module Misc where

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import Data.Bits

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-- | Smallest integer @k@ such that @2^k@ is larger or equal to @n@
ceilingLog2 :: Integer -> Int
ceilingLog2 0 = 0
ceilingLog2 n = 1 + go (n-1) where
  go 0 = -1
  go k = 1 + go (shiftR k 1)

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