#include <iostream>
#include <vector>

using namespace std;

//define the node structure
struct Node
{
  int ID;
  vector<Node*> neighbors;
};

int main()
{
  //the main node list
  vector<Node> nodeList;

  //example nodes
  Node nodeA;
  Node nodeB;

  //link A & B
  nodeA.neighbors.push_back(&nodeB);

  cout << "Node A now has "
       << nodeA.neighbors.size()
       << " neighbor(s)" << endl;

  return 0;
}