Stringy\Stringy::longestCommonSubstring PHP Method

    public function longestCommonSubstring($otherStr)
    {
        // Uses dynamic programming to solve
        // http://en.wikipedia.org/wiki/Longest_common_substring_problem
        $encoding = $this->encoding;
        $stringy = static::create($this->str, $encoding);
        $strLength = $stringy->length();
        $otherLength = \mb_strlen($otherStr, $encoding);
        // Return if either string is empty
        if ($strLength == 0 || $otherLength == 0) {
            $stringy->str = '';
            return $stringy;
        }
        $len = 0;
        $end = 0;
        $table = array_fill(0, $strLength + 1, array_fill(0, $otherLength + 1, 0));
        for ($i = 1; $i <= $strLength; $i++) {
            for ($j = 1; $j <= $otherLength; $j++) {
                $strChar = \mb_substr($stringy->str, $i - 1, 1, $encoding);
                $otherChar = \mb_substr($otherStr, $j - 1, 1, $encoding);
                if ($strChar == $otherChar) {
                    $table[$i][$j] = $table[$i - 1][$j - 1] + 1;
                    if ($table[$i][$j] > $len) {
                        $len = $table[$i][$j];
                        $end = $i;
                    }
                } else {
                    $table[$i][$j] = 0;
                }
            }
        }
        $stringy->str = \mb_substr($stringy->str, $end - $len, $len, $encoding);
        return $stringy;
    }