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

int main() {
    // 输入一堆字符串
    std::vector<std::string> inputs = {
        "digit=[0-9]",
        "alpha=[a-zA-Z]",
        "alnum=[a-zA-Z0-9]"
    };

    // 遍历处理每个字符串
    for (const auto& input : inputs) {
        std::stringstream ss(input);
        std::string token;

        // 分割字符串
        std::string left;
        std::string right;

        // 以等号分割
        std::getline(ss, left, '=');
        std::getline(ss, right);

        // 输出分割结果
        std::cout << "左边: " << left << std::endl;
        std::cout << "右边: " << right << std::endl;
    }

    return 0;
}