indegree(V) = at any one time in algorithm, is the number of edges comming IN to the vertex V

Indegree of: CS1020 = 0 CS1160 = 1 CS2360 = 1 CS2430 = 1 CS3240 = 2

Pseudocode from Weiss Book

void Graph::topsort()
{
        Queue<Vertex> q;
        int counter =0;

        q.makeEmpty();

        for each Vertex v in G
           if( v.indegree == 0)
               q.enqueu(v);

       while(!q.isEmpty() )
       {
           Vertex v = q.dequeue();
           v.topNum = ++counter;

           for each Vertex w adjacent to v
               if( --w.indegree == 0)
                   q.enqueue(w);
       }

      if(counter != num_vertices)
          throw CycleFoundException();

}