What's outputs of code

Question

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main ()
{
int first[] = {5, 10, 15, 20, 25};
int second[] = {50, 40, 30, 20, 10};
vector<int> v(10);
vector<int> :: iterator it;
sort (first, first + 5);
sort (second, second + 5);
it = set_union (first, first + 5, second, second + 5, v.begin());
v.resize(it-v.begin());
for (it = v.begin(); it != v.end(); ++it)
cout << ' ' << *it;
cout << '\n';
return 0;
}

Answer 1

you can copy the element that are common in 2nd one and set_union should be used