Encode and Decode Strings

You are given a list of strings `strs`, where each string may contain any of the 256 valid ASCII characters (including special characters and empty strings). Your task is to implement two methods: - `encode(strs)`: Encodes the list of strings into a single string. - `decode(s)`: Decodes the single string back into the original list of strings. The encoded string produced by `encode` must contain all the information necessary to reconstruct the original list exactly, even if some strings are empty or contain special characters. You are **not allowed** to use any built-in serialization methods (such as `eval`). **Constraints:** - `1 <= strs.length <= 200` - `0 <= strs[i].length <= 200` - Each `strs[i]` may contain any ASCII character. Return the encoded string from `encode`, and the decoded list of strings from `decode`.