2、定义一个CPU类，包含频率（frequency）、电压(voltage)等私有数据成员, 每个数据成员有两个公有函数用于读写操作。有两个公有的成员函数run、stop表示运行和停止（可用输出信息表示）。其中frequency为整型数的频率值，voltage为浮点型的电压值。写出默认构造函数， 带参数的构造函数，拷贝构造函数，析构函数。 主函数进行测试。

好的，我会按照您的要求回答问题并给出代码示例：

定义一个CPU类如下：

class CPU {
private:
    int frequency;  // 频率值
    float voltage;  // 电压值
public:
    CPU() {
        frequency = 0;
        voltage = 0.0f;
    }
    CPU(int f, float v) {
        frequency = f;
        voltage = v;
    }
    CPU(const CPU& other) {
        frequency = other.frequency;
        voltage = other.voltage;
    }
    ~CPU() { }
    int getFrequency() const {
        return frequency;
    }
    void setFrequency(int f) {
        frequency = f;
    }
    float getVoltage() const {
        return voltage;
    }
    void setVoltage(float v) {
        voltage = v;
    }
    void run() {
        std::cout << "CPU is running.\n";
    }
    void stop() {
        std::cout << "CPU has stopped.\n";
    }
};

主程序进行测试：

int main() {
    CPU c1;
    c1.setFrequency(2000);
    std::cout << "Frequency: " << c1.getFrequency() << std::endl;
    c1.setVoltage(1.2f);
    std::cout << "Voltage: " << c1.getVoltage() << std::endl;

    CPU c2(3000, 1.4f);
    std::cout << "Frequency: " << c2.getFrequency() << std::endl;
    std::cout << "Voltage: " << c2.getVoltage() << std::endl;

    CPU c3(c2);
    std::cout << "Frequency: " << c3.getFrequency() << std::endl;
    std::cout << "Voltage: " << c3.getVoltage() << std::endl;

    c1.run();
    c1.stop();

    return 0;
}

输出结果如下：

Frequency: 2000
Voltage: 1.2
Frequency: 3000
Voltage: 1.4
Frequency: 3000
Voltage: 1.4
CPU is running.
CPU has stopped.