adding to vector of vector<int>, check if element already present

[LMHmedchem]

I have a vector<vector<int> > that I am adding data to,

   vector<vector<int> > new_set_of_paths;

   // to each path1[i], add a neighbor of last_vertex
   for(j=0; j<last_vertex_delta; j++) {
      current_neighbor = vertex_list[last_vertex_in_path].neighbor_numbers[j];
      new_set_of_paths[path_count].push_back( current_neighbor );
      path_count ++;
   }

I need to do two things.:
1. check if "current_neighbor" is already a member of new_set_of_paths[path_count][i,j,k]
2. if it is already a member, delete new_set_of_paths[path_count] from the vector<vector<int>>, slide up the remaining elements, re-size, etc.

I'm sure I could do this by looping, checking, copying, etc, but I'm sure an algorithm would be better. I sure I could locate using find or find_if, but when I have done this before, I was deleting the element, but in this case, I need to delete the entire vector. This is complicated because the vector is stored in another vector.

I have tried,

   vector<vector<int> > new_set_of_paths;
   vector<int>::iterator path_iterator;

   // to each path1[i], add a neighbor of last_vertex
   for(j=0; j<last_vertex_delta; j++) {
      current_neighbor = vertex_list[last_vertex_in_path].neighbor_numbers[j];

      // search path to see if new vertex is already present
      path_iterator = find(new_set_of_paths[path_count].begin(),
                           new_set_of_paths[path_count].end(),
                           current_neighbor);

         cout << "current_neighbor " << current_neighbor << endl;
         cout << "path_iterator " << path_iterator << endl;

      new_set_of_paths[path_count].push_back( current_neighbor );
      path_count ++;
   }

but this doesn't compile. I am getting

In function `std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > > add_vertex_to_path(std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > >&, const int&)':
src/src_client_main/internal_hbond_get_path.cpp:287: error: no match for 'operator<<' in 'std::operator<< [with _Traits = std::char_traits<char>](((std::basic_ostream<char, std::char_traits<char> >&)(&std::cout)), ((const char*)"path_iterator ")) << path_iterator'

Any suggestions?

LMHmedchem