package graph;

//begin#fragment CC

import exceptions.InvalidKeyException;

/** This class extends DFS to compute the connected components of a graph. */
public class ComponentsDFS<V, E> extends DFS<V, E, Object, Integer> {
  protected Integer compNumber; // Connected component number
  protected Object COMPONENT = new Object(); // Connected comp. selector
  protected void setup() { compNumber = 1; }
  protected void startVisit(Vertex<V> v) {
      try{
      v.put(COMPONENT, compNumber);
      }
      catch (InvalidKeyException e){
      //
      }
  }
  protected Integer finalResult(Integer dfsResult) {
      try{
        for (Vertex<V> v : graph.vertices()) // check for any unvisited vertices
          if (v.get(STATUS) == UNVISITED) {
            compNumber += 1;  // we have found another connected component
        dfsTraversal(v);  // visit all the vertices of this component
          }
        return compNumber;
      }
      catch (InvalidKeyException e){
          //
      }
      return null;
  }
}
//end#fragment CC