题解 | #判断是不是平衡二叉树#

public class Solution {
    public boolean IsBalanced_Solution(TreeNode root) {
        if (root == null) {
            return true;
        }
        if (Math.abs(getHeight(root.left) - getHeight(root.right)) > 1) {
            return false;
        } 
        return IsBalanced_Solution(root.left) && IsBalanced_Solution(root.right);
    }

    private int getHeight(TreeNode root) {
        if (root == null) {
            return 0;
        }
        return Math.max(getHeight(root.left), getHeight(root.right)) + 1;
    }
}