class ProcessMST
{
  ArrayList mst;
  ArrayList edges;
  ArrayList vertices;
  int connected = 0;
  int tree = 0;

  ProcessMST(ArrayList _edges, ArrayList _vertices)
  {
    edges = _edges;
    vertices = _vertices;
    mst = new ArrayList();
  }

  public boolean run()
  {
    if(connected == vertices.size()-1) {
      return false;
    }
    Edge edge = (Edge)edges.remove(0);
    Vertex v0 = edge.v0;
    Vertex v1 = edge.v1;    

    if(v0.tree == -1){
      if(v1.tree == -1){
        v0.tree = tree;
        v1.tree = tree;        
        tree++;
        edge.connected = true;
        mst.add(edge);
        connected++;
      }
      else {
        v0.tree = v1.tree;
        edge.connected = true;
        mst.add(edge);
        connected++;
      }
    }
    else {
      if(v1.tree == -1){
        v1.tree = v0.tree;
        edge.connected = true;
        mst.add(edge);
        connected++;
      }
      else{
        if(v0.tree == v1.tree)
        {
        }
        else{
          int oldTree = v1.tree;
          for(int i = 0; i < vertices.size(); i++){
            Vertex v = (Vertex)vertices.get(i);
            if(v.tree == oldTree){
              v.tree = v0.tree;
            }
          }
          edge.connected = true;
          mst.add(edge);
          connected++;
        }
      }
    }
     if(connected <= vertices.size()-1) {
      drawMST();
       return true;
    }   
    else{
      return false;
    }
  }
  
  public String toString()
  {
    return "Path: " + mst.size();
  }
  
  public void drawMST()
  {
    smooth();
    fill(255, 0, 0, 8);
    stroke(200, 0, 0, 90); 
    strokeWeight(1);   
    if(mst.size() > 0)
    {
      for(int j = 0; j < mst.size(); j++)
      {
        Edge e = (Edge)mst.get(j);
        line(e.v0.x, e.v0.y, e.v1.x, e.v1.y);
      }
    }
  } 
}