Task: Peano curve

C: 

#include <graphics.h>
#include <math.h>

void Peano(int x, int y, int lg, int i1, int i2) {

	if (lg == 1) {
		lineto(3*x,3*y);
		return;
	}
	
	lg = lg/3;
	Peano(x+(2*i1*lg), y+(2*i1*lg), lg, i1, i2);
	Peano(x+((i1-i2+1)*lg), y+((i1+i2)*lg), lg, i1, 1-i2);
	Peano(x+lg, y+lg, lg, i1, 1-i2);
	Peano(x+((i1+i2)*lg), y+((i1-i2+1)*lg), lg, 1-i1, 1-i2);
	Peano(x+(2*i2*lg), y+(2*(1-i2)*lg), lg, i1, i2);
	Peano(x+((1+i2-i1)*lg), y+((2-i1-i2)*lg), lg, i1, i2);
	Peano(x+(2*(1-i1)*lg), y+(2*(1-i1)*lg), lg, i1, i2);
	Peano(x+((2-i1-i2)*lg), y+((1+i2-i1)*lg), lg, 1-i1, i2);
	Peano(x+(2*(1-i2)*lg), y+(2*i2*lg), lg, 1-i1, i2);
}

int main(void) {

	initwindow(1000,1000,"Peano, Peano");

	Peano(0, 0, 1000, 0, 0); 
	
	getch();
	cleardevice();
	
	return 0;
}





Java: import java.io.*;

public class PeanoCurve {
    public static void main(final String[] args) {
        try (Writer writer = new BufferedWriter(new FileWriter("peano_curve.svg"))) {
            PeanoCurve s = new PeanoCurve(writer);
            final int length = 8;
            s.currentAngle = 90;
            s.currentX = length;
            s.currentY = length;
            s.lineLength = length;
            s.begin(656);
            s.execute(rewrite(4));
            s.end();
        } catch (final Exception ex) {
            ex.printStackTrace();
        }
    }

    private PeanoCurve(final Writer writer) {
        this.writer = writer;
    }

    private void begin(final int size) throws IOException {
        write("<svg xmlns='http:
        write("<rect width='100%%' height='100%%' fill='white'/>\n");
        write("<path stroke-width='1' stroke='black' fill='none' d='");
    }

    private void end() throws IOException {
        write("'/>\n</svg>\n");
    }

    private void execute(final String s) throws IOException {
        write("M%g,%g\n", currentX, currentY);
        for (int i = 0, n = s.length(); i < n; ++i) {
            switch (s.charAt(i)) {
                case 'F':
                    line(lineLength);
                    break;
                case '+':
                    turn(ANGLE);
                    break;
                case '-':
                    turn(-ANGLE);
                    break;
            }
        }
    }

    private void line(final double length) throws IOException {
        final double theta = (Math.PI * currentAngle) / 180.0;
        currentX += length * Math.cos(theta);
        currentY += length * Math.sin(theta);
        write("L%g,%g\n", currentX, currentY);
    }

    private void turn(final int angle) {
        currentAngle = (currentAngle + angle) % 360;
    }

    private void write(final String format, final Object... args) throws IOException {
        writer.write(String.format(format, args));
    }

    private static String rewrite(final int order) {
        String s = "L";
        for (int i = 0; i < order; ++i) {
            final StringBuilder sb = new StringBuilder();
            for (int j = 0, n = s.length(); j < n; ++j) {
                final char ch = s.charAt(j);
                if (ch == 'L')
                    sb.append("LFRFL-F-RFLFR+F+LFRFL");
                else if (ch == 'R')
                    sb.append("RFLFR+F+LFRFL-F-RFLFR");
                else
                    sb.append(ch);
            }
            s = sb.toString();
        }
        return s;
    }

    private final Writer writer;
    private double lineLength;
    private double currentX;
    private double currentY;
    private int currentAngle;
    private static final int ANGLE = 90;
}