Re: Node/Tree Data Structure Needed

"Hemal Pandya" <>
21 Dec 2006 23:34:28 -0800
Brian Bagnall wrote:


I'm looking for a data type that will store a group of x,y Point objects. It's
a series of nodes, which in the end is the same as a branching tree structure.

Here goes. I am sure it has bunch of problems and that the experts will
frown. At least I have got the Node <T extends Node<T>> thing right, I
think. Take it for what it is worth...

import java.util.Set;
import java.util.HashSet;

abstract class Node<T extends Node<T>>
  Node parent;
  Set<Node> childs = new HashSet<Node>();
  boolean addChild(Node<T> n) {
    n.setParent(this, 0);
    return addChild(n, 0);
  boolean setParent(Node<T> n) {
    setParent(n, 0);
    return n.addChild(this, 0);
  boolean addChild(Node<T> n, int unused) {
    return childs.add(n);
  void setParent(Node<T> n, int unused) {
    parent = n;

class Point extends Node<Point>
  int _x, _y;
  Point(int x, int y){
    _x = x;
    _y = y;
  public String toString() {
    StringBuffer retVal = new StringBuffer("{Point:"
      + System.identityHashCode(this) +
      "{_x:" + _x + "}{_y:" + _y + "}{parent: "
      + System.identityHashCode(parent) + "}{childs{");
    for (Node n: childs) {
    return retVal.toString();

class Employee extends Node<Employee> {
  String _name;

  Employee(String name)
    _name = name;

class NodeMain {
  public static final void main(final String[] args) {
    Point p = new Point(10,10);
    p.addChild(new Point(20,20));
    Point p2 = new Point(11,11);
    Employee e = new Employee("hemal");
    // e.setParent(p2); // does not compile

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