Given a binary tree, determine if it is height-balanced.
判断一棵树是否为平衡二叉树。
2
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.
对于这个问题，一个高度平衡的二叉树是指每个节点的两个子节点的深度的差异都不超过1的二叉树。
3
Given a binary tree, determine if it is height-balanced.