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@vznvzn
Created August 20, 2015 16:57
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#!/usr/bin/ruby1.8
def dense(n)
s = n.to_s(2)
c = 0
s.length.times \
{
|i|
c += s[i, 1].to_i
}
return c.to_f / s.length
end
def f(n)
n1 = n
c = 0
m = 0
while (n != 1 && n >= n1)
n = (n * 3 + 1) / 2 while (n.odd?)
n /= 2 while (n.even?)
m = [m, n].max
c += 1
end
return {'w' => widthdiff(m, n1),
'c' => c,
'd' => (0.5 - dense(n1)).abs,
'm' => m}
end
def long(m)
l = [{'n' => 1, 'p' => 0}.merge(f(1))]
w = 'w'
loop \
{
l = l.sort_by { |x| [x[w], x['d']] }.reverse
break if (l[0][w] >= m)
x = l.delete_at(rand([l.size, 10].min))
p2 = x['p'] + 1
n2 = x['n'] + 2 ** p2
x1 = x.dup
x1['p'] = p2
l << x1
x2 = {'n' => n2, 'p' => p2}.merge(f(n2))
l << x2
raise if (l.size >= 1000)
}
l = l.sort_by { |x| -x[w] }
return l.first, l.size
end
def widthdiff(x, y)
x.to_s(2).length - y.to_s(2).length
end
def run()
x, c = long(ARGV[0].to_i)
n = x['n']
l = []
while (n != 1)
c1 = c0 = 0
while (n.odd?)
n = (n * 3 + 1) / 2
c1 += 1
end
while (n.even?)
n /= 2
c0 += 1
end
ns = n.to_s(2)
puts([ns.length, c0, c1].join("\t"))
end
end
run()
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