#include "library.h"

int length_collatz(const int N)
{ if (N == 1)
    return 1;
  if (N % 2 == 0)
    return 1 + length_collatz(N / 2);
  else
    return 1 + length_collatz(3 * N + 1); }

void plot(const int current, const int maximum)
{ const int len = length_collatz(current);
  draw_point(current / 10, 600 - len);
  if (current < maximum)
    plot(current + 1, maximum); }

void main()
{ make_window(800, 600);
  set_pen_width(4);
  plot(1, 8000); }