Question

I have such structure with ids and their count:

product[38] = 10;
product[22] = 7;
product[39] = 18;

I need to use some structure for it. But not sure what should serve better (map, unordered_map, set, vector).

I was trying to use:

map<int, int> product;

But not sure is it the best choice. The only thing that I should do with it – sorting.

As a result I need:

product[39] = 18;
product[38] = 10;
product[22] = 7;

UPD: Sort by value.

Answer 1

You may want to make a struct or std::pair and sore them in std::vector

std::vector<std::pair<int, int>> product;

product.push_back(std::pair<int,int>(38, 27));
product.push_back(std::pair<int,int>(22, 7));
product.push_back(std::pair<int,int>(39, 18));

sort by value:

std::sort(product.begin(), product.end(), 
  [](const std::pair<int,int>& p1, const std::pair<int,int>& p2){ return p1.second < p2.second; });