110.Balanced Binary Tree Leetcode problem-solving notes

110.Balanced Binary Tree

Given a binary tree, determine if it is height-balanced.

For this problem, a height-balanced binary tree was defined as a binary tree in which the depth of the Every node never differ by more than 1.

It's been a long time preparing to transfer all these notes to the blog park. One more understanding and the other is good to play again.

This topic gives a binary tree to determine whether the binary tree is balanced and balanced for any one node of the Saozi right sub-tree height difference not more than one

The idea is simple, first of all, a function to derive the height of a tree

The node is empty tree height is zero otherwise the height of the tree is Zuozi and the height of the right subtree is the largest one, plus one means adding the height of the node itself.

Determine if the height of the right subtree of Saozi is greater than one if it returns more than one mark number can be used-1 mark

Direct Code Codes

/** * Definition for a binary tree node.  * public class TreeNode {*     int val, *     TreeNode left, *     TreeNode right; *     TreeNode (int x) {val = x;} *} */public class Solution {public    Boolean isbalanced (TreeNode root) {       return height (root)!=-1;    }    public int height (TreeNode root) {        if (root==null)        return 0;        int Left=height (root.left);        int Right=height (root.right);        if (left==-1| | right==-1| | Math.Abs (left-right) >1)        return-1;        Return Math.max (Left,right) +1;}    }

Once over.

Look at detail.

2ms feels a little bit long I think it should be a 0ms level.

The practice of learning other people's good solutions look at the most popular one in discuss.

public class Solution {public    Boolean isbalanced (TreeNode root) {        if (null = = root) {            return true;        }                return Math.Abs (height (root.left)-height (root.right)) < 2 && isbalanced (root.left) && isbalanced ( root.right);    }        public int height (TreeNode root) {        if (null = = root) {            return 0;        }                Return 1 + math.max (height (root.left), height (root.right));}    }

Well, actually, just like my idea, it's different.

110.Balanced Binary Tree Leetcode problem-solving notes