import java.awt.*;				// Graphics
import javax.swing.*;			// JFrame, JPanel

public class RecursiveI
{
	public static void main(String[] args)
	{
		JFrame frame=new JFrame("");
		frame.setSize(600,800);
		DrawPanel p=new DrawPanel();
		frame.add(p);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setVisible(true);
	}
	
	public static class DrawPanel extends JPanel
	{
		public void paintComponent(Graphics g)
		{
			int x1=300, y1=200, x2=300, y2=500;		// we will start with an I and then with the top and bottom end of the I, we will recursively draw Is there
			create(g, x1,y1, x2, y2, 0, 300);		// our initial size of our line is 300, we halve it with each recursive call
		}
		
		public void create(Graphics g, int x1, int y1, int x2, int y2, int c, int size)	// if c is 0, draw the initial I from x1,y1 to x2,y2 and recurse at both top and bottom of the I
		{
			if(c==0) 
			{
				g.drawLine(x1,y1,x2,y2);
				create(g,x1-size/2,y1,x2+size/2,y1,c+1,size/2);
				create(g,x1-size/2,y2,x2+size/2,y2,c+1,size/2);
			}
			else if(x1!=x2||y1!=y2)					// our base case is when x1==x2 and y1==y2 (1 pixel long line)
			{
				if(c%2==0)							// if c is even, we are drawing a vertical line and then we recurse by drawing lines at the top and bottom of this line 
				{
					g.drawLine(x1,y1,x2,y2);
					create(g,x1-size/2,y1,x1+size/2,y1,c+1,size/2);
					create(g,x2-size/2,y2,x2+size/2,y2,c+1,size/2);
				}
				else								// otherwise c is odd, we are drawing a horizontal line and then we recurse by drawing lines at the left and right of this line
				{
					g.drawLine(x1,y1,x2,y2);
					create(g,x1,y1-size/2,x1,y1+size/2,c+1,size/2);
					create(g,x2,y1-size/2,x2,y1+size/2,c+1,size/2);
				}
			}
		}
	}
}