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 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) {
if(root==null){
return true;
}
if(Math.abs(maxDepth(root.left)-maxDepth(root.right)) > 1){
return false;
}
return isBalanced(root.left) && isBalanced(root.right);
}
private int maxDepth(TreeNode node){
if(node == null){
return 0;
}
return 1+ Math.max(maxDepth(node.left), maxDepth(node.right));
}
}
原文：http://www.cnblogs.com/incrediblechangshuo/p/5476412.html