPIA") and using those letters, must construct as many smaller words as possible (example: "path", "Patio", "eat" and "ate").
We run into a problem though... Sometimes we want to check to see if there are any other words.
So I designed a script, which I do not know how to code... So I am asking, please, if someone could explain to me HOW to script it (is PHP even the right language-choice?) or just to direct me in to best path.
There are three main parts or "functions" I need to be done..

1) Take a value (from, for a text-input or such) and
a) calculate how many letters there are
b) give each letter a value ($letterone, $lettertwo, $letterthree...)
-- Although I'm not sure if "b" is possible.... or even needed, for the next step

2) Take a bunch of letter, and echo each one in every possible order. I was thinking about using something like "x=1; for(x=1,x<9,x++){echo x};" and then setting each number as a different letter... In the previous example would echo E, T, H, I, O, P, I, A... but then how would I be able to echo each one 8 times, and for each set of 8, one of each of the next letter (so like: EE, ET, EH, EI...etc)? I'm sure there is another way to do this

3) Take all the echoed words, or all the words on a page/document and compare them all to a dictionary, to see if they are real words (if they are, keep them... if they aren't delete them).

Any help at all would be much appreciated. Thank you!

I don't know if there's a really smart way of doing this. Of course, you could try all possible words, but that would not be very effective. Quite the opposite in fact. For a 8 letter word, there would be a total of 8! combinations of 8-letter words, which is 40320 combinations (8! = 8*7*6*5*4*3*2*1). Then plus all the combinations when only using 7 letters, 6 letters and so on.

So the total amount of combinations would be
8 1-letter words, plus (8*7) 2-letter words, (8*7*6) 3-letter words etc.
Which equals 109 600 combinations in total

And just to make a point of how ineffective this is, and how fast the count of possible combinations increase.
8! = 40 320
10! = 3 628 800
15! = 1 307 674 368 000

Any way, here is a function which will try all possible combinations. You'll have to figure out how to validate a word against a dictionary your self :P

PHP Code:

function tryAll($current, $letters) {
   for($i = 0; $i < count($letters); $i++) {
      $letter = $letters[$i];
      $str = $current.$letter;

      // Check if $str is a valid word, with a dictionary in a
      // database, file or what ever smart solution you may find

      // Make a copy of $letters, without the currently one selected
      // (since that letter is already used, you dont wanna use it again)
      $copy = $letters;
      unset($copy[$i]);
      
      // run recursive call to same function
      tryAll($str, $copy);
   }
}

$word = array('e', 't', 'h', 'i', 'o', 'p', 'i', 'a');
tryAll('', $word); 


I dont know if this will help understanding it, but what is does is basically add the first available letter and check if it's a valid word, add the next letter and check again etc. When all letters are used, it backs up to the last point where it had several letters left, and try the other one. Then it keeps doing that until it has backed all the way to the start and tried all the different letters.

It would go like this

e, et, eth, ethi, ethio, ethiop, ethiopi, ethiopia, ethiopa, ethiopai, ethioi, ethioip, ethioipa, ethioia, ethioiap, ethioa, ethioap, ethioapi, ethioai, ethioaip ...

Thank you very much.. Yes I understand how enormous the job would be... but what you've done has helped me a lot!!

Actualy... something seems to be going wrong.. I added "echo $str . "<br>";" so that it would echo it all out so that I could see... but it just echos
e
e
e
e
e
e
etc... why is that?

And why wouldn't your code
ethiopia
ethiopie
ethiopit
ethiopih
etc...
Sorry for all the theoretical questions, i'm just trying to better understand learn.

Sorry, my mistake. It's the unset() part that doesn't work. When you unset a array value, apparently it's not completely removed from the array, only the actual value. That is, after unsetting the 'e', the array still looks like this

PHP Code:

array(
   0 => ,
   1 => 't',
   2 => 'h',
   // and so on ...
) 


That's why it kept repeating the e. I solved it by making this change

PHP Code:

   // This
   $copy = $letters;
   unset($copy[$i]);

   // Becomes this
   $copy = array();
   foreach ($letters as $key => $letter) {
      if ($key != $i) {
         $copy[] = $letter;
      }
   } 


I also tried to gererate all words and it took about 7-8 sec just to go through it and print the words. I imagine that checking each word in a dictionary would make it go a whole lot slower.