Balanced Binary Tree

The problem Given a binary tree, determine if it is height-balanced. A height-balanced binary tree is a binary tree in which the depth of the two subtrees of every node never differs by more than one. Examples Input: root = [3,9,20,null,null,15,7] Output: true Input: root = [1,2,2,3,3,null,null,4,4] Output: false Input: root = [] Output: true Constraints The number of nodes in the tree is in the range [0, 5000]. -10^4 <= Node.val <= 10^4 Explanation From the description of the problem, we learn that we need to find if the tree is height-balanced, and that we can do it by determining if the difference between the height of every single node in the left and right subtrees is no more than 1. ...