Euler14.rb

ans = {}

for i in 1..1_000_000
  moves = 0
  morph = i
  until morph == 1 do
    if ans[morph] != nil
      moves += ans[morph]
      break
    else
      moves += 1
      if morph % 2 == 0
        morph /= 2
      else
        morph *= 3
        morph += 1
      end
    end
  end
  ans[i] = moves
end

puts ans.key(ans.values.max)