Hey all, basically, i have an array:
array('a', 'b', 'c');
Now i run it through an array permutation function and the result is:
Array
(
[0] => Array
(
[0] => C
)
[1] => Array
(
[0] => B
)
[2] => Array
(
[0] => B
[1] => C
)
[3] => Array
(
[0] => C
[1] => B
)
[4] => Array
(
[0] => A
)
[5] => Ar开发者_C百科ray
(
[0] => A
[1] => C
)
[6] => Array
(
[0] => C
[1] => A
)
[7] => Array
(
[0] => A
[1] => B
)
[8] => Array
(
[0] => B
[1] => A
)
[9] => Array
(
[0] => A
[1] => B
[2] => C
)
[10] => Array
(
[0] => A
[1] => C
[2] => B
)
[11] => Array
(
[0] => B
[1] => A
[2] => C
)
[12] => Array
(
[0] => B
[1] => C
[2] => A
)
[13] => Array
(
[0] => C
[1] => A
[2] => B
)
[14] => Array
(
[0] => C
[1] => B
[2] => A
)
)
Now my question is, how can i clean that array up so that:
array ( C, B )
is the same as
array ( B, C )
and it removes the second array
How would i do that?
EDIT... after some research based on your answers, this is what I came up with:
array_walk($array, 'sort');
$array = array_unique($array);
sort($array); // not necessary
Just sort the constituent arrays:
foreach ($arrays AS &$arr)
{
sort($arr);
}
So {"C", "B"} becomes => {"B", "C"}
and {"B", "C"} becomes => {"B", "C"}
which are identical.
array_multisort($array);
array_unique($array);
You can also use the pear package Math_Combinatorics.
require_once 'Combinatorics.php';
$combinatorics = new Math_Combinatorics;
$a = array('a', 'b', 'c');
// creating and storing the combinations
for($combinations = array(), $n=1; $n<=count($a); $n++) {
$combinations = array_merge($combinations, $combinatorics->combinations($a, $n));
}
// test output
foreach($combinations as $c) {
echo join(', ', $c), "\n";
}
prints
a
b
c
a, b
a, c
b, c
a, b, c
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