Scrabble word generator - php

Question

After watching my brother cheating in an iphone game like scrabble I was wondering what was the algotithm behing it.
Given some letters: A B C T E E
And SQL table full of correct words.
How would I create all combinations of letters for making afterwars a select like:
Select * from words where word IN ('A','AT',...), just to take from those combinations the ones that are correct ?¿
Another possible way could be a SQL table with every letter in a column for each word.
But afterwards the system should verify that any word form the select has more time the same letter given.
Ex:
c1 c2 c3 c4
t e e
a i r
This question is just for feeding curiosity, and learning witch algorithm it might be used in for creating all those combinations (with full and partial given letters) to check afterwards if they exist.
Thanks!
font: http://icon.cat/worder/wordsfinder

Answer 1

To find all possible valid word this are the following steps
Find all possible combination
Find each permutation for each word in the combination
Search Database for the words
List the words
Script
$tiles = array( "A", "B", "C", "T", "E", "E") ;
$words = array();
$set = powerSet($tiles,2);
$mysql = new mysqli("localhost","root","","word");
$sql = "SELECT id from dic WHERE word = '%s'" ;
foreach ($set as $key => $value)
{
$word = implode("", $value);
$wordPermutation = permute($word);
foreach($wordPermutation as $keyWord)
{
if(!in_array($keyWord, $words))
{
//if($result = $mysql->query(sprintf($sql,$keyWord)))
//{
//var_dump(sprintf($sql,$keyWord));
//if($result->num_rows > 0)
//{
$words[] = $keyWord ;
//}
//}
}
}
}
print_r($words);
Functions
function powerSet($in, $minLength = 1, $max = 10) {
$count = count ( $in );
$members = pow ( 2, $count );
$return = array ();
for($i = 0; $i < $members; $i ++) {
$b = sprintf ( "%0" . $count . "b", $i );
$out = array ();
for($j = 0; $j < $count; $j ++) {
if ($b {$j} == '1')
$out [] = $in [$j];
}
if (count ( $out ) >= $minLength && count ( $out ) <= $max) {
$return [] = $out;
}
}
return $return;
}
function permute($str) {
if (strlen($str) < 2) {
return array($str);
}
$permutations = array();
$tail = substr($str, 1);
foreach (permute($tail) as $permutation) {
$length = strlen($permutation);
for ($i = 0; $i <= $length; $i++) {
$permutations[] = substr($permutation, 0, $i) . $str[0] . substr($permutation, $i);
}
}
return $permutations;
}
Please note that i commented out the database verification section so that the demo can work
See Demo
http://codepad.viper-7.com/oG6E6w

Answer 2

I would try something like
WHERE (word like '%A%' and not word like '%A%A%')
AND (word like '%B%' and not word like '%B%B%')
and so on. But I'm sure there must be more professional solutions!

Answer 3

I finally got it working.
If someone is ever interested on making a self word generator, this is how I made it.
MySQL, a table with:
[id] , [Word]
a view for each length:
V1 = Select Word from TABLE where LENGTH(Word) = 1
V2 = Select Word from TABLE where LENGTH(Word) = 2
[...]
php side:
Using the functions of baba, I made an array where: array[2] are the combinations of letters that have a length of 2, and so on.
Finally all i had to do is a Select for each array to the view like
Select Word from V3 where Word like ('asd','dsa',....);
There must be a faster way, but with a less than a second (localhost) and word diccionary of 700K made its way.

Answer 4

A better way to achieve unscrambling is to use anagrams. So instead of having a library of all the possible words, use an associative array using the letters that make up the words as the index.
anagram['aer'] = ['are', 'ear', 'era']
To implement this, loop through all of your dictionary words and push each one into an array where the index is the letters of the word in alphabetical order.
for(var i = 0; i < dictionary.length; i++) {
//Loop through dictionary array
var str = words[i].split('').sort().join('');
//break apart the word and sort it alphabetically
if(!anagram[str]) {
//check if there is already an index with that same anagram
anagram[str] = [];
}
anagram[str].push(words[i]);
//Add the word to the anagram array
}
This way allows you to quickly index the library without going through thousands of possible permutations.
An example of this method in javascript: Word Unscrambler

Answer 5

Here is great article about World fastest scrabble program
You just should have some knowledge in Descrete Math(Word Automats). Hope it will help you :)