Mandelbrot Fractal in Terminal with Zoom

main.c

int main() {
  double z_factor = 2; //zoom factor
  double center_x = -0.5; //x coordinate of zoom center
  double center_y = 0; //y coordinate of zoom center
  double width = 128;
  double height = 40;
  int k = 0;
  double i, j, r, x, y = -height/2;
  while(puts(""), y++ < height/2 + 1) {
    for(x = 0; x++<width;) { 
      if(k == 10001) putchar(' ');
      else putchar('.');

      for(i=k=r=0; 
        j = r*r - i*i + x/(25*z_factor) + center_x - width/(2*25*z_factor), i = 2*r*i+y/(10*z_factor) + center_y, j*j + i*i <= 2.0 && k++<10000;
        r = j);
      }
  }
  return 0;
}