// a nearest neighbor in the set to point p; null if the set is empty
public Point2D nearest(Point2D p) {
if (null == p) {
throw new java.lang.NullPointerException();
}
if (this.isEmpty()) {
return null;
}
Point2D res = null;
double dis = Double.MAX_VALUE;
LinkedList<Node> q = new LinkedList<Node>();
q.add(root);
while (!q.isEmpty()) {
Node tp = q.pollFirst();
double cur = p.distanceSquaredTo(tp.getP());
if (cur < dis) {
dis = cur;
res = tp.getP();
}
Node lch = tp.getLb();
Node rch = tp.getRt();
if (null != lch && lch.getRect().distanceSquaredTo(p) < dis) {
q.add(lch);
}
if (null != rch && rch.getRect().distanceSquaredTo(p) < dis) {
q.add(rch);
}
}
return res;
}
// all points that are inside the rectangle
public Iterable<Point2D> range(RectHV rect) {
LinkedList<Point2D> res = new LinkedList<Point2D>();
if (null == this.root) {
return res;
}
LinkedList<Node> q = new LinkedList<Node>();
q.add(this.root);
while (!q.isEmpty()) {
Node tp = q.pollFirst();
if (rect.contains(tp.getP())) {
res.add(tp.getP());
}
Node lch = tp.getLb();
if (null != lch && rect.intersects(lch.getRect())) {
q.add(lch);
}
Node rch = tp.getRt();
if (null != rch && rect.intersects(rch.getRect())) {
q.add(rch);
}
}
return res;
}