i have to add an [edge/vertex], delete, edit of a graph

how do we go about implenting this using STL lists

do we have to create a class to store vetices and edges
any sample code would be really helpful

Please, give us more detail about what you have to do, and what is your doubt.

For now, I can say that you can create a class to hold the adjacency matrix. This may be done as a two-dimension matrix, where the elements are a <vector> (vector<vector<int> > v). However, if you have to add more attributes to an edge (like weight) you have to add another dimension (or change the "int" by a struct.

I hope this help.

It sounds like he's trying to use an adjacency list, not an adjacency matrix.

The simplest solution would be to use an slist<int> where each integer in the list is the index of a vertex (assuming that the vertices are stored in an array or vector).