Open hashing

#include <iostream>
#include <string>
#include <list>
#include <unordered_map>
#include <vector>
#include <fstream>
#include <sstream>
#include <iterator>
#include <sstream>

std::size_t hash32shiftmult(std::size_t key) {
    std::size_t c2=0x27d4eb2d;
    key = (key ^ 61) ^ (key >> 16);
    key = key + (key << 3);
    key = key ^ (key >> 4);
    key = key * c2;
    key = key ^ (key >> 15);
    return key;
}


class KeyHasher {
public:
    std::size_t operator()(const int& k) const {
//        return k%5; // Función Hash 1
//        return k%15; // Función Hash 2
        return hash32shiftmult(k)%15; // Función Hash 3
    }
};

template <class T>
std::string listToString(std::list<T> l){
    std::stringstream ss;
    for(std::list<int>::iterator it = l.begin(); it!=l.end(); ++it){
        ss << *it;
        if(std::distance(it, l.end())>1)
            ss << ", ";
    }
    return "[" + ss.str() + "]";
}


int main () {
    std::list<int> lints = {66, 81, 133, 121, 99, 96, 60, 117, 128, 122};
    std::unordered_map<int,int, KeyHasher> mymap;
    mymap.reserve(15);

    for(auto v : lints){
        mymap.insert({v,v});
    }
    std::cout << std::endl << listToString(lints);

    unsigned n = mymap.bucket_count();

    std::cout << "mymap has " << n << " buckets.\n";

    for (unsigned i=0; i<n; ++i) {
        std::cout << "bucket #" << i << " contains: ";
        for (auto it = mymap.begin(i); it!=mymap.end(i); ++it)
            std::cout << "[" << it->first << ":" << it->second << "] ";
        std::cout << "\n";
    }
    return 0;
}