/in/foo.cc: In function 'int main()':
/in/foo.cc:21:29: error: cannot convert 'std::set<std::basic_string<char> >::iterator {aka std::_Rb_tree_const_iterator<std::basic_string<char> >}' to 'const char*' for argument '1' to 'int strcmp(const char*, const char*)'
    if(strcmp(s.find(two),two)!=strcmp(s.end(),two) ) cout<<"YES"<<endl;
                             ^
/in/foo.cc:21:50: error: cannot convert 'std::set<std::basic_string<char> >::iterator {aka std::_Rb_tree_const_iterator<std::basic_string<char> >}' to 'const char*' for argument '1' to 'int strcmp(const char*, const char*)'
    if(strcmp(s.find(two),two)!=strcmp(s.end(),two) ) cout<<"YES"<<endl;
                                                  ^