vary4.rb

def f2(n)
	return n.odd? ? (n * 3 + 1) / 2 : n / 2

end

def count(n, l = [])

	c = 0
	n1 = n
	while (n > 1)
		n = f2(n)
		l << n
		c += 1
	end
	return c
	
end

def dense(w, d)
	w2 = w - 1
	
	a = (0...w2).to_a
	s = '0' * w2
	(1..(d * w - 1)).map { a.delete_at(rand(a.size)) }.each { |x| s[x, 1] = '1' }
	return ('1' + s)
	
end

def sample()
	
	l = []
	w = 200
	100.times \
	{
		ns = dense(w, 0.5)
		n = ns.to_i(2)
		c = count(n, l1 = [])
		
		redo if (l1.size <= 600) 
		l << {'ns' => ns, 'l1' => l1}
	}

	return l.map { |x| x['l1'][600] }.select { |x| x.to_s(2).length == 50 }

end

def fmt(l, f)

	w = l.max_by { |x| x.length }.length
	
	f.puts("set colors classic; \\")
	f.puts("plot \\")
	f.puts("[0:#{w}][0:#{l.size - 1}] '-' matrix with image title ''")
	
	l.each_with_index \
	{
		|z, i|
		
		c = w - z.length
		z[z.length...w] = '0' * c
		
		f.puts(z.split('').join(' '))
	}
	f.puts("eof")
	f.puts("eof")
#	f.puts("pause -1;")
end

def grid(l)
	
	f = File.open(fn = "gnuplot1.cmd", 'w')
	f.puts("set palette negative grayscale; unset colorbox;")
	
	fmt(l.map { |x| x.to_s(2).reverse }, f)
	f.close

end

l = []
100.times { l += sample() }


l.each \
{
	|x|
	count(x, l1 = [])
	p(l1.size)
}

l.size.times \
{
	ns = dense(50, 0.5)
	count(ns.to_i(2), l1 = [])
	p(l1.size)
}