Thread: help with Map and Vector

Sorry people, maybe I was not specific enough originally. This should be a simple problem for you gurus!

I have a map:

map<int, vector<EDGE*> > myMap

when I myMap.find(5) and then
PAIR.second.push_back(EDGE*) ... I am only able to add two elements, the third addition overwrites the last element. Aren't Vector dynamic? What is going on. Code is below

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I am looking up a Vector stored in a Map via an int. This seems to work ok. I am able to add 2 elements to the Vector using push_back and that is it. The Vector stored at the Map entry of int X overwrites the last entry in the Vector and will never hold more than 2 elements ... I thought a Vector would grow and I have even used reserve to set it up larger than 2. I am doing something stupid, please point me in the right direction.

Code:

for (int i=0; i<edge_cnt; i++)
{
    file >> origin;
    file >> dest;
#ifdef DEBUG3
  cout << "origin: " << origin << " dest: " << dest << endl;
#endif

    // undirected
    // check for origin node in map
    EDGE2 *edge1 = new EDGE2(origin, dest, 0);
    EDGE2 *edge2 = new EDGE2(dest, origin, 0);
    map<int, vector<EDGE2*> >::iterator iii;
    pair<int, vector<EDGE2*> > PAIR;
    iii=graph->edgeMap.find(origin);
    vector<EDGE2*> v;
    v.reserve(edge_cnt);  // where edge_cnt = 10

    if (iii == graph->edgeMap.end())
    {
      v.push_back(edge1);
      map<int, vector<EDGE2*> >::value_type vt(origin, v);
      graph->edgeMap.insert(vt);
#ifdef DEBUG
  cout << "Location " << origin << " not in map, inserting and adding edge with origin=" << edge1->origin <<
          " dest=" << edge1->dest << endl;
#endif
    }
    else
    {
      // get vector and add edge to it
      PAIR=(*iii);
      PAIR.second.push_back(edge1);
#ifdef DEBUG
  cout << "Location " << PAIR.first << " is in the map, adding an edge ..." << endl;
  cout << "  This vector can hold " << v.capacity() << " elements up to " << v.max_size() << endl;
  cout << "  Added edge with origin=" << edge1->origin << " dest=" << edge1->dest << endl;
  cout << "  Location " << PAIR.first << " now has " << PAIR.second.size() << " edges ..." << endl;
  vector<EDGE2*>::iterator eiii;
  cout << "       Iterating vector ..." << endl;
  cout << "       ====================" << endl;
  for (eiii=PAIR.second.begin(); eiii!=PAIR.second.end(); eiii++)
    cout << "       origin=" << (*eiii)->origin << " dest=" << (*eiii)->dest << endl;
#endif
    }
}