# Balanced Binary Tree

## Question

### Problem Statement

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

For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1.

#### Example

Given binary tree A={3,9,20,#,#,15,7}, B={3,#,20,15,7}

The binary tree A is a height-balanced binary tree, but B is not.