Pv913FileLetterFreq

#include <iostream>
#include <map>
#include <set>
#include <algorithm>
#include <fstream>

template <typename ElemType>
class Printer {
    std::ostream& out;
    char delimiter;
public:
    Printer(std::ostream& outStream = std::cout, char delimChar = 0) : out{ outStream }, delimiter{ delimChar }{};
    void operator()(ElemType elem) const {
        out << elem;
        if (delimiter) { out << delimiter; };
    }
};

std::ostream& operator<<(std::ostream& out, std::pair<char, int> el)
{
    return out << el.first << "\t:\t" << el.second << '\n';;
}

int main()
{
    auto comp = [](std::pair<char, int> el1, std::pair<char, int> el2) { return el1.second < el2.second; };
    std::map<char, int> map;
    //for(int i{0}; i<1000; ++i)
    //{
    //  ++map[('a' + rand() % 25)];
    //}
    //
    //std::cout << "### sorted by key ###\n";
    //for (auto mapEl{ map.begin() }; mapEl != map.end(); ++mapEl)
    //{
    //  //std::cout << mapEl->first << "\t:\t" << mapEl->second << '\n';
    //  std::cout << *mapEl;
    //}
    //return 0;

    std::ifstream inf{ "../Study/Study.cpp" };
    std::istreambuf_iterator<char> infIt(inf);
    std::istreambuf_iterator<char> infEOF;

    //std::ostream_iterator<char> outIt(std::cout, " ");
    //
    //std::copy(infIt, infEOF, outIt);

    //return 0;

    for (; infIt != infEOF; ++infIt)
    {
        ++map[*infIt];
    }

    std::cout << "### sorted by key ###\n";
    for (auto mapEl{ map.begin() }; mapEl != map.end(); ++mapEl)
    {
        //std::cout << mapEl->first << "\t:\t" << mapEl->second << '\n';
        std::cout << *mapEl;
    }

    std::cout << "### sorted by value ###\n";
    std::set<std::pair<char, int>, decltype(comp)> set(map.begin(), map.end(), comp);

    //  for(auto setEl{set.begin()}; setEl != set.end(); ++setEl)
    //  {
    //      //std::cout << setEl->second << "\t:\t" << setEl->first << '\n';
    //      std::cout << *setEl;
    //  }

    //  std::for_each(set.begin(),set.end(),[](auto el){ std::cout << el;});

    std::for_each(set.begin(), set.end(), Printer<std::pair<char, int>>(std::cout, ' '));

    //  std::ostream_iterator<std::pair<char,int>> outIt(std::cout, "");
    //  std::copy(set.begin(),set.end(), outIt);

    return 0;
}