题解 | #多态实现计算器功能#

//既然父类函数不用实现，那么直接定义成抽象类即可
#include <iostream>
using namespace std;

class BaseCalculator {
    public:
        int m_A;
        int m_B;
       virtual int getResult() = 0;
        
};

// 加法计算器类
class AddCalculator : public BaseCalculator {
    int getResult()
    {
        return m_A + m_B;
    }
    
};

// 减法计算器类
class SubCalculator : public BaseCalculator {
    int getResult()
    {
        return m_A - m_B;
    }
    
};


int main() {

    BaseCalculator* cal = new AddCalculator;
    cal->m_A = 10;
    cal->m_B = 20;
    cout << cal->getResult() << endl;
    delete cal;

    cal = new SubCalculator;
    cal->m_A = 20;
    cal->m_B = 10;
    cout << cal->getResult() << endl;
    delete cal;

    return 0;
}