Leetcode
2020.05.01 16:43
110. Balanced Binary Tree
조회 수 256 추천 수 0 댓글 0
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 left and right subtrees of every node differ in height by no more than 1.
Example 1:
Given the following tree [3,9,20,null,null,15,7]
:
3 / \ 9 20 / \ 15 7
Return true.
Example 2:
Given the following tree [1,2,2,3,3,null,null,4,4]
:
1 / \ 2 2 / \ 3 3 / \ 4 4
Return false.
/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode() {} * TreeNode(int val) { this.val = val; } * TreeNode(int val, TreeNode left, TreeNode right) { * this.val = val; * this.left = left; * this.right = right; * } * } */ class Solution { public boolean isBalanced(TreeNode root) { if(root == null){ return true; } return getHeight(root) > -1; } public int getHeight(TreeNode node){ if(node == null){ return 0; } int left = getHeight(node.left); int right = getHeight(node.right); if(left == -1 || right == -1){ return -1; } if(Math.abs(left - right) > 1){ return -1; } return Math.max(left, right) + 1; } }
[문제] https://leetcode.com/problems/balanced-binary-tree/