leetcode -- Balanced Binary Tree TODO

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 everynode never differ by more than 1.

[解题思路]

检查每个node是否是balanced，大数据集挂掉了

 /**
  * Definition for binary tree
  * public class TreeNode {
  *     int val;
  *     TreeNode left;
  *     TreeNode right;
  *     TreeNode(int x) { val = x; }
  * }
  */
 public class Solution {
     public boolean isBalanced(TreeNode root) {
         // Start typing your Java solution below
         // DO NOT write main() function
         if(root == null){
             return true;
         }

         return checkBalance(root);
     }

     public boolean checkBalance(TreeNode node){
         if(node == null){
             return true;
         }
         int left = getDepth(node.left);
         int right = getDepth(node.right);
         if(Math.abs(left - right) > 1){
             return false;
         }
         return checkBalance(node.left) && checkBalance(node.right);
     }

     public int getDepth(TreeNode node){
         if(node == null){
             return 0;
         }
         int left = getDepth(node.left);
         int right = getDepth(node.right);
         return Math.max(left, right) + 1;
     }
 }