Get combination from given array and string

question_1.php

<?php

function getStringCombination($word, $dict)
{
    $result = [];
    if (empty($word)) {
        return $result;
    }

    foreach ($dict as $index => $str) {
        if (strpos($word, $str) === 0) {
            $substr = substr($word, strlen($str));

            $clonedDict = $dict;
            unset($clonedDict[$index]);

            $subResult = getStringCombination($substr, $clonedDict);

            if (! empty($subResult)) {
                foreach ($subResult as $subRes) {
                    $result[] = array_merge([$str], $subRes);
                }
            } else {
                $result[] = [$str];
            }
        }
    }

    return $result;
}

$dictionary = ['pro', 'gram', 'merit', 'program', 'it', 'programmer'];
$input		= 'programmerit';

print_r(getStringCombination($input, $dictionary));