LeetCode 110. Balanced Binary Tree

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We can use pre order traversal: Self Node, Left Child, Right Child

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as we traverse left child we keep track of the num of left child, and afterwards as we are traverse right child we keep track of how many right child there is.

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What is a Balanced Binary Tree: Summary:

at any node in the tree the height of left child and height of right child. the difference should not be more than one

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Balanced Factor | height of left subtree - height of right subtree | <= 1

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absolute of left height - right height

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Summary: There are two approaches

1. Top Down
2. Bottom Up

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Bottom Up

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