sides3.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
	begin
		l << (n = f1(n))
	end 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 (0.5 - d).abs
        
end

def mx2(n)
	l = seq2(n)
	ls = l.size
	
	l2 = [l]
	c = 0
	mx = nil
	while (!l2.empty?)
		c += 1
		
		l = l2.shift
		mx = [mx, l2.size].compact.max
		loop \
		{
			break if (l.size <= 2)
			m = (0...l.size).max_by { |x| l[x] }
			if (m == 0) then
				l.shift
				next
			end
			if (m == l.size - 1) then
				l.pop
				next
			end
			
			l2.push(l[0...m])
			l2.push(l[(m+1)..-1])
			break
		}
	end

	case ARGV[0].to_i
		when 1
			m = c
		when 2
			m = mx
	end

	d = d(n.to_s)
	return {'by' => [-m, d], 'fmt' => [c, mx, ls, n.to_s(2).length].join("\t")}
end

def mx_(n)
	return mx2(n)
end

def hard(c)
		
		
	l = [{'n' => 1, 'p' =>0}.merge(mx_(1))]
	
	loop \
	{
		l.sort_by! { |x| x['by'] }

		fmt = l[0]['fmt']
		return l[0] if (l.size == c)
		
		x = l.delete_at(rand([l.size, 50].min))
		
		
		p = x['p'] + 1
		n = x['n']
		
		x1 = x.dup
		x1['p'] = p
		l.push(x1)
		
		x2 = {}
		n |= (1 << p)
		
		x2['n'] = n
		x2['p'] = p
		x2.merge!(mx_(n))
		l.push(x2)
		
		$f.puts([l.size, fmt, x2].join("\t"))
		$f.flush
	}
	
	
end

$f = File.open("out#{ARGV[0]}.txt", 'w')

z = hard(10000)