简化PHP代码：for $a = $j = $i = 0; $i $mystr_length; $i++ $a = $a + 1 256; $j = $j + $box$a 256; $tmp = $box$a; $box$a = $box$j; $box$j = $tmp; $result = chror

$a = $j = 0; for ($i = 0; $i < $mystr_length; $i++) { $a = ($a + 1) % 256; $j = ($j + $box[$a]) % 256; [$box[$a], $box[$j]] = [$box[$j], $box[$a]]; $result .= chr(ord($mystr[$i]) ^ ($box[($box[$a] + $box[$j]) % 256])); }