Find array in array, in sequence

Question

How to code up a [find-array-in-array] function?

Psuedo-code

Haystack:

array(0=a, 1=b, 2=a, 3=b, 4=c,         


        

Answer 1

My attempt at creating this function;

function find_array_in_array($needle, $haystack) {
    $keys = array_keys($haystack, $needle[0]);
    $out = array();
    foreach ($keys as $key) {
        $add = true;
        $result = array();
        foreach ($needle as $i => $value) {
            if (!(isset($haystack[$key + $i]) && $haystack[$key + $i] == $value)) {
                $add = false;
                break;
            }
            $result[] = $key + $i;
        }
        if ($add == true) { 
            $out[] = $result;
        }
    }
    return $out;
}

$haystack = array('a', 'b', 'a', 'b', 'c', 'c', 'a', 'b', 'd', 'c', 'a', 'b', 'a', 'b', 'c');

$needle = array('a', 'b', 'c');

print_r(find_array_in_array($needle, $haystack));

Outputs;

Array
(
    [0] => Array
        (
            [0] => 2
            [1] => 3
            [2] => 4
        )

    [1] => Array
        (
            [0] => 12
            [1] => 13
            [2] => 14
        )

)