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 7Return 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/
