What is the most efficient way to create a subset from 2 sets that contains values from both of them? Any C++ STL library can be used to solve this (without Boost library if possible):
Set A = {2, 3, 5, 7, 11, ...}
Set B = {1, 3, 5, 7, 9, 11, ...}
Subset should be = {3, 5, 7, 11, ...}
You can do it by using set_intersection, you will find an example there how to use it:
#include <iostream>
#include <vector>
#include <algorithm>
#include <iterator>
int main()
{
std::vector<int> v1{2, 3, 5, 7, 11};;
std::vector<int> v2{1, 3, 5, 7, 9, 11};
std::sort(v1.begin(), v1.end());
std::sort(v2.begin(), v2.end());
std::vector<int> v_intersection;
std::set_intersection(v1.begin(), v1.end(),
v2.begin(), v2.end(),
std::back_inserter(v_intersection));
for(int n : v_intersection)
std::cout << n << ' ';
}
Results will be:
3 5 7 11