#include<iostream>#include<map>#include<functional>#include<string>using namespace std;int add(int a,int b){    return a+b;}struct divide{    int operator()(int denominator,int divisor)    {        return denominator/divisor;    }};auto mode=[](int i,int j) { return i%j;};int main(){    int (*pf)(int,int)=add;    map<string,function<int(int,int)>> binops;    binops.insert({"+",add});    binops.insert({"+",pf});    binops.insert({"-",minus<int>()});    binops.insert({"*",[](int i,int j) {return i*j;}});    binops.insert({"/",divide()});    binops.insert({"%",mode});    cout<<binops["+"](1,3)<<endl;    cout<<binops["-"](2,5)<<endl;    cout<<binops["*"](1,2)<<endl;    cout<<binops["/"](4,2)<<endl;    cout<<binops["%"](4,2)<<endl;    return 0;}