Balanced Binary Tree leetcode java

题目：

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.

题解：

采用递归的方法，要记录depth用来比较。

代码如下：

 1     public int checkBalanced(TreeNode t){
 2         if(t==null)
 3             return 0;
 4             
 5         int leftheight = checkBalanced(t.left);
 6         if(leftheight == -1)
 7             return -1;
 8         
 9         int rightheight = checkBalanced(t.right);
         if(rightheight == -1)
             return -1;
         
         if(Math.abs(leftheight-rightheight)>1)
             return -1;
         else
             return Math.max(leftheight,rightheight)+1;
     }
     
     public boolean isBalanced(TreeNode root) {
         if(checkBalanced(root) == -1)
             return false;
         else
             return true;
     }