如何在C++的Caesar Cipher程序中包含空格？

#include <iostream>
#include <cctype>

std::string caesarCipher(std::string text, int shift) {
    std::string result = "";
    for (char c : text) {
        if (isspace(c)) {
            result += c;  // 如果是空格字符，直接输出空格
        } else {
            char shifted = (c - 'a' + shift) % 26 + 'a';  // 字母替换操作
            result += shifted;
        }
    }
    return result;
}

int main() {
    std::string text = "hello world";
    int shift = 3;
    std::string encrypted = caesarCipher(text, shift);
    std::cout << "Encrypted text: " << encrypted << std::endl;
    return 0;
}