{- | Description: Post-order sequence of a tree Copyright: Copyright (C) 2021 Yoo Chung License: GPL-3.0-or-later Maintainer: dev@chungyc.org Part of Ninety-Nine Haskell "Problems". Some solutions are in "Solutions.P72". -} module Problems.P72 (postOrderSequence) where import Problems.MultiwayTrees import qualified Solutions.P72 as Solution -- $setup -- >>> import Problems.MultiwayTrees -- | Construct the post-order sequence of the tree nodes. -- -- === Examples -- -- >>> postOrderSequence multitree5 -- "gfcdeba" -- -- === __Notes__ -- -- The problem in the original list specifies a "bottom-up" order. -- There is no widespread common understanding of what this is -- (i.e., does this mean post-order, or all nodes at a level -- being sequenced before nodes at a higher level?), -- so post-order is specified instead. postOrderSequence :: MultiwayTree a -> [a] postOrderSequence :: forall a. MultiwayTree a -> [a] postOrderSequence = forall a. MultiwayTree a -> [a] Solution.postOrderSequence