Balanced Binary Tree, Leetcode 解题笔记

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.


 * Definition for binary tree
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
public class Solution {
    public boolean isBalanced(TreeNode root) {
        if(root == null) return true;
        if(Math.abs(getHeight(root.left) - getHeight(root.right)) > 1) return false;
        return isBalanced(root.left) && isBalanced(root.right);
    public int getHeight(TreeNode root){
        if(root == null) return 0;
        return 1 + Math.max(getHeight(root.left), getHeight(root.right));

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s