题解 | 实现简单计算器功能

#include <iostream>
using namespace std;

class calculation{
    private:
        int a;
        int b;
    public:
        virtual int calc(int num1, int num2) const  = 0;
        virtual ~ calculation() = default;

};
class add : public calculation{
    public:
        int calc(int num1, int num2) const override{
            return num1+num2;
            }
};
class sub : public calculation{
    public:
        int calc(int num1, int num2) const override{
            return num1-num2;
            }
};
class mul : public calculation{
    public:
        int calc(int num1, int num2) const override{
            return num1*num2;
            }
};
class divs : public calculation{
    public:
        int calc(int num1, int num2) const override{
            return num1/num2;
            }
};
int main() {

    char str[100] = { 0 };
    cin.getline(str, sizeof(str),' ');
    int a, b;
    // write your code here......
    cin>>a>>b;
    
    calculation* subs = new sub;
    calculation* muls = new mul;
    calculation* div = new divs;
    if(str[0] == 'a'){
        calculation* adds = new add;
        cout<<adds->calc(a, b);
        delete adds;
    }else if (str[0] == 's') {
        cout<<subs->calc(a, b);
    }else if (str[0] == 'm') {
        cout<<muls->calc(a, b);
    }else if (str[0] == 'd') {
        if(b!=0){cout<<div->calc(a, b);}
        else{cout<<"Error";}
    }

    return 0;
}