Balanced Binary Tree
Link:http://oj.leetcode.com/problems/balanced-binary-tree/
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.
1 /** 2 * Definition for binary tree 3 * public class TreeNode { 4 * int val; 5 * TreeNode left; 6 * TreeNode right; 7 * TreeNode(int x) { val = x; } 8 * } 9 */ 10 public class Solution { 11 public boolean isBalanced(TreeNode root) { 12 if (root == null) 13 return true; 14 int left = getHeight(root.left); 15 int right = getHeight(root.right); 16 if (Math.abs(left - right) > 1) 17 return false; 18 19 return isBalanced(root.left) && isBalanced(root.right); 20 } 21 22 public int getHeight(TreeNode root) { 23 if (root == null) 24 return 0; 25 return Math.max(getHeight(root.left), getHeight(root.right)) + 1; 26 } 27 }