定义并实现一个CPU类。包含等级(rank)、频率(frequency)、电压(voltage)等属性;包含无参构造函数、有参构造函数、复制构造函数、析构函数、公有成员函数run、stop以及和属性对应的公有成员函数set、get。其中ra

nk、frequency、voltage均为私有属性，可以使用set和get函数进行访问和修改。run函数表示CPU运行，stop函数表示CPU停止运行。以下是代码实现：

class CPU {
private:
    int rank;
    float frequency;
    float voltage;
public:
    CPU() : rank(0), frequency(0.0), voltage(0.0) {}
    CPU(int r, float f, float v) : rank(r), frequency(f), voltage(v) {}
    CPU(const CPU& cpu) : rank(cpu.rank), frequency(cpu.frequency), voltage(cpu.voltage) {}
    ~CPU() {}
    void run() {
        cout << "CPU is running." << endl;
    }
    void stop() {
        cout << "CPU has stopped." << endl;
    }
    void setRank(int r) {
        rank = r;
    }
    void setFrequency(float f) {
        frequency = f;
    }
    void setVoltage(float v) {
        voltage = v;
    }
    int getRank() const {
        return rank;
    }
    float getFrequency() const {
        return frequency;
    }
    float getVoltage() const {
        return voltage;
    }
};

可以使用以下代码进行测试：

int main() {
    CPU cpu(1, 2.5, 1.2);
    cout << "Rank: " << cpu.getRank() << endl;
    cout << "Frequency: " << cpu.getFrequency() << endl;
    cout << "Voltage: " << cpu.getVoltage() << endl;
    cpu.setRank(2);
    cpu.setFrequency(3.0);
    cpu.setVoltage(1.5);
    cout << "Rank: " << cpu.getRank() << endl;
    cout << "Frequency: " << cpu.getFrequency() << endl;
    cout << "Voltage: " << cpu.getVoltage() << endl;
    CPU cpu2 = cpu;
    cout << "Rank: " << cpu2.getRank() << endl;
    cout << "Frequency: " << cpu2.getFrequency() << endl;
    cout << "Voltage: " << cpu2.getVoltage() << endl;
    cpu.run();
    cpu.stop();
    return 0;
}