height balanced binary tree

基本解释

Given a binary tree, determine if it is height-balanced.
給出一個二叉樹，判斷它高度是不是平衡的。
For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees ofeverynode never differ by more than 1.
注意平衡樹的定義，每一個點的左右子樹高度差不超過1，竝不是葉子結點的最大深度和最小深度不超過1。
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.
對於這個問題，一個高度平衡的二叉樹是指每個節點的兩個子節點的深度的差異都不超過1的二叉樹。