PHP array combinations

You can use the solution found here http://stereofrog.com/blok/on/070910.

Incase the link goes down here's the code....

class Combinations implements Iterator{    protected $c = null;    protected $s = null;    protected $n = 0;    protected $k = 0;    protected $pos = 0;    function __construct($s, $k) {        if(is_array($s)) {            $this->s = array_values($s);            $this->n = count($this->s);        } else {            $this->s = (string) $s;            $this->n = strlen($this->s);        }        $this->k = $k;        $this->rewind();    }    function key() {        return $this->pos;    }    function current() {        $r = array();        for($i = 0; $i < $this->k; $i++)            $r[] = $this->s[$this->c[$i]];        return is_array($this->s) ? $r : implode('', $r);    }    function next() {        if($this->_next())            $this->pos++;        else            $this->pos = -1;    }    function rewind() {        $this->c = range(0, $this->k);        $this->pos = 0;    }    function valid() {        return $this->pos >= 0;    }    protected function _next() {        $i = $this->k - 1;        while ($i >= 0 && $this->c[$i] == $this->n - $this->k + $i)            $i--;        if($i < 0)            return false;        $this->c[$i]++;        while($i++ < $this->k - 1)            $this->c[$i] = $this->c[$i - 1] + 1;        return true;    }}foreach(new Combinations("1234567", 5) as $substring)    echo $substring, ' ';

12345 12346 12347 12356 12357 12367 12456 12457 12467 12567 13456 13457 13467 13567 14567 23456 23457 23467 23567 24567 34567

<?phpecho "<pre>";$test = array("test_1","test_2","test_3");// Get Combination$return = uniqueCombination($test);//Sortsort($return);//Pretty Printprint_r(array_map(function($v){ return implode(",", $v); }, $return));function uniqueCombination($in, $minLength = 1, $max = 2000) {    $count = count($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 ++) {            $b{$j} == '1' and $out[] = $in[$j];        }        count($out) >= $minLength && count($out) <= $max and $return[] = $out;        }    return $return;}?>

output

Array(    [0] => test_1    [1] => test_2    [2] => test_3    [3] => test_1,test_2    [4] => test_1,test_3    [5] => test_2,test_3    [6] => test_1,test_2,test_3)

The Math_Combinatorics in PEAR repository does exactly what you want:

A package that returns all the combinations and permutations, without repetition, of a given set and subset size. Associative arrays are preserved.

require_once 'Math/Combinatorics.php';$combinatorics = new Math_Combinatorics;$input = array(1, 2, 3, 4, 5, 6, 7);$output = $combinatorics->combinations($input, 5); // 5 is the subset size// 1,2,3,4,5// 1,2,3,4,6// 1,2,3,4,7// 1,2,3,5,6// 1,2,3,5,7// 1,2,3,6,7// 1,2,4,5,6// 1,2,4,5,7// 1,2,4,6,7// 1,2,5,6,7// 1,3,4,5,6// 1,3,4,5,7// 1,3,4,6,7// 1,3,5,6,7// 1,4,5,6,7// 2,3,4,5,6// 2,3,4,5,7// 2,3,4,6,7// 2,3,5,6,7// 2,4,5,6,7// 3,4,5,6,7