#/***********************************************************
#    dragon.rb -- ドラゴンカーブ
#***********************************************************/
require "plotter.rb"

def dragon(i,  dx,  dy,  sign)
    if (i == 0); draw_rel(dx, dy)
    else 
        dragon(i-1, (dx-sign*dy)/2.0, (dy+sign*dx)/2.0,  1)
        dragon(i-1, (dx+sign*dy)/2.0, (dy-sign*dx)/2.0, -1)
    end
end

printf("位数 = ");  order = gets.to_i
gr_on
move(1, 1);  dragon(order, 2, 0, 1)
gr_off

exit 0