Все возможные комбинации элементов массива

$array[0] = [ 1, 2, 3 ];
$array[1] = [ 4, 5, 6 ];
// и т.д. 
 
// надо получит таким массив.
/*
1-2-6
1-5-6
4-2-3
4-5-3
*/

<?php
 
function pc_permute($items, $perms = array( )) {
    if (empty($items)) { 
        print join(' ', $perms) . "\n";
    }  else {
        for ($i = count($items) - 1; $i >= 0; --$i) {
             $newitems = $items;
             $newperms = $perms;
             list($foo) = array_splice($newitems, $i, 1);
             array_unshift($newperms, $foo);
             pc_permute($newitems, $newperms);
         }
    }
}
 
pc_permute(array(0, 1, 2, 3, 4, 5, 7, 8));

// Количество элементов в массиве ровноы.
$array[0]= ["a1","a2","a3"];
$array[1]= ["b1","b2","b3"];
$array[2]= ["c1","c2","c3"];
//и т.д.

[
[0]=>[a1,a2,b3],
[1]=>[a1,b2,b3],
[2]=>[a1,a2,c3],
[3]=>[a1,c2,c3],
[4]=>[a1,b2,c3],
[5]=>[a1,c2,b3],
 
[6]=>[b1,b2,a3],
[7]=>[b1,a2,a3],
[8]=>[b1,b2,c3],
[9]=>[b1,c2,a3],
[10]=>[b1,c2,c3],
[11]=>[b1,a2,c3],
 
[12]=>[c1,c2,a3],
[13]=>[c1,a2,a3],
[14]=>[c1,c2,b3],
[15]=>[c1,b2,b3],
[16]=>[c1,b2,c3],
[17]=>[c1,b2,a3],
]

// Количество элементов в массиве ровноы.
$array[0]= ["a1","a2","a3"];
$array[1]= ["b1","b2","b3"];
$array[2]= ["c1","c2","c3"];
//и т.д.

[
[0]=>[a1,a2,b3],
[1]=>[a1,b2,b3],
[2]=>[a1,a2,c3],
[3]=>[a1,c2,c3],
[4]=>[a1,b2,c3],
[5]=>[a1,c2,b3],
[6]=>[a1,b2,a3],
[7]=>[a1,c2,a3],
[8]=>[a1,c2,b3],
 
[9]=>[b1,b2,a3],
[10]=>[b1,a2,a3],
[11]=>[b1,b2,c3],
[12]=>[b1,c2,a3],
[13]=>[b1,c2,c3],
[14]=>[b1,a2,c3],
[15]=>[b1,a2,b3],
[16]=>[b1,c2,b3],
 
 
[17]=>[c1,c2,a3],
[18]=>[c1,a2,a3],
[19]=>[c1,c2,b3],
[20]=>[c1,b2,b3],
[21]=>[c1,b2,c3],
[22]=>[c1,b2,a3],
[23]=>[c1,b2,c3],
[24]=>[c1,a2,v3],
 
]