set operations in c++

set_difference.cpp

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

int main() {
  int a[]= {1, 2, 90, 43, 23};
  int b[]= {1, 90, 2, 43, 99};
  
  vector<int> v(10);
  vector<int>::iterator it1, it2;
  
  sort(a, a+5); //sort required
  sort(b, b+5);
  
  it1= set_difference(a, a+5, b, b+5, v.begin()); //a-b
  v.resize(it1- v.begin());
  
  for(auto i= v.begin(); i!= v.end(); i++) {
    cout<<*i<<" "; // 23
  }
  cout<<endl;
  
  it2= set_difference(b, b+5, a, a+5, v.begin()); //b-a
  
  v.resize(it2- v.begin());
  
  for(auto i= v.begin(); i!= v.end(); i++) {
    cout<<*i<<" "; // 99
  }
  
  
  return 0;
}

set_intersection.cpp

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

int main() {
  int a[]= {1, 2, 90, 43, 23};
  int b[]= {1, 90, 2, 43, 99};
  
  vector<int> v(10);
  vector<int>::iterator it;
  sort(a, a+5); //sort required
  sort(b, b+5);
  
  it= set_intersection(a, a+5, b, b+5, v.begin());
  v.resize(it- v.begin());
  
  for(auto i= v.begin(); i!= v.end(); i++) {
    cout<<*i<<" "; // 1, 2, 43, 90
  }
  
  return 0;
}

set_union.cpp

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

int main() {
  int a[]= {1, 2, 90, 43, 23};
  int b[]= {1, 90, 2, 43, 99};
  
  vector<int> v(10);
  vector<int>::iterator it;
  
  sort(a, a+5); //sort required
  sort(b, b+5);
  
  it= set_union(a, a+5, b, b+5, v.begin()); //a-b
  v.resize(it- v.begin());
  
  for(auto i= v.begin(); i!= v.end(); i++) {
    cout<<*i<<" "; // 1, 2, 3, 43, 90, 99
  }
  
  
  return 0;
}