C++ Primer（第5版） 练习 14.44

练习 14.44 编写一个简单的桌面计算器使其能处理二元运算。

环境：Linux Ubuntu（云服务器）

工具：vim

代码块

/*************************************************************************
	> File Name: ex14.44.cpp
	> Author: 
	> Mail: 
	> Created Time: Tue 09 Jul 2024 10:37:09 AM CST
 ************************************************************************/

#include<iostream>
#include<vector>
#include<functional>
#include<algorithm>
#include<map>
using namespace std;

int add(int a, int b){
    return a + b;
}

auto mod = [](int a, int b){ return a % b; };

struct divide{
    int operator()(int a, int b){
        return a / b;
    }
};


int main(){
    map<string, function<int(int, int)>> binops = {
        {"+", add},
        {"-", std::minus<int>()},
        {"/", divide()},
        {"*", [](int a, int b){ return a * b; }},
        {"%", mod}
    };

    int a, b;
    cout<<"Enter a and b: ";
    cin>>a>>b;
    cout<<"a + b = "<<binops["+"](a, b)<<endl;
    cout<<"a - b = "<<binops["-"](a, b)<<endl;
    cout<<"a * b = "<<binops["*"](a, b)<<endl;
    cout<<"a / b = "<<binops["/"](a, b)<<endl;
    cout<<"a % b = "<<binops["%"](a, b)<<endl;

    return 0;
}

运行结果显示如下