std::set_union is an STL algorithm to create the union set of two sorted containers, neither of which must hold duplicate entries.


#include <algorithm>

#include <cassert>

#include <vector>



int main()

{

  //Create the first sorted vector

  std::vector<int> v;

  v.push_back(1); //Unique to v

  v.push_back(2); //Present in v and w

  //Create the second sorted vector

  std::vector<int> w;

  w.push_back(2); //Present in v and w

  w.push_back(3); //Unique to w

  //Create the set union in x

  std::vector<int> x;



  std::set_union(

    v.begin(),v.end(),

    w.begin(),w.end(),

    std::back_inserter(x));



  //Check if algorithm worked as expected

  assert(x.size() == 3);

  assert(x[0] == 1); //Unique in v

  assert(x[1] == 2); //Present in both v and w

  assert(x[2] == 3); //Unique in w

}

External links

Cplusplus.com page about std::set_union

Go back to Richel Bilderbeek's C++ page.

Go back to Richel Bilderbeek's homepage.

(C++) std::set_union

External links