Bigraph help.

I'm trying to figure out an efficient way of implementing a graph, and I'm not sure how to go about it. More specifically, say I have five members (vertices) whose edges are as follows:

Code:

---

A - B
B - D
C - B
E - C
E - A

---

I have a structure of nodes to hold the information about each vertex, and a vector of node* with one entry for each vertex:

Code:

---

struct node
{
    string name;
    int group;
    vector<node *> links;
};

vector<node *> vertex;

---

I also have a function to add a new vertex if it doesn't already exist, and return a pointer to the new node. My problem is that I can not, for the life of me, figure out a way to split the vertices into two groups. With pen and paper, I know that the groups are:

Code:

---

Group 0: A, C, D
Group 1: B, E

---

Something is telling me I might want to use a doubly-linked list in there somewhere, but I am sitting here scratching my head trying to figure this out. Any help would be much appreciated. Thank you.

You might want to look into the Adjacency List storage model. Are you using this to implement pathfinding of some sort?