#include <iostream>
#include <functional>
#include <vector>
#include <numeric>
#include <string>

using namespace std;


    

int main()
{

    vector<int> v{1,2,3,4,5,6};


    function<string(string,int)> f = [](string str, int x) -> string
    {
      string rslt=str+to_string(x) + " ";
      return rslt; 
    };

    cout << "reduce with f : " << accumulate(v.begin(), v.end(), string(" "), f) << endl;
    






    int count=0;
    string name="v";

    function<string(string,int)> fc = [&](string str, int x) -> string
    {
      string rslt=str + name + "[" + to_string(count++) + "]=" + to_string(x) + " ";
      return rslt; 
    };

    cout << "reduce with fc : " << accumulate(v.begin(), v.end(), string(" "), fc) << endl;
    return 0;
}