2021-11-27 ~ 2021-11-28
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ver 0.0.6 ~ 0.0.9: added the following, while updating some description about input data being an array (as opposed to level order)

binarytree.levelorder
binarytree.flatten() # two arguments: (1) target: 'preorder' or 'inorder', (2) inplace: True/False
binarytree.data


2021-11-26
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ver 0.0.5: added the class bst for binary search tree, and its functions:

bst.from_sortedarray()
bst.from_preorder()


2021-11-25
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ver 0.0.3 - 0.0.4: some optimization for binarytree.show(), and added the following functions

binarytree.height
binarytree.inorder
binarytree.preorder
binarytree.postorder


2021-11-24
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ver 0.0.2: initial version. added classes binarytree and Node
