import java.awt.Graphics;

public class c09_brownian extends java.applet.Applet {
  static final double s = 0.5;
  static final int level = 7;
  static final int left = 30;
  static final int w = 300;

  public void paint(Graphics g)
  {
    LineTo lt = new LineTo(g);
    brownian(lt, level, left, w+left, w/2+left, (1-s)*w+left);
    brownian(lt, level, w/2+left, (1-s)*w+left, w+left, w+left);
  }

  void brownian(LineTo lt, int level, double xleft, double yleft, double xright, double yright)
  {
    if (level <= 1) {
      //lt.drawLine((int)xleft, (int)yleft, (int)xright, (int)yright);
      for (int x = (int)xleft; x < (int)xright; x++) {
        double y = (yright*(x-xleft)+yleft*(xright-x))/(xright-xleft);
        lt.drawLine(x, left+w, x, (int)y);
      }
      return;
    }
    double nxleft = xleft;
    double nyleft = yleft;
    double nxright = (xleft+xright)/2;
    double d = s*20*Math.sqrt(nxright-nxleft);
    double r = Math.random() + Math.random() + Math.random() - 1.5;
    double nyright = (yleft+yright)/2 + r*d;
    brownian(lt, level-1, nxleft, nyleft, nxright, nyright);
    nxleft = nxright;
    nyleft = nyright;
    nxright = xright;
    nyright = yright;
    brownian(lt, level-1, nxleft, nyleft, nxright, nyright);
  }
}