Task: Sierpinski pentagon

C: #include<graphics.h>
#include<stdlib.h>
#include<stdio.h>
#include<math.h>
#include<time.h>

#define pi M_PI

int main(){
	
	time_t t;
	double side, **vertices,seedX,seedY,windowSide = 500,sumX=0,sumY=0;
	int i,iter,choice,numSides;
	
	printf("Enter number of sides : ");
	scanf("%d",&numSides);
	
	printf("Enter polygon side length : ");
	scanf("%lf",&side);
	
	printf("Enter number of iterations : ");
	scanf("%d",&iter);

	initwindow(windowSide,windowSide,"Polygon Chaos");
	
	vertices = (double**)malloc(numSides*sizeof(double*));
	
	for(i=0;i<numSides;i++){
		vertices[i] = (double*)malloc(2 * sizeof(double));
		
		vertices[i][0] = windowSide/2 + side*cos(i*2*pi/numSides);
		vertices[i][1] = windowSide/2 + side*sin(i*2*pi/numSides);
		sumX+= vertices[i][0];
		sumY+= vertices[i][1];
		putpixel(vertices[i][0],vertices[i][1],15);
	}
	
	srand((unsigned)time(&t));
	
	seedX = sumX/numSides;
	seedY = sumY/numSides;
	
	putpixel(seedX,seedY,15);
	
	for(i=0;i<iter;i++){
		choice = rand()%numSides;
		
		seedX = (seedX + (numSides-2)*vertices[choice][0])/(numSides-1);
		seedY = (seedY + (numSides-2)*vertices[choice][1])/(numSides-1);
		
		putpixel(seedX,seedY,15);
	}
	
	free(vertices);
	
	getch();
	
	closegraph();
	
	return 0;
}





Java: import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.geom.Path2D;
import static java.lang.Math.*;
import java.util.Random;
import javax.swing.*;

public class SierpinskiPentagon extends JPanel {
    
    final double degrees072 = toRadians(72);

    
    final double scaleFactor = 1 / (2 + cos(degrees072) * 2);

    final int margin = 20;
    int limit = 0;
    Random r = new Random();

    public SierpinskiPentagon() {
        setPreferredSize(new Dimension(640, 640));
        setBackground(Color.white);

        new Timer(3000, (ActionEvent e) -> {
            limit++;
            if (limit >= 5)
                limit = 0;
            repaint();
        }).start();
    }

    void drawPentagon(Graphics2D g, double x, double y, double side, int depth) {
        double angle = 3 * degrees072; 

        if (depth == 0) {

            Path2D p = new Path2D.Double();
            p.moveTo(x, y);

            
            for (int i = 0; i < 5; i++) {
                x = x + cos(angle) * side;
                y = y - sin(angle) * side;
                p.lineTo(x, y);
                angle += degrees072;
            }

            g.setColor(RandomHue.next());
            g.fill(p);

        } else {

            side *= scaleFactor;

            
            double distance = side + side * cos(degrees072) * 2;

            
            for (int i = 0; i < 5; i++) {
                x = x + cos(angle) * distance;
                y = y - sin(angle) * distance;
                drawPentagon(g, x, y, side, depth - 1);
                angle += degrees072;
            }
        }
    }

    @Override
    public void paintComponent(Graphics gg) {
        super.paintComponent(gg);
        Graphics2D g = (Graphics2D) gg;
        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);

        int w = getWidth();
        double radius = w / 2 - 2 * margin;
        double side = radius * sin(PI / 5) * 2;

        drawPentagon(g, w / 2, 3 * margin, side, limit);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            JFrame f = new JFrame();
            f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            f.setTitle("Sierpinski Pentagon");
            f.setResizable(true);
            f.add(new SierpinskiPentagon(), BorderLayout.CENTER);
            f.pack();
            f.setLocationRelativeTo(null);
            f.setVisible(true);
        });
    }
}

class RandomHue {
    
    final static double goldenRatioConjugate = (sqrt(5) - 1) / 2;
    private static double hue = Math.random();

    static Color next() {
        hue = (hue + goldenRatioConjugate) % 1;
        return Color.getHSBColor((float) hue, 1, 1);
    }
}