istream

#include<fstream>#include<iterator>#include<string>#include<vector>#include<algorithm>

using namespace std;

int main(){ string from,to;  cin>>from>>to;

 ifstream ifs(from.c_str());

 istream_iterator<string>ii(ifs); istream_iterator<string>eos;

 vector<string>v;

 copy(ii,eos,back_inserter(v)); sort(v.begin(),v.end()); copy(v.begin(), v.end(),ostream_iterator<string>(cout, " ") );

 ofstream ofs(to.c_str(),ios_base::app); ostream_iterator<string>oo(ofs); unique_copy(v.begin(),v.end(),*oo);

 ifs.close(); ofs.close();  system("pause");

 return 0;}