stl之set

#include<set>
#include<list>
#include<vector>
#include<algorithm>
#include<iostream>
#include<iterator>
using namespace std;

set<int> a, b, c;
int main()
{
 set<int>::iterator it;
 int i;
 
 for(i = 1; i < 10; i++)
 {
   a.insert(i);
   b.insert(i-5);
 }
 
 set_union(a.begin(), a.end(), b.begin(), b.end(), inserter(c, c.begin()) );
 
 copy(c.begin(), c.end(), ostream_iterator<int>(cout, " ") );
 cout << endl;
 
 c.clear();
 set_intersection(a.begin(), a.end(), b.begin(), b.end(), inserter(c, c.begin()) );
 copy(c.begin(), c.end(), ostream_iterator<int>(cout, " ") );
 cout << endl;
 
 c.clear();
 set_difference(a.begin(), a.end(), b.begin(), b.end(), inserter(c, c.begin()) );
 copy(c.begin(), c.end(), ostream_iterator<int>(cout, " ") );
 cout << endl;
 
 c.clear();
 set_symmetric_difference(a.begin(), a.end(), b.begin(), b.end(), inserter(c, c.begin()) );
 copy(c.begin(), c.end(), ostream_iterator<int>(cout, " ") );
 cout << endl;
 
 c.erase(-3);
 copy(c.begin(), c.end(), ostream_iterator<int>(cout, " ") );
 cout << endl;
 system("pause");
 return 0;
}