Translator

class Translator {
public:

    Translator() = default;

    void Add(std::string_view source, std::string_view target) {
        words_.insert(std::string(source));
        words_.insert(std::string(target));
        forward_[*words_.find(std::string(source)) ] = *words_.find(std::string(target));
        backward_[*words_.find(std::string(target))] = *words_.find(std::string(source));
    }

    std::string_view TranslateForward(std::string_view source) const {
        if (forward_.find(source) == forward_.end()) {
            return "";
        }
        return forward_.at(source);
    }

    std::string_view TranslateBackward(std::string_view target) const {
        if (backward_.find(target) == backward_.end()) {
            return "";
        }
        return backward_.at(target);

    }

private:
    std::set<std::string> words_;
    std::map<std::string_view, std::string_view> forward_;
    std::map<std::string_view, std::string_view> backward_;
};