Height Balanced tree

#1

Please explain this question and how the code is implemented. Not able to understand from video

#2

Question is that
you have to check whether binary tree is height balance or not

Rules
An empty tree is height-balanced
A non-empty binary tree T is balanced if

  1. Left subtree of T is balanced
  2. Right subtree of T is balanced
  3. The difference between heights of left subtree and right subtree is not more than 1.

Approach
To check if a tree is height-balanced, get the height of left and right subtrees. Return true if difference between heights is not more than 1 and left and right subtrees are balanced, otherwise return false.

now watch the video again
you will understand it