열혈강의 c++ 문제 3-2 클래스의 정의

#include <iostream>
 
using namespace std;
 
class calculator {
    int add_c, sub_c, mul_c, div_c;
 
public:
    void Init();
    void add(double a, double b); //덧셈
    void sub(double a, double b);//뺄셈
    void mul(double a, double b);//곱셈
    void div(double a, double b);//나눗셈
    void showopcount();
};
 
void calculator::Init() {
    add_c = 0;
    sub_c = 0;
    mul_c = 0;
    div_c = 0;
}
 
void calculator::add(double a, double b) {
    cout << a << " + " << b << " = " << a + b << endl;
    add_c++;
}
 
void calculator::sub(double a, double b) {
    cout << a << " - " << b << " = " << a - b << endl;
    sub_c++;
}
 
void calculator::mul(double a, double b) {
    cout << a << " * " << b << " = " << a * b << endl;
    mul_c++;
}
 
void calculator::div(double a, double b) {
    cout << a << " / " << b << " = " << a / b << endl;
    div_c++;
}
 
 
void calculator::showopcount() {
    cout << "덧셈: " << add_c << ", 뺄셈: " << sub_c << ", 곱셈: " << mul_c << ", 나눗셈: " << div_c << endl;
}
 
int main() {
    calculator cal;
    cal.Init();
    cal.add(3.2, 2.4);
    cal.div(3.5, 1.7);
    cal.sub(2.2, 1.5);
    cal.div(4.9, 1.2);
    cal.showopcount();
    return 0;
}