import java.util.*;
/** Active Edge List for Scan Line Algorithm*/

class AEL extends EdgeList{

  /* add edge at appropriate place in v */
  void add (Edge e, int y) {
    //find right spot to add it at
    float x = e.xof(y+0.5f);

    int i;
    for (i = 0; i < size() && elementAt(i).xof(y+0.5f)<x; i++) {
      /*nothing*/
    }
    v.insertElementAt(e,i);
  }
  
  /* delete edges with max y = y */
  void deleteEdges(int y) {
    for (int i = size()-1; i >= 0; i--) {
      if (elementAt(i).maxy() == y) {
	v.removeElementAt(i);
      }
    }
  }

  /* string representation of AEL */
  public String toString(){
    StringBuffer sb = new StringBuffer();
    for (int i = 0; i < size(); i++) {
      sb.append(elementAt(i));
      sb.append("\n");
    }
    return sb.toString();
  }

}