从字符串c++中提取单个单词

#include <iostream>
#include <string>
#include <vector>

std::vector<std::string> extractWords(const std::string& str) {
    std::vector<std::string> words;
    std::string word;
    for (char c : str) {
        if (std::isalpha(c)) {
            word += c;
        } else if (!word.empty()) {
            words.push_back(word);
            word.clear();
        }
    }
    if (!word.empty()) {
        words.push_back(word);
    }
    return words;
}

int main() {
    std::string input = "Hello, world! This is a C++ string.";
    std::vector<std::string> words = extractWords(input);
    for (const std::string& word : words) {
        std::cout << word << std::endl;
    }
    return 0;
}