Method insert

LabEnv/05Lab/KdTree.java:36–41

(Point2D p)

    // add the point to the set (if it is not already in the set)
    public void insert(Point2D p) {
        if (p == null) throw new IllegalArgumentException();
        if (contains(p)) return;
        root = put(root, p, true, 0, 0, 1, 1);
        n++;
    }

    private Node put(Node x, Point2D p, boolean isXPartition, double xmin, double ymin, double xmax,
                     double ymax) {