Description: Given a binary tree, determine if it is height-balanced.

Brute-force Approach

Simple recursion, calculate height of the left and right subtrees and check if the node is balanced. Recursively check if the left and right subtrees are balanced.

Time: O(n^2)

Space: O(1), Recursive stack space: O(n)

Optimal Approach

Using post order recursion, calculate height and check if the tree is balanced simultaneously.

Time: O(n)

Space: O(1), Recursive stack space: O(n)