How to find the intersection and union of two sets. - C++ STL

C++ examples for STL:set

  1. HOME
  2. C++
  3. STL
  4. set

Description

How to find the intersection and union of two sets.

Demo Code

#include <iostream>
#include <string>
#include <set>
#include <algorithm>
#include <iterator>

using namespace std;

void DumpClass(set<string> *myset)
{
  set<string>::iterator iter = myset->begin();

  while (iter != myset->end())
  {//from   w ww .ja v a  2  s. c  om
    cout << *iter << endl;
    iter++;
  }
}

int main()
{
  set<string> EnglishClass;
  set<string> HistoryClass;

  EnglishClass.insert("Z");
  EnglishClass.insert("M");
  EnglishClass.insert("V");
  EnglishClass.insert("U");
  EnglishClass.insert("C");

  HistoryClass.insert("V");
  HistoryClass.insert("U");
  HistoryClass.insert("R");
  HistoryClass.insert("O");

  set<string> Union;
  set<string> Intersection;

  insert_iterator<set<string>> IntersectIterate(Intersection, Intersection.begin());

  insert_iterator<set<string>> UnionIterate(Union, Union.begin());

  set_intersection(EnglishClass.begin(), EnglishClass.end(), HistoryClass.begin(), HistoryClass.end(), IntersectIterate);

  cout << "===Intersection===" << endl;

  DumpClass(&Intersection);

  set_union(EnglishClass.begin(), EnglishClass.end(), HistoryClass.begin(), HistoryClass.end(), UnionIterate);

  cout << endl << "===Union===" << endl;

  DumpClass(&Union);

  return 0;
}

Result


Related Tutorials