grow9.rb

def f1(n)
        n = (n * 3 + 1) / 2 while (n % 2 == 1)
        n /= 2 while (n % 2 == 0)
        return n
end

def seq2(n)
	l = [n]
	n1 = n
	l << (n = f1(n)) while (n >= n1 && n != 1)
	return l
end

def d(s)
        c = s.split('').select { |x| x == '1' }.size
	d = c.to_f / s.length
        return d
        
end

def val(n)
	return {'ls' => seq2(n).size, 'd' => d(n.to_s(2))}
	
end

def stat(l)
        return 0, 0, 0, 0 if (l.empty?)
        t = t2 = 0
        l.each \
        {
		|x|
		t += x
		t2 += x ** 2
        }
        c = l.size
        a = t.to_f / c
        z = t2.to_f / c - a ** 2
        sd = Math.sqrt(z < 0 ? 0 : z)

	return l.size, a, sd, l.max, l.min
end

def fmt(l)
	
	return l.map { |x| sprintf("%.3g", x).to_f }
	
end

l = [{'n' => 1, 'p' =>0}.merge(val(1))]

t1 = Time.now.to_i
seen = {}

80.times \
{
	l1 = []
	l2 = []
	while (!l.empty?)
			
		x = l.shift

		p = x['p'] + 1
		n = x['n']
		
		x1 = x.dup
		x1['p'] = p
		l2.push(x1)
		
		x2 = {}
		n |= (1 << p)
		
		x2['n'] = n
		x2['p'] = p
		
		x2.merge!(val(n))
		if (x2['ls'] > x['ls']) then
			l2.push(x2) 
			l1.push(x2) if (!seen.member?(x2['n']))
			seen[x2['n']] = nil
		end
	end
	lx = l1.map { |x| x['d'] }
	ly = l1.map { |x| x['ls'] }
	puts([l2.size, fmt(stat(lx)), fmt(stat(ly))].join("\t"))
	$stdout.flush
	l = l2
}