/* vim: set expandtab tabstop=4 shiftwidth=4 : */

import java.util.TreeSet;

public class PointSET
{
    private TreeSet<Point2D> set;
    // construct an empty set of points
    public PointSET()
    {
        set = new TreeSet<Point2D>();
    }

    // is the set empty?
    public boolean isEmpty()
    {
        return set.isEmpty();
    }

    // number of points in the set
    public int size()
    {
        return set.size();
    }

    // add the point p to the set (if it is not already in the set)
    public void insert(Point2D p)
    {
        set.add(p);
    }

    // does the set contain the point p?
    public boolean contains(Point2D p)
    {
        return set.contains(p);
    }

    // draw all of the points to standard draw
    public void draw()
    {
        for (Point2D p : set) p.draw();
    }

    // all points in the set that are inside the rectangle
    public Iterable<Point2D> range(RectHV rect)
    {
        Stack<Point2D> stack = new Stack<Point2D>();

        for (Point2D p : set)
            if (rect.contains(p)) stack.push(p);

        return stack;
    }

    // a nearest neighbor in the set to p; null if set is empty
    public Point2D nearest(Point2D p)
    {
        if (set.isEmpty()) return null;

        Point2D p0 = null;
        double d = Double.MAX_VALUE;
        for (Point2D o : set)
        {
            double d2 = p.distanceSquaredTo(o);
            if (d2 < d) {
                d = d2;
                p0 = o;
            }
        }
        return p0;

    }
}