Sample Code: GraphCity.java

package examples;
import becker.robots.*;

public class GraphCity extends City
{
   /** Create a special kind of city that includes "data" (piles of things)
       to creat a graph.  The piles are all on the same avenue on consecutive
       intersections.  The size of each pile is determined by a random number
       generator.
       @param numPiles the number of piles of things
       @param startAve the avenue to place them on
       @param startStr the first street to contain a pile
       @param maxDataInPile the maximum amount of data in any pile */
   public GraphCity(int numPiles, int startAve, int startStr, int maxDataInPile)
   {  super();
      for(int s=startStr; s<startStr + numPiles; s++)
      {  int size = (int)(Math.random() * maxDataInPile) + 1;
         this.makeThingPile(startAve, s, size);
      }
   }

   /** Make a pile of things.
       @param ave The avenue where the things should be placed
       @param str The street where the things should be placed
       @param num The number of things to put in the pile */
   private void makeThingPile(int ave, int str, int size)
   {  for(int d=0; d<size; d++)
      {  new Thing(this, ave, str);
      }
   }
}