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Imagejdevelop wrote in Imagecpp

STL question

Can somebody please suggest more efficient way to solve that task:

We have map<string, string> test and set<string> test1
The result set<string> test2 should contain values from test which are exists in test1.

I've tried the set_intersection algorithm, but for some reason it was placing extra-elements in resulting set,so i used the for_each algorithm.

#include <iostream>
#include <string>
#include <map>
#include <set>
#include <vector>
#include <algorithm>

using namespace std;

typedef string type;
typedef map< type, type > typemap;
typedef set< type > typeset;


class compare
{
        typeset &ts;
        typeset &ins;

    public:
        compare( typeset &s, typeset &target ) : ts( s ), ins( target )
        {}

        void operator() ( pair<type, type> it )
        {
            if ( ts.find( it.second ) != ts.end() )
                ins.insert( it.second );
        }
};

class print
{
    public:
        void operator() ( const type what )
        {
            cout << what << ",";
        }
};

int main()
{
    typemap test;
    test[ "123" ] = "1";
    test[ "124" ] = "2";
    test[ "125" ] = "3";
    test[ "126" ] = "4";
    test[ "127" ] = "5";
    test[ "128" ] = "6";
    test[ "129" ] = "7";

    typeset test1;
    test1.insert( "1" );
    test1.insert( "3" );
    test1.insert( "5" );
    test1.insert( "7" );
    test1.insert( "9" );

    typeset test2;

    for_each (
        test.begin(),
        test.end(),
        compare( test1, test2 )
    );

    for_each( test2.begin(), test2.end(), print() );
    cout << endl;
}

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