import java.util.*;

public class Test2Answers
{
    public  static class TreeNode {
        String info;
        TreeNode  left;
        TreeNode  right;
        TreeNode(String val, TreeNode  lptr, TreeNode  rptr)
        {
            info = val;
            left = lptr;
            right = rptr;
        }
    }
    
     /**
      * Return sorted list containing same values stored in search tree t.
      * @param t is a search tree
      * @return sorted list containing same values in t
      */
     public static ArrayList tree2list(TreeNode t){
         ArrayList list = new ArrayList();
         tree2listAux(t,list);
         return list;
     }
     /**
      * Add values of tree to list in sorted order.
      * @param list stores values (in order) already visited
      * @param root is the root of the (sub) tree to be added to list
      */
     private static void tree2listAux(TreeNode root, ArrayList list){
         if (root != null){
	     tree2listAux(root.left,list);
	     list.add(root.info);
	     tree2listAux(root.right,list);
	 }
     }
    private static TreeNode list2treeAux(ArrayList list, int first, int last){
        if (first > last) return null;
        int mid = (first + last)/2;

        String rootValue = (String) list.get(mid);

        // add code here
	return new TreeNode((String) list.get(mid),
			    list2treeAux(list,first,mid-1),
			    list2treeAux(list,mid+1,last));
    }	 
}