mapからvectorへ

sample3.cpp

#include <vector>
#include <unordered_map>
#include <algorithm>
#include <iostream>

auto main()->int
{
    std::ios::sync_with_stdio(false);

    // vector -> map
    std::unordered_map<std::string, int> m {{"a",1},{"b",2},{"c",3},{"d",4}};
    std::vector<int> v;
    std::transform(m.begin(), m.end(), back_inserter(v),
        [](decltype(m)::value_type& kv) { return kv.second; });
    //一応valueででソート
    sort(v.begin(), v.end());
    for (const auto& i : v) {
        std::cout << i  << ","; // => 1,2,3,4,
    }
}